采用胶束共聚法将丙烯酸(AA)与少量甲基丙晞酸十八酯(OMA)共聚,制备具有自修复功能的聚丙晞酸(PAA)水凝肢.采用红外光谱表征PAA水凝胶的结构,采用拉力实验表征PAA水凝胶的自修复功能和测试其拉伸强度,并分别研究PAA水凝胶在水中和氯化钠溶液中的溶胀行为.结果表明,PAA具有良好的自修复性能,修复后PAA水凝胶能保持修复前80K以上的拉伸强度,并且修复后的水凝胶断裂伸长率接近于修复前的水凝胶9PAA水凝胶的自修复功能归功于羧基间形成的氢键网络和OMA与表面活性剂形成的疏水缔合网络的联合作用.PAA水凝胶在水中的溶胀主要受水分子在凝胶中渗透扩散过程控制,而在氯化钠溶液中的溶胀主要受聚合物链段的松他过程影响.
The self-healable polyacrylic acid(PAA)hydrogels were prepared by micellar copolymerization of acrylic acid(AA)with a small amount of octadecyl methyl acrylate(OMA)in sodium dodecyl benzene sulfonate(SDBS)solution.Infrared spectrum was used to characterize the structure of PAA hydrogels.The tensile experiments were used to characterize the self-healing function and determine the tensile strength of PAA hydrogels.The swelling behavior of PAA hydrogels in water and sodium chloride solution was also investigated.Results show that PAA hydrogels had excellent self-healing performances.The self-healed PAA hydrogels could maintain the tensile strength higher than 80%.The elongation at break of self-healed PAA hydrogels approached that of untouched PAA hydrogels.The self-healing functions were attributed to the cooperation of network formed by the hydrogen bonding of carboxyl groups with network formed by the hydrophobic association of OMA and surfactant.The swelling of PAA hydrogels in water was dominated by the permeation and diffusion of water into the hydrogels.The swelling of PAA hydrogels in sodium chloride was dominated by the relaxation of chain segment of polymers.