Synthetic Polymers

What polymers are formed from each monomer?

a. 

b. 

Draw the structure of the polymer formed by chain-growth polymerization of each monomer.

a. 

b. 

What monomer(s) are used to prepare each polymer or copolymer?

a. 

b. 

Draw the structure of the polymer formed by step-growth polymerization of each monomer or pair of monomers.

a. 

b. 

Draw the structure of the polymer that results from anionic polymerization of p-trichloromethylstyrene using ethylene oxide as the electrophile to terminate the chain.

Although styrene undergoes both cationic and anionic polymerization equally well, one method is often preferred with substituted styrenes. Which method is preferred with each compound? Explain.

a. 

b. 

c. 

d. 

Rank the following compounds in order of increasing ability to undergo anionic chain-growth polymerization.

Although chain branching in radical polymerizations can occur by intermolecular H abstraction as shown in Mechanism 30.2, chain branching can also occur by intramolecular H abstraction to form branched polyethylene that contains butyl groups as branches.

a. Draw a stepwise mechanism that illustrates which H must be intramolecularly abstracted to form butyl substituents.

b. Suggest a reason why the abstraction of this H is more facile than the abstraction of other H’s.

The reaction of urea $\left[\left({\mathrm{NH}}_2\right)C=O\right]$ and formaldehyde $\left({\mathrm{CH}}_2=O\right)$ forms a highly cross-linked polymer used in foams. Suggest a structure for this polymer. [Hint: Examine the structures of Bakelite (Figure 30.7) and Melmac (Problem 30.58).]