【作者】 郑亮；

【导师】 蹇锡高； 廖功雄；

【作者基本信息】 大连理工大学 ， 高分子材料， 2009， 博士

【摘要】 连续纤维增强高性能热塑性树脂基复合材料具有耐热等级高、质量轻、高比强度和高比模量,维护费用低、可回收再利用、耐腐蚀和耐辐射等优异性能,广泛应用于航天航空、国防、化工等高科技领域,并成为当今航天航空新材料的研究重点和发展方向。杂萘联苯结构聚芳醚(PPAE)是本课题组研发的一种新型高性能热塑性树脂,具有高玻璃化转变温度(Tg=263～305℃),突出的高温稳定性,优异的机械性能和耐辐射性。更为可贵的是PPAE可溶解于特定的有机溶剂,可进行溶液加工。因此,PPAE成为制备高性能复合材料非常理想的基体选材。本论文针对杂萘联苯聚芳醚树脂可溶于特定有机溶剂的特性,采用溶液浸渍法制备复合材料预浸料。充分利用树脂溶液粘度低,易浸渍纤维的优势,选用价格较低的较大丝束碳纤维(T700-12K)和E玻璃纤维作为增强纤维。并针对杂萘联苯聚醚砜酮(PPESK)熔融粘度大影响成型阶段纤维浸润和成型质量的问题,采用不同的方法对基体树脂进行改性,详细考察了基体树脂结构及性能、纤维含量、界面作用和制备工艺等因素对复合材料性能的影响。通过溶液浸渍,热压成型法制备CF/PPESK和GF/PPESK复合材料。系统研究了PPESK树脂溶液粘度,纤维浸润质量和纤维体积含量对复合材料性能的影响,并通过紧密接触模型模拟,PPESK树脂熔融流变性分析及成型时间的考察优化了复合材料成型工艺。结果表明低粘度有利于树脂溶液对纤维浸润,复合材料纤维体积含量随树脂溶液粘度的升高而降低。随着复合材料纤维体积含量的增加,CF/PPESK和GF/PPESK复合材料弯曲强度和层间剪切强度呈现出先增大后减小的趋势,弯曲模量呈现线性增大的趋势。通过与粉末层压法制备的相同纤维体积含量复合材料的性能对比表明,溶液浸渍技术在制备连续纤维增强高性能热塑性树脂基复合材料方面具有优势。沸水浸泡试验和高温力学性能测试表明PPESK基复合材料较环氧树脂基复合材料具有优异的耐湿热性能和耐高温性能。复合材料断面形貌分析表明PPESK基复合材料界面作用较弱,受力破坏模式为界面脱粘破坏。纤维表面红外光谱分析表明:CF/PPESK和GF/PPESK复合材料界面未产生化学键合,界面作用力主要由机械嵌合力和范德华力等作用力构成。为了考察树脂熔体粘度对复合材料性能的影响,选用具有相似性能但熔体粘度较低的共聚型杂萘联苯结构聚醚砜(PPBES)树脂作为基体,通过溶液浸渍,热压成型法制备CF/PPBES和GF/PPBES复合材料。详细考察了溶液粘度、纤维体积含量对CF/PPBES和GF/PPBES复合材料性能的影响并优化了复合材料成型工艺。结果表明,CF/PPBES复合材料的最佳纤维体积含量为60%,GF/PPBES复合材料的最佳纤维体积量为57%。CF/PPBES和GF/PPBES复合材料的力学性能及耐湿热性能均优于相应的PPESK基复合材料。高温力学性能测试表明PPBES基复合材料的耐高温性能优异,CF/PPBES和GF/PPBES复合材料150℃弯曲性能保持率均超过88%。复合材料断面形貌分析表明,PPBES树脂基复合材料界面作用强于PPESK树脂基复合材料。CF/PPBES复合材料受力破坏模式以树脂基体内部破坏为主,GF/PPBES复合材料受力破坏模式为界面脱粘破坏和树脂基体内部破坏同时存在的混合破坏模式。将熔融粘度较低韧性较好的可溶性高性能热塑性树脂聚醚砜(PES)引入到PPESK树脂基体中,通过溶液浸渍,热压成型工艺制备CF/PPESK/PES和GF/PPESK/PES复合材料。当PES的含量小于20%时,树脂基体具有优异的耐热性能。PES的加入大幅降低了树脂基体的熔融粘度并大幅提高了树脂基体的韧性,从而使复合材料的界面作用和成型质量得以改善。CF/PPESK/PES复合材料的受力破坏模式由界面脱粘破坏转变为树脂基体内部破坏;GF/PPESK/PES复合材料的受力破坏模式由界面脱粘破坏转变为树脂基体内部破坏模式为主,树脂基体内部破坏模式和界面脱粘破坏模式共存的混合破坏模式。但是,PES的过多加入将增大树脂溶液的粘度,导致纤维在溶液浸渍阶段浸润质量的下降。从而使CF/PPESK/PES和GF/PPESK/PES复合材料的力学性能随树脂基体中PES含量的增加先增大后减小,出现峰值。经优化工艺后,当PES含量为7%时,CF/PPESK/PES复合材料弯曲强度,弯曲模量和层间剪切强度分别为1470.9MPa、137.4GPa和62.8MPa;GF/PPESK/PES复合材料弯曲强度,弯曲模量和层间剪切强度为959.2MPa、45.2GPa和55.1MPa。经45h沸水浸泡,CF/PPESK/PES复合材料的饱和吸水率,弯曲强度和弯曲模量保持率分别为0.66%、93.4%和93.7%;GF/PPESK/PES复合材料的饱和吸水率,弯曲强度和弯曲模量保持率分别为0.76%、85.3%和88.5%。高温力学性能测试表明PPESK/PES基复合材料150℃弯曲性能保持率均超过89%。将熔融粘度较低韧性较好的可溶性高性能热塑性树脂聚醚酰亚胺(PEI)引入到PPESK树脂基体中,通过溶液浸渍,热压成型工艺制备CF/PPESK/PEI和GF/PPESK/PEI复合材料。当PEI的含量小于20%时,树脂基体具有优异的耐热性能,PEI的加入在没有影响溶液浸渍质量的同时,大幅降低了树脂基体的熔融粘度并大幅提高了树脂基体的韧性,从而使复合材料的界面作用和成型质量得以改善。CF/PPESK/PEI和GF/PPESK/PEI复合材料的受力破坏模式由界面脱粘破坏转变为树脂基体内部破坏。在研究范围内,CF/PPESK/PEI和GF/PPESK/PEI复合材料的力学性能随树脂基体中PEI含量的增加而增大。经优化工艺后,当PEI含量为20%时,CF/PPESK/PEI复合材料弯曲强度,弯曲模量和层间剪切强度分别为1566.1MPa、128.3GPa和68.1MPa;GF/PPESK/PEI复合材料弯曲强度,弯曲模量和层间剪切强度为936.5MPa、52.2GPa和64.2MPa。经45h沸水浸泡,CF/PPESK/PEI复合材料的饱和吸水率,弯曲强度和弯曲模量保持率分别为0.46%、95.7%和96.9%;GF/PPESK/PEI复合材料的饱和吸水率,弯曲强度和弯曲模量保持率分别为0.67%、87.5%和92.5%。高温力学性能测试表明PPESK/PEI基复合材料150℃弯曲性能保持率均超过87%。更多还原

【Abstract】 Continuous fiber reinforced high performance thermoplastic composites have been extensively used in the field of aerospace, weaponry, and chemical industries because of their inherent properties such as light weight, high strength and stiffness, recyclability, repairability, corrosion resistance, radiation stability, etc. Continuous fiber reinforced high performance thermoplastic composites have attracted more and more attentions.Poly(aryl ether) containing phthalazinone moiety (PPAE) is a novel amorphous high performance thermoplastics with very high glass transition temperatures (T_g =263～305℃), outstanding high temperature stability, excellent mechanical properties and radiation stability. Moreover, PPAE shows good solubility in some organic solvents, therefore the solution processing can be adopted to prepare fiber reinforced composites. Hence, PPAE is a very ideal alternative of matrix for advanced composites potentially used in some harsh environmental conditions. In this work, composite prepregs are prepared by using solution impregnation process. Taking full advantage of the low viscosity of the polymer solution, which impregnates fiber easily, the large bundle carbon fiber (T700-12K) with lower price and E glass fiber as reinforcement are selected to produce unidirectional composites. The processing, structure and properties of continuous carbon fiber and glass fiber reinforced Poly (phthalazinone ether sulfone ketone) (PPESK) composites are investigated. In view of high melting viscosity, which makes it difficult to impregnate and consolidate well in hot-press molding process, the resin matrix is modified by different method, and the effect of properties of composites on properties of resin matrixs, fiber content, interfacial adhesion and processing are studied systematically.CF/PPESK and GF/PPESK composites are produced by solution impregnation and hot-press molding method. The effects of PPESK solution viscosity, fiber impregnation and fiber volume loading on mechanical properties of the final composites are studied systematically. The molding process is optimized by using intimate contacting model simulation, analysis of PPESK rheological property and investigation of dwell time. The results show that the resin solution with low viscosity is more suitable for fiber impregnation. The fiber volume content decreases with increasing viscosities of resin solutions. With increasing fiber volume content, the flexural strength and interlaminar shear strength of PPESK composites go to the peak and then decrease with more fiber volume content. The flexural modulus increases linearly with increasing fiber volume content. Compared with the composites of the same fiber volume content produced by power laminated method, the solution impregnation technique has a big advantage in producing continuous fiber reinforced high performance thermoplastics composites. Moreover, the moisture resistant, heat resistant and interfacial adhesion properties of PPESK composites are also investigated. The results show that CF/PPESK and GF/PPESK composites, which are compared with fiber/epoxy composites, have excellent humidity resistant properties and heat resistant properties. The flexural properties residual of CF/PPESK and GF/PPESK composites at 150℃are above 90%. The interfacial adhesion of CF/PPESK and GF/PPESK composites are not ideal. The fracture modes of composites are interface failure. Fourier transform infrared (FT-IR) spectrum of fiber surface shows that there is no chemical reaction between fiber and matrix. The composite interfacial adhesion is mainly composed of van der Waals’ forces and mechanical forces.CF/PPBES and GF/PPBES composites are produced by solution impregnation and hot-press molding method. The effects of PPBES solution viscosity and fiber volume content on mechanical properties of the final composites are studied systematically. The molding process is also optimized. The resuls show that the optimal fiber cntent is 60 vol. % for CF/PPBES composite and 57 vol. % for GF/PPBES composite; the mechanical and humidity resistant properties of PPBES composites are both better than those of PPESK composites. CF/PPBES and GF/PPBES composites have excellent heat resistant properties. The flexural properties residual of CF/PPBES and GF/PPBES composites at 150℃are above 88%.The analysis of the fracture surfaces of CF/PPBES and GF/PPBES composites indicates that the interfacial adhesion of CF/PPBES and GF/PPBES composites is better than that of CF/PPESK and GF/PPESK composites. Matrix failure has been found to be the dominant fracture mode for CF/PPBES composite. For GF/PPBES composite, interfacial failure and matrix failure are observed at the same time.Polyethersulfone (PES) with lower melting viscosity and better toughness is introduced to PPESK. CF/PPESK/PES and GF/PPESK/PES composites are produced by solution impregnation and hot-press molding method. The effect of addition of PES on the resultant composites was studied. The results show that when the PES mass fraction is less than 20%, the resin matrix still has excellent heat resistance. The addition of PES significantly lowers the melting viscosity of resin matrix and substantially increases the toughness of matrix, which improves interfacial adhesion and consolidation of composites. The fracture mode of CF/PPESK/PES composites changes from interface failure to matrix failure; the fracture mode of GF/PPESK/PES composites changes from interface failure to matrix failure as the main form and both interface failure and matrix failure are in coexistence. However, the overmuch addition of PES increases the viscosity of polymer solution, which results in insufficient impregnation of fibers in solution impregnation process. Hence, the mechanical properties of CF/PPESK/PES and GF/PPESK/PES composites have the peak value with increasing PES mass fraction. After optimizing process, with 7% PES mass fraction, the flexural strength, flexural modulus and interlaminar shear strength of CF/PPESK/PES composites are 1470.9MPa, 137.4GPa and 62.8MPa, respectively; the flexural strength, flexural modulus and interlaminar shear strength of GF/PPESK/PES composites are 959.2MPa, 45.2GPa and 55.1MPa, respectively. CF/PPESK/PES and GF/PPESK/PES composites have excellent humidity resistant properties. After being exposed to boiling water for 45h, the maximum moisture content, flexural strength and modulus residual of CF/PPESK/PES composite are 0.66%, 93.4% and 93.7%, respectively; the maximum moisture content, flexural strength and modulus residual of GF/PPESK/PES composite are 0.76%, 85.3% and 88.5%, respectively. The flexural properties residual of CF/PPESK/PES and GF/PPESK/PES composites at 150℃are above 89%.Polyetherimide (PEI) with lower melting viscosity and better toughness is introduced to PPESK. CF/PPESK/PEI and GF/PPESK/PEI composites are produced by solution impregnation and hot-press molding method. The effect of addition of PEI on the final composites was studied. The results show that when the PEI mass fraction is less than 20%, the resin matrix still has excellent heat resistance. The addition of PEI has no impact on solution impregnation, significantly lowers the melting viscosity of resin matrix and substantially increases the toughness of matrix, which improves interfacial adhesion and consolidation of composites. The fracture modes of CF/PPESK/PEI and GF/PPESK/PEI composites change from interface failure to matrix failure. The mechanical properties of CF/PPESK/PEI and GF/PPESK/PEI composites increase with increasing PEI mass fraction. After optimizing process, with 20% PEI mass fraction, the flexural strength, flexural modulus and interlaminar shear strength of CF/PPESK/PEI composites are 1566.1MPa, 128.3GPa and 68.1MPa, respectively; the flexural strength, flexural modulus and interlaminar shear strength of GF/PPESK/PEI composites are 936.5MPa, 52.2GPa and 64.2MPa, respectively. CF/PPESK/PEI and GF/PPESK/PEI composites have excellent humidity resistance. After being exposed to boiling water for 45h, the maximum moisture content, flexural strength and modulus residual of CF/PPESK/PEI composite are 0.46%, 95.4% and 96.9%, respectively; the maximum moisture content, flexural strength and modulus residual of GF/PPESK/PEI composite are 0.67%, 87.5% and 92.5%, respectively. The flexural properties residual of CF/PPESK/PEI and GF/PPESK/PEI composites at 150℃are above 87%.更多还原