Synthesis and properties of substituted polyacetylenes having cyclohexyl groups

Abstract

Disubstituted acetylenes containing cyclohexyl groups (RC≡CC 6H4-p-cvclo-C6H11, R = Ph, p-Me 3SiPh, p-tert-BuMe2SiOPh, Me, Cl, 1a-e, respectively) were polymerized with Ta- or Mo-based catalyst, and 1a, 1c, and 1e provided high molecular weight polymers. Free-standing membranes of poly(1a) and poly(1c) were fabricated from toluene solution. Hydroxy-containing membrane poly(2c) was prepared by desilylation of siloxy-containing poly(lc) using trifluroacetic acid. According to thermogravimetric analysis (TGA), the produced polymers exhibited high thermal stability, and the onset temperatures of weight loss in air were ∼340°C The oxygen permeability coefficients of these membranes were in the range of 17-230 barrers. The point of poly(2c) in the P CO2 vs. PCO2/PCH4 plot were located above Robeson's upper bound. © 2007 The Society of Polymer Science.