Kinetics of the emulsion polymerization of vinylidene fluoride and hexafluoropropylene

The kinetics of emulsion polymerization of vinylidene fluoride (VDF) and hexafluoropropylene (HFP) has been investigated both experimentally and through the development of an appropriate model. Despite the practical relevance of this copolymer, information about the polymerization kinetics in the literature are rather scarce. A reasonable polymerization mechanism involves quite a number of kinetic parameters, which all need to be evaluated independently. This was obtained by running a limited number of polymerization reactions, but performing a rather accurate characterization of the polymer produced, including the polymerization rate, molecular weight, and chain end group distribution. These quantities allow for the reliable estimation of the involved kinetic parameters. The reliability of the developed model has been assessed by comparison with a second independent set of experimental data, where different operating conditions, in terms of pressure, initial concentration of the initiator, and chain-transfer agent, have been considered.