Miniemulsion copolymerization of butyl mathacrylate (BMA) with fluoroacrylate (HFMA, TFMA) was carried out at 70 ℃ by employing potassium persulphate (KPS) as initiator. Copolymer compositions at low conversion levels were determined by ^1H NMR spectra techniques. The reactivity ratios were evaluated by employing Kellen-Tudos (K-T) methods, which yields the apparent reactivity ratios, rBMA = 0.74, rHFMA = 0.87 and rBMA = 0.73, rTFMA = 0.75, respectively, and Q- and e-values of HFMA and TFMA were calculated by the Alfrey-Price method. The results show that HFMA and TFMA are more active than BMA, and the cross-propagation rate constant is greater than the self-propagation one in these two copolymerizations.
Qing Hua Zhang Zhen Huan Luo Xiao Li Zhan Feng Qiu Chen