Phenol and formaldehyde undergo condensation to give a polymar (A) which on heating with formaldehyde gives a thermosetting polymer (B). Name the polymers. Write the reactions involved in the formation of (A). What is the structural difference between two polymers?

Question

Philoid · Accepted Answer

Polymer ‘A’ is Novolac and ‘B’ is Bakelite.

Novolac on heating with HCHO undergoes the cross-linkage to give an infusible solid called Bakelite. Novalac has a linear polymer chain whereas Bakelite is a cross-linked polymer.