Synthesis and Properties of Polymer Brush Consisting of Poly(phenylacetylene) Main Chain and Poly(dimethylsiloxane) Side Chains

Abstract A novel polymer brush consisting of poly(phenylacetylene) (PPA) main chain and poly(dimethylsiloxane) (PDMS) side chains was synthesized by the polymerization of phenylacetylene-terminated PDMS macromonomer (M-PDMS). The macromonomer was prepared by the esterfication of monohydroxy-ended PDMS (PDMS-OH, degree of polymerization (DP) = 42) with p -ethynylbenzoic acid. The polymerization of M-PDMS using [(nbd)RhCl] 2 /Et 3 N catalyst led to polymer brush, poly(M-PDMS), with M n up to 349 000 (DP of main chain 104). Poly(M-PDMS) with narrow molecular weight distribution ( M n  = 39 900, M w / M n  = 1.11) was obtained with a vinyl-Rh catalyst, [Rh{C(Ph) CPh 2 }(nbd){P(4-FC 6 H 4 ) 3 }]/(4-FC 6 H 4 ) 3 P. Poly(M-PDMS)s were brown to orange viscous liquids and soluble in organic solvents such as toluene and CHCl 3 . The UV–vis absorptions of poly(M-PDMS) were observed in the range of 350–525 nm, which are attributable to the PPA main chain.