Journal of Polymer Science Part B: Polymer Physics, Vol.41, No.23, 3089-3093, 2003
The size and number of local free volumes in polypropylenes: A positron lifetime and PVT study
The temperature dependence of the mean size of local free volumes in an amorphous atactic (aPP) and a semicrystalline syndiotactic polypropylene (sPP), and an amorphous ethylene-propylene copolymer (E-co-P48) has been studied. Pressure-volume-temperature (PVT) experiments were performed for aPP, from which the hole fraction h of the Simha-Someynsky theory and the number density of holes were estimated. (C) 2003 Wiley Periodicals, Inc.