Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma, Nara, 630-0192, Japan.
Macromol Rapid Commun. 2021 Jul;42(13):e2100128. doi: 10.1002/marc.202100128. Epub 2021 May 14.
Thermoresponsive degradable polyurethane (PU) hydrogels are expected as the next-generation biomedical devices, although they have an important trade-off relationship between toughness and thermoresponsive properties. Tough and thermoresponsive comb PU hydrogels are prepared by one-shot poly-addition between hexamethylene diisocyanate, triethylene glycol tartrate ester, poly(ethylene glycol) 300 (PEG300), and glycerol. The swelling ratio change between 4 and 40 °C decreases as the proportion of PEG300 increases and is maintained at 600% switching within 30% PEG300. Moreover, the one-shot preparation of comb PU hydrogel with PEG300 improves toughness up to 100 times compared to the original comb PU hydrogel. Rheological analysis suggests that the bimodal toughening phenomenon for the proportion of PEG300 is due to the network structure and the hydrophobic aggregation domain. This simple toughening method using a heteronetwork based on the kinetic difference of step-growth PU is expected to apply to other chemical structures.
温敏可降解聚氨酯（PU）水凝胶有望成为下一代生物医学设备，尽管它们的韧性和温敏性能之间存在着重要的权衡关系。通过己二异氰酸酯、三乙二醇酒石酸酯、聚乙二醇 300（PEG300）和甘油之间的一次加成聚合反应，制备了具有韧性和温敏性的梳状 PU 水凝胶。在 4 到 40°C 之间，随着 PEG300 比例的增加，水凝胶的溶胀比变化减小，在 30%PEG300 下可以保持 600%的切换。此外，与原始梳状 PU 水凝胶相比，使用 PEG300 的一次制备法可将梳状 PU 水凝胶的韧性提高 100 倍。流变分析表明，PEG300 比例的双模态增韧现象是由于网络结构和疏水性聚集域。这种基于逐步聚合 PU 的动力学差异的杂化网络的简单增韧方法有望应用于其他化学结构。
