In order to synthesize dynamic amphiphilic hydrogels, in the first step, dibenzaldehyde-terminated telechelic poly(ethylene glycol) (PEG-DA) was synthesized via simple one-pot method by using hexamethylene diisocyanate and para-hydroxybenzaldehyde. In the second step, 4-arm star-shaped polycaprolactone tetraaldehyde (4sPCL-TA) was synthesized in three steps. All of the synthesized prepolymers and functionalization reactions were characterized by 1 H-NMR and FT-IR spectroscopy. Finally, a series of new dynamic amphiphilic hydrogels were prepared through dynamic covalent Schiff-base linkages by simply mixing nontoxic chitosan, PEG-DA and 4sPCL-TA solutions. The chemical structure, morphology, thermal properties, gel degradation, mechanical performance, swelling behavior and self-healing capability of hydrogels were investigated. The obtained results showed that the hydrogels present suitable self-healing performance without any external stimulus. These properties of hydrogels can be attributed to covalent Schiff base linkages between the aldehyde and amine groups of prepolymers. Moreover, the hydrogels displayed pH-dependent degradation behavior. Swelling degree and degradation rate of hydrogels decreased with introducing of 4sPCL-TA in hydrogel networks. In addition, the thermal and mechanical properties of hydrogels were improved with incorporation of 4sPCL-TA into the network structure.

中文翻译：

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二苯甲醛封端聚乙二醇的一锅法合成用于制备动态壳聚糖基两亲水凝胶

为了合成动态两亲性水凝胶，第一步，使用六亚甲基二异氰酸酯和对羟基苯甲醛通过简单的一锅法合成了二苯甲醛封端的遥爪聚（乙二醇）（PEG-DA）。第二步，分三步合成四臂星形聚己内酯四醛（4sPCL-TA）。所有合成的预聚物和官能化反应均通过 1 H-NMR 和 FT-IR 光谱进行表征。最后，通过简单地混合无毒壳聚糖、PEG-DA 和 4sPCL-TA 溶液，通过动态共价席夫碱连接制备了一系列新的动态两亲性水凝胶。研究了水凝胶的化学结构、形貌、热性能、凝胶降解、机械性能、溶胀行为和自修复能力。所得结果表明，水凝胶在没有任何外部刺激的情况下表现出合适的自愈性能。水凝胶的这些特性可归因于预聚物的醛和胺基团之间的共价席夫碱键。此外，水凝胶显示出依赖于 pH 值的降解行为。随着4sPCL-TA在水凝胶网络中的引入，水凝胶的溶胀度和降解率降低。此外，通过将 4sPCL-TA 掺入网络结构中，水凝胶的热性能和机械性能得到改善。水凝胶显示出依赖于 pH 值的降解行为。随着4sPCL-TA在水凝胶网络中的引入，水凝胶的溶胀度和降解率降低。此外，通过将 4sPCL-TA 掺入网络结构中，水凝胶的热性能和机械性能得到改善。水凝胶显示出依赖于 pH 值的降解行为。随着4sPCL-TA在水凝胶网络中的引入，水凝胶的溶胀度和降解率降低。此外，通过将 4sPCL-TA 掺入网络结构中，水凝胶的热性能和机械性能得到改善。