Copolymerizations of butyl methacrylate and fluorinated methacrylates via RAFT miniemulsion polymerization

Abstract

AbstractCopolymerizations of n‐butyl methacrylate (BMA) and fluoro‐methacrylates (including 2,2,3,4,4,4‐hexafluorobutyl methacrylate, HFBMA and 2,2,2‐trifluoroethyl methacrylate, TFEMA) were carried out via reversible addition‐fragmentation chain transfer miniemulsion polymerization, using cumyl dithiobenzoate as a chain transfer agent. The experimental results show that the copolymerizations exhibit “living” fashion, with controlled molecular weights and narrow polydispersities. The reactivity ratios of BMA and fluoromethacrylate in this kind of polymerization system were investigated by size exclusion chromatography and nuclear magnetic resonance, from which the Q‐ and e‐values of HFBMA and TFEMA were calculated. Compared with its corresponding non‐fluoric methacrylate, fluorinated methacrylate exhibits higher resonance stability of the radical adducts. The Q‐value of fluorinated methacrylate is higher (QBMA = 0.82 to QHFBMA = 1.70 and QEMA = 0.76 to QTFEMA = 1.01), and e‐value is much larger (eBMA = 0.28 to eHFBMA = 1.24 to and eEMA = 0.17 to eTFEMA = 1.29) for its rather unique high electron‐withdrawing inductive effect of the fluoroalkyl ester group. The thermal property and the wetting property of copolymers were also discussed. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5067–5075, 2007