Chemistry - Polymer Question with Solution | TestHub

Thermosetting polymers are heavily cross-linked or network polymers which on heating undergo extensive cross-linking in moulds and again become infusible. They cannot be reused.

Urea-formaldehyde resin is a heavily cross-linked polymer and is an example of a thermosetting polymer.

Polyvinyl, polystyrene, and nylon 6,6 are examples of thermoplastic polymers or fibers, which can be softened on heating and hardened on cooling.

Answer: Ureaformaldehyde