Pressure–volume–temperature relationships for poly(vinylidene fluoride) and polyamide-11

Experimental specific volume data as a function of temperature (30–269°C) and pressure (0–2000 bar) are presented for two semicrystalline polymers, namely, poly(vinylidene fluoride) and polyamide-11. Data for the melt state were used to determine the characteristic parameters for six theoretical equations of state as well as the empirical Tait equation. The theories employed were the cell models of Flory–Orwoll–Vrij, of Prigogine et al., and of Dee and Walsh, the latticefluid theory of Sanchez and Lacombe, the hole theory of Simha and Somcynsky, and the semiempirical model of Hartmann and Haque. Solid-state data were also fit using the Hartmann–Haque and Tait equations. © 1993 John Wiley & Sons, Inc.