Ab Initio Emulsion RAFT Polymerization of Vinylidene Chloride Mediated by Amphiphilic Macro-RAFT Agents

An amphiphilic copolymer poly(acrylic acid)-block-poly(styrene) (PAA-b-PS) with a trithiocarbonate reactive group was used in the ab initio reversible addition-fragmentation chain transfer (RAFT) emulsion polymerization of vinylidene chloride (VDC). The fast polymerization and high conversion were achieved. The parameters for a good control over the formation of well-defined PAA-b-PS-b-PVDC amphiphilic block copolymers and self-stabilized latexes were identified. To improve the emulsion stability and prevent the desorption of water-soluble initiating radicals, the acid groups of PAA-b-PS were neutralized by NaOH at the later stage of polymerization. The PAA-b-PS-b-PVDC block copolymer with a high molar mass of 30 kg mol(-1) and the stable latex with 30 wt % solid content was obtained. The kinetics of RAFT emulsion copolymerization of VDC in a living manner was first investigated. The as-prepared PAA-b-PS-b-PVDC latex particles were further used as seeds in the emulsion polymerization of styrene, enabling the preparation of novel PAA-b-PS-b-PVDC-b-PS tetra-block copolymers with a molar mass of 76 kg mol(-1) and a relatively low molecular weight distribution of 1.6. (c) 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40391.