classes of polymeric materials -...

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Classes of Polymeric Materials

Professor Joe Greene

CSU, CHICO

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Topics

• Introduction

• Thermoplastics

– General

– Commercial plastics

• Thermosets

– General

– Commercial thermosets

• Elastomers

– General

– Commercial elastomers

3

Introduction

• Polymeric materials can be either– Thermoplastics, thermosets, and elastomers.

– Each section is presented in appropriate groups

• Thermoplastics come in a variety of forms

– Pellets, powder (1-100 microns), flake, chip, cube, dice,

– Shipped in packages of choice

– Bags (50 lbs), drums (200 lbs), boxes, cartons, gaylords (1000 lb),

– Tank-truck loads (15 tons), rail cars (40 – 80 tons)

• Bulk supplies are stored in silos and conveyed pneumatically

• Thermosets are supplied in powder or liquid form

– Supplied in drums, tank-trucks, and railroad cars.

• Rubbers are supplied in bale form.

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Commercial Thermoplastics • Olefins

– Unsaturated, aliphatic hydrocarbons made from ethylene gas

– Ethylene is produced by cracking higher hydrocarbons of natural gas or petroleum

• LDPE commercialized in 1939 in high pressure process

• Branched, high pressure, and low density polyethylene

• HDPE commercialized in 1957 in low pressure process

• Linear, low pressure, high density

• The higher the density the higher the crystallinity

• Higher the crystallinity the higher the modulus, strength, chemical resistance,

• PE grades are classified according to melt index (viscosity) which is a strong indicator of molecular weight.

– Injection molding requires high flow, extrusion grade is highly elastic, thermoforming grade requires high viscosity or consistency

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Principal Olefin Monomers• Ethylene Propylene

• Butene-1 4-Methylpentene

C C

H H

H H

C C

C2H5 H

H H

C C

CH3 H

H H

C C

C5H6 H

H H

CH3

6

Several Olefin Polymers• Polyethylene Polypropylene

• Polyisobutene Polymethylpentene

C C

C5H6 H

H H

CH3

n

C C

H H

H H

n

C C

C2H5 H

H H

n

C C

CH3 H

H H

n

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Polymers Derived from Ethylene Monomer

X Position Material Name AbbreviationH Polyethylene PE

Cl Polyvinyl chloride PVCMethyl group Polypropylene PPBenzene ring Polystyrene PSCN Polyacrylonitrile PAN

OOCCH3 Polyvinyl acetate PvaCOH Polyvinyl alcohol PVACOOCH3 Polymethyl acrylate PMA

F Polyvinyl fluoride PVF

Note:Methyl Group is:

|H – C – H

|H

Benzene ring is:

X Position Y Position Material Name AbbreviationF F Polyvinylidene fluoride PVDF

Cl Cl Polyvinyl dichloride PVDC

CH3 (Methyl group) CH3 Polyisobutylene PB

COOCH3 CH3 Polymethyl methacrylate PMMA

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Addition Polymerization of PE• Polyethylene produced with low (Ziegler) or high pressure (ICI)

• Polyethylene produced with linear or branched chains

OR

C C

H H

H H

C C

H H

H H

C C

H H

H H

C C

H H

H H

C C

H H

H H

……

C C

H H

H H

C C

H H

H H

C C

H

H H

C C

H H

H H

C C

H H

H H

……

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Mechanical Properties of Polyethylene

• Type 1: (Branched) Low Density of 0.910 - 0.925 g/cc

• Type 2: Medium Density of 0.926 - 0.940 g/cc

• Type 3: High Density of 0.941 - 0.959 g/cc

• Type 4: (Linear) High Density to ultra high density > 0.959

Mechanical PropertiesBranched LowDensity

MediumDensity

HighDensity

Linear High Density

Density 0.91- 0.925 0.926- 0.94 0.941-0.95 0.959-0.965

Crystallinity 30% to 50% 50% to 70% 70% to 80% 80% to 91%

MolecularWeight

10K to 30K 30K to 50K 50K to 250K 250K to 1.5M

TensileStrength, psi

600 - 2,300 1,200 - 3,000 3,100 - 5,500 5,000 – 6,000

TensileModulus, psi

25K – 41K 38K – 75 K 150K – 158K

150K – 158 K

TensileElongation, %

100% - 650% 100%- 965% 10% - 1300% 10% - 1300%

Impact Strengthft-lb/in

No break 1.0 – nobreak

0.4 – 4.0 0.4 – 4.0

Hardness, Shore D44 – D50 D50 – D60 D60 – D70 D66 – D73

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Physical Properties of Polyethylene

Physical Properties of polyethylene

Branched Low

Density

Medium Density High

Density

Linear High Density

Optical

Transparent to opaque




Tmelt

98 – 115 C 122 – 124 C 130 – 137 C 130 –137 C

Tg -100 C -100 C -100 C -100 C

H20 Absorption

Low < 0.01 Low < 0.01 Low < 0.01 Low < 0.01

Oxidation

Resistance

Low, oxides

readily

Low, oxides

readily

Low, oxides readily Low, oxides readily

UV Resistance

Low, Crazes

readily

Low, Crazes

readily

Low, Crazes readily Low, Crazes readily

Solvent Resistance

Resistant below 60C

Resistant below 60C

Resistant below 60C Resistant below 60C

Alkaline

Resistance

Resistant Resistant Resistant Resistant

Acid Resistance

Oxidizing Acids

Oxidizing Acids Oxidizing Acids Oxidizing Acids

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Processing Properties of Polyethylene

Processing Properties

Branched Low

Density

Medium Density High

Density

Linear High Density

Tmelt 98 – 115 C 122 – 124 C 130 – 137 C 130 –137 C

Recommended TempRange

(I:Injection, E:Extrusion)

I: 300F – 450FE: 250F – 450F

I: 300F – 450FE: 250F – 450F

I: 350F – 500FE: 350F – 525F

I: 350F – 500FE: 350F – 525F

Molding Pressure 5 – 15 psi 5 – 15 psi 12 – 15 psi 12– 15 psi

Mold (linear) shrinkage

(in/in)

0.015 – 0.050 0.015 – 0.050 0.015 – 0.040 0.015 – 0.040

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Special Low Versions of PolyethyleneProduced through catalyst selection and regulation of reactor conditions

• Very Low Density Polyethylene (VLDPE)• Densities between 0.890 and 0.915

• Applications include disposable gloves, shrink packages, vacuum cleaner

hoses, tuning, bottles, shrink wrap, diaper film liners, and other health care

products

• Linear Low Density Polyethylene (LLDPE)• Densities between 0.916 and 0.930

• Contains little if any branching by co-polymerizing ethylene at low pressures

in presence of catalysts with small amounts of α-olefin co-monomers

(butene, hexene, octene) which play the role of uniform short branches along

linear backbone.

• Properties include improved flex life, low warpage, improved stress-crack

resistance, better impact, tear, or puncture versus conventional LDPE

• Applications include films for ice, trash, garment, and produce bags at

thinner gage.

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Special High Versions of PolyethyleneProduced through catalyst selection and regulation of reactor conditions

• Ultra High Molecular Weight Polyethylene (UHMWPE)

– Extremely high MW at least 10 times of HDPE (MW=3M to 6M)

– Process leads to linear molecules with HDPE

– Densities are 0.93 to 0.94 g/cc and Moderate cost

– High MW leads to high degree of physical entanglements that

• Above Tmelt (130 C or 266F), the material behaves in a rubber-like

molecule rather than fluid-like manner causing processing troubles,

high viscosities

• Processed similar to PTFE (Teflon)

– Ram extrusion and compression molding are used.

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Special High Versions of PolyethyleneProduced through catalyst selection and regulation of reactor conditions

• Ultra High Molecular Weight Polyethylene (UHMWPE)

– Properties include outstanding properties like engineering plastic

or specialty resin

• Chemical inertness is unmatched; environmental stress cracking

resistance and resistance to foods and physiological fluids,

• Outstanding wear or abrasion resistance, very low coefficient of

friction, excellent toughness and impact resistance.

– Applications:

• pump parts, seals, surgical implants, pen tips, and butcher-block

cutting surfaces. , chemical handling equipment, pen tips, prosthetic

wear surfaces, gears

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Special Forms of Polyethylene• Cross-linked PE (XLPE)

– Chemical cross-links improve chemical resistance and improve

temperature properties.

– Cross-linked with addition of small amounts of organic peroxides

• Dicumyl peroxide, etc.

– Crosslinks a small amount during processing and then sets up after

flowing into mold.

– Used primarily with rotational molding

– Extruded Products

• Films (shrink wrap film in particular)

• Pipes

• Electrical wire and cable insulation

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Copolymers of Polyethylene• Ethylene-Vinyl Acetate (EVA)

– Repeating groups is ethylene with a vinyl acetate functional that reduces the

regularity of the chain; thus the crystallinity and stiffness

– Part of the pendent group are highly polar which makes film with increased water

vapor permeability, increased oil resistance and cling.

– Vinyl acetate reduces crystallinity and increases chemical reactivity because of high

regions of polarity.

– Applications include flexible packaging, shrink wrap, auto bumper pads, flexible

toys, and tubing with vinylacetate up to 50%

C C

H H

H H

C C

H O

C = O

C

H H

n m

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Copolymers of Polyethylene• Ethylene-vinyl alcohol (EVOH)

• Contains equal amounts of two repeat units that act as

– Barrier layers or as interlayers (tie layers) between incompatible

materials due to strong bonding of vinylalcohol repeat units.

• Ethylene-ethyl acrylate (EEA) Ethylene-methyl acrylate (EMA)

• Properties range from rubbery to tough ethylene-like properties

• Applications include hot melt adhesives, shrink wrap, produce bags,

bag-in-box products, and wire coating.

• Produced by addition of methyl acrylate monomer (40% by weight)

with ethylene gas

– reduces crystallinity and increases polarity

• Tough, thermally stable olefin with good rubber characteristics.

• Applications include food packaging, disposable medical gloves,

heat-sealable layers, and coating for composite packaging

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Copolymers of Polyethylene• Ethylene-carboxylic acid (EAA, EMAA)

– Small amounts of acrylic acid (AA) or methacrylic acid (MAA) that feature

carboxyl acid groups (COOH) are notable adhesives, especially to polar

substrates, including fillers and reinforcements

– Problems include tackiness and corrosive to metals and crosslinking nature

• Ionomers

– Modified ethylene-methacrylic acid copolymers where some of the carboxyl

acid groups are converted into corresponding metallic salts (metal metacrylate),

where the metals are sodium or zinc.

– Ionic bonds are formed between these cationic and the remaining anionic acid

groups. Results in a quasi crosslinked polymer at low temperature and is

reversible at high temperature

– Useful properties, e.g., adhesive and paints to metals (polarity), resistance to

fats and oils, Flex, puncture, impact resistance

– Applications: golf balls, bowling pin covers, ski boot shells, films

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Copolymers of Polyethylene• Ethylene-Propylene (EPM)

– Ethylene and propylene are copolymerized in random manner and causes a delay

in the crystallization.

– Thus, the copolymer is rubbery at room temp because the Tg is between HDPE

(-110C) and PP (-20C).

– Ethylene and propylene can be copolymerized with small amounts of a

monomer containing 2 C=C double bonds (dienes)

– Results in a co-polymer, EPR, or thermoplastic rubber, TPR

C C

H H

H H

n

C C

CH3 H

H H

m

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Mechanical Properties of PE Blends

Mechanical Properties of PE BlendsEthylene-vinyl

acetate

Ethylene-vinyl

alcohol

Ethylene-

ethyl acrylate

Ethylene-methyl

acrylate

Density 0.922 – 0.943 1.14 – 1.19 0.93 0.942 – 0.945

TensileStrength, psi

2,200 – 4,000 8,520 – 11,600 1,600 – 2,100 1,650

TensileModulus, psi

7K – 29K 300 K – 385 K 4K – 7.5 K 12 K

Tensile

Elongation, %

300% - 750% 180%- 280% 700% - 750% 740%


No break 1.0 – 1.7 No break

Hardness, Shore D17 – D45 D27 – D38

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Processing Properties of PE Blends


Ethylene-vinyl

acetate

Ethylene-vinyl

alcohol

Ethylene-ethyl

acrylate

Ethylene-methyl

acrylate

Tmelt 103 – 108 C 142 – 181 C 83 C

Recommended TempRange (C: Compression)


C: 200-300FI: 300F – 430F

E: 300F – 380F

I: 365F – 480FE: 365F – 480F

C: 200 – 300FI: 250F – 500F

E: 300F – 620F

Molding Pressure 1 – 20 psi 1 – 20 psi


(in/in)

0.007 – 0.035 0.015 – 0.035

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Polypropylene History

• Prior to 1954 most attempts to produce plastics from

polyolefins had little commercial success

– PP invented in 1955 by Italian Scientist F.J. Natta by addition

reaction of propylene gas with a sterospecific catalyst titanium

trichloride.

– Isotactic polypropylene was sterospecific (molecules are

arranged in a definite order in space)

– PP is not prone to environmental stress-cracking like PE

• Polypropylene is similar in manufacturing method and in

properties to PE

• Tg of PP = -25C versus Tg of PE of -100C

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Chemical Structure

• Propylene

• Isotactic- CH3 on one side of polymer chain (isolated).Commercial PP is 90% to 95% Isotactic

C C

CH3 H

H H

C C

CH3 H

H H

C C

CH3 H

H H

C C

CH3 H

H H

C C

CH3 H

H H

C C

CH3 H

H H

n

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Polypropylene Stereostatic Arrangements

•Atactic- CH3 in a random order (A- without; Tactic- order) Rubbery and of

limited commercial value.

•Syndiotactic- CH3 in a alternating order (Syndio- ; Tactic- order)

C C

CH3 H

H H

C C

H H

H CH3

C C

CH3 H

H H

C C

H H

H CH3

C C

CH3 H

H H

C C

CH3 H

H H

C C

H H

H CH3

C C

H H

H CH3

C C

CH3 H

H H

C C

H H

H CH3

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Addition Polymerization of PP• Polypropylene produced with low pressure process (Ziegler)

• Polypropylene produced with linear chains

• Polypropylene is similar in manufacturing method and in properties to

PE

• Differences between PP and PE are

– Density: PP = 0.90; PE = 0.941 to 0.965

– Melt Temperature: PP = 176 C; PE = 110 C

– Tg of PP = -25C versus Tg of PE of -100C

– Service Temperature: PP has higher service temperature

– Hardness: PP is harder, more rigid, and higher brittle point

– Stress Cracking: PP is more resistant to environmental stress cracking

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Advantages/Disadvatages of Polypropylene• Advantages

– Low Cost

– Excellent flexural strength

– Good impact strength

– Processable by all thermoplastic

equipment

– Low coefficient of friction

– Excellent electrical insulation

– Good fatigue resistance

– Excellent moisture resistance

– Service Temperature to 126 C

– Very good chemical resistance

• Disadvantages– High thermal expansion

– UV degradation

– Poor weathering resistance

– Subject to attack by chlorinated

solvents and aromatics

– Difficulty to bond or paint

– Oxidizes readily

– flammable

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Mechanical Properties of Polypropylene

Mechanical Properties of PolypropylenePolypropylene LDPE

(For Comparison)HDPE(For Comparison)

Density 0.90 0.91- 0.925 0.959-0.965

Crystallinity 30% to 50% 30% to 50% 80% to 91%

Molecular Weight 200K to 600K 10K to 30K 250K to 1.5M

Molecular Weight

Dispersity MWD

(Mw/Mn)

Range ofMWD forprocessing

Range of MWDfor processing

Range of MWDfor processing

Tensile Strength,

psi

4,500 – 5,500 600 - 2,300 5,000 – 6,000

Tensile Modulus,

psi

165K – 225K 25K – 41K 150K – 158 K

Tensile

Elongation, %

100% - 600% 100% - 650% 10% - 1300%


0.4 – 1.2 No break 0.4 – 4.0

Hardness, Shore R80 - 102 D44 – D50 D66 – D73

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Physical Properties of Polyethylene

Physical Properties of Polypropylene

Polypropylene LDPE HDPE

Optical Transparent toopaque

Transparent toopaque


Tmelt 175 C 98 – 115 C 130 –137 C

Tg -20 C -100 C -100 C

H20

Absorption

0.01 – 0.03 Low < 0.01 Low < 0.01

Oxidation

Resistance

Low, oxidesreadily

Low, oxidesreadily

Low, oxides readily

UV Resistance Low, Crazesreadily

Low, Crazesreadily

Low, Crazes readily

Solvent

Resistance

Resistant

below 80C

Resistant below

60C

Resistant below 60C

Alkaline

Resistance

Resistant Resistant Resistant

Acid

Resistance

OxidizingAcids

Oxidizing Acids Oxidizing Acids

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Processing Properties of Polyethylene


Polypropylene LDPE HDPE

Tmelt 175 C 98 – 115 C 130 –137 C



I: 400F – 550FE: 400F – 500F

I: 300F – 450FE: 250F – 450F

I: 350F – 500FE: 350F – 525F

Molding Pressure 10 -20 psi 5 – 15 psi 12– 15 psi


(in/in)

0.010 – 0.025 0.015 – 0.050 0.015 – 0.040

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Several Olefin Polymers• Polybutylene (PB)

– Based on butene-1 monomer

– Plus comonomers (small amt)

– Melt Point 125C similar to PE

– Tg, -25C is closer to PP

– Good creep & ESC resistance

– Good for pipe and film extrusions

C C

C2H5 H

H H

n

C C

HCH H

H H

H3C C CH3

n

• Polymethylpentene (PMP)

– Trade name is TPX

– Crystallizes to high degree (60%)

– Highly transparent (90% transmis)

– Properties similar to PP

– Density is 0.83 g/cc, Tg =30C

– Stable to 200C, Tm=240C

– Creep and chemical resistance is good

and low permeability.

– Electrical properties are excellent

– Process by injection & extrusion

– Good for lighting, packaging, trays,

bags, coffee makers, wire covering,

connectors, syringes.

– Poor ESC and UV

H

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Polyolefin_Polybutylene

• History

– PB invented in 1974 by Witco Chemical

– Ethyl side groups in a linear backbone

• Description

– Linear isotactic material

– Upon cooling the crystallinity is 30%

– Post-forming techniques can increase crystallinity to 55%

– Formed by conventional thermoplastic techniques

• Applications (primarily pipe and film areas)

– High performance films

– Tank liners and pipes

– Hot-melt adhesive

– Coextruded as moisture barrier and heat-sealable packages

C C

CH2 H

H H

CH3

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Properties of Polybutylene

Mechanical Properties of PolybutylenePolybutylene Polypropylene LDPE

(For Comparison)

HDPE

(For Comparison)

Density 0.908 -.917 0.90 0.91- 0.925 0.959-0.965

Crystallinity 30% to 50% 30% to 50% 30% to 50% 80% to 91%

Tensile Strength,

psi

4,000 4,500 – 5,500 600 - 2,300 5,000 – 6,000

Tensile Modulus,

psi

10K – 40K 165K – 225K 25K – 41K 150K – 158 K

Tensile

Elongation, %

300% - 400% 100% - 600% 100% - 650% 10% - 1300%


No break 0.4 – 1.2 No break 0.4 – 4.0

Hardness Shore D55 – D65 R80 - 102 D44 – D50 D66 – D73

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Polyolefin_Polymethylpentene (PMP)• Description

– Crystallizes to 40%-60%

– Highly transparent with 90% transmission

– Formed by injection molding and blow molding

• Properties

– Low density of 0.83 g/cc; High transparency

– Mechanical properties comparable to polyolefins with higher temperature

properties and higher creep properties.

– Low permeability to gasses and better chemical resistance

– Attacked by oxidizing agents and light hydrogen carbon solvents

– Attacked by UV and is quite flammable

• Applications

– Lighting elements (Diffusers, lenses reflectors), liquid level

– Food packaging containers, trays, and bags.

C C

CH2 H

H H

H3C-CH-CH3

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Properties of Polymethylpentene

Mechanical Properties of PolymethylpentenePolymethyl-

pentene

Polypropylene LDPE

(For Comparison)

HDPE

(For Comparison)

Density 0.83 0.90 0.91- 0.925 0.959-0.965

Crystallinity 40% to60% 30% to 50% 30% to 50% 80% to 91%

Tensile Strength,

psi

4,000 – 5,000 4,500 – 5,500 600 - 2,300 5,000 – 6,000

Tensile Modulus,

psi

160K – 200K 165K – 225K 25K – 41K 150K – 158 K

Tensile

Elongation, %

100% - 400% 100% - 600% 100% - 650% 10% - 1300%


0.4 – 1.0 0.4 – 1.2 No break 0.4 – 4.0

Hardness R80 – R100 R80 - 102 D44 – D50 D66 – D73

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PVC Background • Vinyl is a varied group- PVC, PVAc, PVOH, PVDC, PVB

– Polyvinyls were invented in 1835 by French chemist V. Regnault when he

discovered a white residue could be synthesized from ethylene dichloride in an

alcohol solution. (Sunlight was catalyst)

– PVC was patented in 1933 by BF Goodrich Company in a process that

combined a plasticizer, tritolyl phosphate, with PVC compounds making it

easily moldable and processed.

– PVC is the leading plastic in Europe and second to PE in the US.

– PVC is made by suspension process (82%), by mass polymerization (10% ), or

by emulsion (8%)

– All PVC is produced by addition polymerization from the vinyl chloride

monomer in a head-to-tail alignment.

– PVC is amorphous with partially crystalline (syndiotactic) due to structural

irregularity increasing with the reaction temperature.

– PVC (rigid) decomposes at 212 F leading to dangerous HCl gas

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PVC and Vinyl Products

• Rigid-PVC

– Pipe for water delivery

– Pipe for structural yard and garden structures

• Plasticizer-PVC or Vinyl– Latex gloves

– Latex clothing

– Paints and Sealers

– Signs

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PVC and PS Chemical Structure• Vinyl Groups (homopolymers produced by addition polymerization)

– PVC - poly vinylidene - polyvinylalcohol (PVOH)

chloride (PVDC)

– polyvinyl acetate (PVAc) - PolyStyrene (PS)

C C

H Cl

H H

n

C C

H Cl

H Cl

n

C C

H OCOCH3

H H

n

C C

H OH

H H

n

C C

H

H H

n

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Mechanical Properties of Polyvinyls

Mechanical PropertiesPVC (rigid) PVC (Flexible) PVB PVDC

Density, g/cc 1.30-1.58 1.16-1.35 1.05 1.65-1.72

Tensile Strength,psi

6,000 - 7,500 1,500 -3,500 500 - 3,000 3,500 - 5,000

Tensile Modulus,psi

350K – 600K 160K –240K

TensileElongation, %

40% - 80% 200%-450% 150% - 450% 160% -240%


0.4 - 22 Range Range 0.4 - 1

Hardness Shore D65-85 Shore A50-100 M60-65

CLTE

10-6 mm/mm/C

50 -100 70-250 190

HDT 264 psi 140 F -170F 130F -150F

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Physical Properties of Polyvinyls

PVC (rigid) PVC (Flexible) PVB PVDCOptical Transparent Transparent Transparent Transparent

Tmelt 75 – 105 C 75 – 105 C 49 172C

Tg 75 -105C 75-105C 49 -15C

H20

Absorption

0.04-0.4% (24h) 0.15-0.75% (24h) 0.09-0.16% (24h) 0.1% (24h)

Oxidation

Resistance

good good good good

UV Resistance Poor Poor Poor good

Solvent

Resistance

Soluble in

Acetone, andCyclohexanol.Partially in

Toluene

Soluble in

Acetone, andCyclohexanol.Partially in

Toluene

Dissolved in ketones

and esters

good

Alkaline

Resistance

Excellent Excellent Excellent good

Acid

Resistance

good good good good

Cost $/lb $0.27 $0.27 $ $1.62

40

Processing Properties of Polyvinyls

PVC (rigid) PVC (Flexible) PVB PVDCTmelt 75 – 105 C 75 – 105 C 49 172C

Recommended TempRange (I:Injection, E:Extrusion,C: Compression)

I: 300F – 415FC: 285F-400F

I: 320F – 385FC: 285F - 350F

I: 250F – 340FC: 280F-320F

I: 300F – 400FC: 260F-350FE: 300F-400F

Molding Pressure 10-40 kpsi 8-25 kpsi 0.5-3kpsi 5 - 30 kpsi

Mold (linear) shrinkage(in/in)

0.002 – 0.006 0.010 – 0.050 0.005 - 0.025

41

Vinylchloride Co-Polymers• Chlorinated PVC (CPVC)

– Possible to chemically modify PVC by substituting Cl for H

– Cl content can be raised from 56.8% in PVC to 62%-72%

– CPVC has improved chemical and temperature resistance that can be used for pipe and hot water applications, even boiling water.

• Vinylchloride-vinylacetate (PVC-VAC)– Internally plasticizing PVC with 3% to 30% vinyl acetate

– Impact properties and processing ease are improved for

• Floor coverings, phonograph records.

• Polyalloys– Improves impact resistance of rigid PVC by blending with elastomers, e.g.,

EVA, Nitrile rubber (NBR), Chloronated PE.

– Blend PVC with PMMA and SAN for better transparency

– Blend PVC with ABS for improved combustion resistance

42

Vinylchloride Co-Polymers• Polyvinylidenechloride (PVDC)

– Homopolymer can crystallize. Tg = -18C, Tm = 190C

• Decomposition temperature is slightly above melt temperature of abut 200C

• PVDC has outstanding barrier properties for O2, CO2, and H2O.

• Copolymerized with 10-15% vinyl chloride to create Saran Wrap.

• Copolymerize with acrlonitrile and acrylate esters up to 50%.

• Coplymerization reduces crystallinity to 35-45% and the Tmelt ot 175C

• Polyvinyl acetate (PVAC)

– Not used as a plastic

• Noncrystallizing

• Low Tg = 30C, it is

– It is best as a major ingredient in adhesives and paint, Elmers Glue

– Vinylacetate repeat units form the minor component in imporant copolymers

with vinylchloride (PVC-PVAC) and ethylene (EVA)

C C

H Cl

H Cl

n

C C

H OCOCH3

H H

n

43

Vinylchloride Co-Polymers• Polyvinylalcohol (PVAL or PVOH)

– Homopolymer is very polar can crystallize

– Water soluable. Tg = 80C, Tm = 240C

– Random copolymer that is derived from PVAC

– Used as a release film for reinforced plastics or barrier film.

• Polyvinylbutyral (PVB)– Random copolymer (PVB-PVAL)

• containing 10-15% VAL

• Low Tg = 50C

– Used in plasticized form as adhesive interlayer

• For windshield safety glass (Saflex from Monsanto)

• Powder is extruded into sheet and then placed between two layers of glass

– Requires

• Toughness, transparency, weatherability, and adhesion to glass.

C C

H OH

H H

n

C C

H CH2

H H

nCH2CH3

44

PS Background • PS is one of the oldest known vinyl compounds

– PS was produced in 1851 by French chemist M. Berthelot by passing benzene and ethylene through a red-hot-tube (basis for today)

– Amorphous polymer made from addition polymerization of styrene

– Homopolymer (crystal): (2.7 M metric tons in ’94) GPPS (General Purpose PS)

• Clear and colorless with excellent optical properties and high stiffness.

• It is brittle until biaxially oriented when it becomes flexible and durable.

– Graft copolymer or blend with elastomers- High Impact Polystyrene (HIPS):

• Tough, white or clear in color, and easily extruded or molded.

• Properties are dependent upon the elastomer %, but are grouped into

– medium impact (Izod<1.5 ft-lb), high impact (Izod between 1.5 to 2.4 ft-lb) and super-high impact (Izod between 2.6 and 5 ft-lb)

– Copolymers include SAN (poly styrene-acrylonitrile), SMA (maleic anhydride), SBS (butadiene), styrene and acrylic copolymers.

– Expandable PS (EPS) is very popular for cups and insulation foam.

• EPS is made with blowing agents, such as pentane and isopentane.

• The properties are dependent upon cell size and cell size distribution

45

Polystyrene Polymers

• Poly-para-methyl-styrene (PPMS)– Similar to PS (Tg=100C) with a slightly higher Tg=110C

– Low cost alternative to PS in homo and co-polymers

• Poly-alpha-methyl-styrene (PAMS)

– High Tg =160C and better Temp resistance

– Not much commercial importance by itself

– Has significant use in copolymers

• Rubber-toughened impact polystyrene (HIPS)– Random copolymerization with small fraction of elastomer type repeat units.

Lowers Tg

– Block copolymerization of elastomeric component is more expensive, but keeps

Tg same as PS

C C

H

H H

nCH3

C C

H

H

n

CH3

46

PSB, SAN, ABS Chemical Structure

• PSB (copolymer -addition) * Styrene- acrylonitrile (SAN)

• ABS acrylonitrile butadiene styrene (Terpolymer- addition)

C C

H

H H

km

C C

H C:::N

H H

n

C C

CH3 CH3

H H

C C

H

H H

k m

C C

CH3CH3

H H

C C

H

H H

k

C C

H C:::N

H H

n

47

Polystyrene Co-Polymers

• Styrene-Butadiene (PSB) – Tg= % of each PS (100C) and Butadiene (-80C)

• Example, 50% PS and 50% B, Tg=10C

– Easy to copolymerize and can be rubbery (butadiene-dominant) or plastic like

(styrene-like), out 70% of the PSB is styrene dominant

– Random (styrene dominant) copolymers have been used in emulsion (latex)

form to produce coatings (paints).

– Block copolymers are commercial butadiene styrene-plastics

• Styrene Acrylonitrile (SAN)

– Random copolymer of 30% polyacrylonitrile repeat units yields

• Increased Temp performance and transparent, ease to process

• Resistant to food and body oils

– Used for transparent medical products, houseware care items

– Polyalloys (blends) with polysulphone

48

Polystyrene Co-Polymers• Acrylonitrile Butadiene Styrene (ABS)

– First introduced in the late 1940s as replacement for rubber.

– Terpolymer: Three repeat units vary according to grade (20%A, 20%B, 60%S)

• Acrylonitrile for chemical and temperature resistance

• Butadiene for impact resistance; Styrene for cost and processability

• Graft polymerization techniques are used to produce ABS

– Very versatile applications that are injection molded and extruded

• Rigid pipes and fittings, thermoformed refrigerator door liners, Legos toys

• Small boat hulls, telephone and computer housings

• Family of materials that vary from high gloss to low matte finish, and

from low to high impact resistance.

• Additives enable ABS grades that are flame retardant, transparent,

high heat-resistance, foamable, or UV-stabilized

• ABS-based polyalloys (blends)

– PVC/ABS for flame resistance

– TPU/ABS for polyurethane; PSU/ABS for polysulphone

– PC/ABS for temperature and impact resistance (Saturn door)

49

Mechanical Properties of PS, ABS, SANMechanical Properties

PS ABS SAN

Density, g/cc 1.04 1.16-1.21 1.07

Tensile Strength,

psi

5,000 - 7,200 3,300 - 8,000 10,000 -12,000

Tensile Modulus,

psi

330K-475K 320K-400K 475K-560K

Tensile

Elongation, %

1.2% - 2.5% 1.5%-25% 2%-3%


0.35-0.45 1.4-12 0.4-0.6

Hardness M60-75 R100-120 R83, M80

CLTE

10-6 mm/mm/C

50 -83 65- 95 65-68

HDT 264 psi 169F - 202F 190F - 225F 214F - 220F

C C

H

H H

n

Tg =100C

50

Physical Properties of PS, ABS, SAN

PS ABS SAN Optical

Transparent Transparent Transparent

Tmelt

100 C 125C 120C

Tg 70 -115C 110 -125C 120C

H20

Absorption

0.01-0.03% (24h)

0.2-0.6% (24h)

0.15-0.25% (24h)

Oxidation

Resistance

good good good

UV Resistance

fair fair fair

Solvent

Resistance

Soluble in Acetone, Benzene,

Toluene and Methylene dichloride

Soluble in Toluene and Ethylene dichloride, Partially in Benzene

Dissolved in ketones and esters

Alkaline

Resistance

Excellent Excellent Poor: attacked by oxidizing agents

Acid

Resistance

Poor: attacked by oxidizing agents

Poor: attacked by oxidizing agents

good

Cost $/lb

$0.41 $0.90 $0.87

51

Processing Properties of PS, ABS, SAN

PS ABS SAN

Tmelt 100 C 125C 120C



I: 350F – 500FE: 350F- 500F

C: 300F - 400F

I: 380F – 500FC: 350F - 500F

I: 360F – 550FE: 360F -450F

C:300F - 400F

Molding Pressure 5 - 20 kpsi 8-25 kpsi 5-20 kpsi


0.004 – 0.007 0.004 – 0.008 0.003 – 0.005

52

Acrylic and Cellulosic Background • Acrylics (1901)

– Includes acrylic and methacrylic esters, acids, and derivatives.

– Used singularly or in combination with other polymers to produce

products ranging from soft, flexible elastomers to hard, stiff

thermoplastics and thermosets.

• Cellulosics (1883)

– Cellulose nitrate was first developed in the 1880s.

– First uses were billiard balls, combs, and photographic film.

– Cellulose acetate was developed in 1927 reduced the limitations of

flammability, and solvent requirement.

– In 1923, CA became the first material to be injection molded.

– Cellulose acetate butyrate (CAB) in1938 and Cellulose acetate

propionate (CAP) in 1945 found applications for hair brushes,

toothbrushes, combs, cosmetic cases, hand tool handles, steering

wheels, knobs, armrests, speakers, grilles, etc.

53

Acrylics Chemical Structure

• Acrylics- Basic formula - Polymethyl acrylate

• Polymethyl methacrylate -AcrylateStyreneAcrylonitrile (ASA)

C C

H COOR2

H R1

n

C C

H COOCH3

H H

n

C C

H COOCH3

H CH3

n

C C

H C:::N

H H

k

C C

H

H H

m

C C

H COOH

H H

n

54

Applications for PC and Acrylics

• PC (high impact strength, transparency, excellent creep and

temperature)

– lenses, films, windshields, light fixtures, containers, appliance

components and tool housings

– hot dish handles, coffee pots, popcorn popper lids, hair dryers.

– Pump impellers, safety helmets, beverage dispensers, trays, signs

– aircraft parts, films, cameras, packaging

• Acrylics

– Optical applications, outdoor advertising signs, aircraft windshields,

cockpit covers, bubble bodies for helicopters

– Plexiglass, window frames, (glass filled): tubs, counters, vanities

55

Mechanical Properties of Acrylic, PC,

PC/ABSMechanical Properties

Acrylic PC ABS PC/ABS

Density, g/cc 1.16- 1.19 1.2 1.16-1.21 1.07 - 1.15


5,000 - 9,000 9,500 3,300 - 8,000 5,800 - 9,300

Tensile Modulus,

psi

200K – 500K 350 K 320K-400K 350K -450K

Tensile

Elongation, %

20 - 70% 110% 1.5%-25% 50%-60%


0.65 -2.5 16 1.4-12 6.4 - 11

Hardness M38-M68 M70 R100-120 R95 -R120

CLTE

10-6 mm/mm/C

48 - 80 68 65- 95 67

HDT 264 psi 165-209F 270 190F - 225F 225F

56

Physical Properties of Acrylic, PC, PC/ABS

Acrylic PC ABS PC/ABSOptical Transparent Transparent Transparent Transparent

Tmelt 105C 150C 125C 135C

Tg 75 -105C 110 -125C 110 -125C 120C

H20

Absorption

0.01-0.03% (24h) 0.2-0.6% (24h) 0.2-0.6% (24h) 0.15-0.25% (24h)

Oxidation

Resistance

good good good good

UV Resistance fair fair fair fair

Solvent

Resistance

Soluble in

Acetone, Benzene,Toluene, ethylene

dichloride

Partially Soluble in

Acetone, Benzene,Toluene. Dissolves inhot benzene-toluene

Soluble in Toluene

and Ethylenedichloride, Partially in

Benzene

Soluble in Toluene

and Ethylenedichloride, Partially in

BenzeneAlkaline

Resistance

Excellent Excellent Excellent Poor: attacked byoxidizing agents

Acid

Resistance

Poor: attacked byoxidizing agents



good

Cost $/lb $0.41 $0.90 $0.90 $0.87

57

Advantages

• PC

– High impact strength, excellent creep resistance, transparent

– Very good dimensional stability and continuous temp over 120 C

• Acrylics

– Optical clarity, weatherability, electrical properties, rigid, high

gloss

Disadvantages• PC

– High processing temp,UV degradation

– Poor resistance to alkalines and subject to solvent cracking

• Acrylics

– Poor solvent resistance, stress cracking, combustibility, Use T 93C

58

Polyamide History • PA is considered the first engineering thermoplastic

• PA is one of many heterochain thermoplastics, which has

atoms other than C in the chain.

• PA invented in 1928 by Wallace Carothers, DuPont, in

search of a “super polyester” fiber with molecular weights

greater than 10,000. First commercial nylon in 1938.

• PA was created when a condensation reaction occurred

between amino acids, dibasic acids, and diamines.

• Nylons are described by a numbering system which

indicates the number of carbon atoms in the monomer

chains

– Amino acid polymers are designated by a single number, as nylon

6

– Diamines and dibasic acids are designated with 2 numbers, the first

59

Chemistry & Chemical Structurelinear polyamides• Thermoplastic nylons have amide (CONH) repeating link

• Nylon 6,6 - poly-hexamethylene-diamine (linear)

NH2(CH2)6NH2 + COOH(CH2)4COOH

hexamethylene diamine + Adipic Acid

n[NH2(CH2)6NH . CO (CH2)4COOH ] + (heat)

nylon salt

[NH2(CH2)6NH . CO (CH2)4CO ]n + nH2O

Nylon 6,6 polymer chain

• Nylon 6 - polycaprolactam (linear)

[NH(CH2)5CO ]n

60

Chemistry & Chemical Structurelinear polyamides

• Nylon 6, 10 - polyhexamethylenesebacamide (linear)

[NH2(CH2)6NH . CO (CH2)8CO]n

• Nylon 11 - Poly(11-amino-undecanoic-amide (linear)

[NH(CH2)10CO ]n


[NH(CH2)11CO ]n

• Other Nylons

– Nylon 8, 9, 46, and copolymers from other diamines and acids

61

Chemistry & Chemical StructureAromatic polyamides (aramids)

• PMPI - poly m-phenylene isophthalamide (LCP fiber)

[ -NHCO - NHCO ]n

• PPPT - poly p-phenylene terephthalamide (LCP fiber)

[ -NHCO - NHCO ]n

• Nomax PMPI -

– first commercial aramid fiber for electrical insulation. LCP

fibers feature straight chain crystals

• Kevlar 29 PPPT-

– textile fiber for tire cord, ropes, cables etc.

• Kevlar 49 PPPT - reinforcing fiber for thermosetting resins

62

Chemistry & Chemical StructureTransparent polyamides

• PA- (6,3,T)

[CH2C3H6C2H4-NHCO - NHCO ]n

• PA - (6,T)

[(CH2) 6NHCO - NHCO ]n

• Transparent polyamides are commercially available

• Reduced crystallization due to introduction of side

groups

63

Applications for Polyamides

• Fiber applications

– 50% into tire cords (nylon 6 and nylon 6,6)

– rope, thread, cord,belts, and filter cloths.

– Monofilaments- brushes, sports equipment, and bristles (nylon 6,10)

• Plastics applications

– bearings, gears, cams

– rollers, slides, door latches, thread guides

– clothing, light tents, shower curtains, umbrellas

– electrical wire jackets (nylon 11)

• Adhesive applications

– hot melt or solution type

– thermoset reacting with epoxy or phenolic resins

– flexible adhesives for bread wrappers, dried soup packets,

64

Mechanical Properties of Polyamides

Mechanical Properties of NylonNylon 6 Nylon 6,6 Nylon 6,10 Nylon 6,12

Density, g/cc 1.13-1.15 1.13-1.15 1.09 1.06-1.10

Crystallinity 30-% - 50% 30-% - 50% 30-% - 50% 30-% - 50%

Molecular Weight 10,000–30,000 10,000–30,000 10,000–30,000 10,000–30,000

Tensile Strength,

psi

6,000 – 24,000 14,000 8,500 – 8,600 6,500 – 8,800

Tensile Modulus,

psi

300K 230K – 550K 250 K 220 - 290 K

Tensile

Elongation, %

30% - 100% 15%-80% 70% 150%

Impact Strength

ft-lb/in

0.6 – 2.2 0.55 – 1.0 1.2 1.0 –1.9

Hardness R80 - 102 R120 R111 M78

65

Physical Properties of PolyamideNylon 6 Nylon 6,6 Nylon 6,10 Nylon 6,12

Optical Translucent toopaque

Translucent toopaque

Translucent to opaque Translucent to opaque

Tmelt 210C -220 C 255C – 265C 220 C 195 -219 C

Tg

H20

Absorption

1.3-1.9% (24h)8.5-10 (Max)

1.0-2.8% (24h)8.5% (Max)

1.4% (24h)3.3% (Max)

0.4 – 1.0% (24h)2.5 –3 % (Max)

Oxidation

Resistance

good good good good

UV Resistance Poor Poor Poor Poor

Solvent

Resistance

Dissolved by

phenol &formic acid

Dissolved by

phenol & formicacid

Dissolved by phenol &

formic acid


formic acid

Alkaline

Resistance


Acid

Resistance

Poor Poor Poor Poor

Cost $/lb $1.30 $1.30 $3.00 $3.10

66

Advantages Disadvantages of Polyamide• Advantages

– Tough, strong, impact resistant


– Abrasion resistance

– High temperature resistance

– Processable by thermopalstic methods

– Good solvent resistance

– Resistant to bases

• Disadvantages

– High moisture absorption with dimensional instability

• loss of up to 30 % of tensile strength and 50% of tensile modulus

– Subject to attack by strong acids and oxidizing agents

– Requires UV stabilization

– High shrinkage in molded sections

– Electrical and mechanical properties influenced by moisture content

– Dissolved by phenols

67

Additives and Reinforcements to PA

• Additives- antioxidants, UV stabilizers, colorants, lubricants

• Fillers

– Talc

– Calcium carbonate

• Reinforcements

– Glass fiber- short fiber (1/8” or long fiber 1/4”)

– Mineral fiber (wolastonite)

– carbon fibers

– graphite fibers

– metallic flakes

– steel fibers

68

Properties of Reinforced Nylon

Nylon 6,6 Nylon 6,6 with30% short glass

Nylon 6,6 with30% long glass

Nylon 6,6 with30% carbon fiber

Density, g/cc 1.13-1.15 1.4 1.4 1.06-1.10

Crystallinity 30-% - 50% 30-% - 50% 30-% - 50% 30-% - 50%

Molecular Weight 10,000–30,000 30,000 10,000–30,000 10,000–30,000

Tensile Strength,

psi

14,000 28,000 28,000 32,000

Tensile Modulus,

psi

230K – 550K 1,300K 1,400 K 3,300 K

Tensile

Elongation, %

15%-80% 3% 3% 4%


0.55 – 1.0 1.6-4.5 4.0 1.5

Hardness R120 R120 E60 R120

Moisture % 1.0-2.8% (24h)8.5% (Max)

0.7-1.1 (24h)5.5-6.5 (Max)

0.9 (24h)5.5-6.5 (Max)

0.7 (24h)5 (Max)

Cost $/lb $1.40 $1.70 $2.00 $2.70

69

Other Heterochain Polymers

• Polyimide

– Developed by Du Pont in 1962

– Obtained from a condensation polymerization of aromatic diamine

and an aromatic dianhydride

– Characterized as Linear thermoplastics that are difficult to process

– Many polyimides do not melt but are fabricated by machining

– Molding can occur if enough time for flow is allowed for T>Tg

• Advantages

– High temperature service (up to 700C)

– Excellent barrier, electrical properties, solvent and wear resistance

– Good adhesion and ezpecially suited for composite fabrication

ON

C

O

N

C

O

C C

70

Other Heterochain Polymers• Polyimide Disadvantages

– Difficulty to fabricate and requires venting of volatiles

– Hydroscopic and Subject to attacks by alkalines

– Comparatively high cost

• Applications

• Aerospace, electronics, and nuclear uses (versus flurocarbons)

• Office and industrial equipment; Laminates, dielectrics, and coatings

• Valve seats, gaskets, piston rings, thrust washers, and bushings

• Polyamide-imide

• Amorphous member of imide family, marketed in 1972 (Torlon), and

used in aerospace applications such as jet engine components

• Contains aromatic rings and nitrogen linkage

• Advantages include: High temperature properties (500F), low

coefficient of friction, and dimensional stability.

71


• Polyacetal or Polyoxymethylene (POM)

• Polymerized from formaldehyde gas

• First commercialized in 1960 by Du Pont

• Similar in properties to Nylon and used for plumbing fixtures, pump

impellers, conveyor belts, aerosol stem valves, VCR tape housings

• Advantages

• Easy to fabricate, has glossy molded surfaces, provide superior

fatigue endurance, creep resistance, stiffness, and water resistance.

• Among the strongest and stiffest thermoplastics.

• Resistant to most chemicals, stains, and organic solvents

• Disadvantages

• Poor resistance to acids and bases and difficult to bond

• Subject to UV degradation and is flammable

• Toxic fumes released upon degradation

H-O-(CH2-O-CH2-O)NH:R

72

Mechanical Properties

Nylon 6 Acetal Polyimid Polyamide-imideDensity, g/cc 1.13-1.15 1.42 1.43 1.41

Crystallinity 30-% - 50%

Molecular Weight 10,000–30,000

Tensile Strength,

psi

6,000 – 24,000 10,000 10,000 26,830

Tensile Modulus,

psi

300K 520K

Tensile

Elongation, %

30% - 100% 40% - 75%


0.6 – 2.2 0.07 0.9 2.5

Hardness R80 - 102 R120 E50 E78

Tmelt 210 - 220 C 175-181 C Tg=275CMoisture

24 hr

max

1.3 - 1.9%8.5 - 10%

0.25 to 0.40%1.41%

0.32% .28%



opaque Transparent toopaque

73

Polyester History

• 1929 W. H. Carothers suggested classification of polymers

into two groups, condensation and addition polymers.

• Carothers was not successful in developing polyester fibers

from linear aliphatic polyesters due to low melting point and

high solubility. No commercial polymer is based on these.

• p-phenylene group is added for stiffening and leads to

polymers with high melting points and good fiber-forming

properties, e.g., PET.

• Polymers used for films and for fibers

• Polyesters is one of many heterochain thermoplastics, which

has atoms other than C in the chain.

• Polyesters includes unsaturated (thermosets), saturated and

aromatic thermoplastic polyesters.

74

Chemistry & Chemical Structurelinear polyesters (versus branched)

• Thermoplastic polyesters have ester(-C-O) repeating link

• Polyester (linear) PET and PBT

C6H4(COOH)2 + (CH2)2(OH)2 -[(CH2)2 -O- C - C-

O]-

terephthalic acid + ethylene glycol Polyethylene terephthalate (PET)


O]-

terephthalic acid + butylene glycol Polybutylene terephthalate (PBT)

O

O O

O O

75


• Wholly aromatic copolyesters (LCP)

– High melting sintered: Oxybenzoyl (does not melt below its

decomposition temperature. Must be compression molded)

– Injection moldable grades: Xydar and Vectra

– Xydar (Amoco Performance Products)

• terephthalic acid, p,p’- dihydroxybiphenyl, and p-hydroxybenzoic

acid

– Grade 1: HDT of 610F

– Grade 2: HDT of 480 F

– Vectra (Hoechst Celanese Corp.)

• para-hydroxybenzoic acid and hydroxynaphtholic acid

– Contains rigid chains of long, flat monomer units which are thought to

undergo parallel ordering in the melt and form tightly packed fibrous

chains in molded parts.

76

PET Chemical Structure and Applications• The flexible, but short, (CH2)2 groups tend to leave the

chains relatively stiff and PET is notes for its very slow

crystallization. If cooled rapidly from the melt to a Temp

below Tg, PET solidifies in amorphous form.

• If PET is reheated above Tg, crystallizaiton takes place to

up to 30%.

• In many applications PET is first pre-shaped in

amorphous state and then given a uniaxial (fibers or

tapes) or biaxial (film or containers) crystalline

orientation.

• During Injection Molding PET can yield amorphous

transparent objects (Cold mold) or crystalline opaques

objects (hot mold)

77

PBT Chemical Structure and Applications

• The longer, more flexible (CH2)4 groups allow for more

rapid crystallization than PET.

• PBT is not as conveniently oriented as PET and is

normally injection molded.

• PBT has a sharp melting transition with a rather low melt

viscosity.

• PBT has rapid crystallization and high degree of

crystallization causing warpage concerns

78

Thermoplastic Aromatic Copolyesters• Polyarylesters

– Repeat units feature only aromatic-type groups (phenyl or aryl

groups) between ester linkages.

– Called wholly aromatic polyesters

– Based on a combination of suitable chemicals

• p-hydroxybenzoic acid

• terephthalic acid

• isophthalic acid,

• bisphenol-A

– Properties correspond to a very stiff and regular chain with high

crystallinity and high temperature stability

– Applications include bearings, high temperature sensors, aerospace

applications

– Processed in injection molding and compression molding

– Most thermoplastic LCP appear to be aromatic copolyesters

79

Applications for Polyesters (PET)• Blow molded bottles

• 100% of 2-liter beverage containers and liquid products


• 25% of market in tire cords, rope, thread, cord, belts, filter cloths.

• Monofilaments- brushes, sports equipment, clothing, carpet, bristles

• Tape form- uniaxially oriented tape form for strapping

• Film and sheets

• photographic and x-ray films; biaxial sheet for food packages

• Molded applications- Reinforced PET [Rynite, Valox, Impet]

• luggage racks, grille-opening panels, functional housings such as

windshield wiper motors, blade supports, and end bells

• sensors, lamp sockets, relays, switches, ballasts, terminal blocks

• Appliances and furniture

• oven and appliance handles, coil forms for microwaves

• panel pedestal bases, seat pans, chair arms, and casters

80

Applications for Polyesters (PBT and LCP)

• PBT - 30 M lbs in 1988

• Molded applications (PBT) [Valox, Xenoy, Vandar, Pocan]

– distributers, door panels, fenders, bumper fascias

– automotive cables, connectors, terminal blocks, fuse holders and

motor parts, distributor caps, door and window hardware

• Extruded applications

– extrusion-coat wire

– extruded forms and sheet produced with some difficulty

• Electronic Devices (LCP) [26 M lbs] [Terylene, Dacron, Kodel]

– fuses, oxygen and transmission sensors

– chemical process equipment and sensors

– coil

81

Mechanical Properties of Polyesters

Mechanical Properties of polyesterPET PBT LCP Polyester

Density, g/cc 1.29-1.40 1.30 - 1.38 1.35 - 1.40

Crystallinity 10% - 30% 60% >80%

Molecular Weight

Tensile Strength,

psi

7,000 – 10,500 8,200 16,000 – 27,000

Tensile Modulus,

psi

400K - 600K 280K – 435K 1,400K - 2,800K

Tensile

Elongation, %

30% - 300% 50%-300% 1.3%-4.5%


0.25 - 0.70 0.7 - 1.0 2.4 - 10

CLTE

10-6 in/in/C

65 60-95 25-30

HDT 264 psi 70F -100F 122F - 185F 356F -671F

82

Physical Properties of Polyester

PET PBT LCP Polyester

Optical Transparent toOpaque

Opaque Opaque

Tmelt 245C -265 C 220C – 267C 400 C - 421 C

Tg 73C - 80C

H20

Absorption

0.1 - 0.2% (24h) 0.085% (24h)0.45% (Max)

<0.1% (24h)<0.1% (Max)

Oxidation

Resistance

good good good

UV Resistance Poor Poor none

Solvent

Resistance

Attacked byhalogen

hydrocarbons

good good

Alkaline

Resistance

Poor Poor Poor

Acid

Resistance

Poor Poor fair

Cost $/lb $0.53 $1.48 $7.00 - $10.00

83

Advantages and Disadvantages of

Polyesters• Advantages

– Tough and rigid and PBT has low moisture absorption

– Processed by thermoplastic operations

– Recycled into useful products as basis for resins in such

applications as sailboats, shower units, and floor tiles

– PET flakes from PET bottles are in great demand for fiberfill for

pillows and sleeping bags, carpet fiber, geo-textiles, and regrind

for injection and sheet molding

• Disadvantages

– Subject to attack by acids and bases

– Low thermal resistance

– Poor solvent resistance

– Must be adequately dried in dehumidifier prior to processing to

prevent hydrolytic degradation.

84

Thermoplastic Copolyesters• Copolyester is applied to those polyesters whose synthesis

uses more than one glycol and/or more than one dibasic

acid.

• Copolyester chain is less regular than monopolyester chain

and as a result has less crystallinity

• PCTA copolyester (Poly cyclo-hexane-dimethanol-

terephthalate acid) [amorphous]

– Reaction includes cyclohexanedimethanol and terephthalic acid

with another acid substituted for a portion of the terephthalic acid

– Extruded as transparent film or sheets that are suitable for

packaging applications (frozen meats shrink bags, blister packages,

etc..)

• Glycol-modified PET (PETG) [amorphous]

– Blow-molded containers, thermoformed blister packages.

85

ABS, PC Background • ABS was invented during WWII as a replacement for

rubber

– ABS is a terpolymer: acrylonitrile (chemical resistance), butadiene

(impact resistance), and styrene (rigidity and processing ease)

– Graft polymerization techniques are used to produce ABS

– Family of materials that vary from high gloss to low matte finish,

and from low to high impact resistance.

– Additives enable ABS grades that are flame retardant, transparent,

high heat-resistance, foamable, or UV-stabilized.

• PC was invented in 1898 by F. Bayer in Germany

– Commercial production began in the US in 1959.

– Amorphous, engineering thermoplastic that is known for

toughness, clarity, and high-heat deflection temperatures.

– Polycarbonates are linear, amorphous polyesters because they

contain esters of carbonic acid and an aromatic bisphenol.

86

Polyamide History • PA is considered the first engineering thermoplastic

• PA is one of many heterochain thermoplastics, which has


• PA invented in 1928 by Wallace Carothers, DuPont, in

search of a “super polyester” fiber with molecular weights

greater than 10,000. First commercial nylon in 1938.

• PA was created when a condensation reaction occurred

between amino acids, dibasic acids, and diamines.

• Nylons are described by a numbering system which

indicates the number of carbon atoms in the monomer

chains

– Amino acid polymers are designated by a single number, as nylon

6

– Diamines and dibasic acids are designated with 2 numbers, the first

87

Chemistry & Chemical Structurelinear polyamides• Thermoplastic nylons have amide (CONH) repeating link

• Nylon 6,6 - poly-hexamethylene-diamine (linear)

NH2(CH2)6NH2 + COOH(CH2)4COOH

hexamethylene diamine + Adipic Acid

n[NH2(CH2)6NH . CO (CH2)4COOH ] + (heat)

nylon salt

[NH2(CH2)6NH . CO (CH2)4CO ]n + nH2O

Nylon 6,6 polymer chain

• Nylon 6 - polycaprolactam (linear)

[NH(CH2)5CO ]n

88

Chemistry & Chemical Structurelinear polyamides

• Nylon 6, 10 - polyhexamethylenesebacamide (linear)

[NH2(CH2)6NH . CO (CH2)8CO]n


[NH(CH2)10CO ]n


[NH(CH2)11CO ]n

• Other Nylons

– Nylon 8, 9, 46, and copolymers from other diamines and acids

89

Chemistry & Chemical StructureAromatic polyamides (aramids)

• PMPI - poly m-phenylene isophthalamide (LCP fiber)

[ -NHCO - NHCO ]n

• PPPT - poly p-phenylene terephthalamide (LCP fiber)

[ -NHCO - NHCO ]n

• Nomax PMPI - first commercial aramid fiber for

electrical insulation. LCP fibers feature straight chain

crystals

• Kevlar 29 PPPT- textile fiber for tire cord, ropes, cables

etc.

90

Chemistry & Chemical StructureTransparent polyamides

• PA- (6,3,T)

[CH2C3H6C2H4-NHCO - NHCO ]n

• PA - (6,T)

[(CH2) 6NHCO - NHCO ]n

• Transparent polyamides are commercially available

• Reduced crystallization due to introduction of side

groups

91

Applications for Polyamides


– 50% into tire cords (nylon 6 and nylon 6,6)

– rope, thread, cord,belts, and filter cloths.

– Monofilaments- brushes, sports equipment, and bristles (nylon 6,10)

• Plastics applications

– bearings, gears, cams

– rollers, slides, door latches, thread guides

– clothing, light tents, shower curtains, umbrellas

– electrical wire jackets (nylon 11)

• Adhesive applications

– hot melt or solution type

– thermoset reacting with epoxy or phenolic resins

– flexible adhesives for bread wrappers, dried soup packets,

92

Mechanical Properties of Polyamides

Mechanical Properties of NylonNylon 6 Nylon 6,6 Nylon 6,10 Nylon 6,12

Density, g/cc 1.13-1.15 1.13-1.15 1.09 1.06-1.10

Crystallinity 30-% - 50% 30-% - 50% 30-% - 50% 30-% - 50%

Molecular Weight 10,000–30,000 10,000–30,000 10,000–30,000 10,000–30,000

Tensile Strength,

psi

6,000 – 24,000 14,000 8,500 – 8,600 6,500 – 8,800

Tensile Modulus,

psi

300K 230K – 550K 250 K 220 - 290 K

Tensile

Elongation, %

30% - 100% 15%-80% 70% 150%

Impact Strength

ft-lb/in

0.6 – 2.2 0.55 – 1.0 1.2 1.0 –1.9

Hardness R80 - 102 R120 R111 M78

93

Physical Properties of PolyamideNylon 6 Nylon 6,6 Nylon 6,10 Nylon 6,12



Translucent to opaque Translucent to opaque

Tmelt 210C -220 C 255C – 265C 220 C 195 -219 C

Tg

H20

Absorption

1.3-1.9% (24h)8.5-10 (Max)

1.0-2.8% (24h)8.5% (Max)

1.4% (24h)3.3% (Max)

0.4 – 1.0% (24h)2.5 –3 % (Max)

Oxidation

Resistance

good good good good

UV Resistance Poor Poor Poor Poor

Solvent

Resistance

Dissolved by

phenol &formic acid

Dissolved by

phenol & formicacid


formic acid


formic acid

Alkaline

Resistance


Acid

Resistance

Poor Poor Poor Poor

Cost $/lb $1.30 $1.30 $3.00 $3.10

94

Advantages Disadvantages of Polyamide

• Advantages– Tough, strong, impact resistant


– Abrasion resistance

– High temperature resistance

– Processable by thermopalstic methods

– Good solvent resistance

– Resistant to bases

• Disadvantages

– High moisture absorption with dimensional instability

• loss of up to 30 % of tensile strength and 50% of tensile modulus

– Subject to attack by strong acids and oxidizing agents

– Requires UV stabilization

– High shrinkage in molded sections

– Electrical and mechanical properties influenced by moisture content

95

Additives and Reinforcements to PA

• Additives- antioxidants, UV stabilizers, colorants, lubricants

• Fillers

– Talc

– Calcium carbonate

• Reinforcements

– Glass fiber- short fiber (1/8” or long fiber 1/4”)

– Mineral fiber (wolastonite)

– carbon fibers

– graphite fibers

– metallic flakes

– steel fibers

96

Properties of Reinforced Nylon

Nylon 6,6 Nylon 6,6 with30% short glass

Nylon 6,6 with30% long glass

Nylon 6,6 with30% carbon fiber

Density, g/cc 1.13-1.15 1.4 1.4 1.06-1.10

Crystallinity 30-% - 50% 30-% - 50% 30-% - 50% 30-% - 50%

Molecular Weight 10,000–30,000 30,000 10,000–30,000 10,000–30,000

Tensile Strength,

psi

14,000 28,000 28,000 32,000

Tensile Modulus,

psi

230K – 550K 1,300K 1,400 K 3,300 K

Tensile

Elongation, %

15%-80% 3% 3% 4%


0.55 – 1.0 1.6-4.5 4.0 1.5

Hardness R120 R120 E60 R120

Moisture % 1.0-2.8% (24h)8.5% (Max)

0.7-1.1 (24h)5.5-6.5 (Max)

0.9 (24h)5.5-6.5 (Max)

0.7 (24h)5 (Max)

Cost $/lb $1.40 $1.70 $2.00 $2.70

97


• Polyimide

– Developed by Du Pont in 1962

– Obtained from a condensation polymerization of aromatic diamine

and an aromatic dianhydride

– Characterized as Linear thermoplastics that are difficult to process

– Many polyimides do not melt but are fabricated by machining

– Molding can occur if enough time for flow is allowed for T>Tg

• Advantages

– High temperature service (up to 700C)

– Excellent barrier, electrical properties, solvent and wear resistance

– Good adhesion and ezpecially suited for composite fabrication

ON

C

O

N

C

O

C C

98

Other Heterochain Polymers• Polyimide Disadvantages

– Difficulty to fabricate and requires venting of volatiles

– Hydroscopic

– Subject to attacks by alkalines

– Comparatively high cost

• Applications

– Aerospace, electronics, and nuclear uses (competes with

flurocarbons)

– Office and industrial equipment; Laminates, dielectrics, and

coatings

– Valve seats, gaskets, piston rings, thrust washers, and bushings

• Polyamide-imide

– Amorphous member of imide family, marketed in 1972 (Torlon),

and used in aerospace applications such as jet engine components

– Contains aromatic rings and nitrogen linkage

99


• Polyacetal or Polyoxymethylene (POM)

– Polymerized from formaldehyde gas

– First commercialized in 1960 by Du Pont

– Similar in properties to Nylon and used for plumbing fixtures,

pump impellers, conveyor belts, aerosol stem valves, VCR tape

housings

• Advantages

– Easy to fabricate, has glossy molded surfaces, provide superior

fatigue endurance, creep resistance, stiffness, and water resistance.

– Among the strongest and stiffest thermoplastics.

– Resistant to most chemicals, stains, and organic solvents

• Disadvantages

– Poor resistance to acids and bases and difficult to bond

– Subject to UV degradation and is flammable

H-O-(CH2-O-CH2-O)NH:R

100

Mechanical Properties

Nylon 6 Acetal Polyimid Polyamide-imideDensity, g/cc 1.13-1.15 1.42 1.43 1.41

Crystallinity 30-% - 50%

Molecular Weight 10,000–30,000

Tensile Strength,

psi

6,000 – 24,000 10,000 10,000 26,830

Tensile Modulus,

psi

300K 520K

Tensile

Elongation, %

30% - 100% 40% - 75%


0.6 – 2.2 0.07 0.9 2.5

Hardness R80 - 102 R120 E50 E78

Tmelt 210 - 220 C 175-181 C Tg=275CMoisture

24 hr

max

1.3 - 1.9%8.5 - 10%

0.25 to 0.40%1.41%

0.32% .28%



opaque Transparent toopaque

101

Polyester History

• 1929 W. H. Carothers suggested classification of polymers

into two groups, condensation and addition polymers.

• Carothers was not successful in developing polyester fibers

from linear aliphatic polyesters due to low melting point and

high solubility. No commercial polymer is based on these.

• p-phenylene group is added for stiffening and leads to

polymers with high melting points and good fiber-forming

properties, e.g., PET.

• Polymers used for films and for fibers

• Polyesters is one of many heterochain thermoplastics, which

has atoms other than C in the chain.

• Polyesters includes unsaturated (thermosets), saturated and


102


• Thermoplastic polyesters have ester(-C-O) repeating link

• Polyester (linear) PET and PBT


O]-

terephthalic acid + ethylene glycol Polyethylene terephthalate (PET)


O]-

terephthalic acid + butylene glycol Polybutylene terephthalate (PBT)

O

O O

O O

103


• Wholly aromatic copolyesters (LCP)

– High melting sintered: Oxybenzoyl (does not melt below its

decomposition temperature. Must be compression molded)

– Injection moldable grades: Xydar and Vectra

– Xydar (Amoco Performance Products)

• terephthalic acid, p,p’- dihydroxybiphenyl, and p-hydroxybenzoic

acid

– Grade 1: HDT of 610F

– Grade 2: HDT of 480 F

– Vectra (Hoechst Celanese Corp.)

• para-hydroxybenzoic acid and hydroxynaphtholic acid

– Contains rigid chains of long, flat monomer units which are thought to

undergo parallel ordering in the melt and form tightly packed fibrous

chains in molded parts.

104

PET Chemical Structure and Applications

• The flexible, but short, (CH2)2 groups tend to leave the

chains relatively stiff and PET is notes for its very slow

crystallization. If cooled rapidly from the melt to a Temp

below Tg, PET solidifies in amorphous form.

• If PET is reheated above Tg, crystallizaiton takes place to

up to 30%.

• In many applications PET is first pre-shaped in

amorphous state and then given a uniaxial (fibers or

tapes) or biaxial (film or containers) crystalline

orientation.

• During Injection Molding PET can yield amorphous

transparent objects (Cold mold) or crystalline opaques

objects (hot mold)

105

PBT Chemical Structure and Applications

• The longer, more flexible (CH2)4 groups allow for more

rapid crystallization than PET.

• PBT is not as conveniently oriented as PET and is

normally injection molded.

• PBT has a sharp melting transition with a rather low melt

viscosity.

• PBT has rapid crystallization and high degree of

crystallization causing warpage concerns

106

Thermoplastic Aromatic Copolyesters• Polyarylesters

– Repeat units feature only aromatic-type groups (phenyl or aryl

groups) between ester linkages.

– Called wholly aromatic polyesters

– Based on a combination of suitable chemicals

• p-hydroxybenzoic acid

• terephthalic acid

• isophthalic acid,

• bisphenol-A

– Properties correspond to a very stiff and regular chain with high

crystallinity and high temperature stability

– Applications include bearings, high temperature sensors, aerospace

applications

– Processed in injection molding and compression molding


107

Applications for Polyesters (PET)• Blow molded bottles

– 100% of 2-liter beverage containers and liquid products


– 25% of market in tire cords, rope, thread, cord, belts, and filter

cloths.

– Monofilaments- brushes, sports equipment, clothing, carpet,

bristles

– Tape form- uniaxially oriented tape form for strapping

• Film and sheets

– photographic and x-ray films; biaxial sheet for food packages

• Molded applications- Reinforced PET [Rynite, Valox, Impet]

– luggage racks, grille-opening panels, functional housings such as

windshield wiper motors, blade supports, and end bells

– sensors, lamp sockets, relays, switches, ballasts, terminal blocks

• Appliances and furniture

108

Applications for Polyesters (PBT and LCP)

• PBT - 30 M lbs in 1988

• Molded applications (PBT) [Valox, Xenoy, Vandar, Pocan]

– distributers, door panels, fenders, bumper fascias

– automotive cables, connectors, terminal blocks, fuse holders and

motor parts, distributor caps, door and window hardware

• Extruded applications

– extrusion-coat wire

– extruded forms and sheet produced with some difficulty

• Electronic Devices (LCP) [26 M lbs] [Terylene, Dacron, Kodel]

– fuses, oxygen and transmission sensors

– chemical process equipment and sensors

– coil

109

Mechanical Properties of Polyesters

Mechanical Properties of polyesterPET PBT LCP Polyester

Density, g/cc 1.29-1.40 1.30 - 1.38 1.35 - 1.40

Crystallinity 10% - 30% 60% >80%

Molecular Weight

Tensile Strength,

psi

7,000 – 10,500 8,200 16,000 – 27,000

Tensile Modulus,

psi

400K - 600K 280K – 435K 1,400K - 2,800K

Tensile

Elongation, %

30% - 300% 50%-300% 1.3%-4.5%


0.25 - 0.70 0.7 - 1.0 2.4 - 10

CLTE

10-6 in/in/C

65 60-95 25-30

HDT 264 psi 70F -100F 122F - 185F 356F -671F

110

Physical Properties of Polyester

PET PBT LCP Polyester

Optical Transparent toOpaque

Opaque Opaque

Tmelt 245C -265 C 220C – 267C 400 C - 421 C

Tg 73C - 80C

H20

Absorption

0.1 - 0.2% (24h) 0.085% (24h)0.45% (Max)

<0.1% (24h)<0.1% (Max)

Oxidation

Resistance

good good good

UV Resistance Poor Poor none

Solvent

Resistance

Attacked byhalogen

hydrocarbons

good good

Alkaline

Resistance

Poor Poor Poor

Acid

Resistance

Poor Poor fair

Cost $/lb $0.53 $1.48 $7.00 - $10.00

111

Advantages/Disadvantages of Polyesters• Advantages

– Tough and rigid

– Processed by thermoplastic operations

– Recycled into useful products as basis for resins in such

applications as sailboats, shower units, and floor tiles

– PET flakes from PET bottles are in great demand for fiberfill for

pillows and sleeping bags, carpet fiber, geo-textiles, and regrind

for injection and sheet molding

– PBT has low moisture absorption

• Disadvantages

– Subject to attack by acids and bases

– Low thermal resistance

– Poor solvent resistance

– Must be adequately dried in dehumidifier prior to processing to

prevent hydrolytic degradation.

112

Thermoplastic Copolyesters• Copolyester is applied to those polyesters whose synthesis

uses more than one glycol and/or more than one dibasic

acid.

• Copolyester chain is less regular than monopolyester chain

and as a result has less crystallinity

• PCTA copolyester (Poly cyclo-hexane-dimethanol-

terephthalate acid) [amorphous]

– Reaction includes cyclohexanedimethanol and terephthalic acid

with another acid substituted for a portion of the terephthalic acid

– Extruded as transparent film or sheets that are suitable for

packaging applications (frozen meats shrink bags, blister packages,

etc..)

• Glycol-modified PET (PETG) [amorphous]

– Blow-molded containers, thermoformed blister packages.

113

ABS Background

• ABS was invented during WWII as a replacement for

rubber

– ABS is a terpolymer: acrylonitrile (chemical resistance), butadiene

(impact resistance), and styrene (rigidity and processing ease)

– Graft polymerization techniques are used to produce ABS

– Family of materials that vary from high gloss to low matte finish,

and from low to high impact resistance.

– Additives enable ABS grades that are flame retardant, transparent,

high heat-resistance, foamable, or UV-stabilized.

114

PEEK History

• Polyether-ether-ketone (PEEK) and Polyether ketone (PEK)

– PEEK invented by ICI in 1982. PEK introduced in 1987

• PEEK and PEK are aromatic polyketones

– Volume for polyketones is 500,000 lbs per year in 1990. Estimated

to reach 3 to 4 million by 2000.

– Cost is $30 per pound (as of October 1998)

• Product Names– ICI: Vivtrex

– BASF: Ultrapak

– Hoechst Celanese: Hostatec

– DuPont: PEKK

– Amoco: Kadel

115

Chemistry & Chemical Structure

• PEEK- Poly-ether-ether-ketone

O O C

• PEK- Poly-ether-ketone

O C

O

n

O

n

116

Chemical Synthesis

• Synthesis of polyketones

– PEK: Formation of the carbonyl link by polyaroylation from low

cost starting materials. Requires solvents such as liquid HF.

Excessive solvents and catalyst cause the high material cost.

– PEEK: Formation of ether link using phenoxide anions to displace

activated halogen.

O

C ClOHF, catalyst

O

n

O C + HCl + CO2 +H20

PEK

K2CO3, DPS

O

C FF OHOH+ PEEK + CO2 +H20 +KF

117

PEEK and PEK Applications• Aerospace: replacement of Al

– Fuel line brakes to replacement of primary structure

• Electrical– wire coating for nuclear applications, oil wells, flammability-critical mass

transit.

– Semi-conductor wafer carriers which can show better rigidity, minimum

weight, and chemical resistance to fluoropolymers.

• Other applications– Chemical and hydrolysis resistant valves (replaced glass)

– Internal combustion engines (replaced thermosets)

– Cooker components (replaced enamel)

– Automotive components (replaced metal)

– High temperature and chemical resistant filters from fiber

– Low friction bearings

118

Mechanical Properties of PEEK

Mechanical PropertiesPEEK LCP Polyester Nylon 6,6

Density, g/cc 1.30-1.32 1.35 - 1.40 1.13-1.15

Tensile Strength,

psi10,000 – 15,000 16,000 – 27,000 14,000

Tensile Modulus,

psi

500K 1,400K - 2,800K 230K – 550K

Tensile

Elongation, %

30% - 150% 1.3%-4.5% 15%-80%


0.6 – 2.2 2.4 - 10 0.55 – 1.0

Hardness R120 R124 R120

CLTE

10-6 mm/mm/C

40 - 47 25-30 80

HDT 264 psi 320 F 356F -671F 180F

119

Physical Properties of PEEKPhysical Properties

PEEK LCP Polyester Nylon 6,6

Optical Opaque Opaque Translucent to opaque

Tmelt 334 C 400 C 255C – 265C

Tg 177 C

H20

Absorption

0.1-0.14% (24h)0.5% (Max)

0.1% (24h)0.1% (Max)

1.0-2.8% (24h)8.5% (Max)

Oxidation

Resistancegood Good good

UV Resistance Poor good Poor

Solvent

Resistance

good good Dissolved by phenol &formic acid

Alkaline

Resistance

good Poor Resistant

Acid

Resistance

good fair Poor

Cost $/lb $30 $7 - $10 $1.30

120

Properties of Reinforced PEEK

Mechanical Properties ReinforcedPEEK PEEK 30%

glass fibers

PEEK with 30%

carbon fibers

Density, g/cc 1.30-1.32 1.52 1.43


10,000 – 15,000 23,000 – 29,000 31,000

Tensile Modulus,psi

500K 1,300K – 1,600K 1,900K – 3,500K

Tensile

Elongation, %

30% - 150% 2%-3% 1% - 4%


1.6 2.1 – 2.7 1.5 – 2.1

Hardness R120 R120

CLTE10-6 mm/mm/C

40 - 47 12-22 15-22

HDT 264 psi 320 F 550F -600F 550F -610F

121

Processing Properties of PEEK


PEEK LCP Polyester Nylon 6,6

Tmelt 334 C 400 C - 420 C 255C – 265C



I: 660F – 750FE: 660F – 725F

I: 540F – 770F I: 500F – 620F

Molding Pressure 10 -20 kpsi 5 - 16 kpsi 1 -20 kpsi


0.011 0.001 – 0.008 0.007 – 0.018

122

Advantages and Disadvantages of Polyketones

• Advantages

– Very high continuous use temperature (480F)

– Outstanding chemical resistance

– Outstanding wear resistance

– Excellent hydrolysis resistance

– Excellent mechanical properties

– Very low flammability and smoke generation

– Resistant to high levels of gamma radiation

• Disadvantages

– High material cost

– High processing temperatures

123

Polyphenylene Materials

•Several plastics have been developed with the benzene ring in

the backbone »Polyphenylene

»Polyphenylene oxide

(amorphous)

»Poly(phenylene sulfide)

(crystalline)

»Polymonochloroparaxylene

O OO

S S S

CH2 CH2

Cl Cl

124

PPO and PPS Materials

*Advantages of PPS *Advantages of PPO

- Usage Temp at 450F - Good fatigue and impact

strength

- Good radiation resistance - Good radiation resistance

- Excellent dimensional stability - Excellent dimensional stability

- Low moisture absorption - Low oxidation

- Good solvent and chemical resistance

- Excellent abrasion resistance

*Disadvantages of PPS *Disadvantages of PPO

- High Cost - High cost

- High process temperatures -Poor resistance to certain

chemicals

- Poor resistance to chlorinated hydrocarbons

125

PPO and PPS Applications

*PPS Applications *PPO Applications

- Computer components - Video display terminals

- Range components - Pump impellers

- Hair dryers - Small appliance housings

- Submersible pump enclosures - Instrument panels

- Small appliance housings - Automotive parts

126

PPS and PPO Mechanical PropertiesMechanical Properties

PPS PPO Nylon 6,6

Density, g/cc 1.30 1.04 – 1.10 1.13-1.15

Tensile Strength,

psi

9,500 7,800 14,000

Tensile Modulus,

psi

480K 360K 230K – 550K

Tensile

Elongation, %

1% - 2% 60% - 400% 15%-80%


< 0.5 4 - 6 0.55 – 1.0

Hardness R123 R115 R120

CLTE

10-6 mm/mm/C

49 60 80

HDT 264 psi 275 F 118F -210F 180 F

127

PPS and PPO Physical Properties

Physical Properties

PPS PPO Nylon 6,6

Optical Opaque Opaque Translucent to opaque

Tmelt 290 C 250 C 255 C – 265 C

Tg 88 C 110 – 140 C

H20

Absorption

> 0.02% (24h) 0.01% (24h) 1.0-2.8% (24h)

8.5% (Max)

Oxidation

Resistance

good good good

UV Resistance fair fair Poor

Solvent

Resistance

Poor inaromatics

Poor inaromatics

Dissolved by phenol &formic acid

Alkaline

Resistance

good good Resistant

Acid

Resistance

poor good Poor

Cost $/lb $2 $1.80 $1.30

128

PPS and PPO Processing Properties


PPS PPO Nylon 6,6

Tmelt 290 C 250 C 255C – 265C

Recommended Temp Range (I:Injection, E:Extrusion)

I: 600F – 625F I: 400F – 600FE: 420F – 500F

I: 500F – 620F

Molding Pressure 5 – 15 kpsi 12 - 20 kpsi 1 -20 kpsi

Mold (linear) shrinkage (in/in) 0.007 0.012 – 0.030 0.007 – 0.018

• PPS frequently has glass fibers loaded up to 40% by weight

»Tensile strength = 28 kpsi, tensile modulus = 2 Mpsi, HDT = 500F

•PPO is frequently blended with PS over a wide range of percentages.

(Noryl from G.E.)

129

Section Review – Polyesters is one of many heterochain thermoplastics, which has


– Polyesters includes unsaturated (thermosets), saturated and


– Condensation polymerization for Polyester

– Thermoplastic polyesters have ester(-C-O) repeating link

– Linear and aromatic polyesters


– Effects of reinforcements on polyester

– Effects of moisture environment on nylon

– If cooled rapidly from the melt to a Temp below Tg, PET solidifies

in amorphous form. If reheated PET acquires 30% crystallinity

– PET has rigid group of (CH2)2 ; PBT has more flexible (CH2)4

– Copolyester chain is less regular than monopolyester chain and as

a result has less crystallinity

O

130

Section Review

– PEEK and PEK are aromatic polyketones.

– Ketone groups have R - O - R functionality.

– Chemical structure of PEEK and PEK depicts benzene - oxygen -

benzene in backbone.

– PEEK and PEK are used primarily in applications requiring high

temperature use and chemical resistance.

– AP2C is a special version of PEEK with 68% continuous carbon

fiber.

– Polyphenylene materials are plastics with the benzene ring in the

backbone.

– PPO and PPS are characterized as heterochain thermoplastics,

which has atoms other than C in the chain.

– PPO and PPS are made via Condensation Polymerization.

– PPS frequently has glass fibers loaded up to 40% by weight.

– PPO is frequently blended with PS over a wide range of

O

131

Section Review • Major Topics

– Vinyl is a varied group- PVC, PVAc, PVOH, PVDC, PVB.

– PVC is the leading plastic in Europe and second to PE in the US.

– PVC is produced by addition polymerization from the vinyl chloride monomer in a head-

to-tail alignment.

– PVC is partially crystalline (syndiotactic) with structural irregularity increasing with the

reaction temperature.

– PVC (rigid) decomposes at 212 F leading to dangerous HCl gas

X1

– Vinyls have (CH2CX2) repeating link

– PS is Amorphous and made from addition polymerization

– PC is amorphous and made from condensation polymerization

– Effects of reinforcements on PP and PS

132

Section Review • Major Topics

– Isotactic, atactic, sydiotactic polypropylene definitions

– Differences between PP and PE

– Molecular Weight definition and forms (Weight Average, Mw, and

Number Average, MA )

– Polydispersity definition and meaning

– Relation between Molecular weight and Degree of Polymerization

(DP)

– Mechanical, physical, and processing properties of PP,

Polybutylene, and polymethylpentene

– PP is produced with linear chains

133

Section Review

• Key Terms and Concepts

– Polyolefin

– Molecular weight

– Number average molecular weight, weight average MW

– Polydispersity

– Polymer shrinkage

– Polymer blends

– Tensile Modulus

– Izod Impact Strength

134

Homework Questions #21. Define Polyvinyls, PS, PP, HDPE, chemical structure.

2. Compare the density PVC, PVB, PS, and PVDC which is higher/lower than PP.

3. Compare the density of HDPE, LDPE, UHMWPE, LLDPE to PP?

4. What is the tensile strength of PP with 0%, 30% glass fibers? What is the tensile modulus?

5. Plot tensile strength and tensile modulus of PVC, PS, PP, LDPE and HPDE to look like:

Tensile

Strength,

Kpsi

Tensile Modulus, Kpsi200 500

10

50

xLDPE

xHDPE

135

Homework Questions #2

6. Four typical Physical Properties of PVC are Optical = _______, Resistance to

moisture= ______ , UV resistance= _____, solvent resistance=_______

7. The Advantages of PP are ________, ________, _______, and __________.

8. The Disadvantages of PP are ________, ________, _______, and __________.

9. Glass fiber affects PP by (strength) ________, (modulus)________,

(impact)_______, (density) __________, and (cost) ____________.

10. Two Blends PVC are ___________, and __________.

136


11. Define Polypropylene chemical structure

12. Does commercial PP have Isotactic, atactic, sydiotactic form.

13. If MW of PP is 200,000, what is the approx. DP?

14. Polydispersity represents the distribution of _______and _____

15. Density of PP is _____ which is higher/lower than HDPE.

16. PP mechanical properties are higher/lower than LDPE and HDPE

17. Plot tensile strength and tensile modulus of PP, LDPE and HPDE to look like the

following

Tensile

Modulus,

Kpsi

Tensile Strength, Kpsi2 5

10

50

xLDPE

xHDPE

137


18. Four typical Physical Properties of PP are Optical = _______, Resistance to moisture= ______ , UV resisance= _____, solvent resistance=_______

19. The Advantages of PP are ________, ________, _______, and __________.

20. The Disadvantages of PP are ________, ________, _______, and __________.

21. Glass fiber affects PP by (strength) ________, (modulus)________, (impact)_______, (density) __________, and (cost) ____________.

22. Five polyolefins are ________, ________, _______, ______, and __________.

138

Homework Questions

1. Define PEEK, PPO and PPS chemical structures.

2. How are the properties of PEEK and PPS alike?

3. Density of PEEK is _____, PPS is _____ , and PPO is

_____ , which is higher/lower than PBT and nylon?

4. What is the tensile strength of PEEK with 0%, 30% glass

fibers? What is the tensile modulus?

5. Plot tensile strength and tensile modulus of PEEK, PPO,

PPS, PET, PBT, Nylon 6, PP, LDPE and HPDE to look like

the followingTensile

Modulus,

Kpsi


10

50

xLDPE

xHDPE

139

Homework Questions

6. Four typical Physical Properties of PEEK are Optical =

_______, Resistance to moisture= ______ , UV resistance=

_____, acid resistance=_______

7. The Advantages of PEEK are ________, ________,

_______, and __________.

8. The Disadvantages of PEEK are ________, ________,

_______, and __________.

9. How are the properties of PPO and PPS alike? How are they

different?

10. What are 3 advantages that Nylon has over PPO and

PPS?_________________________________

________________________________________________

_.

140

Homework Questions

1. Define PBT and PET chemical structure.

2. Why was Carothers not successful in developing polyesters?

3. Density of PET is _____ which is higher/lower than PBT

and nylon?.

4. What is the tensile strength of PET with 0%, 30% glass


5. Plot tensile strength and tensile modulus of PET, PBT,

Nylon 6, PP, LDPE and HPDE to look like the following

Tensile

Modulus,

Kpsi


10

50

xLDPE

xHDPE

141

Homework Questions

6. Four typical Physical Properties of Polyester are Optical =

_______, Resistance to moisture= ______ , UV resistance=

_____, acid resistance=_______

7. The Advantages of Polyester are ________, ________,

_______, and __________.

8. The Disadvantages of Polyester are ________, ________,

_______, and __________.

9. Glass fiber affects Polyester by (strength) ________,

(modulus)________, (elongation)_______, (density)

__________, and (cost) ____________.

10. What affect does the copolymer have on the crystallinity of

polyesters and

why?_________________________________

142

Homework Questions

1. Define Nylon 6,6 and Nylon 6 and Nylon 6,12 chemical

structure

2. If MW of PA is 50,000, what is the approx. DP?

3. Density of PA is _____ which is higher/lower than PP.

4. What is the tensile strength of nylon 6,6 with 0%, 30% glass


5. Plot tensile strength and tensile modulus of Nylon 6, PP,

LDPE and HPDE to look like the following

Tensile

Modulus,

Kpsi


10

50

xLDPE

xHDPE

143

Homework Questions

6. Four typical Physical Properties of PA are Optical =

_______, Resistance to moisture= ______ , UV resisance=

_____, solvent resistance=_______

7. The Advantages of PA are ________, ________, _______,

and __________.

8. The Disadvantages of PP are ________, ________,

_______, and __________.

9. Glass fiber affects PA by (strength) ________,

(modulus)________, (impact)_______, (density)

__________, and (cost) ____________.

10. Two Aromatic PA are ___________, and __________.

classes of polymeric materials -...

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