Question

Show the mechanism for the formation of a segment of poly(vinyl chloride) that contains three units of vinyl chloride and is initiated by hydrogen peroxide.

Short answer

The mechanism for the formation of polyvinyl chloride that contains three units of vinyl chloride is shown below

Step-by-step solution

Radical polymerization

Chain growth polymerization initiated by monomer undergo radical mechanism in which substituent group in an alkene species stabilize the radical by electron delocalization.

Mechanism for the formation of polyvinyl chloride that contains three units of vinyl chloride

Radical polymerization is initiated by initiators which undergo homolytic cleavage to form radicals. Hydrogen peroxide endure homolytic cleavage to make 2 OH radicals. One of the OH radical attacks the steric hindered carbon of vinyl chloride to form a rearranged product.

In next step substituent attached carbon radical again attacks another vinyl chloride to form two units of vinyl chloride. This will continue for the third step and lastly polyvinyl chloride containing three units of vinyl chloride is formed as product.

Thus, mechanism for the formation of a segment of poly (vinyl chloride) that contains three units of vinyl chloride is explained.