Synthesis of poly(vinyl chloride)-b-poly(n-butyl acrylate)-b-poly(vinyl chloride) by the competitive single-electron-transfer/degenerative-chain-transfer-mediated living radical polymerization in water

The synthesis of a block copolymer poly(vinyl chloride)-b-poly(n-butyl acrylate)-b-poly(vinyl chloride) is reported. This new material was synthesized by single-electron-transfer/degenerative-chain-transfer-mediated living radical polymerization (SET-DTLRP) in two steps. First, a bifunctional macroinitiator of alpha,omega-di(iodo)poly (butyl acrylate) [alpha,omega-di(iodo)]PBA] was synthesized by SET-DTLRP in water at 25 degrees C. The macroinitiator was further reinitiated by SET-DTLRP, leading to the formation of the desired product. This ABA block copolymer was synthesized with high initiator efficiency. The kinetics of the copolymerization reaction was studied for two PBA macroinitiators with number-average molecular weight of 10 k and 20 k. The relationship between the conversion and the number-average molecular weight was found to be linear. The dynamic mechanical thermal analysis suggests just one phase, indicating that copolymer behaves as a single material with no phase separation. This methodology provides the access to several block copolymers and other complex architectures that result from combinations of thermoplastics (PVC) and elastomers (PBA). From industrial standpoint, this process is attractive, because of easy experimental setup and the environmental friendly reaction medium. (c) 2006 Wiley Periodicals, Inc.