Question

Write a detailed note on Classification of polymers on basis of Molecular forces .
Also provide PIcture of examples.

Answer 1

Over 10,983,000 live tutoring sessions served!
To get the best deal on Tutoring, call 1-855-666-7440 (Toll Free)

HomeHow it worksAbout Us



Home
ChemistryChemistry IVPolymers
Top
Classification Based on Molecular Forces

Elastomers are polymers in which the polymer chains are held by weakest intermolecular forces. These forces permit the polymers to be stretched. A few cross links are introduced between the chains to help the polymer retract to its original position after the force is released.


FibersBack to Top
These polymers possess high tensile strength and high modulus, because of strong intermolecular forces like hydrogen bonding which operate in polyamides. These strong forces also lead to close packing of chains and thus impart crystalline nature. As a result these polymers show sharp melting points. These polymers are used for making fibers.

Examples: Nylon and terylene
ThermoplasticsBack to Top
In thermoplastics, the intermolecular forces are intermediate between elastomers and fibers and the polymer chain has no cross-links.

Thus thermoplastics can be moulded on heating. These polymers have no cross-linking between chains.
Examples: Polyethylene, polystyrene etc.

Thermosetting polymersBack to Top
Thermosetting polymers made from relatively low molecular mass semi-fluid polymers which when heated in a mould forms an insoluble hard mass which is infusible. This is due to extensive crosslinks between the different polymer chains forming three dimensional network of bonds.

Example: Bakelite and melamine

Answer 2

elastomers are  polymers in which the polymer chains are held by weakest intermolecular forces. these forces permit the polymers to be stretched.  a few cross lare introdeuced  between the chains to help the polymer retract to its original position  after the force is realesed . 

example--vulcanized rubber