Question

Polyvinyl alcohol is an important polymer. The structure is given below



It is prepared by polymerization of

• A. $CH_{2}=CH-OH$
• B. $CH_{2}=CH-OCOCH_{3}$ , followed by hydrolysis
• C. $CH_{2}=CH-CN$ , followed by hydrolysis
• D. $CH_{2}=CH-COOCH_{3}$ , followed by hydrolysis

Answer 1

Answer: (B)

PVA is prepared by hydrolysis of polyvinyl acetate. Other vinyl ester-derived polymers are sometimes used, with formate, chloroacetate groups instead of acetate. The conversion of the polyesters is usually conducted by base-catalysed transesterification with ethanol:

$\left(\left[C H_{2} C H \left(O A c\right)\right]\right)_{n}+C_{2}H_{5}OH \rightarrow \left(\left[C H_{2} C H \left(O H\right)\right]\right)_{n}+C_{2}H_{5}OAc$