稀土溶液改性PBO纤维增强聚酰亚胺复合材料界面作用机理及其摩擦学性能研究

发布时间：2018-03-21 07:08

本文选题：稀土溶液　切入点：PBO纤维　出处：《上海交通大学》2015年博士论文　论文类型：学位论文

【摘要】：作为一种由芳杂环与苯环共同构成的刚棒状高分子聚合物,聚对苯撑苯并双VA唑(PBO)纤维具有优异的力学、减摩耐磨、阻燃及耐高温性能,其比强度和比模量位于各种纤维前列,在国防军事和航空航天等领域中被视为高性能树脂基复合材料的新一代增强纤维。然而,PBO纤维表面呈化学惰性且非常光滑,难以与树脂基体形成良好的浸润和有效的化学键合,极大地限制了其在高性能复合材料领域的应用。因此,开展PBO纤维表面改性工作,改善其与树脂基体之间的界面粘接性能,成为PBO纤维增强树脂基复合材料(PFRC)的研究重点。本论文根据PBO纤维表面性质和稀土元素特殊的化学特性,采用稀土溶液对PBO纤维进行表面改性处理,以改善PBO纤维/聚酰亚胺(PBO/PI)复合材料的界面粘接性能,从而有效地提高了PBO/PI复合材料的力学及摩擦学性能。第一,采用稀土溶液(RES)对PBO纤维进行表面改性处理,制备PBO/PI复合材料。通过常规力学性能测试及试样断口SEM分析,研究RES改性工艺和PBO/PI复合材料力学性能之间的关系,确定了RES的最佳浓度值。结果表明:与硅烷偶联剂改性处理方法相比,RES改性处理在常温和高温环境中更加有效地提高了PBO/PI复合材料的力学性能,且高温条件下,RES改性PBO/PI复合材料的力学性能常温保持率更高。第二,采用傅立叶变换红外光谱(FT-IR)及X射线光电子能谱(XPS)分析技术,对RES改性处理前后PBO纤维表面的化学状态进行表征,建立了RES改性PBO/PI复合材料界面层的结构模型,阐明了RES对PBO纤维表面改性的作用机理。结果表明:RES改性方法通过稀土离子的配位化学反应,增加了PBO纤维表面含氧极性官能团的浓度;当PBO纤维与PI树脂复合时,稀土离子可以与PI分子链上的含氧基团继续发生配位化学反应,在纤维与树脂基体之间产生配位键合,使PBO纤维与PI树脂基体之间的界面具有强韧性结构,从而使PBO/PI复合材料力学性能得到显著改善。第三,研究了常温环境中法向载荷、滑动速度和润滑条件等因素对RES改性PBO/PI复合材料摩擦学性能的影响。结果表明:在干摩擦条件下,复合材料摩擦系数随滑动速度和载荷的增加而下降,而其比磨损率均呈上升趋势;油摩擦条件下,复合材料摩擦系数随滑动速度的增加而下降,随载荷的增加而上升,但其比磨损率均呈下降趋势。在相同的试验条件下,RES改性PBO/PI复合材料的减摩耐磨性能优于硅烷偶联剂改性复合材料。第四,考察了130℃和260℃环境中RES改性PBO/PI复合材料的摩擦学性能。结果表明:在相同的法向载荷和滑动速度下,复合材料在260℃环境中的摩擦系数均低于其在130℃环境中的摩擦系数,但比磨损率均有所增加。与硅烷偶联剂改性处理相比,RES改性PBO/PI复合材料在相同试验条件下均具有最佳的减摩耐磨性能。第五,探讨了RES改性PBO/PI复合材料减摩耐磨性能得以提高的机理。RES改性方法使PBO/PI复合材料界面具有粘接强度高、韧性强和耐高温等特点,摩擦过程中PBO纤维承担摩擦界面间主要载荷,减少PI基体与对偶件之间的粘着,从而降低了PBO/PI复合材料的摩擦磨损。本论文采用RES对PBO纤维进行表面改性处理,阐明了PBO纤维表面RES改性的作用机理,制备出具有优异减摩耐磨性能的RES改性PBO/PI复合材料,系统地研究了复合材料在常温和高温环境中的摩擦磨损机理及其变化规律,扩大了稀土在有机纤维表面改性方面的应用,同时也丰富和发展了PFRC的摩擦学理论。
[Abstract]:As a kind of composed of aromatic heterocyclic ring and rigid rod polymer, poly phenylene and double VA triazole (PBO) fiber has excellent mechanical, antifriction and wear resistant, flame retardant and high temperature performance, the strength and modulus of fibers in the forefront, in military and aerospace fields as a new generation of high performance fiber reinforced resin matrix composites. However, the surface of PBO fiber is chemically inert and very smooth, it is difficult to form a chemical bond of good wetting and effective with resin matrix, which greatly limits its application in the field of high performance composite materials. Therefore, to carry out the work of PBO fiber the surface modification, improve the interface between the resin and the adhesive properties as PBO fiber reinforced resin matrix composites (PFRC) the focus of research. This thesis according to the chemical characteristics of the surface properties of PBO fiber and rare earth elements special, with dilute The surface modification of PBO fiber soil solution to improve PBO fiber / polyimide (PBO/PI) composite interfacial adhesion, thus effectively improving the mechanical and Tribological Properties of PBO/PI composites. First, using rare earth solution (RES) on PBO fiber surface modification and preparation of PBO/PI composite materials through the test and fracture analysis of mechanical properties of conventional SEM, RES study on the relations between the modified process and mechanical properties of PBO/PI composite, the optimum concentration of RES value. The results showed that: compared with silane coupling agent modification method, RES modification in normal and high temperature more effectively improve the mechanics the performance of PBO/PI composite materials, and under the condition of high temperature, room temperature mechanical properties of RES modified PBO/PI composites maintain higher rate. Second, using Fu Liye transform infrared spectroscopy (FT-IR) and X (X-ray photoelectron spectroscopy XPS) analysis techniques were used to characterize the chemical state of RES modified PBO fibers before and after treatment, establishes a structure model of RES modified PBO/PI composites interface layer, the effect mechanism of RES on surface modification of PBO fiber. The results showed that RES modified by rare earth ion coordination chemical reaction, increase the concentration of PBO fiber surface oxygen-containing polar functional groups; when the PBO fiber and PI composite resin, rare earth ions with PI molecular chain of oxygen containing groups to the coordination of chemical reaction, generate coordination bonding between fibers and resin matrix, the matrix between PBO fiber and PI resin with strong interface the toughness of structure, so that the mechanical properties of PBO/PI composites were significantly improved. Third of normal temperature normal load, sliding speed and the influence of lubrication conditions on the tribological properties of PBO/PI composites modified by RES results. Show that under dry friction, the friction coefficient decreases with the increase of sliding speed and load, while the wear rate increased; the oil friction condition, the friction coefficient increases with sliding velocity decreased, and increased with the increase of load, but the wear rate decreased trend. Under the same experimental conditions, RES modified PBO/PI Composites by friction and wear resistance properties than composites modified by silane coupling agent. Fourth, the tribological properties of PBO/PI composites modified by RES 130 degrees and 260 degrees in the environment were investigated. The results show that: in the same normal load and sliding speed. The friction coefficient of the composite material at 260 DEG C was lower than that of its friction coefficient at 130 DEG C, but the wear rate increased. Compared with the silane coupling agent modified RES modified PBO/PI composites under the same experimental conditions are Have the best antifriction property. Fifth, RES modified PBO/PI composite antifriction property to.RES mechanism to improve the method of modification of the interface of PBO/PI composites with high bonding strength of the strong toughness and resistance to high temperature, friction between the main load interface of PBO fiber friction in the process of commitment, reduce the adhesion between PI matrix and dual parts, thereby reducing the friction and wear of PBO/PI composites. The surface modification of PBO fiber RES, illustrates the PBO RES fiber surface modification mechanism, prepared with excellent antifriction and wear resistance of RES modified PBO/PI composites were systematically studied friction the wear mechanism and variation of composite materials in normal and high temperature in the expansion of rare earth in surface modification of organic fiber and the application of, but also enriched and developed the theory of tribology PFRC.

【学位授予单位】：上海交通大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TB332

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