A-level Physics (Advancing Physics)/Polymers/Worked Solutions

1. Different crystalline structures have different refractive indexes. Why does this mean that a polycrystalline polymer is translucent?

The refractive index of each area is different, so the angle of refraction is different for each area. As a result, the image is blurred.

2. What sort of polymer is a pane of perspex?

Crystalline

3. What sort of polymer does the pane of perspex become when shattered (but still in one piece)?

Polycrystalline

4. What sort of polymer is a rubber on the end of a pencil?

Amorphous

5. What happens to the translucency of an amorphous polymer when it is put under stress?

The polymer becomes more translucent, as it becomes more polycrystalline as the chains are stretched and straightened.