Ques. 1AIPMT 2005
The monomer of the polymer [figure]
- [figure]
- CH3CH=CHCH3
- CH3CH=CH2
- (CH3)2C=C(CH3)2
Answer
(1) [figure]
Solution
The chain is made of repeating units -CH2-C(CH3)2- and ends in a carbocation -CH2- C(CH3)2, i.e. it is a growing chain of cationic addition polymerisation.
⇒ Each repeating unit -CH2-C(CH3)2- comes from the alkene CH2=C(CH3)2 (2-methylpropene, isobutylene).
nCH2=C(CH3)2 H - [CH2-C(CH3)2 ]n - (polyisobutylene)
∴ The monomer is H2C=C(CH3)2.
Answer: (1)
Out of syllabus