Natural rubber is a polymer of ....

Identify the polymer obtained by heating $n$ moles of isobutylene with $n$ moles of isoprene at $100^{\circ} C$ in the presence of anhydrous $AlCl_{3}$.

Identify the polymer used to prepare disposable cups and plates.

Given below are two statements,one is Assertion $(A)$ and the other is Reason $(R).$
Assertion $(A):$ Natural rubber is a linear polymer of isoprene called cis-polyisoprene with elastic properties.
Reason $(R):$ The cis-polyisoprene molecules consist of various chains held together by strong polar interactions with a coiled structure.
In the light of the above statements,choose the correct one from the options given below:

Isoprene is a valuable substance for making

What is the process of heating rubber with sulfur called?