Poly(vinyl chloride)-b-poly(hydroxypropyl acrylate)-b-Poly(vinyl chloride): Understanding the synthesis of an amphiphilic PVC block copolymer on a pilot scale

The aim of this work was to develop an understanding of the major difficulties associated with the scale-up of the technology for the synthesis of poly(vinyl chloride) (PVC) block copolymers that contain hydrophilic segments, thus providing important directions to be followed in order to produce such new materials on the industrial scale. The synthesis was carried out in a two-step process. First, the macroinitiator α,ω-di(iodo)poly(hydroxypropyl acrylate) was synthesized in an aqueous medium by (single electron transfer)/(degenerative chain transfer) living radical polymerization (SET-DTRP) catalyzed by Na2S2O4. The block copolymer was then prepared by SET-DTRP of vinyl chloride (VC) from the iodine-terminal active chain ends of the macroinitiator, thereby leading to the formation of the block copolymer poly(vinyl chloride)-b-poly(hydroxypropyl acrylate)-b-poly(vinyl chloride). This report covers important aspects related to the characterization of the block copolymer produced and to the identification of the major limitations that must be overcome in order to produce this new material on the industrial scale. The results clearly show the differences between the theoretical predictions and the block copolymer compositions obtained by using a suspension polymerization method, which is the most-used polymerization process in the PVC industry. J. VINYL ADDIT. TECHNOL., 19:94–104, 2013. © 2013 Society of Plastics Engineers