Preparation of hydrophilic membranes by grafting acrylic acid onto pre‐irradiated teflon‐FEP films

Grafting of acrylic acid onto pre‐irradiated poly(tetrafluoroethylene‐hexafluoropropylene) (Teflon‐FEP) films was investigated, and the reaction parameters dose, dose rate, monomer concentration and grafting temperature were examined. The results show that the degree of grafting depends on the dose (5‐60 kGy), the weight of grafted specimen increased up to 37%. The degree of grafting was found to be independent of the dose rate. The overall activation energies were calculated to be 28.8 and 81.6 kJ mol‐1 for treatments at above and below 50°C, respectively. The swelling of grafted films was measured in water, aqueous potassium hydroxide and methanol. The degree of swelling was found to increase with the length of grafted chains.