Question

Identify the polymer obtained by heating n moles of isobutylene with n moles of isoprene at 100°C in the presence of anhydrous AlCl\(_3\).

• A. Butyl rubber
• B. Buna-N
• C. Buna-S
• D. Neoprene rubber

Hint:

Butyl rubber is formed by the copolymerization of isobutylene and isoprene using anhydrous AlCl\(_3\) as a catalyst.

Answer 1

The Correct Option is A

Step 1: Understanding the reaction.
Butyl rubber is a polymer formed by the copolymerization of isobutylene and isoprene in the presence of anhydrous AlCl\(_3\) at 100°C. This polymer is known for its excellent impermeability to gases and is widely used in tire inner linings and other applications requiring airtight seals.

Step 2: Analyzing the options.
(A) Butyl rubber: Correct. This is the polymer obtained in the described reaction.
(B) Buna-N: Incorrect. Buna-N is formed by the copolymerization of acrylonitrile and butadiene, not isobutylene and isoprene.
(C) Buna-S: Incorrect. Buna-S is a copolymer of styrene and butadiene, not isobutylene and isoprene.
(D) Neoprene rubber: Incorrect. Neoprene is made from the polymerization of chloroprene, not from isobutylene and isoprene.

Step 3: Conclusion.
The correct answer is (A) Butyl rubber, as it is the polymer formed by the reaction described.