Question

Distinguish between thermoplastic and thermosetting polymer.

Answer 1

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 .