Non-ionic fluorinated amphiphilic block copolymer via RAFT polymerization and their application as surfactant in emulsion polymerization

Abstract

This investigation reports the synthesis of block copolymer of poly(ethylene glycol) methyl ether methacrylate (PPEGMA) with poly(heptafluorobutyl acrylate) (PHFBA). The blockcopolymer was prepared via reversible addition-fragmentation chain transfer polymerization (RAFT). The RAFT end-capped poly[poly(ethylene glycol) methyl ether methacrylate] (PPEGMA) macro-chain transfer agent (CTA) was prepared using 2-cyano-2-propyl dithiobenzoate (CPBT) as RAFT agent. The synthesized PPEGMA was later used as macro-RAFT agent for the polymerization of 2,2,3,3,4,4,4-heptafluorobutyl acrylate (HFBA) which yielded well-defined block copolymers of varied lengths. The PPEGMA-b-PHFBA block copolymer self-assembles in water produces spherical micelles with core-shell nano-structure where the core made of hydrophobic block (PHFBA) and shell is of hydrophilic block (PPEGMA). The synthesized block copolymers, PPEGMA−b−PHFBA, an amphiphilic block copolymers were used as surfactant in the surfactant free emulsion polymerization of styrene. Aqueous micellar solutions of the block copolymers were characterized by DLS and TEM analyses. The CMC value of polymeric surfactant was 0.046 mg. mL−1, determined by surface tension analysis. The block copolymers were characterized by GPC, 1H NMR, FT-IR, DSC analyses.