分子支架对聚丙烯酰胺双网络水凝胶的性能调控

Properties of Double Network Polyacrylamide Hydrogel by Introducing Molecular Stent

通过向中性水凝胶聚丙烯酰胺(PAAm)中引入聚电解质聚2-丙烯酰胺-2-甲基丙磺酸(PAMPS)的方法,制备了双交联网络(双网络)聚丙烯酰胺/聚2-丙烯酰胺-2-甲基丙磺酸分子支架/聚丙烯酰胺(PAAm/St-PAMPS/PAAm)水凝胶。测试了其溶胀性能,并采用拉伸-回缩滞后实验对水凝胶的力学性能与破坏原理进行了研究。结果表明:带聚电解质的PAAm/St-PAMPS/PAAm和PAAm/PAAm/St-PAMPS双网络水凝胶的体积比溶胀度都显著高于PAAm/PAAm双网络水凝胶。由拉伸-回缩滞后实验发现,PAAm/PAAm与PAAm/PAAm/St-PAMPS双网络水凝胶两层网络均匀受力直至完全破坏;而PAAm/St-PAMPS/PAAm双网络水凝胶在拉伸过程中第一层网络先破坏并耗散了能量,达到大应变后第二层网络才逐渐破坏,因此该水凝胶具有更大的断裂伸长率与拉伸强度。

Poly（acrylamide）/poly（2-acrylamide-2-methylpropane-sulfonie acid） as molecular stent/poly（acrylamide）（PAAm/St-PAMPS/PAAm） was synthesized using the method of polyelectrolyte as molecular stent in neutral hydrogel in the study. The swelling properties, mechanical properties and fracture mechanism via a cyclic tensile measurements methods were investigated. Results show that the swelling degrees of PAAm/St-PAMPS/PAAm and PAAm/PAAm/St-PAMPS hydrogel are higher than that of the PAAm/PAAm hydrogel. During the cyclic tensile test, the deformation of the double network in PAAm/PAAm/St-PAMPS and PAAm/PAAm hydrogel is homogeneously until sample is totally destroyed. But the first network of PAAm/St-PAMPS/PAAm hydrogel was broken first, which energy is dissipated, then, with an increase of strain, the second network is gradually broken. Meanwhile, PAAm/St-PAMPS/PAAm hydrogel has high failure strain and failure stress.