Method of preparing high quality vinylidene fluoride polymer in aqueous emulsion

In a process for preparing high molecular weight vinylidene fluoride polymer by emulsion polymerization of monomer in a stirred aqueous reaction medium containing a fluoroalkyl surfactant emulsifier, the improvement which comprises using diisopropyl peroxydicarbonate as the polymerization initiator and isopropyl alcohol as the chain transfer agent and wherein monomer, initiator and chain transfer agent are added separately but simultaneously to the system, incrementally or continuously over the polymerization cycle, the initiator being added as the emulsified component of an aqueous emulsion in which a fluorosurfactant, readily soluble in cold water and capable of emulsifying the initiator for the duration of the polymerization is used.