Abstract

Binary copolymers possessing thermal stability up to 290°C and suitable for the formation of ion-exchange membranes have been obtained by free radical copolymerization of sodium p-styrene sulfonate and 1-vinylimidazole with subsequent conversion to the H-form. The composition and structure of the copolymers are confirmed by elemental analysis and IR and NMR spectroscopy. Multicomponent membranes based on the copolymers of sodium p-styrene sulfonate and 1-vinylimidazole have been obtained using poly(vinyl alcohol) crosslinked by oxalic acid as a film-forming agent. It is shown by scanning electron microscopy that the surface and cut of the membranes have a uniform structure. The specific electric conductivity of the membranes with different concentrations of styrene sulfonic acid (20 to 80 mol % in the copolymer) increases with an increase in the fraction of styrene sulfonic acid and is 29.5 to 52.0 mS cm⁻¹ at 80°C. The activation energy of proton transport of the membranes is 12.5 to 15.5 kJ mol⁻¹. The water uptake of the membranes decreases with the increase in the concentration of the basic (imidazole) component in them, which may be associated with the increase in the density of ionic crosslinking due to the acid–base interaction of the sulfo groups and pyridine nitrogen atoms of the imidazole cycle. The formation of acid–base pairs results in the formation of continuous proton transport channels in addition to the sulfonic acid channels, which is confirmed by the high values of specific electric conductivity even in the case of a decrease in the concentration of sulfostyrene in the composition of the membrane. Increasing the concentration of 1‑vinylimidazole in the composition of the copolymer from 20 to 80 mol % leads to an increase in the relative elongation at break from 3 to 6%, an increase in the tensile strength at break from 4 to 7 MPa, a decrease in the Young modulus of the membranes from 127 to 102 MPa, and a decrease in the water uptake from 45 to 15.

中文翻译：

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对酸磺酸质膜交换膜的对苯乙烯磺酸钠-1-维尼咪唑共聚物

摘要

通过对-苯乙烯磺酸钠和1-乙烯基咪唑的自由基共聚并随后转化为H-型，已经获得了具有高达290℃的热稳定性并且适合于形成离子交换膜的二元共聚物。共聚物的组成和结构通过元素分析以及IR和NMR光谱确认。基于钠p共聚物的多组分膜使用由草酸交联的聚乙烯醇作为成膜剂，可以得到-苯乙烯磺酸盐和1-乙烯基咪唑。扫描电子显微镜显示膜的表面和切口具有均匀的结构。具有不同浓度的苯乙烯磺酸（在共聚物中为20至80摩尔％）的膜的比电导率随苯乙烯磺酸的分数的增加而增加，并且在80℃下为29.5至52.0mS cm ^-1。膜的质子传输的活化能为12.5至15.5 kJ mol ^-1。膜中的水分吸收随着碱性（咪唑）组分浓度的增加而降低，这可能是由于磺基与吡啶氮的酸碱相互作用而导致离子交联密度增加的原因。咪唑循环的原子。除磺酸通道外，酸碱对的形成还导致了连续的质子传输通道的形成，即使在组合物中磺基苯乙烯浓度降低的情况下，高比电导率值也证实了这一点。膜的 将共聚物组合物中1-乙烯基咪唑的浓度从20 mol％增加到80 mol％，会使相对断裂伸长率从3％增加到6％，