Water sorption kinetics in Poly(aryl-ether-ether-ketone

The kinetics of diffusion of water from different activity vapors and liq. phase were investigated in glassy amorphous PEEK films at 60° and in glassy semicryst. PEEK sheets at different temps., resp. In the case of the amorphous PEEK films (250 mm thick), the data at low activity levels were interpreted via a purely Fickian mechanism. At higher activity levels, the material showed the presence of a relaxation process; in this case the data were interpreted using a model proposed by Berens and Hopfenberg. Equil. sorption isotherm is also reported. Liq. water sorption in semicryst. (30%) PEEK sheets (2 mm thick) followed the classical Fickian mechanism