Pressure–volume–temperature relationships of solid and molten polypropylene and poly(butene-1)

Experimental data on the dependence of the specific volume on temperature and pressure (PVT data) to 2000 kg/cm2 of isotactic polypropylene and isotactic poly(butene-1) are reported and discussed. The temperature range covered is 30–297°C for polypropylene and 30–246°C for poly(butene-1), thus encompassing the solid and molten states of both materials. An empirical equation of state based on the Tait equation can be fitted to the melt data of both materials. The coefficients reported reproduce the measured specific volumes with a standard deviation of less than 0.001 cm3/g.