【作者】 孙周强；

【导师】 梁国正；

【作者基本信息】 苏州大学 ， 材料学， 2009， 硕士

【摘要】 高性能透波复合材料属光电磁和结构功能复合材料范畴,为“结构一防热一透波”一体化功能材料,是航天器“眼睛”的重要组成部分。随着航空航天工业的飞速发展,飞行器的飞行马赫数在不断提高,对透波材料提出了更高的性能要求,即具有突出的耐热性、优异的介电性能、良好的成型工艺性和力学性能。树脂性能是决定复合材料的重要性能（介电性能、耐热性、耐湿性）的关键因素,所以,先进透波材料的研制应以高性能树脂为基体。基于氰酸酯树脂（CE）和磷酸铝（AlPO₄）优良的综合性能,本文采用“复合技术”,设计并制备了新型高性能复合树脂（AlPO₄/CE）,全面深入地探讨了复合树脂的界面性质、AlPO₄含量与复合树脂性能的关系;为进一步改善AlPO₄/CE的力学性能和耐湿性,制备了基于环氧改性甲基苯基有机硅树脂（E-Si）、AlPO₄和CE的三元复合材料,研究了E-Si的含量对AlPO₄/CE复合材料性能的影响;采用化学合成法合成了磷酸铝胶（s-AlPO₄）,制备了玻璃布增强s-AlPO₄/CE复合材料,重点讨论了复合材料的力学性能和介电性能。通过本文的研究,初步建立了设计与制备新型高性能树脂及其透波复合材料的新理论和新方法。研究了不同偶联剂对磷酸铝/CE性能的影响,制备了AlPO₄/CE和AlPO₄（KH-550）/CE复合材料,研究了复合材料的热性能、介电性能和吸湿性能。研究结果表明,不同偶联剂对磷酸铝/CE的固化行为以及磷酸铝和CE之间的界面作用力影响不同。AlPO₄（KH-550）和AlPO₄（KH-560）对CE固化反应的催化作用以及与CE间的界面作用力稍高于AlPO₄（H-2）,所以AlPO₄（KH-550）/CE复合材料的综合性能最佳。AlPO₄（KH-550）/CE复合材料的性能与AlPO₄（KH-550）含量密切相关。AlPO₄（KH-550）加入到CE中使材料的热分解机理从两步变为三步。随着AlPO₄（KH-550）含量的增加,材料的导热系数和贮存模量逐渐增大,tanδ不断下降,Tg降低,吸水率几乎不变。由适当含量AlPO₄（KH-550）组成的AlPO₄（KH-550）/CE复合材料具有比纯CE树脂更佳的综合性能。将兼具突出耐热性和韧性的环氧改性甲基苯基有机硅树脂（E-Si）加入到AlPO₄/CE复合材料中,设计、制备了E-Si/AlPO₄/CE三元复合材料,系统研究了三元复合材料的性能,并与CE树脂和二元复合材料的性能进行了对比。研究结果表明,与二元复合材料和CE树脂相比,三元复合材料的冲击强度大幅度提高,当E-Si含量为15%时,三元复合材料的冲击强度增幅达50%。三元复合材料的初始热分解温度提高,热分解过程仍为三步,但第一最大分解速率峰向低温方向移动,Yc降低。在介电损耗正切值保持不变的情况下,三元复合材料介电常数、平衡吸水率、扩散系数均低于二元复合材料的相应值。采用研磨法,以磷酸、氢氧化铝和水为反应物制备了磷酸铝胶（S-AlPO₄）,其为多种磷酸铝的混合体系,pH值为3-4,具有很强的粘接性。与CE/EW-210二元复合材料相比,磷酸铝胶增加了材料的界面效应,从而提高了材料的力学性能。含15%S-AlPO₄的复合材料的冲击强度、弯曲强度、弯曲模量以及层间剪切强度分别提升了38%、6%、32%和45%。三元S-AlPO₄/CE/EW-210复合材料的热膨胀系数仅约为CE/EW-210的50%。15%AlPO₄/CE/EW-210具有最小的ε值（3.353）和最大的tanδ值（0.0133）。S-AlPO₄的加入改变了CE/EW-210复合材料的损耗峰形状,但其对Tg无负面影响。更多还原

【Abstract】 Advanced wave-transparent composites are“structural-heat resistant-wave transparent”composites, which are the main components of“eyes”for spacecrafts. With the repaid developments of aviation and aerospace industries, the Mach number of spacecrafts is increasing, so the wave-transparent composites should have more and higher properties, they are outstanding thermal resistance, excellent dielectric property, good processing characteristics and mechanical properties.Property of the matrix is the key factor of determining the main properties （such as dielectric, thermal and moisture properties） of a composite, so high performance matrix should be employed for developing advanced wave-transparent composites.Based on outstanding integrate properties of both cyanate ester （CE） and phosphate aluminum （AlPO₄）, a novel kind of composite （AlPO₄/CE） was designed and prepared in this thesis by employing the“composite technology”, the effects of the interfacial nature and AlPO₄ content on the properties of the new composite are discussed; in order to improve the toughness and moisture-resistance of AlPO₄/CE composite, a ternary composite made up of epoxidized methyl phenyl silicone epoxy （E-Si）, AlPO₄ and CE were developed, the influence of E-Si content on properties of AlPO₄/CE are evaluated; a mixture of some kinds of aluminum phosphates with a pH value of 3-4 and good adhesion, s-AlPO₄, was synthesized by grinding phosphoric acid, aluminum hydroxide and water, and glass fiber cloth reinforced composites （s-AlPO₄/CE/EW-210） were prepared, then the mechanical and dielectric properties of s-AlPO₄/CE/EW-210 composites were emphasized. By the investigations of this thesis, new theory and technology for developing new kinds of high performance resins and wave-transparent composites are set up preliminarily.Three kinds of coupling agents （KH-550, KH-560 and H-2） were used to surface treat AlPO₄. The chemical nature of coupling agents on the properties of aluminum phosphate/CE composites were discussed, Results show that different coupling agents have different effects on the curing behavior and the interfacial adhesion of aluminum phosphate/CE composites. AlPO₄（KH-550） and AlPO₄（KH-560） have bigger effects than AlPO₄（H-2）,so AlPO₄（KH-550）/CE has the optimum properties among three composites. The properties of AlPO₄（KH-550）/CE composites are closely related with AlPO₄（KH-550） content. The thermal-decomposition of AlPO₄（KH-550）/CE composites can be divided into 3 steps, while that of CE resin is 2 steps. With the increase of AlPO₄（KH-550） content in composites,both the thermal conductivity and storage modulus increase, but dielectric loss （tanδ） and glass transition temperature （Tg） decrease,while water absorption almost does not change. AlPO₄（KH-550）/CE composite with desirable AlPO₄（KH-550） content has better properties than CE resin.Comparing to AlPO₄/CE composite, E-Si/AlPO₄/CE composites have effectively improved impact strength, for example, the impact strength of the ternary composite with 15wt% E-Si is improved about 50%. In addition, the ternary composite has higher initial decomposition temperature; its thermal decomposition still has 3 steps, but the first temperature of the maximum decomposition temperature shifts to low temperature, and the char yield （Yc） decreases. On the other hand, the dielectric constant and water absorption of E-Si/AlPO₄/CE composites are lower than AlPO₄/CE composites.Comparing to CE/EW-210 composites,S-AlPO₄/CE/EW-210 composites show higher mechanical properties due to increased the interfacial effect by the addition of S-AlPO₄. For example, the impact strength, flexible strength and modulus as well as interfacial shear strength of S-AlPO₄/CE/EW-210 composite with 15% S-AlPO₄ increase about 38%, 6%, 32% and 45%, respectively, while the thermal expansion coefficient of the latter is only about 50% of that of the former. In addition, the ternary composite has the lowest dielectric constantε（3.353）and highest tanδ（0.0133）. Although the addition of S-AlPO₄ into CE/EW-210 changes the shapes of damping factor in dynamic mechanical analyses, which does not decline Tg values.更多还原