Morphology of polyvinylidenefluoride and the copolymer of tetrafluoroethylene with ethylene using thermomechanical analysis

The morphology of polyvinylidenefluoride (PVDF) and the copolymer of tetrafluoroethylene with ethylene (CTE) were investigated by thermomechanical analysis. Both granules and highly dispersed powders of the polymers have similar morphology. Polymer granules contain amorphous and crystalline regions. The morphology of the polymer powders were determined under two analytical conditions: coaxial, when the vectors of polymer loading and vector of compression pressure are in the same plane, or when they are perpendicular to each other. One amorphous and two crystal blocks were found at coaxial orientations of the vectors. Thermomechanical analysis showed that the polymers had a completely amorphous diblock morphology at the perpendicular orientation of the vectors. Parameters that characterize a degree of interchain interaction, such as coefficients of thermal expansion, free volume, and temperatures of polymer transformation into the glassy, high-elastic, or flow-viscous state were determined. PVDF and CTE have similar topographic composition, but different molecular mass and temperatures of phase transitions. (C) 2008 Wiley Periodicals, Inc.