先进树脂基复合材料技术发展及应用现状

简要介绍了先进树脂基复合材料的特性,从应用的角度总结了先进树脂基复合材料体系、主要成型技术的发展现状和趋势,回顾了先进树脂基复合材料在航空工业的应用历程,介绍了低温固化和电子束固化复合材料、结构/吸波复合材料和纳米复合材料的最新研究进展,最后依据国内航空装备发展的需求,讨论分析了国内先进树脂基复合材料的发展重点.     

环氧树脂及其复合材料微波固化研究

介绍了微波热效应原理,综述了近年来环氧树脂及其复合材料的微波固化研究进展,重点讨论了环氧、环氧微波固化工艺及其与加热固化的比较,热塑性树脂改性环氧,颗粒、纤维增强环氧复合材料的微波固化研究.     

高固体分环氧海洋防腐蚀涂料的研究进展

海洋环境中,钢结构的腐蚀不可避免,有机涂层是一种延缓金属腐蚀的最有效、最经济的材料之一。其中高固体分环氧涂料由于绿色环保、涂层致密性好、可厚涂等特点在海洋重防腐中得到广泛的应用。对目前高固体分环氧厚膜、超厚膜涂料的研究进展,存在的问题及解决方法进行了详细的介绍。其中,环氧树脂、胺类固化剂作为环氧涂料中的主要的成膜物质,对涂层的性能起着关键的作用。总结了几种在高固体分环氧涂料中切实可行的环氧树脂增韧改性方法,同时指出开发耐冲击性能优异,耐高温,低温固化、水下固化的环氧固化剂也是环氧固化剂的发展趋势。通过曼尼希碱改性合成的环氧固化剂,恰好能满足各种性能的要求,阐述了该类环氧固化剂的合成研究进展状况。     

固化剂类型与固化条件对环氧/粘土纳米复合材料插层剥离行为的影响

本文作者选用了5种不同类型的胺类固化剂:二乙烯三胺(DETA),二氨基二苯基甲烷(DDM),2.4.6三(二甲氨基甲基)苯酚(DMP-30),增韧改性胺和低温固化改性胺。考察了固化剂类型,固化温度和时间对环氧树脂/粘土纳米复合材料插层剥离行为的影响。固化程度和粘土层间距分别采用FT-IR和XRD,TEM检测。结果表明:环氧/粘土的插层与剥离行为与所选用的五种固化剂类型关系不大,而主要取决于固化工艺参数。在合适的固化条件下,当环氧树脂在粘土层间的固化速度大于层外固化速度,达到基本固化时,就能实现粘土的剥离,得到环氧/粘土纳米复合材料。     

环氧树脂及其复合材料微波固化研究进展

在介绍微波固化技术的原理及其优点的基础上,综述了环氧树脂及其复合材料的微波固化研究进展,重点讨论了微波固化对环氧树脂及其复合材料固化体系的固化速率、固化产物力学性能和热性能的影响,介绍了颗粒增强环氧树脂和纤维增强环氧树脂两种适合微波固化的复合材料系及工业应用关键技术问题,并对环氧树脂及其复合材料微波固化的应用前景进行了展望。     

防火玄武岩纤维中空织物复合材料的制备及性能

采用手工铺料法制备了水性无机硅树脂/玄武岩纤维中空织物复合材料，在其表面涂覆防火涂料，三次固化制备出防火玄武岩纤维中空织物复合材料。采用电子万能试验机、氧-乙炔烧蚀试验机、热重分析仪表征了复合材料的力学性能、阻燃性能和耐高温性能。详细考察了防火涂料用量和固化工艺对复合材料力学性能和阻燃性能的影响，研究了材料的结构和耐高温性能。结果表明：防火涂料用量为14.5%,第一次固化温度80℃/固化时间5h,第二次固化温度120℃/固化时间4h,第三次固化温度120℃/固化时间1.5h,在上述固化工艺条件下复合材料的力学性能和耐烧蚀性能较好；其拉伸强度、弯曲强度、质量烧蚀率分别为34.97MPa、60.36MPa、61mg/s;复合材料热失重15%的温度为683.9℃;防火涂料的涂覆有助于提升复合材料的耐高温性能。     

国内外有关网络聚合物材料的文献摘录：环氧树脂部分

具有良好阻燃性及层问粘接强度的环氧绝缘膜及其多层印刷线路板；用作齿科修复材料的光固化环氧纳米复合材料；固化促进剂母炼胶及其具有优异流动性，贮存稳定性及低温固化性的单组分环氧组成物；耐热及耐冲击环氧树脂组成物；无须压力即可粘接的热固性环氧树脂粘接片及其制备……     

双马来酰亚胺改性酚醛型环氧树脂的研究

试图合成一种具有良好力学性能的耐高温胶粘剂,以满足耐高温吸波涂层的需要.用二苯甲烷型双马来酰亚胺(BMI)对酚醛型环氧树脂(F-51)进行改性,合成了耐高温新型环氧胶粘剂.实验结果表明:最佳的固化工艺是在180℃下固化2h;胶粘剂中BMI含量越高,其附着力越大,热分解温度越高,耐热性越好,但剪切强度较差.借助于红外光谱分析、热分析等现代测试手段探讨了环氧胶粘剂固化反应机理.     

航空级树脂基复合材料的低成本制造技术

在综述大量相关文献、会议报告的基础上,概要介绍了航空级树脂基复合材料的几种主要低成本制造技术,如自动铺带技术、自动铺丝技术、低温固化预浸料技术、电子束固化、液体成型技术结合纤维编织及缝编技术和树脂膜渗透成型技术(RFI),列举了空客公司最新飞机A380使用RFI工艺制造后压力舱隔板隔框的工艺过程.     

快速固化环氧树脂及其碳纤维/环氧复合材料性能

采用双酚A型环氧树脂（DGEBA）、改性咪唑（MIM）及改性脂肪胺（MAA）研制快速固化树脂体系。分别利用DSC和流变仪测试了树脂体系的固化特性与流变行为,优选了树脂配方。采用真空辅助树脂灌注工艺（VARIM）制备了快速成型的碳纤维/环氧复合材料层板,考察了层板的成型质量和力学性能,并与常规固化的层板性能进行了对比。结果表明：采用优选的树脂配方,120 ℃下树脂在5 min内固化度达95%,碳纤维/环氧复合材料层板成型固化时间可控制在13 min以内,固化度达95%以上,并且没有明显缺陷;与常规固化相比（固化时间大于2 h）,快速固化碳纤维/环氧复合材料层板的弯曲性能和耐热性能降低幅度较小。     

Study on the Effect of Cure Cycle on the Process Induced Deformation of Cap Shaped Stiffened Composite Panels

Cap-shaped stiffened composite panels offer many excellent properties such as low density, high strength, high stiffness to weight ratio, and design flexibility. During their manufacturing processes, however, thermo-curing inherently produces the undesired residual stresses and cure deformations, which limits the applications of composite structures in a certain degree. In order to reduce the cure deformation, in this paper, the effect of cure cycle (curing temperature, curing pressure, cooling rate) on the process-induced deformation of cap-shaped stiffened composite panels was presented. A simple mathematical model based on the curing dynamics was established to predict the deformation of the cap-shaped stiffened composite panels. The deformation calculated by the mathematical model and experimental studies were compared, and an Error Correction Model was established. The Error Correction Model showed a good agreement with the experimental results.     

紫外光固化导电胶基体固化动力学分析

紫外光固化导电胶作为新型电子连接材料,具有环保、节能等优点。导电胶中基体胶的固化性能是影响导电胶使用可靠性的重要因素。利用实时红外分析研究环氧树脂基体胶的固化过程和固化过程的动力学特征。研究表明基体胶的固化是通过体系中-C=C-双键的互联来实现,随固化反应的进行,双键的相对浓度降低。光引发剂的添加量影响体系的固化速度和固化程度,光引发剂的添加量存在阈值Cmax。     

Cure kinetics and rheology characterisation and modelling of ambient temperature curing epoxy resins for resin infusion/VARTM and wet layup applications

Ambient temperature curing epoxy resins are widely used as the matrix material in fibre reinforced plastics in the marine and wind energy sectors, where they are popular due to their relatively high mechanical performance yet low processing and tooling costs. To date, the characterisation of ambient curing epoxy resins has been limited to relatively simple measures, not suitable for use in heat transfer and flow process models. A complete cure kinetics and rheology model allows the prediction of the progression of degree of cure and viscosity for any time–temperature history. The progression of degree of cure of two epoxy resin systems was measured by differential scanning calorimeter and fitted to an nth order model incorporating vitrification effects. Viscosity was measured using an oscillatory rheometer and fitted to a model from the literature. The resulting cure kinetics and rheology model enables the improvement of resin infusion and wet layup processes by providing a thorough understanding of the interlinked relationship between time, temperature, degree of cure and viscosity.     

GFRP厚板制件固化过程固化度分布

采用真空导入模塑工艺(VIMP) 制备了85 mm 厚玻璃纤维增强环氧树脂层合板, 单面刚性模具加热固化, 沿铺层厚度方向设置热电偶, 进行了实时固化温度监测, 发现固化时厚度方向存在明显的温度差异。通过DSC方法得到等温环氧树脂固化度-时间实验数据, 建立了基于自催化反应模型的等温固化反应动力学方程, 模型计算值和实验值符合良好; 提出了时间离散分步计算法, 对非等温固化条件下, 厚度方向的固化度分布进行了计算。结果表明: 固化过程中厚度方向固化度存在差异, 短时间的后固化可以消除此差异。该方法可以模拟出由温度差异导致的固化度的不均匀分布, 用于指导优化固化工艺。      

Preparation of Microcellular Epoxy Foams through a Limited‐Foaming Process: A Contradiction with the Time–Temperature–Transformation Cure Diagram

3D cross‐linking networks are generated through chemical reactions between thermosetting epoxy resin and hardener during curing. The curing degree of epoxy material can be increased by increasing curing temperature and/or time. The epoxy material must then be fully cured through a postcuring process to optimize its material characteristics. Here, a limited‐foaming method is introduced for the preparation of microcellular epoxy foams (Lim‐foams) with improved cell morphology, high thermal expansion coefficient, and good compressive properties. Lim‐foams exhibit a lower glass transition temperature (T_g) and curing degree than epoxy foams fabricated through free‐foaming process (Fre‐foams). Surprisingly, however, the T_g of Lim‐foams is unaffected by postcuring temperature and time. This phenomenon, which is related to high gas pressure in the bubbles, contradicts that indicated by the time–temperature–transformation cure diagram. High bubble pressure promotes the movement of molecular chains under heating at low temperature and simultaneously suppresses the etherification cross‐linking reaction during post‐curing.     

Inverse algorithm for optimal processing of composite materials

During thermoset composite materials processing, the chemical reaction is highly exothermic and because of the low thermal conductivity of the material, significant temperature and state of cure gradients can be generated in thick parts. This creates non-uniform stresses that provoke defects. We propose to control the transformation by monitoring the temperature of the mold walls. A general inverse analysis based on the conjugate gradient method of minimization associated to the adjoint equations is used. After having detailed the method, we propose two examples. The first one presents an optimal cycle to obtain uniform conversion at the end of the curing of an epoxy/glass-fiber composite. The second example is concerned with the control of the temperature variations during the curing of a polyester/glass-fiber composite. The method is experimentally validated and proves to be very powerful and flexible.     

纳米Al2O3改性环氧树脂复合材料的低温力学性能研究

通过机械搅拌的方法将纳米Al2O3颗粒分散在环氧树脂基体中,用干燥箱对其固化来制备纳米Al2O3,环氧树脂复合材料,然后进行低温冷冻处理,从而对其进行力学性能测验。研究表明环氧树脂在120℃下烘烤12h所取得的固化效果较好;而低温处理后的环氧树脂复合材料具有优于未处理的环氧树脂复合材料的力学性能,尤其是在耐压和韧性方面。     

一种中温固化环氧树脂的研究

利用苯胺-甲醛与双氰胺反应得到了一种改性产物。相对于双氰胺, 它在环氧树脂和某种低沸点溶剂中有良好的溶解性。在促进剂作用下, 可以在125℃左右固化环氧树脂, 固化后的浇铸体有良好的力学性能和耐湿热性。用该树脂体系可湿法制作复合材料预浸布, 其玻璃布复合材料在力学性能和耐湿热性能上可达到国外同类产品的水平。      

稀释剂对环氧树脂电子束辐射固化性能的影响

对分别加入4 种稀释剂的双酚A 环氧树脂和酚醛环氧树脂的电子束辐射固化性能进行了研究。分析了稀释剂种类及含量对环氧树脂体系辐射产物的固化度、固化均匀性、固化区域大小及其动态力学性能的影响规律。结果表明: 电子束固化环氧树脂体系中加入稀释剂后, 辐射产物的固化度、玻璃化转变温度及储能模量有所下降, 但固化均匀性得到提高; 加入稀释剂的环氧树脂电子束固化区域的厚度均小于未加稀释剂树脂, 而底面直径却大于未加稀释剂树脂; 随着树脂中实际稀释剂含量的增加, 电子束固化环氧树脂固化度逐渐降低, 固化层厚度减小, 固化区域的底面直径先增加后减小。      

季铵盐对热熔预浸料用环氧树脂胶膜室温贮存期的影响

采用通常用作阳离子型表面活性剂和相转移催化剂的苄基三乙基氯化铵,作为酸酐/环氧树脂体系的促进剂,制备了复合材料预浸料用环氧树脂胶膜,研究了其室温和高温固化特征。结果表明,与咪唑类促进剂相比,季铵盐作促进剂的环氧树脂室温固化反应速率小,而高温固化反应速率和凝胶时间几乎相等,在保证环氧树脂固化体系高温固化速率的前提下,季铵盐对环氧树脂胶膜的室温固化产生明显的阻缓作用,实测环氧树脂胶膜室温贮存期由使用咪唑类的5 d延长为8 d,理论室温极限贮存时间由8 d延长为11 d。