Study of the kinetic features of emulsion copolymerization of vinylidene fluoride with hexafluoropropylene

Abstract The kinetic features of the emulsion copolymerization of vinylidene fluoride with hexafluoropropylene have been studied both in the absence of and in the presence of an emulsifier. It has been shown that without emulsifier, at a small content of copolymer in the latex, the process occurs by a radical mechanism, in quasi-homogeneous conditions. The introduction of an emulsifier into the reaction medium, whilst not essentially changing the mechanism, permits principally emulsion polymerization to take place. The kinetic features of the system are mainly due to the heterophase-type process, the dispersivity of the system and the size of the interphase surface. The use of an emulsifier permits the process to be carried out at a high rate and the production of copolymer of high MW whose polydispersivity is not changed. An increase in the amount of copolymer introduced does not cause an increase in the MW of the product, but only a broadening of its MWD, at the expense of high molecular weight fractions.