Question

What does make a network polymer very hard and rigid?

Answer 1

1. Extensive cross-linking between polymer chains forms a three-dimensional network.
2. These cross-links prevent the movement of chains, making the structure infusible and insoluble.
3. The rigid framework resists stretching and bending, giving the polymer high mechanical strength.
4. Examples include bakelite and melamine-formaldehyde resin.