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The relationship between the pressure, volume, and temperature (PVT) of poly(vinylidene fluoride) homopolymers (PVDF) and poly(vinylidene fluoride)–hexafluoropropylene (PVDF–HFP) copolymers was determined in the pressure range of 200–1200 bar and in the temperature range of 40°C–230°C. The specific volume was measured for two homopolymers having a molecular weight (Mw) of 160,000–400,000 Da and three copolymers containing between 3 and 11 wt % HFP with a molecular weight range of 320,000–480,000 Da. Differential scanning calorimetry (DSC) was used to simulate the cooling process of the PVT experiments and to determine the crystallization temperature at atmospheric pressure. The obtained results were compared to the transitions observed during the PVT measurements, which were found to be pressure dependent. The results showed that the specific volume of PVDF varies between 0.57 and 0.69 cm3/g at atmospheric pressure, while at high pressure (1200 bar) it varies between 0.55 and 0.64 cm3/g. For the copolymers, the addition of HFP lowered its melting point, while the specific volume did not show a significant change. The TAIT state equation describing the dependence of specific volume on the zero‐pressure volume (V0,T), pressure, and temperature has been used to predict the specific volume of PVDF and PVDF–HFP copolymers. The experimental data was fitted with the state equation by varying the parameters in the equation. The use of the universal constant, C (0.0894), and as a variable did not affect the predictions significantly. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 230–241, 2001

Poly(vinylidene fluoride) (PVDF) experimental samples containing sparsely distributed chain branching were compared to commercial reference samples. The results showed a lower onset of shear thinning for the branched samples over the reference counterparts. The storage modulus of the branched samples at low frequency shows a significant increase for the low-molecular weight sample while the higher-molecular weight sample showed a moderate increase suggesting a strong contribution of chain branching. The branched PVDF samples exhibited a lower radius of gyration (R G ) and intrinsic viscosity than the commercial samples over the entire molecular weight range. NMR revealed the presence of tertiary carbons, suggesting that the branches are covalently bonded and not of a physical nature. Extensional viscosity data showed that the branched samples display a significant degree of strain hardening while the reference samples exhibit a small degree of strain hardening.