Polymer Basics - Fundamentals of Industrial Chemistry: Pharmaceuticals, Polymers, and Business - page 87

H H

CC

H

x

Polystyrene

In the anionic mechanism, the carbanion reacts with styrene to form a new
benzylic carbanion. This reacts with another molecule of styrene to form the
dimer, which then continues to add styrene molecules to form, eventually,
polystyrene.
Another polymerization technique is cationic polymerization. For example,
styrene can be polymerized by treatment with a small amount of 1-phenethyl
chloride, tin tetrachloride, and tetra-n-butylammonium chloride [2]. Presum-
ably, the mechanism is as follows.

Cl

SnCl 4
nBu 4 NCl

H H

CC

H

x

Polystyrene