Question

Why are cross-linked polymers very hard and rigid?

Answer 1

1. Cross-links join polymer chains into a three-dimensional network, creating strong covalent bonds between chains.
2. These connections prevent chains from sliding or bending, greatly reducing molecular mobility.
3. Restricted mobility and strong interchain bonds make the material stiff, hard, and often brittle.
4. Cross-linked polymers show high rigidity and strong resistance to deformation.