$R$ is one of the monomers for the formation of a polymer called

Which of the following statements are correct?
$(1)$ Biodegradable polymers can be converted into essential life substances after degradation.
$(2)$ Non-biodegradable polymers are active towards environmental processes.
$(3)$ Non-biodegradable polymers can be converted into essential life substances.
$(4)$ $PHBV$ is degraded by bacteria under environmental conditions.

Discuss the main purpose of vulcanisation of rubber.

Gun-cotton is

Consider the Assertion and Reason given below.
Assertion $(A):$ Ethene polymerized in the presence of Ziegler-Natta catalyst at high temperature and pressure is used to make buckets and dustbins.
Reason $(R):$ High density polymers are closely packed and are chemically inert.
Choose the correct answer from the following:

Which of the following polymers is used in paints?