Semi-interpenetrating polymer network (sIPN) proton exchange membranes are prepared from sulfonated polyimides (SPIs) and cross-linkable sulfonated poly(arylene ether)s (SPAEs) with 3,3′-diaminobenzidine (DAB) as cross-linker. The cyclocondensation between DAB and benzyl moiety in SPAEs results in a covalently cross-linked SPAE networks where SPIs can be immobilized by interlocking; meanwhile, the interlocked structure is also strengthened by acid–base ionic interactions between the sulfonic acid groups of sulfonated polymers (SPAEs and SPIs) and quinoxaline moieties formed in cross-linking. For comparison, the corresponding SPAE/SPI blend membranes are also prepared and evaluated. The proton conductivity, dimensional changes, mechanical properties, oxidative stability, water stability as well as methanol permeability are investigated for the membranes. The results show that the sIPN membranes have obviously higher performance than the pristine SPAE, SPI and SPAE/SPI blend membranes due to the interlocked structures. The sIPN membrane sIPN-SPAEK(2/1)-SPI with ion exchange capacity of 2.00 mequiv g−1 shows good mechanical properties, high stability, reasonably high proton conductivity of 128 mS cm−1 and low methanol permeability of 0.58 × 10–6 cm2 s−1.

中文翻译：

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作为质子交换膜的磺化聚（亚芳基醚）和磺化聚酰亚胺的喹喔啉基半互穿聚合物网络

半互穿聚合物网络 (sIPN) 质子交换膜由磺化聚酰亚胺 (SPI) 和可交联的磺化聚亚芳基醚 (SPAE) 和 3,3'-二氨基联苯胺 (DAB) 作为交联剂制备。DAB 和 SPAE 中的苄基部分之间的环缩合产生共价交联的 SPAE 网络，其中 SPI 可以通过互锁固定；同时，互锁结构也通过磺化聚合物（SPAEs 和 SPIs）的磺酸基团与交联中形成的喹喔啉部分之间的酸碱离子相互作用而得到加强。为了比较，还制备和评估了相应的 SPAE/SPI 混合膜。质子电导率、尺寸变化、机械性能、氧化稳定性、研究了膜的水稳定性和甲醇渗透性。结果表明，由于互锁结构，sIPN 膜的性能明显高于原始的 SPAE、SPI 和 SPAE/SPI 混合膜。sIPN 膜 sIPN-SPAEK(2/1)-SPI 的离子交换容量为 2.00 mequiv g−1，显示出良好的机械性能、高稳定性、128 mS cm−1 的合理高质子传导率和 0.58 × 10– 的低甲醇渗透率6 cm2 s−1。