Question

Polystyrene can be polymerized from the starting monomer (styrene) pictured below.

CH2

a. Anionic polymerization is one method of polymerization that can be used to generate polystyrene from styrene. Explain what type of initiator should be used for this reaction
and draw an example of a styrene monomer that has reacted with initiator.

b. Using this anionic polymerization method and a starting concentration of 1M styrene and 1mM initiator, what degree of polymerization (Xn) would you expect if you use up 99% of the monomer (p = 0.99)?

c. Draw a short segment of the resulting polystyrene polymer and determine the molecular weight of a repeat unit.

d. Given the MW of polymer fractions from a polystyrene reaction (below), calculate the weight average molecular weight (Mw) and the number average molecular weight (Mn) for this polymer sample.

e. What is the polydispersity index for this polymer sample?

Answer 1