纤维增强PMR型聚酰亚胺复合材料研究概况

自20世纪70年代开始,国内外相继开展了PMR型热固性聚酰亚胺树脂及其复合材料的研究工作。截止目前,纤维增强PMR型聚酰亚胺复合材料最高使用温度可达450℃。介绍了聚酰亚胺树脂的改性方法与纤维增强PMR型聚酰亚胺复合材料成型工艺及其发展现状,并对其未来发展趋势进行了展望。     

高性能聚酰亚胺复合材料的研究进展

综述了国内外高性能聚酰亚胺复合材料的研究进展,主要包括以双马来酰亚胺树脂、反应型聚酰亚胺（PMR型聚酰亚胺）树脂及乙炔基封端聚酰亚胺树脂作为基体材料的复合材料,也包括以聚酰亚胺纤维作为增强体的复合材料,针对结构与性能的关系以及材料的性能优化进行了介绍,并对聚酰亚胺复合材料的发展方向进行了展望。     

工艺参数对热压PMR聚酰亚胺复合材料性能的影响

本文研究工艺参数对纤维增强PMR聚酰亚胺复合材料的热压成型和性能的影响.用超声波C扫描和显微照相分析法检查了复合材料的孔隙含量.说明了每组工艺参数的工艺特性及其对复合材料在室温和316℃时力学性能的影响.     

三维浅交弯联复合材料结构与力学性能研究

以2400tex的玻璃纤维为原料,在SGA598型三维织机上,织制出三层和六层两种三维浅交弯联机织物作为三维机织复合材料预制体,将两块三层三维浅交弯联机织物层叠在一起以保持两种机织物的纬纱层数一致。将环氧树脂E51与聚醚胺WHR-H023以质量比为3∶1的比例混合后制成树脂基体,采用手糊成型的方式将预制体与树脂基体按照质量比为1∶1的比例复合成型,制备出两种三维浅交弯联机织复合材料。借助Instron 3385H型万能材料试验机对材料的拉伸及弯曲力学性能进行测试;通过实验过程及对破坏断面的观察比较两种复合材料的力学性能。实验结果表明,三维浅交弯联机织复合材料在承受拉伸及弯曲载荷时,主要表现为脆性破坏模式;六层三维浅交弯联机织物作为复合材料的预制体时,该复合材料的弯曲性能和拉伸性能均优于两块三层三维浅交弯联机织物层叠在一起作为增强体的复合材料;且六层机织物可以更好地保护复合材料,提高其使用寿命。     

三维间隔连体织物酚醛泡沫复合材料性能研究

制备了三维间隔连体织物酚醛泡沫复合材料。研究发现,随着密度增加,泡沫孔的刚性提高,纤维增强效应增加,材料的压缩强度近似呈现指数增长;随着三维间隔连体织物高度的增加,复合材料的压缩强度呈现下降趋势。酚醛树脂经聚酰胺树脂增韧后,韧性提高,泡沫伴随纤维错动、屈曲的可能性增加,复合材料的压缩强度有所降低。泡沫与纱线之间的协同增强效应使得材料在灼烧后保持良好的几何形状,复合材料的耐灼烧性能及隔热性能良好,经过最高热面温度1200℃的石英灯静热测试后,1200 s时背面温度为151.1℃。     

三维机织热塑性复合材料的拉伸性能测试与分析

本研究对三维机织热塑性复合材料的拉伸力学性能进行了测试,分析了三维机织热塑性复合材料预型件的结构(纱线的直径、三维机织物的结构)、预型件的预拉伸工艺(经纱和接结经的伸直程度)、复合成型工艺(成型压力)对复合材料的力学性能的影响.     

聚氨酯-酰亚胺复合材料的制备与表征

通过改变聚酰亚胺的用量,制备出系列聚氨酯-酰亚胺复合材料。采用FT-IR(傅里叶转换红外光谱)、DSC(差示扫描量热仪)、TG(热重分析)、拉伸测试和化学耐性测试等方法对聚氨酯-酰亚胺复合材料的胶膜结构和性能进行测试表征。探讨聚酰亚胺含量对聚氨酯-酰亚胺复合材料性能的影响。结果表明:随着聚酰亚胺用量的增加,聚氨酯-酰亚胺胶膜的拉伸强度呈现先增加后减小的趋势,断裂伸长率降低;胶膜的耐热性、耐水性、耐碱性和耐酸性都有所增强。     

经编织物预型件的研究进展

经编增强织物复合材料大多具有三维立体结构、良好的准各向同性,受到了复合材料专家的高度重视。经编织物预型件的制备和研究是轻质高强复合材料的热点,与普通织物预型件相比,经编预定向织物赋予了复合材料更优异的力学性质,可以制备无屈曲织物预型件而使其原料适应性更加广泛,为复合材料提供了更广阔的应用空间。概述了经编织物预型件的制备方法、结构和性能,并展望了经编增强织物预型件的研究前景。     

平面三向织物增强橡胶复合材料的偏轴拉伸性能研究

研究了平面三向织物增强橡胶复合材料的偏轴拉伸性能,并与平纹织物增强橡胶复合材料的偏轴拉伸性能进行了对比,同时分析了试样形状（长方形和哑铃形）对织物增强橡胶复合材料的偏轴拉伸的影响。结果表明,平面三向织物增强橡胶复合材料在各个方向的拉伸断裂强度及断裂伸长率变化较小,表现出准各向同性,而平纹织物增强橡胶复合材料则表现为明显的各向异性;哑铃形试样更适合织物增强橡胶复合材料的偏轴拉伸性能测试。     

三维角链锁机织物弹道侵彻性能实验研究

选用一种三维角链锁组织结构进行实弹侵彻测试,研究三维角链锁机织物的弹道侵彻性能。实弹测试时,由靶道两侧两对发光二极管测试弹体入射速度与剩余速度,并结合弹体和织物靶体几何结构参数计算三维角链锁机织物的弹道侵彻性能指标,从而预测三维角链锁机织物的弹道侵彻性能。实弹测试后采用微距相机观察织物靶体实弹侵彻后的变形与破坏,从而揭示三维角链锁机织物的能量吸收机理。     

多壁碳纳米管/聚酰亚胺复合材料制备及其性能研究

聚酰亚胺的前聚体,聚酰胺酸,是通过4,4-二氨基二苯醚(ODA)与3,3,4,4二苯甲酮四羧酸二酐(BTDA)反应制备的.未改性的、酸改性和胺改性的多壁碳纳米管(MWCNT)被分别地单独加入到聚酰胺酸溶液中,并加热至300℃,从而制成聚酰亚胺/碳纳米管复合材料.扫描型电子显微镜(SEM)和透射电子显微镜(TEM)的显微...     

Forced torsional properties of PMR composites with varying nadic ester concentrations and processing histories

PMR polyimide resin was prepared from 4,4′-methylenedianiline (MDA), the dimethyl ester of 3,3′,4,4′- benzophenonetetracarboxylic acid (BTDE) and the monomethyl ester of 5-norbornene-2,3-dicarboxylic acid (NE). The NE group serves as a chain terminator and crosslinking site. PMR/Celion 6000 composites were fabricated from resins having varying NE concentrations using two molding processes, and the laminates characterized in forced torsion. Glass transition temperatures (T_g) of 360–390°C were observed in the crosslinked resins, as compared with the literature value of 284°C reported for the uncrosslinked systemT_g did not decrease with decreasing NE concentrations over the range from 2.0 to 1.25 moles. Stoichiometry, within the range studied, showed little influence on shear properties; however, a 25% variation in matrix shear modulus with processing was observed. The G₁₂ values determined in forced torsion were in excellent agreement with those reported from tensile tests of ±45° laminates. A branching and possible secondary crosslink mechanism is proposed based on dynamic mechanical behavior and infrared spectra of the composites.     

机织/针织混合铺层对复合材料力学性能的影响

为使纺织复合材料同时具有机织结构复合材料和针织结构复合材料的综合力学性能,通过混合铺层方式制备机织/针织混合结构复合材料。以芳纶机织平纹织物和针织罗纹织物为增强体,以环氧树脂为基体,调整复合材料中增强体的铺层顺序,利用真空辅助成型技术制备四层层压机织/针织混合结构复合材料。通过对复合材料拉伸性能、弯曲性能和冲击性能的测试,分析混合铺层和铺层顺序对芳纶环氧树脂复合材料力学性能的影响。结果表明,混合铺层和铺层顺序对芳纶环氧树脂复合材料的弯曲强度和冲击强度有较大影响,特别是对罗纹结构复合材料纬向弯曲强度和冲击强度的改善。当采用相同铺层方式,罗纹织物为受力面时,机织/针织混合结构复合材料具有较大弯曲强度和冲击强度。     

含苯炔基侧链的聚酰亚胺树脂及其复合材料

采用联苯酐(3,4′-BPDA)与4,4′-二氨基二苯醚(4,4-ODA),3,5-二氨基-4′-苯炔基二苯甲酮(DPEB),苯炔基苯酐(PEPA)制备了不同分子质量的聚酰亚胺树脂。通过流变分析,热重分析,红外光谱,动态热力学分析及静态力学性能测试等研究了分子结构,分子质量等因素对聚酰亚胺树脂耐热性和力学性能的影响。结果表明,合成的聚酰亚胺树脂具有优异耐热性能和较高的韧性,固化后树脂的玻璃化转变温度为379℃,5%热失重温度高于550℃,并且浇注体的拉伸强度是61 MPa,断裂伸长率是6.2%.碳纤维复合材料的室温弯曲强度为1 850 MPa,层间剪切强度为84 MPa,316℃时弯曲强度为946 MPa,剪切强度为46 MPa,具有良好的高温力学保持率。     

烯丙基酚醛改性双马来酰亚胺树脂的制备与性能

合成并表征了烯丙基酚醛树脂,再将其与双马来酰亚胺共聚制备了烯丙基酚醛改性双马树脂。通过DSC和FTIR分析了该树脂的固化行为,研究了其工艺性,利用TGA和DMA评价了其固化物的耐热性。结果表明,烯丙基酚醛树脂改性双马树脂可用于RTM等成型工艺,其固化物Tg约为330℃,初始热分解温度约400℃,5%失重温度达410℃,10%失重温度423℃。该树脂耐热性优异,可用作耐高温先进复合材料的基体树脂。     

Preparation and properties of nadic‐end‐capped cyclotriphosphazene‐containing polyimide/carbon fiber composites

New novel fire‐resistant and heat‐resistant cyclotriphosphazene‐containing polyimide resins were prepared in situ by the polymerization of (p‐aminophenoxy)(phenoxy)cyclotriphosphazenes with 3,3′,4,4′‐benzophenonetetracarboxylic acid or 3,3′,4,4′‐diphenylsulfonetetracarboxylic acid and a crosslink agent, 5‐norbornene‐2,3‐dicarboxylic acid and were used as polymer matrix compositing with a woven carbon fiber to prepare nadic‐end‐capped cyclotriphosphazene‐containing polyimide/carbon fiber composites. The thermal stability, flame retardance, morphology of the surface fracture, and some physical properties of the composites were investigated by thermogravimetric analysis, scanning electron microscopy, and a material testing system, respectively. The composites had good thermal stability, flame retardance, and mechanical properties. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 810–818, 2003     

Synthesis and properties of PMR type poly(benzimidazopyrrolone‐imide)s

PMR type poly(benzimidazopyrrolone‐imide) or poly(pyrrolone‐imide) (PPI) matrix resin was synthesized using the diethyl ester of 4,4′‐(hexafluoroisopropylidene)diphthalic acid (6FDE), 3,3′‐diaminobenzidine, para‐phenylenediamine, and monoethyl ester of cis‐5‐norbornene‐endo‐2,3‐dicarboxylic acid (NE) in anhydrous ethyl alcohol with N‐methylpyrrolidone. The homogeneous matrix resin solution (40–50% solid) was stable for a storage period of 2 weeks and showed good adhesion with carbon fibers, which ensured production of prepregs. The chemical and thermal processes in the polycondensation of the monomeric reactant mixture were monitored by Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, scanning electron microscopy, etc. Thermosetting PPI as well as short carbon fiber‐reinforced polymer composites was accomplished at optimal thermal curing conditions. The polymer materials, after postcuring, showed excellent thermal stability, with an initial decomposition temperature > 540°C. Results of MDA experiments indicate that the materials showed > 70–80% retention of the storage modulus at 400°C and glass transition temperatures as high as 440–451°C. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1600–1608, 2001     

Synthesis and properties of new polymerized monomer reactants matrix resins of pyrrolone–benzimidazole copolymers containing pyridine unit

A series of new polymerized monomer reactants (PMR) matrix resins of poly(pyrrolone‐benzimidazole)s containing a pyridine unit (PPBP) were synthesized by polycondensation of monoethyl ester of cis‐5‐norbornene‐endo‐2,3‐dicarboxylic acid, 2,6‐diphenyl ester pyridinedicarboxylic acid or 3,5‐diphenyl ester pyridinedicarboxylic acid, and diethyl ester of 4,4′‐oxydiphthalic acid with 3,3′‐diaminobenzidine in a mixing solution of anhydrous ethyl alcohol and N‐methylpyrrolidone under given temperature and pressure conditions. The resulting resin solutions showed good solubility in polar organic solvents and stability at room temperature. The corresponding PPBP matrix resin, molded powder, and molded plate were prepared by undergoing amidation, imidization, cyclization, and crosslinking reactions when the reaction temperature was increased from 80 to 350°C, successively; the crosslinking structure was formed by the reverse Diels–Alder reaction at 270–290°C under 50 MPa pressure (2.5–3.5 MPa displayed by the pressure meter). The chemical reactions and properties of the resulting PPBP were studied by means of FTIR, TGA, and DMA methods, and the results indicated that the kinds of PPBP materials retain excellent thermal stability and processability; when the initial decomposition temperature was above 620°C the T_g was at 413.5°C for 3,5‐PPBP‐20 molded plate. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3981–3990, 2004     

Influence of unwoven roving and woven fabric carbon fiber reinforcements on reaction-to-fire properties of polymer matrix composites

The influence of carbon fiber orientation on reaction-to-fire characteristics of layered polymer matrix composites is investigated in detail. M18-1/G939 as woven fabric and M18-1/G947 as unwoven roving prepregs with identical, epoxy based matrix composition were laid-up to give 1 to 8 mm thick unidirectional and quasi-isotropic laminates. Fundamental reaction-to-fire properties of these composites are interpreted on basis of the matrix components: epoxy resin and polyetherimide, as well as contained flame retardants magnesium hydroxide and zinc borate. Cone calorimetry and temperature distributions through the laminate show, that the velocity of combustion is influenced by fiber orientation for a given resin. For an unwoven roving it is confirmed that a quasi-isotropic fiber orientation leads to faster ignition, due to preferred delaminations, but retards burning processes more effectively than a unidirectional lay-up. This fundamental principle is extended to woven fabric reinforcements, however with less pronounced effects. Migration velocities of the pyrolysis zone are measured and additionally, decomposition of carbon fibers is considered. A comparison with a similar epoxy based matrix system without toughener and flame retardants: RTM6/G939 is carried out, in order to assess the effects by fiber orientation.