Monomer reactivity ratios for fluoroacrylate and butyl methacrylate in miniemulsion copolymerizations initiated by potassium persulphate

Miniemulsion copolymerization of butyl mathacrylate(BMA)with fluoroacrylate(HFMA,TFMA)was carded 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.