SYNTHESIS AND REACTIONS OF UNIFORM-SIZE POLY(DIMETHYLSILOXANE)S HAVING CARBOXYLIC-ACID AS A SINGLE END GROUP AND BOTH END GROUPS

Uniform-size poly(dimethylsiloxane)s, poly(DMS)s, having carboxylic acid as a single end group and both end groups were synthesized through the reaction of mono- and bifunctional living poly(DMS)s with newly synthesized 4-(dimethylchlorosilyl)butanoic acid trimethylsilyl ester (1). 5-(Dimethylchlorosilyl)-pentanoic acid trimethylsilyl ester (2) was also found to be an effective terminating reagent. The subsequent reaction of monofunctional and bifunctional poly(DMS)s having carboxylic acid end groups with aluminum(III) isopropoxide and with titanium (IV) isopropoxide led to the formation of three- and four-arm star polymers and model networks with well-defined branch points and branch length, respectively.