全物理交联三重互穿网络水凝胶的制备与性能

Preparation and Properties of Fully Physically Cross-Linked Triple Network Hydrogels

为提升水凝胶的综合力学力学性能,设计并研究了一种全物理交联三重互穿网络水凝胶。以自由基乳液聚合法,获得疏水缔合交联的聚丙烯酰胺网络,水凝胶一步成型,依次通过冷冻-融化循环、浸没FeCl_(3)溶液分别形成微晶交联的聚乙烯醇网络及离子交联的海藻酸钠网络。获得P(AM-SMA)/PVA/SA三重互穿网络(HMITN)水凝胶。通过傅里叶变换红外对水凝胶结构进行了表征;通过电子万能试验机对水凝胶的力学性能进行了研究。结果表明,HMITN水凝胶具有良好的强度、韧性、抗疲劳及自恢复性能,强度0.45 MPa,断裂能2.48 MJ/m^(3),在200%应变下进行5次循环拉伸后仍然保持20.3%的韧性,室温下自恢复260 min后,韧性可恢复66.7%。

In order to improve the comprehensive mechanical properties of hydrogels,a fully physically crosslinked triple interpenetrating network hydrogel was designed and studied.One-step free-radical emulsion polymerization method was used to obtain hydrophobically-associated polyacrylamide networks.Freeze-thaw cycles and immersion in FeCl_(3)solution was conducted successively to form microcrystalline crosslinked polyvinyl alcohol networks and ionic crosslinked sodium alginate networks,respectively.P(AM-SMA)/PVA/SA triple interpenetrating network(HMITN)hydrogels were obtained.The structure of the hydrogels was characterized by Fourier transform infrared(FT-IR).The mechanical properties of the hydrogels were studied by electronic universal testing machine.The results show that HMITN hydrogels have excellent strength,toughness,fatigue resistance and self-recovery performance,the stress and fracture energy can reach 0.45 MPa and 2.48 MJ/m^(3),respectively.After 5 cycles of stretching at 200%strain,the dissipated energy of the hydrogel can maintain 20.3%with respect to the first cycle.The hydrogel could recover to 66.7%of its initial toughness after resting for 260 min.