POLY(TETRAFLUOROETHYLENE) - MOLECULAR-WEIGHT DISTRIBUTIONS AND CHAIN STIFFNESS

Low molecular weight poly(tetrafluoroethylenes) have been prepared that, as characterized by DSC, have lower melting points but similar virgin morphologies when compared to high molecular weight polymer. Dynamic rheometry and creep measurements are used to characterize the molecular weight distributions of these polymers. The molecular weight distributions are shown to be bimodal, which is consistent with a heterogeneous polymerization medium where the surfactant plays an important role in determining the morphology of the virgin polymer. Additionally, these results illustrate that the inherent chain stiffness of poly(tetrafluoroethylene) is very similar to that of polyethylene at least in terms of the number of chain atoms between entanglements.