Is supercritical CO2-polymerized poly(vinylidene fluoride) branched?
Lauriane F. Scanu, Joseph M. DeSimone, Saad A. Khan, and George W. Roberts. North Carolina State University, Raleigh, NC Rheological measurements are used to study the influence of molecular weights and molecular weight distributions (MWD) on the melt polymer behavior of poly(vinylidene fluoride) (PVDF). These measurements are aimed at explaining the bimodal MWD displayed by PVDF when it is produced by continuous precipitation polymerization in supercritical CO2 (scCO2). The rheological behavior of polymer melts is strongly influenced by their molecular weight and especially by their architecture and MWD. Three commercial PVDF samples are used for comparison purposes and for testing the accuracy of empirical techniques on inferring structural information for PVDF. The rheological characterization of these three samples reveals a different trend for one of them. Several rheological correlations are applied to the sample data and the presence of branching is identified in this sample. Mo
