کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1517663 | 1511608 | 2008 | 6 صفحه PDF | دانلود رایگان |
The structure parameter x, defining the temperature and structure relative contribution to the relaxation times, was evaluated applying the peak-shift method (PSM) onto volumetric heating data of poly(ethylene terephthalate) (PET) with content of crystallinity 2.6 wt%. The method of mercury-in-glass (MIG) dilatometry and three-step thermal cycle procedure were used. Two sets of heating scans were measured as a function of the amount of volume isothermal relaxation for two different relaxation temperatures below Tg (60 and 52 °C), whereas other experimental variables were kept constant. The experimentally determined heating isobar inflection temperature is a linear function of the amount of volume relaxation, which satisfies the application of PSM method for structure parameter x determination from volumetric heating data. The value of structure parameter of the used PET is independent of relaxation temperature and equal to 0.50±0.02. Finally, the shift of heating isobar inflection temperature with relaxation temperature (60, 56, 52 and 48 °C) measured for constant amount of volume isothermal relaxation was found to be linear, with the slope of 0.13.
Journal: Journal of Physics and Chemistry of Solids - Volume 69, Issue 4, April 2008, Pages 975–980