Foaming of poly(vinylidene fluoride-co-hexafluoropropylene) using supercritical carbon dioxide

Abstract

Abstract This work studied the foaming behavior of poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) in supercritical carbon dioxide (scCO 2 ). The effects of foaming temperature, foaming pressure, saturation time, depressurization time on the foam structure and crystallinity of samples were investigated. The foaming ability varies with different combinations of the foaming temperature and foaming pressure. However, a lower foaming temperature and a higher foaming pressure are more favorable for obtaining uniform foam than a higher foaming temperature and a lower foaming pressure. At a given foaming temperature and saturation time, increasing the foaming pressure leads to the decreased crystallinity and an increase in the melting temperature.