A New PvT Device for the Thermoplastics Characterization in Extreme Thermal Conditions

In this work, we present an apparatus associated to a methodology that is able to determine simultaneously and according to temperature (up to 400°C) the specific volume (up to 200MPa), the thermal conductivity and the temperature function of the crystallization kinetics. The PvT-XT is a home-built device that is able to impose and quantify 1D heat transfer through the radius of a sample. This apparatus controls the applied pressure on the sample while measuring its volume variations. The associated moving boundary model takes into account the temperature and crystallinity gradients. Specific volume is determined from direct measurement whereas inverse methods are used to estimate the thermal conductivity and the crystallization kinetics (with cooling rates up to 200K/min). Specific volume measurements are compared with literature results and exhibit a very good agreement. Thermal conductivity identified in the present paper is also very close to literatures values. Finally identification of kinetic function values is consistent with previous studies.