Polymerization of Si‐containing acetylenes. XIV. Polymerization of diphenylacetylenes with bulky silyl groups and polymer properties

Abstract

AbstractPolymerization and polymer properties of diphenylacetylenes with bulky silyl groups (SiMe2–i‐Pr, SiMe2–t‐Bu, SiMe2Ph, SiEt3) at para or meta position were studied under comparison with those of the SiMe3 derivatives. The present monomers polymerized in good yields with TaCl5‐cocatalysts to form high molecular‐weight polymers (Mw > 4 × 105). The polymer yields of para‐substituted monomers were similar to that of the SiMe3 derivative, while those of meta substituted monomers were lower than that of m‐SiMe3 derivative. Most of the polymers were totally soluble in common solvents such as toluene and CHCl3, although the polymers with p‐SiMe2–t‐Bu and p‐SiMe2Ph groups were partly insoluble in all solvents. These polymers resembled SiMe3‐containing homologues in the UV‐visible absorption and thermal stability. The oxygen permeability coefficients of these polymers were in the range of 10−9−10−8 cm3 (STP) cm/(cm2·s cm Hg)—lower than those of the corresponding SiMe3‐containing polymers. © 1993 John Wiley & Sons, Inc.