Cyclic polymers have unique properties due to their different architecture. To synthesize well-defined cyclics, the application of �click� reactions to well-defined, telechelic (a,?-difunctional) precursors was introduced. Previously, the a,?-divinylpolystyrene precursors for metathesis ring closure to form macrocyclics were prepared using  4-pentenyllithium as anionic initiator for styrene polymerization followed by termination with p-chloromethylstyrene.  This termination results in dimer formation from lithium-halogen exchange followed by Wurtz-coupling reactions. To eliminate this side reaction that reduces the efficiency of the subsequent macrocyclization, a new method has been investigated to form the a,?-divinyl precursors; the intermediate a-pentenylpoly(styryl)lithium (PLi) was coupled with dimethyldichlorosilane to form the a,?-divinylpolystyrene precursor, and the excess PLi was reacted with ethylene oxide to facilitate purification. The products were characterized by SEC, MALDI-TOF MS and NMR.  The results of these investigations will be presented.

New synthesis of cyclic polystyrenes using anionic polymerization, linking chemistry, and metathesis ring closure

245th National Meeting (2013)

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