Synthesis of substituted polyacetylenes grafted with polystyrene chains by the macromonomer method and their characterization

摘要

A macromonomer (1) consisting of a polystyrene chain and an acetylenic chain end ((M) over bar (n) = 2 500, (M) over bar (w)/(M) over bar (n) = 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 polystryrene with (M) over bar (n) of 61 400-144 000 and 19 300-22 500, respectively. Graft copolymer 4 was a yellow solid and thermally stable up to 225 degrees C, whereas 5 was a brown solid with weight loss beginning at 175 degrees 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.