How to achieve the toughening of hydrogels has always been a problem that researchers are committed to solving. Recently, many strategies have been proposed to improve the toughness of hydrogels. However, most of them involve complicated processes, which severely restrict the practical application of hydrogels. Herein, we provide a straightforward method to toughen polyacrylamide (PAM) hydrogels via a degenerative chain transfer effect of allylamine (XBA). The produced hydrogels crosslinked by a traditional crosslinker N,N-methylenebisacrylamide (MBA) possess a relatively uniform network with the existence of entangled pendant chains. The homogeneous network distributes stress evenly, while the disentanglement of the entangled pendant chains dissipates energy and the chemical crosslinks maintain elasticity. As a result, the breaking strain and toughness of the hydrogels can reach 1370% and 1.41 MJ/m³, which are 1.9 and 1.6 folds higher than those of pure PAM hydrogels, respectively. More importantly, the toughening mechanism based on the degenerative chain transfer effect is generalizable to other allyl monomers and other hydrogel systems. Overall, this research offers a facile strategy for designing tough hydrogels and may pave the way for their practical application in industrialized production.

如何实现水凝胶的增韧一直是研究人员致力于解决的问题。最近，已经提出了许多策略来提高水凝胶的韧性。然而，它们大多涉及复杂的工艺，严重限制了水凝胶的实际应用。在此，我们提供了一种通过烯丙胺 (XBA) 的退化链转移效应增韧聚丙烯酰胺 (PAM) 水凝胶的直接方法。生成的水凝胶通过传统交联剂N , N交联-亚甲基双丙烯酰胺 (MBA) 具有相对均匀的网络，并存在缠结的悬链。均质网络均匀分布应力，而缠结悬链的解缠结耗散能量，化学交联保持弹性。结果，水凝胶的断裂应变和韧性可以达到1370%和1.41 MJ/m ³，分别比纯PAM水凝胶高1.9和1.6倍。更重要的是，基于简并链转移效应的增韧机制可推广到其他烯丙基单体和其他水凝胶系统。总的来说，这项研究为设计坚韧的水凝胶提供了一种简便的策略，并可能为其在工业化生产中的实际应用铺平道路。