Preparation and characterization of a proton-exchange membrane by the radiation grafting of styrene onto polytetrafluoroethylene films

• Published in: Journal of applied polymer science 2006-02, Vol.99 (4), p.1415-1428
• Main Authors: Kang, Kai, Kang, Phil Hyun, Nho, Young Chang
• Format: Article
• Language: English
• Subjects: Applied sciences; Exact sciences and technology; Exchange resins and membranes; Forms of application and semi-finished materials; graft copolymers; irradiation; membranes; Polymer industry, paints, wood; polytetrafluoroethylene; radiation; Technology of polymers
• ISSN: 0021-8995; 1097-4628
• DOI: 10.1002/app.22628

Radiation‐induced simultaneous grafting of styrene onto polytetrafluoroethylene (PTFE) films and the subsequent sulfonation in the chlorosulfonic acid/dichloroethane were investigated. The effects of the main radiation grafting conditions, such as the type of solvents, irradiation dose, dose rate, the styrene concentrations, etc., on the degree of grafting (DOG) were studied. To elucidate the influence of both the grafting and sulfonation conditions on the properties of the PTFE‐g‐polystyrene‐sulfonic acid (PSSA) membranes, the sulfonation conditions, including the sulfonation temperature and the concentration of the ClSO3H with respect to the DOG, were systematically evaluated. The grafted and sulfonated membranes were characterized by FTIR–ATR spectra, ion‐exchange capacity (IEC), water uptake, thickness measurement, etc. The as‐prepared PTFE‐g‐PSSA membranes in this work showed a good combination of a high IEC (0.85–2.75 meq g−1), acceptable water uptake (8.86–56.9 wt %), low thickness, and volume expansion and/or contraction. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1415–1428, 2006