The effect of chain transfer agents (CTAs) ethyl acetate (EA), octyl acetate (OA), and isopropyl alcohol (IPA) on the rate of polymerization of vinylidene fluoride (VDF) in an emulsion polymerization and in solution polymerization in dimethyl carbonate (DMC) initiated by tert-butyl peroxypivalate was investigated. Pressure profiles of the polymerizations were recorded. Solids content and rate of polymerization were calculated by gravimetry; size exclusion chromatography was utilized to evaluate CTA activity, and the produced polymer microstructures were characterized by 1 H and 19 F NMR spectroscopies. It is proposed that the observed reduction in polymerization rate in both systems is due to degradative chain transfer reactions.

In order to contribute to a better understanding of the emulsion polymerization of vinylidene fluoride (VDF) an experimental study under conditions of temperature and pressure similar to those found in industrial processes was carried out. It is shown that the initial rate of polymerization is strongly influenced by the agitation of the reactor, with the rate of reaction increasing as the rate of agitation increases. In addition, using a more efficient impeller also increases the polymerisation. It is proposed that this is due to mass transfer limitations. This idea is confirmed by a similar dependence of the average molecular weight on agitation. Experimental data also shows that particles are formed by homogeneous coagulative nucleation. It is proposed that particle nucleation occurs throughout the polymerisation, and that a competition between controlled coagulation and particle generation governs the rate of reaction.

The emulsion polymerization of vinylidene fluoride (VDF) is used to produce a range of commercially important products. Despite this, the current review article will show that very little is known about the kinetics of polymerization, particle nucleation, and role of chain transfer reactions. This is at least in part due to the extreme conditions needed for the polymerization, which can significantly limit the number of academic laboratories able to enable such reactions.