Abstract Functional hydrogels have been used in various fields, but their development might be limited due to the finite variety of crosslinking agents, complicated functional monomer design and synthesis. To address these issues, a new series of polyamino acid-based multifunctional coupling agents, polyaspartic hydrazide-co-aspartic acid polymers (PHAs), were synthesized through a very simple ring-opening reaction in a short time. The structures of these polymers with gradient content of acylhydrazine and carboxyl groups were characterized through 1H NMR and FT-IR. The molecular weight of PHAs and the content of acylhydrazine and carboxyl groups were tested through GPC and colloidal titration method, respectively. By crosslinking between acylhydrazine groups of PHA crosslinkers and carbonyl of diacetone acrylamide (DAAM), DAPHA hydrogels with different PHA structures and contents were prepared from acrylamide (AAM), DAAM and PHA crosslinkers in a one-step reaction. Furthermore, through coordination between pendant carboxyl of PHAs and metal cations, DAPHA-Fe3+ hydrogels were prepared by soaking DAPHA hydrogels in ferric chloride solution. And the structures and mechanical properties of both DAPHA and DAPHA-Fe3+ hydrogels were investigated. Moreover, taking advantage of the complexation and dissociation of DAPHA hydrogel with Fe3+, their shape memory properties were investigated. Finally, magnetic DAPHA-Fe3O4 hydrogels were prepared through in-situ precipitation method, and their magnetism has been studied.

中文翻译：

---

新型高分子交联剂及其功能水凝胶的研究

摘要 功能水凝胶已被应用于各个领域，但由于交联剂种类有限、功能单体设计和合成复杂，其发展可能受到限制。为了解决这些问题，通过非常简单的开环反应在短时间内合成了一系列新的基于聚氨基酸的多功能偶联剂，即聚天冬氨酸酰肼-共聚天冬氨酸聚合物 (PHA)。这些具有酰基肼和羧基梯度含量的聚合物的结构通过1H NMR和FT-IR表征。分别通过GPC和胶体滴定法测定PHA的分子量和酰肼和羧基的含量。通过PHA交联剂的酰基肼基团与双丙酮丙烯酰胺（DAAM）的羰基之间的交联，由丙烯酰胺 (AAM)、DAAM 和 PHA 交联剂通过一步反应制备了具有不同 PHA 结构和含量的 DAPHA 水凝胶。此外，通过PHA的侧羧基与金属阳离子之间的配位，将DAPHA水凝胶浸泡在氯化铁溶液中制备了DAPHA-Fe3+水凝胶。并研究了 DAPHA 和 DAPHA-Fe3+ 水凝胶的结构和力学性能。此外，利用 DAPHA 水凝胶与 Fe3+ 的络合和解离，研究了它们的形状记忆特性。最后，通过原位沉淀法制备了磁性DAPHA-Fe3O4水凝胶，并对其磁性进行了研究。通过PHA的侧羧基与金属阳离子之间的配位，将DAPHA水凝胶浸泡在氯化铁溶液中制备了DAPHA-Fe3+水凝胶。并研究了 DAPHA 和 DAPHA-Fe3+ 水凝胶的结构和力学性能。此外，利用 DAPHA 水凝胶与 Fe3+ 的络合和解离，研究了它们的形状记忆特性。最后，通过原位沉淀法制备了磁性DAPHA-Fe3O4水凝胶，并对其磁性进行了研究。通过PHA的侧羧基与金属阳离子的配位，将DAPHA水凝胶浸泡在氯化铁溶液中制备了DAPHA-Fe3+水凝胶。并研究了 DAPHA 和 DAPHA-Fe3+ 水凝胶的结构和力学性能。此外，利用 DAPHA 水凝胶与 Fe3+ 的络合和解离，研究了它们的形状记忆特性。最后，通过原位沉淀法制备了磁性DAPHA-Fe3O4水凝胶，并对其磁性进行了研究。利用 DAPHA 水凝胶与 Fe3+ 的络合和解离，研究了它们的形状记忆特性。最后，通过原位沉淀法制备了磁性DAPHA-Fe3O4水凝胶，并对其磁性进行了研究。利用 DAPHA 水凝胶与 Fe3+ 的络合和解离，研究了它们的形状记忆特性。最后，通过原位沉淀法制备了磁性DAPHA-Fe3O4水凝胶，并对其磁性进行了研究。