Question

(2 points). Is it possible for a polymer to have both a glass transition temperature, Tg, and a melting temperature, Tm? How is this explained thermodynamically?

Answer 1

Solution:-

The glass transition is not the same thing as melting transition temperature.

* Melting is a transition which occurs in crystalline polymers. Melting happens when the polymer chains fall out of their crystal structures, and become a disordered liquid.

* The glass transition is a different kind of transition which happens to amorphous polymers, it means polymers whose chains are not arranged in ordered solid state crystals.

But in melting transition that is in crystalline polymers have some amorphous portions around in between 40% to 70%

Hence crystalline polymer have both glass transition temperature and a melting temperature.