sheela foam trng report

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Project report 2013

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SHEELA FOAM PRIVATE LIMITED

Project Report on:

Formulation and Characterization of EBT &

EDTA +METAL ION complexed Polyurethane

(PU) Foams

Submitted by:ABHIJEET KUMAR

Roll No. 2K11/PS/001

B.Tech Polymer science and chemical technologyDelhi Technological University


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Acknowledgments

I sincerely thank Mr. Tushaar Gautam (COO) of Sheela Foam Pvt. Ltd. for allowing

me to carry out summer dissertation work at Sheela Foam XL Unit, Greater

Noida.

I also extend my gratitude to Dr. D K Chattopadhyay (AGM R&D) - my project

manager for his advice, moral support and continuous encouragement to take

challenge and complete my project work.

I would like to thank Capt. Dilip Mukherjee (Head HR and Admn. of North Zone)

for arranging my project and necessary administrative support.

I also take this opportunity to thank Mr. D. Balyan (AGM, Operation and

Technical) and Mr. P. Balyan (Executive Manager R&D) for their help and support

during the tenure of the project.

Last but not least, I am grateful to my parents, without whose support and

blessings it would have been impossible to carry out such research activity and

give the final conclusion of this chapter.


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Declaration

I hereby declare that the work reported in this report is original and carried out

by me under the supervision of Dr. Dipak Chattopadhyay at Sheela Foam R&D

centre, Greater Noida. The experimental findings of this report are not copied

from any other source, nor has the thesis been submitted to other place for the

award of any degree or diploma.

(Abhijeet kumar)


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Contents1. Introduction2. History3. Chemistry

3.1. Polymerisation Reaction3.2. Gas Producing Reaction

4. Basic Foam Components4.1. Polyol

4.1.1. Polyol Preparation4.2. Isocyanate4.3. Fillers4.4. Water4.5. Surfactant4.6. Catalysts

4.6.1. Amine Catalyst4.6.2. Organometallic Catalyst

4.7. Chain Extenders and Cross Linkers4.8. Additives

4.8.1. Colorants4.8.2. UV Stabilizers4.8.3. Flame Retardants4.8.4. Plasticizers4.8.5.

Antistatic Agents4.8.6. Compatibilizers

4.8.7. Bacteriostats4.8.8. Cell Openers

4.9. Auxiliary Blowing Agents5. Coordination chemistry principles of EBT, EDTA6. Applications

6.1. Industrial Applications6.2. Consumer Applications

7. Foam Calculations8. Experimental Procedure8.1Testing

8.1.1 Density Test8.1.2 Indentation Force Deflection Test8.1.3 Tension Test8.1.4 Resilience Test

9. Formulations and Test Report/tables10. Conclusions11. References


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1. IntroductionPolyurethane is any polymer consisting of a chain of organic units joined by urethane

(carbamate) links. Polyurethane polymers are formed through step-growth polymerization by

the reaction of a monomer containing at least two isocyanate functional groups with another

monomer containing at least two hydroxyl (alcohol) groups in the presence of a catalyst.

Polyurethane products are often called "urethanes". They should not be confused with

the specific substance urethane, also known as ethyl carbamate. Polyurethanes are neither

produced from ethyl carbamate, nor do they contain it.

2. History of PUThe pioneering work on polyurethane polymers was conducted by Otto Bayer and his

co-workers in 1937 at the laboratories of I.G. Farben in Leverkusen, Germany.[1] Theyrecognized that using the polyaddition principle to produce polyurethanes from liquid

diisocyanates and liquid polyether or polyester diols seemed to point to special opportunities,

especially when compared to already existing plastics that were made by polymerizing olefins,

or by polycondensation.

Commercial production of flexible polyurethane foam began in 1954, based ontoluene

diisocyanate (TDI) and polyester polyols. The invention of these foams was thanks to water

accidentally introduced in the reaction mix. These materials were also used to produce rigid

foams, gum rubber, andelastomers.

The first commercially available polyether polyol, poly (tetramethylene ether) glycol,

was introduced by DuPont in 1956 by polymerizing tetrahydrofuran. Less expensive

polyalkylene glycols were introduced by BASF and Dow Chemical in 1957. These polyether

polyols offered technical and commercial advantages such as low cost, ease of handling, and

better hydrolytic stability over polyester polyols and quickly replaced them in the manufacture

of polyurethane goods. In 1960 more than 45,000 tons of flexible polyurethane foams were

produced. The availability of chlorofluoroalkane blowing agents, inexpensive polyether polyols,

and methylene diphenyl diisocyanate (MDI) heralded the development and use of polyurethane

rigid foams as high performance insulation materials. Rigid foams based on polymeric MDI

(PMDI) offered better thermal stability and combustion characteristics than those based on TDI.

In 1967, urethane modified polyisocyanurate rigid foams were introduced, offering even better

thermal stability and flammability resistance compared to low-density insulation products.

The potential for polyols derived from vegetable oils to replace petrochemical-based

polyols began garnering attention beginning around 2004, partly due to the rising costs of

petrochemical feedstocks and partially due to an enhanced public desire for environmentally

friendly green products.
http://en.wikipedia.org/wiki/Toluene_diisocyanatehttp://en.wikipedia.org/wiki/Toluene_diisocyanatehttp://en.wikipedia.org/wiki/Chemical_reactionhttp://en.wikipedia.org/wiki/Elastomerhttp://en.wikipedia.org/wiki/Elastomerhttp://en.wikipedia.org/wiki/Chemical_reactionhttp://en.wikipedia.org/wiki/Toluene_diisocyanatehttp://en.wikipedia.org/wiki/Toluene_diisocyanate


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3. Chemistry of PUPolyurethane chemistry is based on the reactions of isocyanates with active hydrogen-

containing compounds. Isocyanates are compounds having one or more of the highly reactive

isocyanate group (N=C=O). This group will readily react with hydrogen atoms that are

attached to atoms more electronegative than carbon.

Compounds of primary interest for polyurethane forming reactions are listed in the

table below:

Active Hydrogen Compound Typical StructureRelative Reaction Rate Non-

catalysed at 25C

Primary aliphatic amine RNH2 100,000

Secondary aliphatic amine R2NH 20,000-50,000

Primary aromatic amine ArNH2 200 300

Primary hydroxyl RCH2OH 100

Water HOH 100Carboxylic acid RCOOH 40

Secondary hydroxyl R2CHOH 30

Urea RNHCONHR 15

Tertiary hydroxyl R3COH 0.5

Urethane R = NHCOOR 0.3

Amide RCONH2 0.1

3.1. Polymerisation reaction

The polyurethane polymer-forming reaction occurs between an isocyanate and analcohol as follows:

This is an addition process for which the heat of reaction has been reported to be

approximately 24 kcal/mole of urethane. Depending on the choice of starting materials, the R

and R groups may also contain isocyanate or isocyanate-reactive groups respectively. Whenextended to polyfunctional reactants, this reaction provides a direct route to cross-linked

polymers.

The hydrogen on the nitrogen atom of the urethane group is capable of reacting with

additional isocyanate to form an allophanate group as shown in the figure below:

The formation of allophanate is a high temperature, reversible reaction. If actuallyformed in normal flexible foams, the allophanate linkage would serve to cross-link the polymer


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further. The catalysts generally used in foam formulations do not promote this reaction, and

temperatures greater than 110C are necessary for significant allophanate formation.3.2. Gas producing reaction

To make foam, the polyurethane polymer must be expanded or blown by the

introduction of bubbles and a gas. A convenient source of gas is the carbon dioxide producedfrom the reaction of an isocyanate group with water.

The intermediate product of this reaction is a thermally unstable carbamic acid, which

spontaneously decomposes to an amine and carbon dioxide. Diffusion of the carbon dioxide into

bubbles previously nucleated in the reacting medium causes the expansion of the medium to

make foam.

Blowing can also be achieved by the physical addition of a low-boiling nonreactive liquid

to a foam formulation. Historically, the most commonly used physical blowing agents were the

chlorofluorocarbons, urethane grade methylene chloride and trichloroethane. Vaporization of

these liquids by heat from the exothermic reactions produces gas molecules which diffuse into

nucleated bubbles and contribute to foam expansion.

4. Basic Foam ComponentsFlexible polyurethane foam recipes normally contain a host of ingredients selected to

aid in achieving the desired grade of foam.

Component Parts By Weight

Polyols 100

Inorganic Fillers 0 - 150

Water 1.5 - 7.5

Silicon Surfactant 0.5 - 2.5

Amine Catalyst 0.1 - 1.0

Tin Catalyst 0.0 - 0.5

Chain Extender 0 - 10

Cross Linker 0 - 5

Additive variable

Auxiliary Blowing Agent 0 - 35

Isocyanate 25 85


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4.1. Polyol

The polyol is a source of hydroxyl or other isocyanate reactive groups. Processing and

properties of the resultant foam can be markedly influenced by the choice of starting polyol

structure. Ninety percent of all flexible foams produced today are made from polyether type

polyols. These polyols may be broadly grouped into the following categories:

Polyoxypropylene diols. Polyoxypropylene triols. Polyoxypropylene tetrols and higher analogs. Ethylene-oxide-capped diols, triols, tetrols and higher analogs. Random and block polymers of the above in which the polyol is made with both

ethylene and propylene oxides. When the oxides are fed as a mixed feed, the products

are termed hetero polyols.

Graft or copolymer polyols which contain stable dispersions of a solid particulatepolymeric phase in the liquid polyol phase.

Cross-linkers which are typically short-chain polyfunctional molecules added toincrease load bearing or initial foam stability.

4.1.1. Polyol preparation

A polyether polyol is the polymeric reaction product of an organic oxide and an initiator

compound containing two or more active hydrogen atoms. The active hydrogen compound in

the presence of a base catalyst initiates ring opening and oxide addition, which is continued

until the desired molecular weight is obtained. If the initiator has two active hydrogens, a diol is

formed.

If a trifunctional initiator such as glycerine is used, oxide addition produces chain

growth in three directions, and a triol results.


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These reactions are exothermic. Propylene oxide for example, releases approximately

22kcal/mole. Some of the commonly used initiators for the manufacture of flexible foam polyols

are listed in table:

4.2. Isocyanate

The isocyanate provides the source of NCO groups to react with functional groups from

the polyol, water and cross-linkers in the formulation. All the isocyanates used in the industry

today contain at least two isocyanate groups per molecule. The most commercially viable

methods of producing isocyanates involve the phosgenation of an amine as illustrated below:

Volume wise, aromatic isocyanates account for the vast majority of global diisocyanate

production. Aliphatic and cycloaliphatic isocyanates are also important building blocks for

polyurethane materials, but in much smaller volumes. There are a number of reasons for this.

First, the aromatically linked isocyanate group is much more reactive than the aliphatic one.

Second, aromatic isocyanates are more economical to use. Aliphatic isocyanates are used only if

special properties are required for the final product. For example, light stable coatings and

elastomers can only be obtained with aliphatic isocyanates. Even within the same class of

isocyanates, there is a significant difference in reactivity of the functional groups based on steric


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hindrance. In the case of 2,4-toluene diisocyanate, the isocyanate group in the para position to

the methyl group is much more reactive than the isocyanate group in the ortho position.

The two most important aromatic isocyanates are toluene diisocyanate (TDI) and

diphenylmethane diisocyanate (MDI). TDI consists of a mixture of the 2,4- and 2,6-

diisocyanatotoluene isomers. The most important product is TDI-80 (TD-80), consisting of 80%

of the 2,4-isomer and 20% of the 2,6-isomer. This blend is used extensively in the manufactureof polyurethane flexible slab stock and moulded foam. TDI, and especially crude TDI and

TDI/MDI blends can be used in rigid foam applications, but have been supplanted by polymeric

MDI. TDI-polyether and TDI-polyester prepolymers are used in high performance coating and

elastomer applications.

4.3. Fillers

Finely divided inert inorganic fillers are often purposely added to foam formulations to

increase density, load bearing and sound attenuation. All other foam physical properties are

generally sacrificed. Depending on the nature of the filler, the overall cost of the final foam maybe reduced.

Typical fillers include the many grades of barium sulphate and calcium carbonate. Care

must be taken to dry the fillers or to know the precise water content available and factor that

data into the foam calculations. Normal concentrations used are from 20 to 150 parts per

hundred parts polyol. These fillers are heavy and will settle out of a polyol mixture unless

constant agitation is used.

Due to their abrasive nature, mineral fillers can also increase wear on machinery

components. Calcium carbonate fillers have a significant effect on the gelling reaction and

necessitate a re-balancing of the blowing and gelling reactions.

4.4. Water

Water is a source of active hydrogen. Only demineralised water should be used for foam

production. Isocyanate reacts with water to give carbon dioxide gas and polyurea molecules.

The gas diffuses into nucleated bubbles and aids in foam expansion. The polyurea molecules

enter into and contribute to the properties of the final polymer.

4.5. Surfactant

Almost all flexible polyurethane foams are made with the aid of nonionic, silicone-based

surfactants. In broad terms, surfactants perform several functions as shown below:

Lower surface tension, Emulsify incompatible formulation ingredients, Promote nucleation of bubbles during mixing, Stabilize the rising foam by reducing stress concentrations, Counteract the defoaming effect of any solids added to or formed; e.g., precipitated

polyurea structures, during the foam reaction etc.

Among these functions, stabilization of the cell-walls is the most important. By doing this,

the surfactant prevents the coalescence of rapidly growing cells until those cells have attained

sufficient strength through polymerization to become self-supporting. Without this effect,

continuing cell coalescence would lead to total foam collapse. Surfactants also help to controlthe precise timing and the degree of cell-opening.


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4.6. Catalysts

Catalyst is a substance which changes the rate of reaction to some extent in either

direction. Polyurethane catalysts can be classified into two broad categories, amine compounds

and organometallic complexes.

4.6.1. Amine catalystTertiary amines are the most commonly used flexible polyurethane foam catalysts.

Generally regarded as blowing catalysts, most amines also offer some contribution to the gelling

reaction. The catalytic activity of amines is due to the presence of a free electron pair on the

nitrogen atom. Steric hindrance about the nitrogen atom and the electronic effects of

substituent groups are the main factors influencing the relative catalytic activity of various

amines. In some foam systems, combinations of various amines are used in an attempt to

balance the gelling and blowing reactions so that the foaming process can be adequately

controlled.

The type and concentration of amine catalyst(s) can be selected to satisfy process

requirements such as cream times, rise profiles, gel times and even cure of the outer surface

skin. Choice of amine may also affect the foam properties such as airflow and load bearingthrough influences on the primary and secondary foam reactions.

In general, requirements for good catalytic activity include:

A strong nucleophile capable of attacking the carbon of the isocyanate group. Capable of readily forming an active hydrogen amine complex. Soluble in water and forms stable hydrogen bonds with water.

Traditional amine catalysts have been tertiary amines such as triethylenediamine (TEDA, also

known as 1,4-diazabicyclo[2.2.2]octane), dimethylcyclohexylamine (DMCHA), and

dimethylethanolamine (DMEA).

4.6.2. Organometallic catalyst

The polymer forming or gellation reaction between the isocyanate and a polyol is

promoted by organometallic catalysts. Of the many metals available, tin compounds are the

most widely used. These compounds act as Lewis acids and are generally thought to function by

interacting with basic sites in the isocyanate and polyol compounds.

For flexible slabstock foam, dibutyl tin diluarate (DBTDL), stannous octoate (tin II 2-

ethyl hexoate) are the preferred gelling catalyst. Special handling is necessary since the

compound is easily hydrolyzed and oxidized in the presence of water and tertiary amines. In a

given slabstock foam formulation, varying the concentration of stannous octoate will produce

the typical results as shown below:


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4.7. Chain Extenders and Cross Linkers

Chain extenders (f=2) and crosslinkers (f=3 or greater) are low molecular weight

hydroxyl and amine terminated compounds that play an important role in the polymer

morphology of polyurethane fibers, elastomers, adhesives, and certain integral skin and

microcellular foams. The elastomeric properties of these materials are derived from the phase

separation of the hard and soft copolymer segments of the polymer, such that the urethane hard

segment domains serve as cross-links between the amorphous polyether (or polyester) soft

segment domains. This phase separation occurs because the mainly non-polar, low melting soft

segments are incompatible with the polar, high melting hard segments. The soft segments,

which are formed from high molecular weight polyols, are mobile and are normally present in

coiled formation, while the hard segments, which are formed from the isocyanate and chain

extenders, are stiff and immobile. Because the hard segments are covalently coupled to the soft

segments, they inhibit plastic flow of the polymer chains, thus creating elastomeric resiliency.

Upon mechanical deformation, a portion of the soft segments are stressed by uncoiling, and the

hard segments become aligned in the stress direction. This reorientation of the hard segments

and consequent powerful hydrogen bonding contributes to high tensile strength, elongation,

and tear resistance values. The choice of chain extender also determines flexural, heat, andchemical resistance properties.

4.8. Additives

Additives are the chemicals which enhances the properties of the existing product to

some extent. Various additives may be incorporated into a foaming system to impart specific

desired properties. Some of the more common additives used in flexible foams are as follows:

4.8.1. Colorants

Many flexible foam products are color coded during manufacture to identify product

grade, to conceal yellowing, or to make an appealing consumer product. The historical method

of coloring foam was to blend in traditional pigments or dyes. Typical inorganic coloring agents

included titanium dioxide, iron oxides and chromium oxide. Organic pigments originated from

the azo/diazo dyes, phthalocyanines and dioxazines, as well as carbon black. Typical problems

encountered with these colorants included high viscosity,abrasive tendencies, foam instability,

foam scorch, migrating color and a limited range of available colors.

4.8.2. UV StabilizersAll polyurethanes based on aromatic isocyanates will turn dark shades of yellow upon

aging with exposure to light. The yellowing is a surface event that is not a problem for most

foam applications. Light protection agents, such as hydroxybenzotriazoles, zinc dibutyl

thiocarbamate, 2,6-ditertiary butylcatechol, hydroxybenzophenones, hindered amines andphosphites have been used to improve the light stability of polyurethanes.

4.8.3. Flame RetardantsLow-density, open-celled flexible polyurethane foams have a large surface area and high

permeability to air and thus will burn given the application of sufficient ignition source and

oxygen. Flame retardants are often added to reduce this flammability, at least as it is measured

by various specific, often small-scale tests, conducted under controlled laboratory conditions.

The choice of flame retardant for any specific foam often depends upon the intended service

application of that foam and the attendant flammability testing scenario governing that

application. Aspects of flammability that may be influenced by additives include the initial

ignitability, burning rate and smoke evolution. The most widely used flame retardants are the

chlorinated phosphate esters, chlorinated paraffins and melamine powders.


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4.8.4. PlasticizersNonreactive liquids have been used to soften a foam or to reduce viscosity for improved

processing. The softening effect can be compensated for by using a polyol of lower equivalent

weight, so that a higher cross-linked polymer structure is obtained. These materials increase

foam density and often adversely affect physical properties.

4.8.5. Antistatic AgentsSome flexible foams are used in packaging, clothing and other applications where it is

desired to minimize the electrical resistance of the foam so that buildup of static electrical

charges is minimized. This has traditionally been accomplished through the addition of

ionizable metal salts, carboxylic acid salts, phosphate esters and mixtures thereof. These agents

function either by being inherently conductive or by absorbing moisture from the air. The

desired net result is orders of magnitude reduction in foam surface resistivity. Problems with

permanence of the effect and corrosion of electronic components led to the development of

STATURE static control additive technology. Polyurethane foams containing the patented

STATURE additive provide reliable, noncorrosive static protection regardless of humidity

conditions.4.8.6. Compatibilizers

Compatibilizers are special molecules that allow two or more nonmiscible ingredients to

come together and give one clear, homogeneous liquid phase. Many such molecules are known

to the polyurethane industry. Known classes of compatibilizer compounds include: amides,

amines, hydrocarbon oils, phthalates, polybutylene glycols, and urea.

4.8.7. BacteriostatsUnder certain conditions of warmth and high humidity, polyurethane foams are

susceptible to attack by micro-organisms. When that is a concern, additives against bacteria,

yeast or fungi are added to the foam during manufacture.

4.8.8. Cell-openersIn some polyurethane foams it is necessary to add cell-openers to obtain foam that does

not shrink upon cooling. Known additives for inducing cellopening include silicone-based

antifoamers, waxes, finely divided solids, liquid perfluocarbons, paraffin oils, long-chain fatty

acids and certain polyether polyols made using high concentrations of ethylene oxide.

4.9. Auxiliary blowing agents

Auxiliary blowing agents may be used in a foam formulation to aid in attaining densities

and softness not obtainable with conventional water isocyanate blowing chemistry. Auxiliary

blowing agents function by absorbing heat from the exothermic reactions, vaporizing and

providing additional gas useful in expanding the foam to a lower density. Since they arenonreactive and contribute nothing to the polymer structure, such blowing agents give softer

foams than those blown to the same density with only water. Because the auxiliary blowing

agent acts as a heat sink, higher total catalyst package levels are generally needed to maintain

adequate cure of the foam.


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5. Coordination chemistry principles OF EBT, EDTA:-5.1) Eriochrome black-T

Molecular Formula:C20H12N3NaO7S Average mass: 461.379913 Da Monoisotopic mass: 461.029358 Da

IUPAC nameSodium 3-hydroxy-4-[(E)-(1-hydroxy-2-naphthyl)diazenyl]-7-nitro-1-

naphthalenesulfonate

Figure 1 EBT

5.1.1 complexation of EBT with metals

Eriochrome Black T is acomplexometric indicator that is part of thecomplexometric

titrations,e.g. in thewater hardness determination process. It is anazo dye,Eriochrome is a

trademark ofCiba-Geigy.In its protonated form, Eriochrome Black T is blue It turns red

when it forms acomplex withcalcium,magnesium,or other metal ions, that is why the

polyurethane foams formed by using EBT as complexating agent are blue in colour.

EBT forms complex with metal ions such as copper,nickel,calcium.
http://www.chemspider.com/Molecular-Formula/C20H12N3NaO7Shttp://en.wikipedia.org/wiki/Complexometric_indicatorhttp://en.wikipedia.org/wiki/Complexometric_titrationhttp://en.wikipedia.org/wiki/Complexometric_titrationhttp://en.wikipedia.org/wiki/Water_hardnesshttp://en.wikipedia.org/wiki/Azo_dyehttp://en.wikipedia.org/wiki/Ciba-Geigyhttp://en.wikipedia.org/wiki/Complex_(chemistry)http://en.wikipedia.org/wiki/Calciumhttp://en.wikipedia.org/wiki/Magnesiumhttp://en.wikipedia.org/wiki/Magnesiumhttp://en.wikipedia.org/wiki/Calciumhttp://en.wikipedia.org/wiki/Complex_(chemistry)http://en.wikipedia.org/wiki/Ciba-Geigyhttp://en.wikipedia.org/wiki/Azo_dyehttp://en.wikipedia.org/wiki/Water_hardnesshttp://en.wikipedia.org/wiki/Complexometric_titrationhttp://en.wikipedia.org/wiki/Complexometric_titrationhttp://en.wikipedia.org/wiki/Complexometric_indicatorhttp://www.chemspider.com/Molecular-Formula/C20H12N3NaO7S


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5.2) Ethylene DiaminE Tetra Acetic Acid:- Molar mass:292.24 g/mol Formula:C10H16N2O8 IUPAC ID:2,2',2'',2'''-(Ethane-1,2-diyldinitrilo)tetraacetic acid Density:860.00 kg/m Melting point:237 C Soluble in:Water

Figure 2 EDTA

Ethylenediaminetetraacetic acid, widely abbreviated as EDTA, is

anaminopolycarboxylic acid and a colourless, water-soluble solid. Itsconjugate base is

named ethylenediaminetetraacetate. It is widely used to dissolvelimescale.Its

usefulness arises because of its role as a hexadentate ("six

toothed")ligand andchelating agent,i.e. its ability to "sequester"metalions such as

Ca2+ and Fe3+. After being bound by EDTA, metal ions remain in solution but exhibit

diminished reactivity. EDTA is produced as several salts, notably disodium EDTA and

calcium disodium EDTA.
https://www.google.co.in/search?biw=1034&bih=619&q=tetrasodium+edta+molar+mass&stick=H4sIAAAAAAAAAGOovnz8BQMDgxUHnxCXfq6-gUl2RklFgZZWdrKVfnJGam5mcUlRJYSVnJgTn5yfW5BfmpdilZufk1ikkJtYXDwps_6iwV3u5RwnQ_duulUs5hAgkwIAzz2pn1cAAAA&sa=X&ei=LzDrUsz_KMOPrgfqpYEw&ved=0CIQBEOgTKAEwDQhttps://www.google.co.in/search?biw=1034&bih=619&q=tetrasodium+edta+formula&stick=H4sIAAAAAAAAAGOovnz8BQMDgzkHnxCXfq6-gUl2RklFgZZ6drKVfnJGam5mcUlRJYSVnJgTn5yfW5BfmpdilZZflFuakyi5ymHp38aTJcvFrzBufhhwRyrh0HIA-Qi0cFQAAAA&sa=X&ei=LzDrUsz_KMOPrgfqpYEw&ved=0CIgBEOgTKAEwDghttps://www.google.co.in/search?biw=1034&bih=619&q=tetrasodium+edta+iupac+id&stick=H4sIAAAAAAAAAGOovnz8BQMDgwUHnxCXfq6-gUl2RklFgZZGdrKVfnJGam5mcUlRJYSVnJgTn5yfW5BfmpdilVlakJiskJmyoGmz5br7E_c_kI1fu1no5v2pSuJRAOCMiz1VAAAA&sa=X&ei=LzDrUsz_KMOPrgfqpYEw&ved=0CIwBEOgTKAEwDwhttps://www.google.co.in/search?biw=1034&bih=619&q=tetrasodium+edta+density&stick=H4sIAAAAAAAAAGOovnz8BQMDgzkHnxCXfq6-gUl2RklFgZZ6drKVfnJGam5mcUlRJYSVnJgTn5yfW5BfmpdilZKaV5xZUsk-60bsmV8bZf_l-WWabF3UJRtp1gkA67lI2lQAAAA&sa=X&ei=LzDrUsz_KMOPrgfqpYEw&ved=0CJABEOgTKAEwEAhttps://www.google.co.in/search?biw=1034&bih=619&q=tetrasodium+edta+melting+point&stick=H4sIAAAAAAAAAGOovnz8BQMDgy0HnxCXfq6-gUl2RklFgZZudrKVfnJGam5mcUlRJYSVnJgTn5yfW5BfmpdilZuaU5KZl65QkJ-ZV_Joudrnvf4v9X6rdUxmeXLfZN7C3eYAF_dnXVoAAAA&sa=X&ei=LzDrUsz_KMOPrgfqpYEw&ved=0CJQBEOgTKAEwEQhttps://www.google.co.in/search?biw=1034&bih=619&q=tetrasodium+edta+soluble+in&stick=H4sIAAAAAAAAAGOovnz8BQMDgxUHnxCXfq6-gUl2RklFgZZWdrKVfnJGam5mcUlRJYSVnJgTn5yfW5BfmpdiVZyfU5qUk6qQmafX9b7cN4STK014nVHEy6MClq-vtQAAIwc6NVcAAAA&sa=X&ei=LzDrUsz_KMOPrgfqpYEw&ved=0CJgBEOgTKAEwEghttps://www.google.co.in/search?biw=1034&bih=619&q=properties+of+water&stick=H4sIAAAAAAAAAGOovnz8BQMDgwsHnxCXfq6-gUl2RklFgRIHiG1hbJGmpZWdbKWfnJGam1lcUlQJYSUn5sQn5-cW5JfmpVgV5-eUJuWkKmTm3W3c0f9prT6P9dKJgqsZtvq9XqKpDgCFIqhsYQAAAA&sa=X&ei=LzDrUsz_KMOPrgfqpYEw&ved=0CJkBEJsTKAIwEghttp://en.wikipedia.org/wiki/Aminopolycarboxylic_acidhttp://en.wikipedia.org/wiki/Conjugate_basehttp://en.wikipedia.org/wiki/Limescalehttp://en.wikipedia.org/wiki/Ligandhttp://en.wikipedia.org/wiki/Chelating_agenthttp://en.wikipedia.org/wiki/Metalhttp://en.wikipedia.org/wiki/Ionhttp://en.wikipedia.org/wiki/Ionhttp://en.wikipedia.org/wiki/Metalhttp://en.wikipedia.org/wiki/Chelating_agenthttp://en.wikipedia.org/wiki/Ligandhttp://en.wikipedia.org/wiki/Limescalehttp://en.wikipedia.org/wiki/Conjugate_basehttp://en.wikipedia.org/wiki/Aminopolycarboxylic_acidhttps://www.google.co.in/search?biw=1034&bih=619&q=properties+of+water&stick=H4sIAAAAAAAAAGOovnz8BQMDgwsHnxCXfq6-gUl2RklFgRIHiG1hbJGmpZWdbKWfnJGam1lcUlQJYSUn5sQn5-cW5JfmpVgV5-eUJuWkKmTm3W3c0f9prT6P9dKJgqsZtvq9XqKpDgCFIqhsYQAAAA&sa=X&ei=LzDrUsz_KMOPrgfqpYEw&ved=0CJkBEJsTKAIwEghttps://www.google.co.in/search?biw=1034&bih=619&q=tetrasodium+edta+soluble+in&stick=H4sIAAAAAAAAAGOovnz8BQMDgxUHnxCXfq6-gUl2RklFgZZWdrKVfnJGam5mcUlRJYSVnJgTn5yfW5BfmpdiVZyfU5qUk6qQmafX9b7cN4STK014nVHEy6MClq-vtQAAIwc6NVcAAAA&sa=X&ei=LzDrUsz_KMOPrgfqpYEw&ved=0CJgBEOgTKAEwEghttps://www.google.co.in/search?biw=1034&bih=619&q=tetrasodium+edta+melting+point&stick=H4sIAAAAAAAAAGOovnz8BQMDgy0HnxCXfq6-gUl2RklFgZZudrKVfnJGam5mcUlRJYSVnJgTn5yfW5BfmpdilZuaU5KZl65QkJ-ZV_Joudrnvf4v9X6rdUxmeXLfZN7C3eYAF_dnXVoAAAA&sa=X&ei=LzDrUsz_KMOPrgfqpYEw&ved=0CJQBEOgTKAEwEQhttps://www.google.co.in/search?biw=1034&bih=619&q=tetrasodium+edta+density&stick=H4sIAAAAAAAAAGOovnz8BQMDgzkHnxCXfq6-gUl2RklFgZZ6drKVfnJGam5mcUlRJYSVnJgTn5yfW5BfmpdilZKaV5xZUsk-60bsmV8bZf_l-WWabF3UJRtp1gkA67lI2lQAAAA&sa=X&ei=LzDrUsz_KMOPrgfqpYEw&ved=0CJABEOgTKAEwEAhttps://www.google.co.in/search?biw=1034&bih=619&q=tetrasodium+edta+iupac+id&stick=H4sIAAAAAAAAAGOovnz8BQMDgwUHnxCXfq6-gUl2RklFgZZGdrKVfnJGam5mcUlRJYSVnJgTn5yfW5BfmpdilVlakJiskJmyoGmz5br7E_c_kI1fu1no5v2pSuJRAOCMiz1VAAAA&sa=X&ei=LzDrUsz_KMOPrgfqpYEw&ved=0CIwBEOgTKAEwDwhttps://www.google.co.in/search?biw=1034&bih=619&q=tetrasodium+edta+formula&stick=H4sIAAAAAAAAAGOovnz8BQMDgzkHnxCXfq6-gUl2RklFgZZ6drKVfnJGam5mcUlRJYSVnJgTn5yfW5BfmpdilZZflFuakyi5ymHp38aTJcvFrzBufhhwRyrh0HIA-Qi0cFQAAAA&sa=X&ei=LzDrUsz_KMOPrgfqpYEw&ved=0CIgBEOgTKAEwDghttps://www.google.co.in/search?biw=1034&bih=619&q=tetrasodium+edta+molar+mass&stick=H4sIAAAAAAAAAGOovnz8BQMDgxUHnxCXfq6-gUl2RklFgZZWdrKVfnJGam5mcUlRJYSVnJgTn5yfW5BfmpdilZufk1ikkJtYXDwps_6iwV3u5RwnQ_duulUs5hAgkwIAzz2pn1cAAAA&sa=X&ei=LzDrUsz_KMOPrgfqpYEw&ved=0CIQBEOgTKAEwDQ


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5.2.1) complexation of EDTA with metals

Incoordination chemistry,EDTA4is a member of theaminopolycarboxylic acid family

of ligands. EDTA4usually binds to a metal cation through its two amines and fourcarboxylates. Many of the resultingcoordination compoundsadoptoctahedral geometry.

Although of little consequence for its applications, these octahedral complexesarechiral.The anion [Co(EDTA)]has been resolved intoenantiomers.Many complexes

of EDTA4adopt more complex structures due to (i) the formation of an additional

bond to water, i.e. seven-coordinate complexes, or (ii) the displacement of one

carboxylate arm by water. Ferric complex of EDTA is seven-coordinate. Early work on

the development of EDTA was undertaken byGerold Schwarzenbach in the

1940s. EDTA forms especially strong complexes with Mn(II), Cu(II), Fe(III), Pb (II) and

Co(III).

6. ApplicationsPolyurethanes are one of the most versatile materials today. They have many uses

worldwide:

6.1. Industrial Applications

Flexible Foam: Flexible polyurethane foam's versatility of form and function can be seen in

bedding, furniture, automotive interiors, carpet underlay and packaging. Foam can be created in

almost any variety of shape and firmness. In addition, it's light, durable, supportive and

comfortable.

Rigid Foam: Rigid polyurethane and polyisocyanurate foams form one of the world's most

popular, energy-efficient and versatile insulations. It significantly cuts fuel and construction

costs while making commercial and residential properties safer, better utilized and more

comfortable around the globe.

Thermoplastic Polyurethane: Thermoplastic polyurethane (TPU) offers a myriad of physical

property combinations and processing applications. It's highly elastic, flexible and resistant to

abrasion, impact and weather. TPU's can be colored or fabricated in a wide variety of methods,

and their use increases a product's overall durability.
http://en.wikipedia.org/wiki/Coordination_chemistryhttp://en.wikipedia.org/wiki/Coordination_chemistryhttp://en.wikipedia.org/wiki/Aminopolycarboxylic_acidhttp://en.wikipedia.org/wiki/Complex_(chemistry)http://en.wikipedia.org/wiki/Octahedral_geometryhttp://en.wikipedia.org/wiki/Chirality_(chemistry)http://en.wikipedia.org/wiki/Chirality_(chemistry)http://en.wikipedia.org/wiki/Enantiomerhttp://en.wikipedia.org/wiki/Gerold_Schwarzenbachhttp://www.polyurethane.org/s_api/sec.asp?CID=908&DID=3621http://www.polyurethane.org/s_api/sec.asp?CID=909&DID=3622http://www.polyurethane.org/s_api/sec.asp?CID=909&DID=3622http://www.polyurethane.org/s_api/sec.asp?CID=908&DID=3621http://en.wikipedia.org/wiki/Gerold_Schwarzenbachhttp://en.wikipedia.org/wiki/Enantiomerhttp://en.wikipedia.org/wiki/Chirality_(chemistry)http://en.wikipedia.org/wiki/Octahedral_geometryhttp://en.wikipedia.org/wiki/Complex_(chemistry)http://en.wikipedia.org/wiki/Aminopolycarboxylic_acidhttp://en.wikipedia.org/wiki/Coordination_chemistry


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Coatings, Adhesives, Sealants and Elastomers: Polyurethane coatings make a product look

better and last longer. Polyurethane adhesives provide strong bonding advantages.

Polyurethane sealants provide tighter seals. Polyurethane elastomers can be molded into almost

any shape, are lighter than metal, offer superior stress recovery and can be resistant to many

environmental factors.

6.2. Consumer Applications

Apparel: When scientists discovered that polyurethanes could be made into fine threads, they

were combined with nylon to make more lightweight, stretchable garments. Over the years,

polyurethanes have been improved and developed into Spandex fibres, polyurethane coatings,

and thermoplastic elastomers.

Appliance: Polyurethanes are an important component in major appliances consumers use

every day. In 2004, appliance manufacturing represented a 468 million pound market for

polyurethanes in North America, about 6 percent of total polyurethane consumption.

Automotive:Polyurethanes are used throughout your car - in familiar places like the foam that

makes your car seats comfortable, as well as a few places you might not expect.

Building & Construction: Today's homes demand high-performance materials that are strong,

yet lightweight; that perform well, yet are easily installed; and that are durable, but also

versatile. With well over 1.5 million new homes being constructed in the U.S. each year,

building-material quality and performance must be exceptionally reliable, which is why builders

are consistently turning to polyurethane.

Coatings,Adhesives, Sealants and Elastomers: The spectrum of polyurethane use in coatings,

adhesives, sealants and elastomers not only advances traditional manufacturing methods, it also

substantially expands the lifetime of a host of products.

Composite Wood: Some of today's modern materials are a combination of synthetic and natural

materials. Polyurethanes play a major role in today's modern materials such as in composite

wood.

Electronics:Often referred to as potting compounds, non-foam polyurethanes are frequently

used in the electrical and electronics industries to encapsulate, seal and insulate fragile,

pressure sensitive microelectronic components, underwater cables and printed circuit boards.

Flooring:Either as a foam underlay or on top as a coating, polyurethanes can make the floors

we walk on every day more durable, easier to maintain and more aesthetically pleasing.

Furnishings:Polyurethane, mostly in the form of flexible foam, is the one of the most popular

materials used in home furnishings in places such as furniture, bedding and carpet underlay.

Marine:Boating as a pastime and a sport is increasingly popular. According to recent surveys,

more than 70 million Americans enjoy boating each year.Medical: Polyurethanes are commonly used in a number of medical applications including

catheter and general purpose tubing, hospital bedding, surgical drapes, wound dressings, as

well as in a variety of injection moulded devices.

Packaging: Polyurethane packaging foam (PPF) provides cost-effective, custom form-fitting

cushioning to uniquely and securely protect items that need to stay safely in-place during

transit.

RIM:Car bumpers, electrical housing panels, and computer and telecommunication equipment

enclosures are some of the parts produced with polyurethanes via Reaction Injection Molding

(RIM).

Waterborne Polyurethane Dispersions: Waterborne Polyurethane Dispersions (PUDs) arecoatings and adhesives that use water as the primary solvent
http://www.polyurethane.org/s_api/sec.asp?CID=905&DID=3618http://www.polyurethane.org/s_api/sec.asp?CID=937&DID=3685http://www.polyurethane.org/s_api/sec.asp?CID=937&DID=3685http://www.polyurethane.org/s_api/sec.asp?CID=912&DID=3625http://www.polyurethane.org/s_api/sec.asp?CID=912&DID=3625http://www.polyurethane.org/s_api/sec.asp?CID=905&DID=3618http://www.polyurethane.org/s_api/sec.asp?CID=945&DID=3724http://www.polyurethane.org/s_api/sec.asp?CID=945&DID=3724http://www.polyurethane.org/s_api/sec.asp?CID=916&DID=3629http://www.polyurethane.org/s_api/sec.asp?CID=916&DID=3629http://www.polyurethane.org/s_api/sec.asp?CID=917&DID=3630http://www.polyurethane.org/s_api/sec.asp?CID=917&DID=3630http://www.polyurethane.org/s_api/sec.asp?CID=918&DID=3631http://www.polyurethane.org/s_api/sec.asp?CID=918&DID=3631http://www.polyurethane.org/s_api/sec.asp?CID=919&DID=3632http://www.polyurethane.org/s_api/sec.asp?CID=919&DID=3632http://www.polyurethane.org/s_api/sec.asp?CID=944&DID=3721http://www.polyurethane.org/s_api/sec.asp?CID=944&DID=3721http://www.polyurethane.org/s_api/sec.asp?CID=946&DID=3726http://www.polyurethane.org/s_api/sec.asp?CID=946&DID=3726http://www.polyurethane.org/s_api/sec.asp?CID=947&DID=3727http://www.polyurethane.org/s_api/sec.asp?CID=947&DID=3727http://www.polyurethane.org/s_api/sec.asp?CID=947&DID=3727http://www.polyurethane.org/s_api/sec.asp?CID=946&DID=3726http://www.polyurethane.org/s_api/sec.asp?CID=944&DID=3721http://www.polyurethane.org/s_api/sec.asp?CID=919&DID=3632http://www.polyurethane.org/s_api/sec.asp?CID=918&DID=3631http://www.polyurethane.org/s_api/sec.asp?CID=917&DID=3630http://www.polyurethane.org/s_api/sec.asp?CID=916&DID=3629http://www.polyurethane.org/s_api/sec.asp?CID=945&DID=3724http://www.polyurethane.org/s_api/sec.asp?CID=905&DID=3618http://www.polyurethane.org/s_api/sec.asp?CID=912&DID=3625http://www.polyurethane.org/s_api/sec.asp?CID=937&DID=3685http://www.polyurethane.org/s_api/sec.asp?CID=905&DID=3618


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7. Foam CalculationsA-Side: The isocyanate-containing material.

B-Side: The polyol-containing material, usually a blend of polyol, chain extenders, cross-linker,

water, catalysts and surfactants.

Functionality: The functionality of a B-side foam ingredient is the number of isocyanate

reactive sites on a molecule. For polyols, an average functionality is generally used.

Acid Number: A number arising from a wet analytical method to determine the amount of

residual acidic material in a polyol. It is reported in the same units as hydroxyl number.

Hydroxyl Number (OH Number): A number arising from a wet analytical method for the

hydroxyl content of a polyol; it is the milligrams of potassium hydroxide equivalent to the

hydroxyl content in one gram of polyol or other hydroxyl compound.

where 56.1 is the atomic weight of potassium hydroxide and 1000 is the number of milligrams

in one gram of sample.

The OH number for each lot of polyol is provided by the manufacturer. Polyols are

sometimes characterized by quoting the weight percentage of hydroxyl groups. Conversion to

hydroxyl number is accomplished by:

where the number 33 is obtained by reduction of constants. For a mixture of polyols, the

hydroxyl number of the mixture (OHm) is given by:

Equivalent Weight of a Polyol: The weight of a compound per reactive site.

Since polyols have a molecular weight distribution, an average equivalent weight is

calculated. These calculations are done using the product analysed hydroxyl (OH) content and

acid number:

For most polyols in use today, the acid number is very low and may be omitted. If the

acid number is larger than about 1.0, it should be factored into the above equation.


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Equivalent Weight of an Isocyanate: The weight of an isocyanate compound per isocyanate

site. This is calculated from the analyzed isocyanate (NCO) content.

where 42 is the atomic weight of the NCO group.

Equivalent Weight of an Isocyanate Blend: For foam systems using a blend of different

isocyanates, the net equivalent weight of the blend is given by:

Equivalent Weight of Water: Water reacts with 2 isocyanate groups and thus the equivalent

weight is given by:

Isocyanate Index: The ratio of the equivalent amount of isocyanate used relative to the

theoretical equivalent amount times 100.

The calculation procedure for a foam formulation is:

1. Determine the parts of each polyol. Total parts polyol should equal 100.

2. Determine the parts of other B-side components per 100 parts polyol.

3. Sum the parts of all B-side materials to get the total formula weight.

4. Record the equivalent weight of each B-side component from the above calculations or from a

listing of typical equivalent weights.

5. Calculate the equivalents of each B-side component.

6. Sum the reactive equivalents of each B-side component to get the total B-side equivalents.

7. Record the isocyanate equivalent weight.

8. Select the desired isocyanate index.

9. Calculate the isocyanate parts required.

Amount of wateris determined as:


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8. Experimental ProcedureThe other constituents of the 32 g/cm3PU foam calculated based on per 100 parts of

polyol in the foam formulation are shown below: Isocyanate = 38 parts Water = 3.0 parts Amine Catalyst = 0.18 parts Tin Catalyst = 0.14 parts Silicon Surfactant = 1.2 parts

The following steps were adopted in order to have cured PU foams:

Step I: Desired quantity of isocyanate is weighed in a vessel and kept aside.

Step II: The required quantity of polyol for each sample is taken in another vessel.

Step III: Required amount of water, amine catalyst, tin catalyst and silicon surfactant are

added to the polyol mixture prepared in Step II. The formulation is mixedthoroughly with the help of an electric stirrer.

Step IV: After mixing the formulation for about 25-30 seconds isocyanate is added to it and

the mixing is continued for another 8-10 seconds.

Step V: The thick liquid obtained at the end of Step IV is immediately poured into a

cardboard box mould.

Step VI: At the end of Step V, foam start rising because of the polyol and isocyanate

reaction. This process is known as foaming. The time taken by the foam to rise to

maximum height i.e., foam rise time is recorded.

Step VII: Foam prepared in Step VI is kept for 24-36 hours for curing process.

After all the samples were prepared and cured they were cut into blocks of equal

dimensions for testing.


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8.1. TestingThe following tests were performed on each foam sample for comparison of their properties:

1. Density Test2. Indentation Force Deflection Test3. Tension Test4. Resilience Test

8.1.1 Density Test

Fig. 1. Density determination apparatus.

The density measurement is an apparent or bulk density, not the true polymer density.

This physical property is important because of its parallel relationship with both cost and load

bearing. High densities generally result in higher costs and improved load-bearing properties. In

the test, a representative sample is carefully measured and accurately weighed (Fig. 1). The

density, normally reported in pounds per cubic foot or kilograms per cubic meter is simply the

sample weight divided by its volume.

8.1.2 Indentation Force Deflection (IFD) Test

Fig.2. Determining the hardness of PU foam in Universal Tensile Testing Machine

The indentation force deflection test (IFD) is a measurement of the loadbearing

properties of foam. In this test the force required to depress a circular plate into the foam is

measured. Two types of measurements are important: the indentation resulting from a specified

force and the force required to reach a specified indentation. Experience has shown that these

measurements can vary depending on the temperature and relative humidity conditions under

which the foam was made. The results of foam hardness are taken at 50% compression.


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8.1.3 Tension Test (Tensile Strength)

The tension test measures the strength of foam under tension and gives information about

the foams elasticity. Samples for the test are generally die-cut and are dog bone or dumbbell

shaped. The sample is pulled at a constant rate until it breaks. The force recorded at the

breaking point is the tensile strength of the foam, generally reported in kilopascals. The

maximum extension of the sample as a percentage of its original length is the elongation at

break.

8.1.4 Resilience Test

The resilience of foam is measured in a ball rebound test. The test consists of dropping a

steel ball on a foam sample and visually measuring the height of rebound. Results from this test

have been correlated to overall cushion comfort.


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9. Formulations and Test Reports/Tables:-

9.1. Polyols

Polyester Polyol Trade Name OH Value Viscosity(cp at25C)

Polyol A VORANOL 3322 56

Polyol B FLEXTER Z-013 (UFLEX) 55 660-700

Polyol C FLEXTER Z-015(UFLEX) 245 5000-8000

Polyol D FLEXTER Z-019(UFLEX) 56 1000

Polyol E DIEXTER G-175 54 880010200

9.2. Catalysts&Surfactants

Chemical Name Trade Name NatureTin Catalyst Niax D-19 Catalyst

Amine Catalyst Lupragon N-600 (BASF) Catalyst

Silicon L-618 Surfactant

9.3. Others

Water Tap Water

Isocynate Toluene Diisocynate (BASF)


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9.4 series of formulation

In the series, one polyol is used, Polyol A (VORANOL 3322), Formulations are

shown below (Density: 32 g/cc, Water: 3.5pph, EBT, EDTA, DMG):

Series of formulation:-

POLYOL TDI AMINE SILICON TIN

250 100 0.14 1.2 0.04

EBT NICKEL

PHOSPHATE

CALCIUM

PROPIONATE

COPPER

SULPHATE

CALCIUMCARBONATE

0.1 0.19 0.11 0.216 0.059

0.3 0.59 0.332 0.259 0.162

0.6 1.18 0.66 0.510 0.32

EDTA DMG NICKEL PHOSPHATE

(with DMG)

CALCIUM

CARBONATE

(with edta)

0.1 0.1 0.39 0.06

0.3 0.3 1.2 0.201

0.6 0.6 2.36 0.403


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S.NO EBT+METAL EDTA+METAL %

ELONGATION

PERMIABILITY TENSILE

STRENGTH

1 Ebt+nickel(0.1) 180 30 0.87

2 Ebt+nickel(0.3) 186 28 0.76

3 Ebt+nickel(0.6) 195 25 0.68

4 Ebt+calcium(0.1) 102 20 0.92

5 Ebt+calcium(0.3) 119 24 0.67

6 Ebt+calcium(0.6) 158 28 1.25

7 Ebt+copper(0.1) 211.4 25 1.05

8 Ebt+copper(0.3) 226 27 1.03

9 Ebt+copper(0.6) 232.3 30 1.03

10 Ebt+caco3(0.1) 145.7 43 0.83

11 Ebt+caco3(0.3) 163 41 0.91

12 Ebt+caco3(0.6) 205.7 40 1.29

13 Edta+caco3(0.1) 201.3 34 1.17

14 Edta+caco3(0.3) 203 31 1.00

15 Edta+caco3(0.6) 199 30 1.30


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9.5. Observations :-

All the foams are prepared using polyol A (voranol 3322) and other components asshown in the table.

All the foams have density of 32 g/cc, the foams which are prepared using EBT havefollowing properties

1) colour- violet2) rough surface

3) closed cell (dense)

4) surface has pores

On the other hand, the foams prepared using EDTA have1) smooth surface

2) white in color

3) Good tensile properties and % elongation

The foams prepared using dimethyl glyoxime with nickel phosphate get shrinked andultimately collapsed.

As we increase the concentration of complexating agent the foam shows closed cellstructure, increased tensile properties, and high resilience.

10. Conclusions

The mechanical properties like tensile strength and elongation of the foam increasedwith the addition of glycerol, tween20 and span20 to the mother foam.

Constant improvement in the tensile strength and elongation could be improved withincrease in the concentration of glycerol and tween20 up to 30% addition in the polyolafter which formulating the foams became next to impossible.

The foams obtained using these cross-linkers were softer than the mother foam. The foam samples observed total foam shrinkage and partial shrinkage depending on

the concentration of cross-linkers used with same concentration of tin catalyst.

The corrective measures taken to prevent shrinkage were:o Decrement in tin concentration to prevent shrinkage,o Increment in amine concentration to increase the blowing for cell opening, ando Increment in silicone oil concentration to provide strength to the foam.

The TOES and A-TEOS also increased the crosslinking and further resulting in theclosed cell structures and shrinkage in some cases.

The samples are yet to be tested for thermal stability using TGA and DSC. It is expectedthat the use of TEOS and A-TEOS will improve the thermal stability of the mother foam

manifold.


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11. References

Dow Polyurethanes - Flexible Foam 2ndedition, Editors Ron Harrington and Kathy Hock. Huntsman The Polyurethanes Book, Editors David Randall and Steve Lee, Publisher

John Wiley and Sons Ltd. K. C. Frisch and S. L. Reegen Advamces in Urethane Science and Technology Vol. 1.

Technomic Publishing Co.

Gunter Oertel Polyurethane Handbook. Hanser Publishers. George Woods Flexible Polyurethane Foams. Applied Science Publishers. www.en.wikipedia.org/wiki/Polyurethane www.polyurethane.org
http://www.en.wikipedia.org/wiki/Polyurethanehttp://www.polyurethane.org/http://www.polyurethane.org/http://www.en.wikipedia.org/wiki/Polyurethane

sheela foam trng report

Documents

sheela foam rdcentre

foam calculations8

sheela foam xl unit

basic foam components4

project work

polyurethane polymers

density test8

tension test8