Polymers

Monomer of [figure] is

1. 2-methylpropene
2. styrene
3. propylene
4. ethene

Answer

(1) 2-methylpropene

Solution

The repeating unit is -C(CH3)2-CH2- (polyisobutylene).

⇒ Putting back the double bond between the two carbons of the repeating unit gives the monomer:

n CH2=C(CH3)2 Polymerisation [ -C(CH3)2-CH2- ]n

∴ The monomer is CH2=C(CH3)2, i.e. 2-methylpropene (isobutylene).

Answer: (1)