【作者】 任丹凤；

【导师】 黄凯兵；

【作者基本信息】 湖南大学 ， 材料科学与工程， 2010， 硕士

【摘要】 环氧树脂胶粘剂具有收缩率低、尺寸稳定、电性能优良、耐化学介质等优点,对多种材料具有良好的粘接能力。但同时也存在粘接强度不高、脆性大、耐热性差等缺点。本论文针对普通双酚A型环氧和酚醛环氧混合的粘料树脂与胺类固化体系配合使用的室温/中温固化双组分胶粘剂,采用具有不同微观形态的纳米二氧化硅(nano-SiO2,零维)、钛酸钾晶须(PTW,一维)和有机纳米蒙脱土(OMMT,二维)分别对胶粘剂进行改性。探讨了胶粘剂最佳固化工艺条件,并研究了不同增强材料对胶粘剂的粘接性能、粘度和热性能的影响。另外,对三者增韧改性环氧树脂的逾渗理论模型进行了初步探索。研究结果表明：增强材料对环氧胶粘剂的改性效果显著。胶粘剂的最佳工艺条件为稀释剂含量为15%,DDM+593为固化剂,80℃/4h固化。表面经砂纸打磨并酸洗后,粘接强度明显提高。胶粘剂的适用期与增强材料的种类和用量无关,与施胶的环境温度有关,温度越高,适用期越短。当添加量为2%(wt%)时能有效降低体系的粘度,且表现出一定的触变性能。增强材料的加入能极大提高胶粘剂的耐热性、剪切强度和冲击强度。SEM分析表明三种材料对胶粘剂的增韧机理各不相同。nano-SiO2主要是引发银纹和微裂纹增韧；PTW主要是裂纹偏转、晶须拔出和晶须脱粘增韧；OMMT受冲击时则产生大量不同层次的断裂面使应力分散而增韧。针对三种增强材料改性环氧树脂的冲击性能,建立了逾渗理论模型,证明三者的增韧行为均符合逾渗理论。说明三种增强材料在胶粘剂中起交联点的作用,并在毗邻的聚合物基体中形成了增强区,以致于相互连接贯通形成无限大的逾渗集团,从而达到整体增韧聚合物的效果。用增强材料改性后的环氧胶粘剂综合性能优良,改性工艺简单可行,成本较低,在胶粘剂改性领域有积极的推广和应用价值。更多还原

【Abstract】 Epoxy resin adhesive are widely used for its excellent performance such as low shrinkage, dimensional stability, excellent electrical properties, resistance to chemical media, good bonding ability to a variety of material, etc. But there are also some disadvantages of low adhesive strength, brittleness, heat resistance. This thesis focuses on two-component adhesives which the mixture of common bisphenol A epoxy resin and phenolic epoxy resin was to be the component A. Adhesives cured on the conditions of room/medium temperature with the amine curing system. Using nano/micron reinforced materials with different morphology to modified epoxy resin adhesive, which are nano-SiO2 (zero-dimensional), potassium titanate whiskers (one-dimensional) and nano-organic montmorillonite (two-dimensional). Disused the best adhesive curing process conditions, and studied the effect to adhesive properties, viscosity and thermal properties by three kinds of reinforced materials. In addition, the percolation theory model of three reinforced materials toughened on epoxy resin is preliminarily explored.The results show that:The effect of reinforced materials modified epoxy adhesive is remarkable. The optimum conditions for adhesive is as follows:15wt% diluent content, DDM+593 as curing agent,80℃/4 hours curing. The bond strength of steel pickling treatment after sanding is significantly higher than untreated surface. And the heat-resistant of adhesive is also improved when reinforced materials added. The application of adhesives is unrelated to the type and the amount of reinforced materials. But related to the temperature of sizing, as the environmental temperature of sizing increased, the application shorted. When the addition of 2wt% can lower the viscosity, and show some of the thixotropic property. Reinforced materials can greatly improve the steel-steel shear strength and impact strength of adhesive. SEM pictures of impact fracture showed that the three kinds of reinforced materials have different mechanisms on toughening of adhesive. Nano-SiO2 is mainly by causing crazes and microcracks in the resin matrix to absorb some part of impact energy to toughening. When adding PTW, the crack deflection, whisker pull-out and whisker debonding phenomenons emerged, so the toughening mechanisms is passivating crack tip and preventing crack propagation. And cured resin content with OMMT formed a number of different levels of fracture surfaces when shocked, so the stress can be dispersion and then toughed the adhesive.The paper established a model of percolation theory according to the impact properties of three kinds of reinforced materials modified epoxy resin. The calculations proved that the toughening behavior all of three reinforced materials are in line with percolation theory. It suggesting that three kinds of reinforced materials in the adhesive play a role of crosslinks, then formed the enhanced areas in adjacent to the polymer matrix. So these areas interconnected and impenetrated then form an infinite percolation cluster, ultimately achieved the effect of toughening polymer. Epoxy adhesive modified with reinforced materials have excellent comprehensive properties, the technics is simple and low cost. So the method which reinforced materials modified epoxy adhesive has a positive promotion and application value in the field of structural adhesives.更多还原