Why do plastics not degrade easily?

When hot water is placed into an empty water bottle, the bottle keeps its shape and does not soften. What type of plastic is the water bottle made from?

Bakelite is thermosetting plastics which is obtained from Phenol + ____?

Full form of PHBV biodegradable polymer:

Consider the following: I. Cigarette butts II. Eyeglass lenses III. Car tyres. How many of them contain plastic?

At which stage in its life cycle, does the silkworm yield the fibre of commerce?