Radiation grafting of styrene and maleic anhydride onto PTFE membranes and sequent sulfonation for applications of vanadium redox battery

• Published in: Radiation physics and chemistry (Oxford, England : 1993) Vol. 76; no. 11; pp. 1703 - 1707
• Main Authors: Qiu, Jingyi, Ni, Jiangfeng, Zhai, Maolin, Peng, Jing, Zhou, Henghui, Li, Jiuqiang, Wei, Genshuan
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.11.2007
• Subjects: Maleic anhydride; Poly(tetrafluoroethylene) (PTFE); Radiation grafting; Styrene; Poly(tetrafluoroethylene) (PTFE); Radiation grafting; Styrene; Maleic anhydride
• ISSN: 0969-806X; 1879-0895
• DOI: 10.1016/j.radphyschem.2007.01.012

Using γ-radiation technique, poly(tetrafluoroethylene) (PTFE) membrane was grafted with styrene (St) (PTFE- graft-PS) or binary monomers of St and maleic anhydride (MAn) (PTFE- graft-PS- co-PMAn), respectively. Then grafted membranes were further sulfonated with chlorosulfonic acid into ion-exchange membranes (denoted as PTFE- graft-PSSA and PTFE- graft-PSSA- co-PMAc, respectively) for application of vanadium redox battery (VRB). Micro-FTIR analysis indicated that PTFE was successfully grafted and sulfonated at the above two different conditions. However, a higher degree of grafting (DOG) was obtained in St/MAn binary system at the same dose due to a synergistic effect. Comparing with PTFE- graft-PSSA, PTFE- graft-PSSA- co-PMAc membrane showed higher water uptake and ion-exchange capacity (IEC) and lower area resistance (AR) at the same DOG. In addition, PTFE- graft-PSSA- co-PMAc with 6% DOG also showed a higher IEC and higher conductivity compared to Nafion membrane. Radiation grafting of PTFE in St/MAn binary system and sequent sulfonation is an appropriate method for preparing ion-exchange membrane of VRB.