Proton exchange membranes by radiation grafting of styrene onto fep films. III. Structural investigation
Tóm tắt
Structural investigation on proton‐exchange membranes, obtained by the radiation grafting of styrene onto FEP films and subsequent sulfonation, was carried out by differential scanning calorimetry. The membrane crystallinity was found to show a decreasing trend with increasing degree of grafting. The melting temperature of all the membranes also showed a slight decrease as compared to the ungrafted FEP. The results have been explained in terms of the cumulative effect of the decrease in the crystalline/amorphous ratio by the incorporation of amorphous polystyrene grafts and of disruption of spherulitic crystallites of the FEP component in the membranes. The glass transition temperature of the membranes with different water contents was also evaluated. A correlation of the glass transition temperature with the residual water in dried membranes was established. © 1994 John Wiley & Sons, Inc.
Từ khóa
Tài liệu tham khảo
Scherer G. G., 1989, J. Electrochem. Soc., 135, 307
Büchi F. N., 1992, Proc. IECEC, 3, 3.419
Bozzi A., 1988, Radiat, Phys. Chem., 32, 193
Gupta B., Polym. Adv. Technol.
B.Gupta G. G.Scherer andA.Chapiro unpublished results.
Gupta B., J. Appl. Polym. Sci.