Synthesis and Characterization of Statistical Fluorinated Copolymers via RAFT Miniemulsion Polymerization

Reversible addition fragmentation chain transfer(RAFT) mediated miniemulsion copolymerizations of butyl methacrylate with fluoroacrylate were carried out at 70 degrees C with potassium persulphate as initiator, and the kinetics of copolymerizations were investigated. Copolymer compositions at low conversion levels were determined by H-1 NMR spectra techniques. In the presence of RAFT agent 2-cyanoprop-2-yl dithiobenzoate(CP-DB), the copolymerization of BMA with FMA in miniemulsion exhibited typical features of a controlled molecular weights and narrow polydispersities. The reactivity ratios were evaluated by Kellen-Tudos(K-T) method, which yields the apparent reactivity ratios, r(BMA) = 0.63 and r(FMA) = 0.79. The results show that the monomer FMA with a fluorinated side chain is more reactive than BMA, and the copolymerizations have a tendency to alternate and to produce a higher FMA content in the copolymers. The spontaneous statistical copolymers with soft gradient shapes were obtained using variable initial ratios of BMA and FMA.