Polymer Bulletin, Vol.49, No.2-3, 159-164, 2002
Effect of pressure on the PVT behaviour of iPP as revealed by dilatometric measurements
Isotactic Poly-propylene samples, previously prepared under known conditions of pressure and cooling rate by means of a special apparatus designed and setup by the authors, were subjected to several isobaric runs at low cooling and heating rate in a confining fluid dilatometer.(by GNOMIX). The effect of the previous thermo-mechanical histories and the effect of pressure in the dilatometry on specific volume of the samples was studied. Results show that the initial specific volume depends upon the previous thermo-mechanical histories, which however cancels out after the first heating run. Moreover the reported dilatometric experimental data support the evidence that an increase of pressure at a constant cooling rate acts as an increase of cooling rate at a constant pressure.