S-157酚醛树脂/CBFTC复合材料的研究

制备了连续玄武岩纤维平纹布(CBFTC)增强S-157酚醛树脂复合材料。研究了树脂含量对S-157酚醛树脂/CBFTC复合材料力学性能和烧蚀性能的影响,并借助扫描电子显微镜对复合材料断面的微观形貌进行了分析,同时将S-157酚醛树脂/CBFTC复合材料与S-157酚醛树脂/高强玻璃纤维平纹布(GFTC)复合材料进行了性能对比。结果表明,树脂含量在30%时S-157酚醛树脂/CBFTC复合材料的力学性能和烧蚀性能最佳;S-157酚醛树脂/CBFTC复合材料比S-157酚醛树脂/GFTC复合材料具有更好的力学性能和烧蚀性能。     

高性能酚醛树脂基烧蚀复合材料的研究

本文采用DSC、TG和GPC等测试方法对硼酚醛树脂和S-15X酚醛树脂的固化工艺、热失重特性、分子量及其分布进行了表征和对比,在此基础上对比研究了连续玄武岩纤维、S-2高强玻璃纤维、高硅氧纤维、碳纤维增强硼酚醛树脂和S-15X酚醛树脂复合材料的烧蚀性能和弯曲性能,最后考察了脱模剂对硼酚醛树脂复合材料压制工艺的影响。研究结果表明：硼酚醛树脂复合材料的烧蚀性能、弯曲性能都要优于S-15X酚醛树脂复合材料,通过使用PMR、MIRROR GLAZE代替硬脂酸作为外脱模剂,19W RELEASE代替油酸作为内脱模剂,能良好的解决硼酚醛树脂复合材料压制工艺问题。     

烧蚀复合材料用酚醛树脂的结构表征及性能

采用FTIR、GPC、DSC及TG等方法对4种烧蚀复合材料用酚醛树脂(钨酚醛树脂(WPR)、硼酚醛树脂(BPR)、高残炭酚醛树脂(HCYPR)、S-157酚醛树脂)固化前的结构、分子质量及其分布、固化历程、热失重特性进行了表征和对比,以便为烧蚀复合材料基体的筛选提供理论依据。研究结果发现,S-157PR的分子质量最小,分布最窄,浸润性最好;4种酚醛树脂的固化峰温依次为HCYPR>BPR>WPR>S-157PR;800℃残炭率依次为BPR>HCYPR>WPR>S-157PR。     

新型酚醛树脂基耐烧蚀复合材料的性能研究

本文采用GPC和TG对高残碳酚醛树脂（HCYPR）和硼酚醛树脂（BPR）的分子量及其分布、热失重特性进行了表征和对比。同时对比了S-2GFC／HCYPR和S-2GFC／BPR的力学性能和烧蚀性能。研究结果发现：与HCYPR相比,BPR的分子量更小,分布宽度更窄,与增强体的浸润性更好;BPR的800℃残碳率高于HCYPR;S-2GFC／HCYPR的质量烧蚀率要大于S-2GFC／BPR,但线烧蚀率小于后者。S-2GFC／BPR比S-2GFC／HCYPR强度的提高百分数从59．4％到73．9％不等,其中压缩强度提高了73．9％;模量的提高百分数从27．5％到31．9％不等,其中弯曲模量提高了31．9％。     

连续玄武岩纤维平纹布增强碳纳米管改性酚醛树脂复合材料的研究

采用碳纳米管(CNTs)对S-157树脂基体进行改性,同时研究了不同分散工艺和CNTs质量分数(质量含量)对复合材料力学性能和烧蚀性能的影响。研究结果表明:使用CNTs对S-157酚醛树脂进行改性,采用球磨分散和超声分散相结合的分散工艺,可以明显提高CNTs/CBFTC/S-157PR复合材料的力学性能,但其烧蚀性能略有降低;当CNTs质量分数为0.5%时,CNTs/CBFTC/S-157PR的弯曲强度和压缩强度最大;当CNTs质量分数为1.5%时,CNTs/CBFTC/S-157PR的拉伸强度最大。     

不同种类碳纤维增强酚醛树脂烧蚀复合材料的性能对比

对比了聚丙烯腈(PAN)基碳纤维(PCF)和粘胶基碳纤维(RCF)的密度、平均比热容、拉伸性能,分析了PCF和RCF的表面形貌,研究了PCF增强S-157酚醛树脂(S-157 PF)复合材料(S-157 PF/PCF)和RCF增强S-157PF复合材料(S-157 PF/RCF)的烧蚀性能和弯曲性能,并对复合材料弯曲断口的微观形貌进行分析。结果表明,与PCF相比,RCF的密度略小,平均比热容略大,纤维表面粗糙,拉伸性能远低于前者;S-157 PF/RCF的烧蚀性能优于S-157 PF/PCF,但弯曲性能较差。     

硼酚醛树脂及其复合材料的研究进展

作为目前最成功的改性酚醛树脂品种之一,硼酚醛树脂具有优异的耐热性能和耐烧蚀性能,良好的力学性能、摩擦性能和阻燃性能等。硼酚醛树脂及其复合材料可广泛应用于航空航天、武器装备、汽车制动、防火阻燃等领域。对硼酚醛树脂及其复合材料的研究进展进行了综述。首先概述了硼酚醛树脂的不同制备方法及硼酚醛树脂的改性途径;然后重点总结了硼酚醛树脂基复合材料的常用制备方法及其耐热性能、耐烧蚀性能、力学性能、摩擦性能、阻燃性能、耐水性能;最后,对该领域所存在的问题进行了总结,并展望了其发展趋势。     

热熔胶膜法制备硅硼改性酚醛树脂预浸料及复合材料

纤维增强酚醛树脂基复合材料具有易成型、加工周期短和隔热性能好等优点,可用作烧蚀型热防护材料。本文对热熔胶膜法制备的高硅氧/硅硼改性酚醛预浸料及其复合材料进行了研究。硅硼改性酚醛树脂具有优异的热稳定性,氮气气氛下,800℃残碳率高达75.3%。高硅氧/硅硼改性酚醛预浸料的百分流动度、挥发份和树脂含量分别为21.3%、5.7%和40.2%。对比溶液法制备预浸料成型的层压板,采用热熔胶膜法制备的高硅氧/硅硼改性酚醛复合材料层压板的弯曲强度和层间剪切强度分别提高了56.2%和22.1%。氧乙炔线烧蚀率和质量烧蚀率分别为0.0498mm/s和0.0506g/s。高硅氧/硅硼改性酚醛复合材料优异的耐烧蚀性能有助于降低热防护材料的厚度,减轻火箭、导弹等的总体质量,对提高武器装备的性能具有重要的意义。     

酚醛树脂烧蚀性能研究进展

简单介绍了在酚醛树脂烧蚀性能的改进研究中硼酚醛、铝酚醛、磷酚醛、聚酚醚和酚三嗪树脂的烧蚀性能，也介绍了使用芳基酚、烷基酚与DA改性剂改进的酚醛树脂的烧蚀性能，以及开环聚合酚醛树脂和新型酚醛树脂S-157与S-158的主要性能。同时介绍了氯化磷腈改性酚醛树脂和提高酚醛树脂成炭率的其它改性研究。指出了改性酚醛树脂仍然是今后常规武器系统使用的一种低成本热防护材料的树脂基体。     

纳米改性碳/酚醛树脂基复合材料性能研究

针对碳/酚醛树脂基复合材料层间剪切强度低的缺点,采用纳米填料进行改性。测试了2种纳米填料(纳米碳纤维、碳纳米管)改性后酚醛树脂的热解性能,研究了纳米填料对复合材料力学性能、烧蚀性能以及高温炭化后力学性能的影响,并观察分析了复合材料测试后的微观形貌。研究结果表明,纳米填料改性后,复合材料的力学性能、烧蚀性能均有所改善。其中,纳米碳纤维改性后复合材料的常温层间剪切强度达到24.9 MPa,氧乙炔线烧蚀率为22.75μm/s,质量烧蚀率为23.58 mg/s。纳米碳纤维表面粗糙,与树脂基体的界面强度高,因此其改性后的力学性能和烧蚀性能优于碳纳米管。     

Effects of phenolic resin contents on microstructures and properties of c/sic-diamond composites

In this paper, C/SiC-diamond composites were obtained by chemical vapor infiltration (CVI) and reactive melt infiltration (RMI), and the effects of phenolic resin contents on the microstructures and properties of as-obtained C/SiC-diamond composites were studied. The results suggested a significant influence of phenolic resin contents on the pore structure of the composites before reactive melt infiltration (RMI), as well as phase composition and density of the matrix after RMI. The mechanical properties of composites were shown to correlate with the threshold effect of phenolic resin. Sample R5 prepared with high phenolic resin contents displayed significantly declined mechanical properties. On the other hand, adjustment of the phenolic resin content yielded samples with maximum room temperature thermal conductivity reaching 14.75 W/(m·K). The theoretical thermal conductivity of the composites calculated by the Hasselman-Johnson (H-J) theoretical model was estimated to 24.52 W/(m·K). Overall, the increase in phenolic resin content led to unreacted diamond-C regions and the formation of substantial porosity. These features reduced the thermal conductivity of the resulting C/SiC-diamond composites.     

Effect of quasi‐carbonization processing parameters on the mechanical properties of quasi‐carbon/phenolic composites

In this work, quasi‐carbon fabrics were produced by quasi‐carbonization processes conducted at and below 1200°C. Stabilized polyacrylonitrile (PAN) fabrics and quasi‐carbon fabrics were used as reinforcements of phenolic composites with a 50 wt %/50 wt % ratio of the fabric to the phenolic resin. The effect of the quasi‐carbonization process on the flexural properties, interfacial strength, and dynamic mechanical properties of quasi‐carbon/phenolic composites was investigated in terms of the flexural strength and modulus, interlaminar shear strength, and storage modulus. The results were also compared with those of a stabilized PAN fabric/phenolic composite. The flexural, interlaminar, and dynamic mechanical results were quite consistent with one another. On the basis of all the results, the quasi‐static and dynamic mechanical properties of quasi‐carbon/phenolic composites increased with the applied external tension and heat‐treatment temperature increasing and with the heating rate decreasing for the quasi‐carbonization process. This study shows that control of the processing parameters strongly influences not only the mechanical properties of quasi‐carbon/phenolic composites but also the interlaminar shear strength between the fibers and the matrix resin. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Physical,Chemical and Mechanical Properties of Hibiscus sabdariffa Fiber/Polymer Composite

Tensile, compressive, flexural and wear resistance properties of Hibiscus sabdariffa fiber-reinforced phenolic (Resorcinol Formaldehyde) resin matrix-based composites were evaluated to assess the possibility of using these fibers as a new eco-friendly material in engineering applications. Polymer composite samples were fabricated by a compression-molding technique developed in our laboratory. The effect of fiber dimension on mechanical properties was evaluated. The interfacial bonding between Hibiscus sabdariffa fiber and the polymer matrix has been found to affect the mechanical properties of the resorcinol formaldehyde resin matrix. It has been observed that particle-reinforced polymer composites exhibit better mechanical properties as compared to short and long fiber-reinforced polymeric composites. These composites were further subjected to an evaluation of morphological, thermal, physical (swelling and moisture absorption) and chemical properties.     

环氧液晶/酚醛树脂复合材料的摩擦磨损性能研究

利用自行合成的端基为环氧基的热致性环氧液晶(LCE)与酚醛树脂(PF)通过熔融挤出进行原位复合制备了LCE/PF复合材料。研究了LCE含量对LCE/PF复合材料力学性能、硬度及摩擦性能的影响,使用扫描电子显微镜(SEM)观察了复合材料的磨损面形貌,分析了复合材料的摩擦磨损机理。研究结果表明:LCE含量为2.5%时,摩擦系数比未加LCE的稳定,力学性能也有所提高;在各温度下,LCE含量为7.5%的复合材料的体积磨损率比未加LCE的复合材料的小达,到了GB 5763—2008的要求。     

Mechanical and thermal transmission properties of carbon nanofiber‐dispersed carbon/phenolic multiscale composites

The present article reports the development and characterization of carbon nanofiber (CNF)‐incorporated carbon/phenolic multiscale composites. Vapor‐grown CNFs were dispersed homogeneously in to phenolic resin using an effective dispersion route, and carbon fabrics were subsequently impregnated with the CNF‐dispersed resin to develop carbon fiber/CNF/phenolic resin multiscale composites. Mechanical and thermal transmission properties of multiscale composites were characterized. Elastic modulus and thermal conductivity of neat carbon/phenolic and multiscale composites were predicted and compared with the experimental results. It was observed that incorporation of only 1.5 wt % CNF resulted in 10% improvement in Young's modulus, 12% increase in tensile strength, and 36% increase in thermal conductivity of carbon/phenolic composites. Fracture surface of composite samples revealed the formation of stronger fiber/matrix interface in case of multiscale composites than neat carbon/phenolic composites. Enhancement of above properties through CNF addition has been explained, and the difference between the predicted values and experimental results has been discussed. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Nanoclay and long-fiber-reinforced composites based on epoxy and phenolic resins

In this study, high-performance thermoset polymer composites are synthesized by using both long fibers and nanoclays. Epoxy and phenolic resins, the two most important thermoset polymers, are used as the polymer matrix. The hydrophobic epoxy resin is mixed with surface modified nanoclay, while the hydrophilic phenolic resin is mixed with unmodified raw nanoclay to form nanocomposites. Long carbon fibers are also added into the nanocomposites to produce hybrid composites. Mechanical and thermal properties of synthesized composites are compared with both long-fiber-reinforced composites and polymer- layered silicate composites. The optimal conditions of sample preparation and processing are also investigated to achieve the best properties of the hybrid composites. It is found that mechanical and thermal properties of epoxy and phenolic nanocomposites can be substantially improved. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

BF/CF层间混杂结构对复合材料性能影响

制备了碳纤维/玄武岩纤维(CF/BF)层间混杂增强酚醛树脂基复合材料,通过力学性能测试研究了混杂结构对复合材料性能的影响,并与层数相同叠合压制成型的BF复合材料的性能进行了对比。结果表明,CF/BF混杂纤维增强酚醛树脂基复合材料较BF复合材料力学性能提高,嵌层结构复合材料综合性能好于夹芯结构。     

Hygrothermal cycling effects on the durability of phenolic based composites

Work has been performed to investigate the thermal and mechanical properties of carbon fiber/phenolic resin composites as engineering materials for the aerospace industry. These materials are cost effective while displaying excellent temperature and fire resistance as well as good mechanical properties. All phenolic and epoxy composite specimens used here were prepared by resin transfer molding (RTM) to model a cost‐effective process. Hygrothermal cycling effects on the property changes of phenolic composites were evaluated through thermal, mechanical, and morphological tests. The fracture performance of a phenolic composite modified with a silicone‐based additive decreased after fewer hygrothermal cycles than unmodified phenolic and epoxy composites. Results from dynamic mechanical analysis (DMA) experiments showed that the modified phenolic composite was more significantly affected by the hygrothermal cycling than the unmodified phenolic composites. Fatigue tests showed that the phenolic composites that were not exposed to hygrothermal cycling had more resistance to fatigue cycles than the epoxy composites.