(97c) The Kinetics of Tert-Butyl-Peroxy-Acetate Initiated Polymerization of 1,1-Difluoroethene in a Supercritical Carbon Dioxide Medium

A novel process has been devised and demonstrated at the laboratory scale that produces polyvinylidenefluoride from 1,1-difluoroethylene monomer utilizing supercritical carbon dioxide. Notably, the process has been shown to produce unimodal, gel-free polymer with an average molecular weight of as high as 1.5 million. In the process, the role of 1,1-difluoroethene is two-fold; one as a reacting monomer and the other as a supercritical co-solvent in a binary mixture with CO2. The process concept was demonstrated using an agitated 300-ml bolt-closure, stainless steel reactor. Kinetic studies involved varying the total pressure (12 to 31 MPa), the partial pressures of CO2 and monomer, and the temperature (325 to 400 K). For this paper, kinetic rate constants and Arrhenius activation energies were regressed, for the novel process using tert-butyl-peroxy-acetate as an initiator.