Introduction to Polymer Chemistry — Chemistry STD 12 Science — Question

Polymers having the property of elasticity in which a substance gets stretched by external force and restores its original shape on the release of that force are called elastomers.

Thermoplastic Polymer	Thermosetting Polymer
1. These are formed by addition polymerisation .	These are formed by condensation polymerisation .
2. They have low molecular weight .	They have high molecular weight.
3.They are usually soft ,weak and less brittle .	hey are usually hard ,strong and more brittle
4. They are long chain linear polymer with negligible cross links	They have three-dimensional network structure with number of crosslinks .
5. They are usually soluble in some organic solvents .	Due to strong bonds and crosslinks ,they are insoluble in almost all organic solvents .
6. They get softened on reheating readily because secondary forces between the individual chain can break easily by heat or pressure .	They donot soften on reheating because the crosslinks and bonds retain their strength on heating .
7.Example : Polyethylene ,Polystyrene ,PVC ,PVA .	Example : Phenolformaldehyde,ureaformaldehyde , Nylon 6,6 .