Chemistry
Why Glass Transition Temperature Determines Polymer Processing
Quick fact
The glass transition temperature (Tg) dictates whether a polymer behaves like a rigid cup or a flexible bag at room temperature, and it is the reason that materials like PVC pipes are processed at temperatures above their Tg.
Why this is interesting
Why is a plastic spoon brittle at room temperature but a rubber band stretchy, and why does the temperature at which they change matter so much? This critical temperature, called the glass transition temperature, is the secret behind how every plastic is made.