Synthesis and characterization of a series of poly(alpha,omega-alkyldiynes) and copoly(alpha,omega,-alkyldiynes)

A series of poly(alpha,omega-alkyldiynes) and copoly(alpha,omega-alkyldiynes) were synthesized by catalytic Glaser coupling reactions. Two routes were investigated and developed. These routes were chosen in anticipation that high molar mass, linear and polydisperse, polymers would be achieved. GPC (gel permeation chromatography) curves revealed that this was possible for the majority of polymers synthesized by the first route. However, a wide range of molar masses were obtained by the second route with a significant low molar mass tail present in almost all GPC curves. Very low M(n) (number average molar mass) values by GPC gave correspondingly very high M(n) values by end-group analysis (EGA). Hence, it was proposed that the low molar mass tail was a consequence of cyclic structures. From these results and observations a mechanism for the polymerization of the alpha,omega-alkyldiynes was proposed.