1. PvT measurement difficulties

In a PvT measurement, the variation in a material's specific volume is determined as a function of pressure and temperature. The density of a polymer undergoes significant changes during variations in temperature (thermal expansion) and pressure (compression), which can lead to phase changes and degradation reactions.

Conversely, PvT measurements can be used to study these transitions or to provide derived data (compressibility, modulus of compression, thermal expansion, phase transition kinetics, etc.), of vital importance for many industrial applications. PvT measurements are one of the only thermoanalytical techniques available that include pressure as a variable.

One of the main difficulties encountered in polymer PvT measurements is due to the fact that the volume of a polymer, in general, depends not only on temperature and pressure...