POLY 540 |
| The high yield synthesis of biocompatible random polysiloxanes, poly(caprolactone-co-silane)s was carried out. The non-reductive ring-opening/dehydrocoupling of e–caprolactone with various primary hydrosilanes (RSiH3: phenylsilane, p-tolylsilane, benzylsilane, p-methylbenzylsilane, and phenethylsilane) were performed in the presence of Cp2MCl2/Red-Al (M = Ti, Zr, Hf) combination catalyst. For all the primary hydrosilanes the polymerization yield and molecular weight decreased in the order Ti > Zr > Hf whereas the TGA residue yield increased in the order Ti < Zr < Hf. The polymerization yield, molecular weight, and TGA residue yield increase pronouncedly in the presence of hydrosilane when compared to those in the absence of hydrosilane. The polymerization yield decreases in the order phenylsilane > p-tolysilane > benzylsilane > p-methylbenzylsilane > phenethylsilane. The TGA residue yields were similar for all the primary hydrosilanes. X-ray power pattern (2q = 5~80 o) for the copolymer samples were featureless, which suggests that the polymers adopt an amorphous structure. Thus, the white gummy copolymer products were identified to be a random copolymer [(C=O)(CH2)5O]x[HSiPh]y. |
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Silicones and Silicone-Modified Materials
6:00 PM-8:00 PM, Tuesday, 12 September 2006 Moscone Center -- Hall D, Poster
Division of Polymer Chemistry |