Macromolecules, Vol.33, No.5, 1656-1663, 2000
Molecular weight distribution of fluorinated polymers with long chain branching
The molecular weight distribution (MWD) of branched fluorinated terpolymers made of vinylidene fluoride (VDF), hexafluoropropylene (HFP), and tetrafluoraethylene (TFE) has been investigated. These polymers, as well as all VDF-based polymers, have trifunctional long chain branches originated by the transfer to polymer mechanism. Furthermore, one of the samples here examined has a certain amount of tetrafunctional long chain branches produced by copolymerizing the sample in the presence of a fluorinated diolefin. The MWD of the polymers has been evaluated by combining the size exclusion chromatography data with the intrinsic viscosity of the whole polymer. To highlight the effect of branching over the MWD, the polymer samples have been fractionated and the high molecular weight fractions have been analyzed. The reliability of the adopted approach has been assessed by comparing the obtained Values of weight-average molecular weight with the ones measured by the laser light scattering technique.
Keywords:CHROMATOGRAPHY