Friday, December 25, 2009

CLASSIFICATION OF POLYMERS

1. ON BASIS OF SOURCES:
1. Natural : Starch, cellulose, protein, nucleic acid, natural rubber,etc.
2. Synthetic: polyethene, polypropylene, polystyrene, polyvinyl chloride (PVC) ,nylon, terylene, bakelite, etc.
ON BASIS OF STRUCTURE:
1.Linear: Monomeric units are joined in the form of long straight chains, such polymers have high densities, high tensile strength and high melting point.
LINEAR CHAIN
e. g. Polyethylene, nylons and polyesters.
2.Branched chain: are mainly linear in nature but also possess some branches along the main chain. E.g. low density polyethene (LDPE)
They have densities, lower tensile strength and low melting point

BRANCHED CHAIN
e. g. Amylopectin and glycogen
3.Crossed Linked polymers : Monomeric unit’s are linked together to constitute a three dimensional network. They are hard, rigid, and brittle.

CROSS LINKED
e. g. Bakelite, Melamine formaldehyde resin, etc,
Based on Interparticle forces:
1. Elastomer: Polymer chain is held up by weakest attractive forces. They are amorphous polymers having high degree of elasticity.
E.g. Synthetic rubber.
2. Fibers : These are the polymer which have quite strong Interparticle forces such as H - bond . They have high tensile strength and high modulus.
E.g. Nylon 6,6
3. Thermoplastic polymer: Interparticle forces of attraction are in between those of elastomer and fibers. They are linear, long chain polymers, they are linear, long chain polymers, which can be softened on heating and hardened on cooling reversibly.
e.g. polyethene ( P E ), Polypropylene( P P ), polyvinyl polyethene ( P V C ), polymers ( P S ), Nylons, Polytetrafluoro ethylene ( P T EE or teflon ), etc.
4. Thermosetting polymers: These are the polymers which become hard and infusible on heating. Once they have solidified, they cannot be softened. Heating results excessive cross linking between the chain forming three dimensional network. They are permanent setting polymers.
E.g. polyester (Terylene), bakelite, melamine.











13 comments:

  1. THIS GAVE ME A VERY GOOD IDEA OF CLASSIFICATION
    IN BRIEF.

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  2. Sir, that's a nice and brief description about the thing I've been searching for.

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  3. Thanks Mam,
    This helped me by removing my confusion about classification of polymers. Thanks a lot.

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  4. Thank you Mam. My search stopped here.

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  5. What are you need to understand related to chemistry .I will help you.Send me a topic

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    Replies
    1. hi ma'am .....it's nice to see your profile...i am ms polymer student in saudi arabia....i will need your help..

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  6. the classification is in the undrstandable way......thanks

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  7. respected mam,
    i am sampath from tamil nadu. i joined in your blog. i am studying m.phil in mk university. i have confusion to choose my project. so please help me. please send any project ideas.

    thank u. mam.

    ReplyDelete
  8. mam can polymers can be classified as high polymers and oligo polymer pls tell me mam

    ReplyDelete