Synthesis of Substituted Polyacetylenes Grafted with Polystyrene Chains by the Macromonomer Method and Their Characterization

Abstract

Summary: A macromonomer (1) consisting of a polystyrene chain and an acetylenic chain end ( = 2 500, = 1.20) was prepared by atom transfer radical polymerization. Macromonomer 1 was copolymerized with phenylacetylene (2) and propargyl 2-bromopropionate (3) by using Rh catalysts at varying feed ratios from 10 to 50 wt.-% to produce graft copolymers 4 and 5, respectively. The synthesized copolymers 4 and 5 possessed a conjugated polyene main-chain and polystyrene grafts, and contained 11–34 and 16–77 wt.-% of polystyrene with of 61 400–144 000 and 19 300–22 500, respectively. Graft copolymer 4 was a yellow solid and thermally stable up to 225 °C, whereas 5 was a brown solid with weight loss beginning at 175 °C. Graft copolymers 4 and 5 exhibited UV-vis absorption edges at 525 and 425 nm, respectively, which are attributable to the conjugated main-chain structure. Copolymerization of the acetylene-terminated polystyrene-based macromonomer with monosubstituted acetylenes.