【作者】 陆春；

【导师】 陈平；

【作者基本信息】 大连理工大学 ， 材料学， 2007， 博士

【摘要】 杂萘联苯型聚芳醚砜酮树脂(PPESK)是一种新型的可溶型高性能热塑性树脂基体，与目前广泛应用的聚醚醚酮(PEEK)等热塑性树脂相比，PPESK树脂的耐热性能得到较大幅度提高的同时，加工性能也得到了很大程度的改善，适合溶剂预浸的方法制备纤维／聚芳醚砜酮树脂基复合材料。本文对连续碳纤维增强杂萘联苯型聚芳醚砜酮复合材料的制备工艺、纤维表面改性方法及其在空间环境温度下的热应力分布规律进行了研究。本文在充分研究杂萘联苯型聚芳醚砜酮树脂的溶解特性的基础上，选择适当的溶剂，利用溶液浸渍缠绕的工艺制备CF／PPESK树脂基复合材料预浸料，采用高温模压成型工艺，制备出CF／PPESK复合材料单向板。根据紧密接触模型和能量传递方程对热压成型过程非稳态温度场进行数值分析，探讨了CF／PPESK复合材料的非稳态温度场、成型加工温度和压力与成型时间的关系。采用粘弹性树脂模型对降温过程中复合材料的热应力进行分析，探讨复合材料成型过程中残余热应力的分布规律及对复合材料粘接性能的影响。对CF／PPESK复合材料热压成型工艺参数进行了优化，总结出CF／PPESK复合材料的最佳成型工艺参数。采用空气冷等离子体处理方法对碳纤维表面进行处理，用XPS测试不同等离子体处理时间对碳纤维表面元素组成的影响及其变化规律，采用动态接触角测试分析了不同处理时间下，碳纤维表面浸润性的变化规律，利用AFM测试分析等离子体处理时间对碳纤维表面粗糙度的影响，用ILSS测试方法表征了碳纤维／PPESK复合材料的层间剪切强度，确定了最佳的等离子体处理条件。利用SEM观察碳纤维／PPESK树脂基复合材料的层间剪切破坏形貌，并进一步分析了复合材料界面的粘结机理。研究结果表明，空气等离子体处理可在纤维表面引入-C-N-、-C-O-、-C=O、-COO-等极性基团，使得纤维表面极性基团的含量及表面自由能显著增加；等离子体处理对碳纤维表面具有刻蚀作用，经过等离子体处理的碳纤维表面沟槽增多、粗糙度增大。由于等离子体处理，碳纤维表面极性基团含量、表面粗糙度及浸润性能均得到提高，从而改善了纤维与树脂基体的粘接性能，使得CF／PPESK复合材料的层间剪切强度达到79.5MPa，比未处理的CF／PPESK复合材料提高了13.5％。对CF／PPESK复合材料界面粘接机理的研究表明，纤维与树脂基体之间的化学键合、机械嵌合相互作用均能有效地提高复合材料的界面粘接性能，而机械嵌合作用对提高CF／PPESK复合材料界面粘接性能的贡献大于化学键合相互作用。作为航天器结构的复合材料，在航天器长期在轨运行期间，反复地出入于地球的阴影区域，其表面温度在-160℃-120℃变化，由于碳纤维与树脂基体的热膨胀系数存在较大的差异，因而在空间交变温度场的作用下，复合材料内将产生交变热应力。本文采用有限元分析的方法，对空间环境下CF／PPESK复合材料内热应力的分布规律进行了分析，并与CF／环氧、CF／双马来酰亚胺树脂基复合材料的热应力分布规律进行了研究比较。结果表明，复合材料内部的缺陷区域是复合材料最薄弱的环节，在空间温度场的作用下，复合材料的缺陷区域将产生较大的应力集中，而CF／PPESK复合材料内热应力值比CF／环氧、CF／双马来酰亚胺复合材料的热应力值低。缺陷区域的Parabolic屈服准则分析表明，热应力对CF／环氧、CF／双马来酰亚胺复合材料的影响比较显著，在空间温度场的作用下，复合材料缺陷区域的热应力将导致树脂基体发生屈服破坏，而CF／PPESK复合材料受空间温度场影响较小，缺陷区域的热应力值均未能导致树脂基体的屈服，表现出较高的热稳定性能。更多还原

【Abstract】 Poly (phthalazinone ether sulfone ketone) (PPESK) is a kind of novel thermoplastic with excellent thermal resistance and solubility. Compared with traditional thermoplastic such as PEEK, PES, PEI, the thermal resistance is increased, besides the processing property is also improved significantly. It is suitable for preparing fiber/PPESK composite by using solution impregnation technique. In our experiment, CF/PPESK composite manufacture technique was studied, CF surface modification for improving composite interfacial adhesion was carried out and composite thermal stress distribution in the outer space was analyzed.In our experiment, suitable solution for PPESK matrix was chosen by comparing the solubility of PPESK matrix in different solvents, and continuous fiber reinforced PPESK composite was prepared by using solution impregnated and compression modeling technique. Numeral analysis for non-equilibrium temperature field during compress modeling process was carried out by using intimate contacting model and energy transfer equation. The relation between the modeling temperature, pressure and modeling time were studied under non-equilibrium temperature field. A viscous-elastic finite element model was adopted to analysis the thermal stress distribution in CF/PPESK composite, and the influence of composite cooling rate on composite thermal stress distribution was discussed. At last, the processing parameters of CF/PPESK composite were optimized, and the optimal composite processing parameters were concluded.Air plasma was employed to modified CF surface, for improving the interfacial adhesion between CF and PPESK matrix. Plasma treated CF surface chemical composition was characterized by X-ray photoeletron spectroscopy (XPS). Fiber wettability was analyzed by dynamic contact angle analysis system. CF surface topography was indicated by atomic force microscopy (AFM). Composite failure mechanism was analyzed by scanning electron microscopy, and composite interfacial adhesion mechanism was also studied. Results indicate that air plasma treatment is capable of introducing -C-O-, -C-N-, -C=O as well as -COO- groups onto CF surface. Fiber surface polarity is increased. Besides, air plasma treatment can change carbon fiber surface roughness significantly. After plasma treatment, substantial amount of deep grooves can be found on CF surface. Due to plasma treatment increase CF surface polarity, fiber wettability and fiber surface roughness, composite interlamine shear strength (ILSS) is improved. After plasma treatment, composite ILSS is high up to 79.5MPa, the ILSS is increased by 13.5% compared with that of untreated CF/PPESK composite. Study of composite interfacial adhesion mechanism indicated that both chemical bonding and mechanical bonding interaction have a positive effect on composite interfacial adhesion, however mechanical bonding interaction has a dominant effect than chemical bonding interaction.As structure composite of the space craft, during the long-term serving in the orbit, the space craft travels in and out of the earth shadow area. The temperature on the surface of the space craft varies from -160℃to 120℃. Due to the coefficient of thermal expansion of the fiber and the matrix is quite different, thermal stress is caused when temperature changes. In this paper, finite element analysis method was applied to analyze the thermal stress in CF/PPESK composite, and the thermal stress of CF/PPESK composite was compared with that of CF/EP and CF/BMI composite. Results indicate that, in alternating temperature environment, thermal stress is aroused in CF/plastic composite. Composite interfacial defect zone is the weak point in CF/plastic composite. Thermal stress concentration is located in the defect zone. However, the thermal stress in CF/PPESK composite is lower than that of CF/EP and CF/BMI composite.The Parabolic failure criterion analysis implies that thermal stress has a dominant influence on CF/EP composite and CF/BMI composite, in the alternating temperature environment, thermal stress of composite defect zone will induce the matrix failure, while the influence of alternating temperature on CF/PPESK composite is relatively smaller. Thermal stress of the defect zone can not induce the matrix failure. CF/PPESK composite has a higher stability.更多还原