DMA法评价微胶囊-环氧树脂复合材料自修复率  

Measurement on self-healing efficiency for UF microcapsules-epoxy composites by DMA method

作　　者：倪卓[1] 黄健成[1] 贵大勇[1] 

机构地区：[1]深圳大学化学与环境工程学院,深圳518060

出　　处：《深圳大学学报（理工版）》2015年第5期458-464,共7页Journal of Shenzhen University(Science and Engineering)

基　　金：国家自然科学基金资助项目(51378315);深圳市科学技术研究与发展基金资助项目(JCYJ20130329114709152)~~

摘　　要：以脲醛树脂(urea-formaldehydem,UF)为囊壁,正丁基缩水甘油醚改性环氧树脂的修复剂为囊芯,采用原位聚合法合成了UF自修复微胶囊,并以4',4'-二氨基二苯基甲烷(4',4'-diaminodiphenylmethane,DDM)作为微胶囊固化剂一起埋植到环氧树脂基体中,制成微胶囊-环氧树脂自修复材料.该微胶囊的囊芯质量分数为71.02%,平均粒径和囊壁厚度分别是105和3μm,囊壁表面粗糙而致密,与基体的界面结合较好,微胶囊在环氧树脂中分布均匀.UF微胶囊-环氧树脂复合材料经过恒应变损伤后产生裂纹,并在材料内部破裂,导致改性的环氧树脂修复剂从破裂的微胶囊流出至裂纹表面,改性的环氧树脂与设计的固化剂接触,在高温下发生有效的固化交联反应自动修复裂纹.热处理条件(60℃,2 h)可消除材料基体内残留的环氧活性中心与未反应的基体固化剂二乙烯三胺,在高于玻璃化转变温度tg的区域发生后固化反应,是测量UF微胶囊-环氧树脂复合材料自修复率的重要条件.采用动态力学分析(dynamic mechanical analysis,DMA)法测定的复合材料自修复率为103.03%,该方法便速、无损,具有良好的重复性,可用于表征材料自修复率.Urea-formaldehyde （UF） microcapsules with UF resin as shell and butyl glycidyl ether modified epoxy as core were synthesized by in-situ polymerization. 4＇,4＇-diaminodiphenylmethane （DDM） employed as a latent curing agent for a cross-finking chemical reaction for crack repairing was added together with UF microcapsules into an epoxy substrate to fabricate microcapsule-epoxy self-healing composites. The degree of damage of the UF microcapsule-epoxy composite is effectively controlled by a constant strain three-point bending fixture. The self- repairing performance of the composite was characterized by using dynamic mechanical analysis （DMA）. Results show that rough and compact surfaces of spherical microcapsules with a core content of 71. 02% without accumulation between microcapsules are achieved. The microcapsules are normally distributed with average diameter of 105 um and shell thickness of 3 um. A good dispersion of UF microcapsules in the epoxy composite and a goodinterfacial bonding are obtained. A post curing reaction between the residual epoxide and the unreacted diethylenetriamine （DETA） within the composite cured at room temperature occurs at the temperature over the glass- transition temperature tg, which may interfere with evaluating the self-healing efficiency. A heat treatment condition （60℃ for 2 h） is important for the measurement on the self-healing efficiency. The self-healing efficiency of microcapsule-epoxy composite is measured to be 103.03% by the DMA method. Convenient, rapid, reliable, non-destructive and reproducible, the DMA method can be used to characterize self-healing efficiency.

关 键 词：自修复材料 动态力学分析 无损测试 恒应变损伤 热处理 脲醛树脂 环氧树脂 

分 类 号：O631.2[理学—高分子化学]