Polymerization of Vinylidene Fluoride in Supercritical Carbon Dioxide: Effects of Poly(dimethylsiloxane) Macromonomer on Molecular Weight and Morphology of Poly(vinylidene fluoride)

Abstract

The batch homopolymerization of vinylidene fluoride (VDF) in supercritical carbon dioxide (scCO2) was studied using diethyl peroxydicarbonate (DEPDC) as a free radical initiator. Experiments were carried out to investigate the effects of monomer concentration, initiator concentration, and agitation. It was shown that poly(dimethylsiloxane) monomethacrylate (PDMS-ma) acts effectively as a stabilizer influencing both the morphology and the molecular weight of the poly(vinylidene fluoride) (PVDF) product. Scanning electron microscopy (SEM) and laser scattering particle size analysis were employed to characterize polymer particle morphology and particle size distribution. Thermal analysis of the products by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) is also reported. 19F nuclear magnetic resonance (NMR) was performed to characterize the microstructure of the PVDF polymer chain.