organic polymer recycle

8/6/2019 Organic Polymer Recycle

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Chemistry of OrganicChemistry of OrganicPolymers andPolymers and

RecyclingRecycling

Taz ChoudhuryChem 481

March 2nd, 2006


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Organic Polymers

A macromolecule which is made of structurally similar monomersrepeatedly connected by covalent bonds.

Three main groups of polymers-

1. Thermoplastics- linear or branched chains, readily melted andmolded into any shape.

2. Thermosets- cross-linked chains, once theyre molded or cured it cantbe re melted or remolded.

3. Elastomers- amorphous polymers that can stretch and rebound;usually crosslinked by covalent bonds.

Chemically inert; not attached by air or its pollutants

Very stable towards water


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Molecular Classification


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Chain Growth Polymerization

Butyl lithium

Step 2- Initiation

Step 3- Repeat


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Step Growth Polymerization

Start with

Step 1- Transesterification

Step 2- ester

intermediate


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Making Polyester

Step 3- formation of ethyl terephthalate

Step 3- formation of

bis(2-hydroxyethyl)

terephthalate

Final-

After the bis(2-

hydroxyethyl)terepthalate is

formed, it continues with

more transesterifications

until the product gets biggerand bigger. When the

molecular weight is large

enough, it turns into

poly(ethylene terephalate or

PET. POLYESTER!!


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Physical Properties

Melting point- does not occur over a sharp

temperature range because of its size.

The range can be as much as 50-65 deg C over which the

viscosity of the polymer changes its state.

Boiling Point- Polymers never boil

Solubility- Most polymers are insoluble in water; some aresoluble only with strong organic solvents


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Plastics

Classified according to their polymer backbone (polyvinylchloride, polyethylene, silicone)

Since they are partially crystalline and partially amorphous

in molecular structure, they have a melting point

Plastics take many forms to be useful in our everyday life

Polystyrene

Styrofoam

PVC

Nylon

Teflon


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Problem

The remarkable versatility and usefulness of

plastic comes with a very high price.

They are durable and degrade very slowly

Burning plastics releases toxic fumes in the air that

are harmful to humans, plants and animals

The large amounts of chemicals used to produce

and dispose of plastic materials require the useof our already limited supply of fossil fuels.

Despite all the problems plastic has posed on our

society today, THERE IS GOOD NEWS


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Recycle!

Recycling plastic products is a easy and effective solutionto the problemThermoplastics products can be remelted and reused and

thermoset plastics can be ground up and used as fillers.

Problems with recycling plasticsAutomation of sorting of plastic waste

Unlike metal, a lot of plastics have to be manually sorted (movie)

Recycling certain types of plastic is unprofitable

Q: What percentage of plastics are recycled in the USevery year?


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Resin ID Code


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How Recycling Works


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Future

Product Stewardship

Program

Produce DeskJet

printers fromrecyclable plastics.

Diverts as much as six

million pounds of

plastics from landfills

by only using 25%

recyclable plastic!


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Conclusion

Organic polymers, have been our best friendthroughout history due to its physical andchemical properties.

The problems, however, we face due to ourincreasing use of plastics, made from organicpolymers, are posing to be a challenge

Recycling these products seems to be the

optimal solution to some of the issues and thusmany organizations and scientists are workingon making it an essential part of our lives.


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Citations

Polymers: Chemistry & Physics of Modern Materials, 2ndEdition,J.M.G. Cowie, 1991

Encyclopedia of Polymer ScienceWiley, 1997

Comprehensive Polymer Science: The Synthesis, Characterization,Reaction, and Applications of Polymers, G Allen and J.C.Bevington, 1989

H. Choong, Procurement of Environmentally ResponsibleMaterial,IEEE International Symposium on Electronics and Environment,May 1996

V. Ross, HP DeskJet Printers with Recycled Plastics, 1996


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Questions?

organic polymer recycle

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