alpha-acetal-omega-bis(hydroxymethyl) heterodifunctional polystyrene: Synthesis, characterization, and investigation of intramolecular end-to-end ring closure

A route to macrocyclic polystyrene of controlled dimensions based on a new ring closure process has been investigated. It involved the direct coupling of an alpha -acetal,omega -bis(hydroxymethyl) heterodifunctional linear po lystyrene precursor previously prepared by living anionic polymerization. C yclization was achieved under high dilution, by intramolecular condensation of the polymer ends in the presence of a mild acid as catalyst. Macrocycli c polystyrenes were prepared directly in high yield (> 90%) without any nec essary fractionation step. The synthesis and structural characterization of both the linear alpha,omega -heterodifunctional precursors and the corresp onding cyclized polystyrenes, as well as a preliminary investigation of the ir stability and specific thermal properties, are reported.