环氧/酸酐体系网络结构对形状记忆性能的影响

Shape Memory Properties of Epoxy/Anhydride Systems with Different Network Structures

以环氧/酸酐(双酚A型缩水甘油醚/甲基纳迪克酸酐,DGEBA/MNA)类形状记忆复合材料基体为研究对象,探讨了无定形树脂基体的网络结构与其形状记忆性能之间的关系。以2,4,6-三(二甲胺基甲基)苯酚(DMP-30)和异辛酸锌作为DGEBA/MNA体系的促进剂,调节基体配方获得具有不同网络结构的环氧体系。通过对固化物皂化前后的胶化量测定确定了三种网络结构,即酯网络、醚网络和酯-醚混合网络,并采用动态热机械分析(DMA)测量各体系的动态热力学性能。以形状回复率、形状回复时间和形状回复力为指标,对三种不同网络结构树脂基碳纤维复合材料进行形状记忆折叠-展开测试。结果表明,三种网络结构均具有较高的形状回复率,且反复的热力学循环对三种网络结构形状回复率的影响均很小;酯网络结构、醚网络结构和酯-醚混合网络结构的形状回复时间依次延长,而形状回复力逐渐降低。同时,在较低的回复程度下,三种网络结构的形状回复力均随折叠-展开次数的增加而下降,而随回复程度的增加,回复力的下降幅度逐渐降低。

To explore the relationship between network structures and shape memory properties of amorphous matrix resin,epoxy/anhydride(bisphenol A diglycidyl ether/methyl Nadie anhydride,DGEBA/MNA)matrix systems of shape memory composites were studied.The tris(dimethy-laminomethyl)phenol(DMP-30)and zinc octoate were used as accelerators of DGEBA/MNA system to acquire different network structures by adjusting the matrix formula.Three kinds of network structures of cured samples,namely ester network,ether network and ester-ether mixed network,were determined by gel measurement before and after saponification.The dynamic thermomechanical properties of each system were tes-ted by dynamic mechanical analysis(DMA).Shape recovery ratio,shape recovery time and shape recovery force were used as indexes to cha-racterize the shape memory properties of the corresponding carbon fiber reinforced composites.The results show that the three kinds of network structures all have high shape recovery ratio,and the repeated thermodynamic cycle has little effect on shape recovery ratio of the three network structures;the shape recovery time of ester network,ether network and ester-ether mixed network increases in turn,while the shape recovery force decreases gradually.At the same time,at a lower recovery degree,the shape recovery force of the three kinds of network structures decreases with the increase of the fold-deploy times,while with the increase of recovery degree,the decline amplitude of the recovery force decreases gradually.