PU弹性网络对PAM凝胶吸水/脱水行为的影响

Effects of elastic polyurethane network on swelling/deswelling behaviors of polyacrylamide hydrogels

为改善聚丙烯酰胺凝胶(PAM)在吸水/脱水过程中对环境变化的响应性,制备了多孔聚氨酯弹性体(PU)与PAM的互穿网络结构(IPN),测试其在吸水/脱水过程中的质量和体积变化,并与PAM凝胶的响应行为进行比较,研究PU网络的回弹作用对PAM凝胶吸水/脱水行为的影响.分析表明,吸水过程中PU网络的作用主要表现为后期对溶胀网络的束缚;而在脱水过程中,其回弹行为对溶胀PAM凝胶的初期体积收缩具有明显的加速作用.这种PU/PAMIPN结构可以提高PAM作为传感/驱动器件的环境响应性.

Interpenetrating polymer network (IPN) hydrogels composed of polyacrylamide(PAM) and polyurethane (PU) were synthesized in order to improve the responsive rate of PAM hydrogels.The changes of mass and volume of PU/PAM IPN hydrogels were measured in the process of absorbing-water/air-drying.By comparing the swelling/deswelling behaviors between PU/PAM IPN and PAM hydrogels,the effects of elastic PU network on responsive rate of PAM hydrogels were investigated.In the absorbing-water process,the PU network hindered the further expansion of swollen network rather than increase the swelling rate of PAM hydrogel obviously;whereas,in the initial stage of air-drying process the elastic network of PU could accelerate the deswelling process on a large scale due to the elastic recovery of PU network extended.Owing to the rapid response to the change of water content,the PU/PAM IPN hydrogels have large potentialities to be utilized as sensor and actuator in smart material systems.