Reversible Addition-Fragmentation Chain-Transfer Polymerization for the Synthesis of Poly(4-acetoxystyrene) and Poly(4-acetoxystyrene)-block-polystyrene by Bulk, Solution and Emulsion Techniques

Abstract

The living radical polymerization of 4-acetoxystyrene via the RAFT process has been achieved employing bulk, solution and emulsion techniques. The rate of polymerization was studied between 60°C and 90°C. Increasing the temperature increases the rate of polymerization without affecting the polydispersity. Poly(4-acetoxystyrene) with narrow polydispersity (1.08) was obtained. Various novel dithiocarboxylic esters and dithiocarbamates were screened as chain-transfer agents for the RAFT polymerization of 4-acetoxystyrene. The block copolymerization of poly(4-acetoxystyrene) with styrene leading to poly(4-acetoxystyrene)-block-polystyrene confirmed the presence of active chain ends in the first block. The acetoxy polymers were hydrolyzed to the corresponding hydroxy polymers under mild basic conditions.