کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
635540 1456100 2011 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Hydrolytic degradation of sulfonated polyimide membranes for fuel cells
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی تصفیه و جداسازی
پیش نمایش صفحه اول مقاله
Hydrolytic degradation of sulfonated polyimide membranes for fuel cells
چکیده انگلیسی

The hydrolytic degradation mechanism of sulfonated polyimide (sPI) membranes was determined through the study of model compounds and validated with a fully sulfonated polymer. Two model compounds characteristic of the ionic sequence and of the junction between ionic and neutral sequences in block copolymers were synthesized and aged in water at different temperatures. Liquid chromatography was used to separate and identify the degradation products by means of various spectroscopies (IR, UV, NMR). It is shown that the hydrolysis of the naphthalenic imide rings is an equilibrated reaction and that the imide rings are more stable when located between ionic substituted monomer than in the hydrophilic–hydrophobic junctions. It is concluded that block copolymers with long ionic sequences or blends of sulfonated and non sulfonated homopolymers should be more stable than random copolymers. This conclusion is confirmed by the study of the hydrolytic degradation of fully sulfonated polyimide.

Figure optionsDownload high-quality image (99 K)Download as PowerPoint slideHighlights
► Hydrolytic study of sulfonated polyimide membranes via model compounds.
► Hydrolytic degradation is mainly due to imide ring opening.
► Identified degradation products is an evidence of an equilibrated reaction.
► Quantitative 13C NMR data confirm formation of anhydrides as degradation products.
► Good correlation between model compounds and polymer degradation.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Membrane Science - Volume 379, Issues 1–2, 1 September 2011, Pages 207–214
نویسندگان
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