高强度和自修复PAA-co-PAM/Gelatin双物理网络水凝胶的制备及性能研究

Preparation and Performance Study of PAA-co-PAM/Gelatin Dual-Physical Network Hydrogels with High Strength and Self-Repairing Properties

针对传统的双网络(DN)水凝胶由于缺乏有效的动态交联机制,从而很难同时实现高强度和自愈合性能的问题。文中设计制备了具有双物理网络的水凝胶聚丙烯酸co丙烯酰胺/明胶(PAA-co-PAM/Gelatin),在所制备的凝胶中,聚丙烯酸co丙烯酰胺分子链以氢键交联作为第一网络,明胶通过分子链螺旋化交联作为第二网络。分别考察了不同丙烯酸丙烯酰胺浓度及明胶含量对DN凝胶的力学性能和自修复性能的影响。实验结果表明:当丙烯酸丙烯酰胺总浓度为5 mol·L-1,明胶的质量分数为30%时,制备的水凝胶性能最佳,其弹性模量可达361.8 kPa,断裂强度和断裂伸长率分别为605.3 kPa和835%,冲击强度和耗散能分别为4.26 MJ·m^-3和806.5 kJ·m^-3,自修复效率大于70%。所制备的PAA-co-PAM/Gelatin凝胶兼具良好的力学强度和自愈合性能,能够在4 h内快速修复表面划痕。

It is difficult for the traditional dual network(DN)hydrogel to have both high strength and self healing properties due to the lack of an effective dynamic cross linking mechanism.The polyacrylic acid co polyacrylamide/gelatin(PAA co PAM/Gelatin)hydrogel with dual physical networks were prepared.In the prepared hydrogel,the PAA co PAM molecular chain was cross linked by the hydrogen bond as the first cross linking network,and gelatin was cross linked by the molecular chain triple helixes as the second network.The effects of different polymer monomer concentrations and gelatin content on the mechanical properties and self healing properties of DN hydrogels were investigated.Experimental results show that when the concentration of the copolymer monomer was 5 mol·L-1 and the gelatin mass fraction was 30%,the prepared hydrogel performed the best.Its elastic modulus reached 361.8 kPa,its breaking strength and the breaking elongation were 605.3 kPa and 835%,respectively,and its impact strength and dissipation energy were 4.26 MJ·m^-3 and 806.5 kJ·m^-3,respectively,with its self healing efficiency greater than 70%.It is concluded that the prepared PAA co PAM/Gelatin gel has good mechanical strength and self healing property,and the surface cracks and scratches can be repaired within 4 hours.