Question

How does annealing affect polymer crystallinity? Why does it have such an effect?

Answer 1

Annealing is a heat treatment process that changes the microstructure of a substance to change its mechanical and electrical properties.

In semi-crystalline thermoplastics, annealing is performed at a temperature above glass transition temperature of the polymer to get higher degree of crystallinity. So annealing process improves the crystallinity of the this kind of polymer.These changes are related to changes in morphological structure .The heating process leads to reorganization of structure leading to low state of order with lower free energy.