The repeating unit of a polymer is shown below.This polymer is formed by
A)addition of ethylene.
B)addition of trans-2-butene.
C)1,2 addition of butadiene.
D)1,4 addition of butadiene.

Question

The repeating unit of a polymer is shown below.This polymer is formed by 
A)addition of ethylene. 
B)addition of trans-2-butene. 
C)1,2 addition of butadiene. 
D)1,4 addition of butadiene.

Quizplus · Accepted Answer

The repeating unit has two vinyl groups (C=C double bonds) separated by two methylene groups (-CH2-CH2-). This is only possible if the polymer is formed by the 1,4 addition of butadiene. In this reaction, the two terminal carbons of butadiene add to each other, while the central double bond remains intact, resulting in the formation of a polymer with repeating units that contain two C=C double bonds separated by two methylene groups.

The Repeating Unit of a Polymer Is Shown Below