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The effect of stress (hydrostatic compression) on the free volume of poly(chlorotrifluoroethylene) has been investigated using the position annihilation lifetime (PAL) technique in the pressure range of 0-14 kbar at room temperature. The variation of the annihilation parameters indicates that the free volume compression occurs at a higher pressure (>8 kbar) compared to molecular compression (4...
Positron lifetimes and X-ray diffraction measurements were carried out on poly(chlorotrifluoroethylene) films annealed between 25 and 215°C. The positron lifetime results were used to determine the free volume and XRD data were used to determine the apparent crystallite size and crystallinity. The glass transition temperature (T g ) of 52°C obtained from positron results is in agreement...
Abstract.Positron Annihilation Lifetime Spectroscopy (PALS) is used to probe the micro-structural changes in the polymer polycarbonate in terms of the changes in free volume hole size and their content as a function of temperature. The measured spectra are best fitted to three lifetime component analysis. The average hole size in the amorphous regions is determined from the measured Ortho Positronium...
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