A newly designed experiment for high-pressure solidification of transparent materials

Abstract : The growth kinetics of a polymer spherulite is function of temperature and pressure. While the link with temperature is well understood, little comprehensive study has been conducted to quantify the effect of pressure. This is yet required for polymer processing. An original experiment has been constructed for pressure and temperature controls up to 200 MPa and 300°C, respectively. The cell design takes advantage from the optical properties of the semi-crystalline spherulites to conduct in-situ real time light depolarizing microscopic observations. Preliminary analyses of isothermal isobaric holding of a model polymer shows the influence of temperature and pressure on nucleation and growth kinetics of spherulites, as well as on the crystallization morphology. Simple modeling dealing with the Avrami equation and the Hoffman and Lauritzen theory is introduced.