Price, Duncan M.; Bashir, Zahir; A study of the porosity of water-plasticised polyacrylonitrile films by thermal analysis and microscopy. Thermochimica Acta 249 (1995) 351-366
The thermal behaviour of the water-plasticised polyacrylonitrile (PAN) at sub-ambient temperatures was examined. When the film was cooled below room temperature, 2 distinct exothermic peaks were observed at -17° and -38°C due to the formation of ice. By analysing the data in terms of thermoporometry, which has been more widely used to study the freezing of condensates in porous ceramic materials, it was concluded that the water-plasticised films had a micro-porous morphology The DSC results suggested a bimodal distribution of pore sizes, but SEM revealed a third category of pores with larger size. These large pores were not detected by calorimetry because they were not fully filled with water.