2003 AIPMT PolymersSynthetic Rubbers: Neoprene Easy Question 31 of 34 in Polymers

Which one of the following monomers gives the polymer neoprene on polymerization : -

A $CH_2=CHCl$
B $CCl_2=CCl_2$
C $CH_2=C(Cl)-CH=CH_2$
D $CF_2=CF_2$

The answer is C.

Solution

Neoprene is a synthetic rubber formed by free radical polymerisation of chloroprene (2-chlorobuta-1,3-diene), $CH_2=C(Cl)-CH=CH_2$:
$n\,CH_2=C(Cl)-CH=CH_2 \rightarrow [-CH_2-C(Cl)=CH-CH_2-]_n$
Neoprene is resistant to oils and is used to make conveyor belts, gaskets and hoses.
$CH_2=CHCl$ gives PVC and $CF_2=CF_2$ gives Teflon.
So the monomer of neoprene is $CH_2=C(Cl)-CH=CH_2$.

Concept Chloroprene as monomer of neoprene

Polymers in past papers

34 questions from this chapter have appeared across 23 exam years.