Thermosetting Polymer
They are often formed by condensation polymerization with three dimensional network structures.
They do not soften on heating and on prolonged heating, however charring of polymers is caused.
They cannot be reshaped and reused.
They are usually hard, strong and more brittle.
They cannot be reclaimed from wastes.
Due to strong bonds having inter and intra-chain cross-linking, these are insoluble in almost all organic solvents.
Adjacent polymer chains are held together only by strong covalent bonding.
During molding further polymerization and cross-linking occurs.
These are brittle materials.
Example: Epoxy resins, silicones, Bakelite etc.
Natural and Synthetic polymers:
Natural polymers: Obtained from animal and plant origin.
Examples--Cellulose, starch, protein, wool, silk, leather.
Synthetic polymers: Synthetically prepared in the laboratory.
