芳纶纤维/AFR树脂复合材料界面粘结性能的研究

为了改善芳纶纤维复合材料的界面粘结性能,合成了一种新型树脂(AFR)作为基体,以未经任何表面处理的芳纶纤维作增强材料,制备了芳纶纤维/AFR复合材料。采用测定表面能、接触角、层间剪切强度、横向拉伸性能和扫描电镜观察形貌等方法,从宏观和微观等方面研究了芳纶纤维/AFR复合材料的界面粘结性能。结果表明,AFR树脂与芳纶纤维有相近的表面能,AFR树脂溶液与芳纶纤维的接触角为42.8°,而环氧树脂(EP)与芳纶纤维的接触角为68°,说明AFR树脂对芳纶纤维的润湿性优于EP树脂;芳纶/AFR复合材料的层间剪切强度、横向拉伸强度和纵向拉伸强度分别为74.64MPa、25.34MPa和2256MPa,比芳纶/EP复合材料的相应强度分别提高了28.7%、32.5%和13.4%,其复合材料破坏面的形貌也说明芳纶纤维与AFR树脂之间的界面粘结性能较好。     

芳纶纤维复合材料基体(AFR-TE)的性能研究

为了改善芳纶纤维增强树脂基复合材料的界面粘结性能,本文从树脂基体入手,依据相似相容原理和芳纶的结构特点,合成出新型热固性树脂(AFR-TE)用作芳纶复合材料的基体.采用非等温DSC法研究了AFR-TE树脂体系的固化反应动力学,确定了合理的固化制度;测定了AFR-TE树脂浇铸体的力学性能和耐热性能;探讨了芳纶/AFR-TE复合材料的界面粘结性能.结果表明,AFR-TE树脂固化反应级数为一级;AFR-TE树脂浇铸体的热变形温度(123.5℃)比E-51环氧树脂提高了25％,AFR-TE树脂各项力学性能都优于E-51环氧树脂,韧性得到明显改善;芳纶纤维/AFR-TE树脂复合材料的层间剪切强度和横向拉伸强度为71.2MPa和30.2MPa,分别比芳纶/E-51环氧复合材料提高了22.8％和58.1％,这表明AFR-TE树脂对芳纶的界面粘结性明显优于环氧树脂.     

碳纳米管改性环氧树脂/碳纤维复合材料的界面性能

采用碳纳米管对环氧树脂体系以及碳纤维进行改性处理,得到四种试样,即CNTs-00 (不添加碳纳米管)、CNTs-01 (碳纳米管与活性分子预反应)、CNTs-02 (碳纳米管与树脂体系直接混合)、CNTs-03 (碳纤维表面生长碳纳米管)。采用视频接触角测量仪以及界面性能测试仪对树脂浸渍国产T800S碳纤维单丝形成的微球形态、微球与纤维的界面接触角及界面剪切强度(IFSS)等进行了分析表征;同时采用模压法制备了复合材料单向板,从宏观尺度表征了其层间剪切强度(ILSS)。结果表明,与CNTs-00相比,CNTs-01的树脂界面浸润性以及复合材料IFSS有了较大提高,接触角减小了3.1°,IFSS提高了12.7%,ILSS提高了9%;CNTs-02的树脂界面浸润性略有降低,接触角增大了0.9°,IFSS降低了8.6%,ILSS与CNT–00基本相同;CNTs-03的界面浸润性降低,浸润角增大了4.5°,IFSS降低了5.7%,ILSS降低了11.5%。     

芳纶纤维等离子体接枝改性处理研究

采用等离子体接枝对芳纶纤维表面进行改性处理,采用XPS、浸润性、界面剪切强度对等离子体接枝处理前后的表面组成、复合材料界面粘接性能等进行了研究,结果表明:等离子体接枝处理可以有效地提高芳纶纤维表面的极性官能团,增加与基体树脂-环氧树脂的浸润性,进而提高芳纶/环氧复合材料的界面粘接强度.     

纳米SiO2改性EP对基体力学性能和芳纶纤维/EP复合材料界面性能的影响

研究了纳米SiO2对环氧树脂(EP)基体力学性能的影响,并进一步采用对位芳纶纤维(F-12)增强环氧树脂,制备了NOL环复合材料,通过复合材料层间剪切性能测试考核了F-12与环氧树脂之间的界面粘接性能.结果表明:环氧树脂中添加适量的纳米SiO2能够有效提高环氧树脂浇注体的拉伸强度、拉伸弹性模量、冲击强度.纳米SiO2的加入,可以有效改善F-12与环氧树脂基体之间的界面粘接性能,降低复合材料的空隙率,F-12/纳米SiO2(6%)-EP复合材料的层间剪切强度(ILSS)提高约60.3%.     

高能辐照对国产芳纶纤维/环氧复合材料界面性能影响

芳纶纤维因其表面惰性、光滑使其与树脂浸润性差,界面结合强度低。以环氧氯丙烷为介质1,采用60Coγ-射线辐照方法对国产芳纶纤维进行表面改性,以界面剪切强度（IFSS）和层间剪切强度（ILSS）表征芳纶/环氧复合材料界面结合性能。结果表明在400kGy辐照剂量下改性效果最好;经高能辐照处理的芳纶纤维表面能升高,并失去了原有的光滑表面,且纤维表面氧含量有大幅度提高,使得纤维表面活性增大。     

环氧树脂/多巴胺增强芳纶纤维界面性能

由于芳纶纤维表面光滑且呈现化学惰性,与环氧树脂等基体材料结合后界面性能较差。为此,采用多巴胺在不同时间下对改进型芳纶Ⅲ纤维表面进行改性处理,并研究了对环氧树脂/多巴胺改性芳纶纤维界面性能的影响。对扫描电子显微镜对纤维改性前后表面形貌进行表征,发现纤维改性后表面粗糙度提高,利于与环氧树脂间界面结合。利用傅里叶变换红外光谱、X射线光电子能谱对纤维改性前后基团和表面元素含量进行表征,改性后纤维表面活性基团增加,极性增强。通过热重分析表明聚多巴胺成功吸附在纤维表面。测量纤维表面接触角,改性后的接触角更小,有利于环氧树脂润湿纤维。采用横向丝束复合材料的拉伸强度表征环氧树脂/芳纶纤维的界面性能。最终确定了多巴胺浓度为2 g/L,在多巴胺溶液中处理4 h为最佳条件,在该条件拉伸强度比为改性前提高了28.06%,拉伸弹性模量提高了14.68%。     

纳米SiO2对EP／国产芳纶Ⅲ纤维复合材料性能的影响

选择纳米SiO2作为增强材料改性环氧树脂(EP)基体,与国产芳纶Ⅲ纤维缠绕成复合材料。研究了不同含量的纳米SiO2对EP基体拉伸性能和冲击性能的影响;通过NOL环复合材料剪切强度测试和纤维缠绕Φ150mm容器水压爆破实验,研究了不同含量纳米SiO2对EP/国产芳纶Ⅲ纤维复合材料层间剪切强度和纤维强度转化率的影响。结果表明,EP基体中纳米SiO2质量分数为3%时,对基体拉伸和冲击性能均有显著改善,拉伸强度和冲击强度分别提高28.8%和22.6%,EP/国产芳纶Ⅲ纤维复合材料的层间剪切强度达到最大值,比未改性配方高出约56.8%;Φ150mm容器水压爆破结果表明,纳米SiO的加入使纤维强度转化率平均提高7%以上。     

碳纤维湿法缠绕用高模量高韧性环氧树脂基体

设计了一系列针对碳纤维湿法缠绕的环氧树脂基体,测试了树脂浇注体及其复合材料的力学性能和热机械性能,研究了树脂基体对碳纤维复合材料界面性能的影响.试验结果表明,对韧性树脂体系,树脂基体的模量是发挥纤维强度的关键因素,模量的提升将大幅提高复合材料的综合性能.经复配和优化的树脂体系兼具高模量和高韧性,其T700碳纤维复合材料NOL环拉伸强度达到2480MPa,T800碳纤维复合材料NOL环拉伸强度达到2780MPa,玻璃化温度(Tg)超过200℃,具有优异的界面性能和耐热性能.     

改性EP/S–GF单向复合材料缠绕成型工艺及性能

以4,4’-二氨基二苯甲烷、苯酚和甲醛为原料合成二胺型苯并恶嗪(MDA–BOZ),并用其改性环氧树脂(EP)。采用湿法缠绕成型方法制备单向高强玻璃纤维(S–GF)增强改性EP基复合材料。用T–β外推法和凝胶化时间法确定了复合材料的成型工艺,并测试了其在室温和高温下的拉伸强度、弯曲强度、层间剪切强度等力学性能。与EP/4,4’–二氨基二苯砜(DDS)/S–GF复合材料相比,EP/MDA–BOZ/DDS/S–GF复合材料综合力学性能有较大提高。EP/MDA–BOZ/DDS/S–GF复合材料室温弯曲强度达1 428.3 MPa,层间剪切强度达79.92 MPa,纵向拉伸强度1 134.1 MPa,拉伸弹性模量为40.15 GPa。复合材料在100℃时,弯曲强度保持率为78.95%,层间剪切强度保持率为81.06%。扫描电子显微镜分析发现,改性树脂与玻璃纤维界面粘结性较好。     

Surface ammonification of the mutual‐irradiated aramid fibers in 1,4‐dichlorobutane for improving interfacial properties with epoxy resin

The mutual irradiated aramid fibers in 1,4‐dichlorobutane was ammoniated by ammonia/alcohol solution, in an attempt to improve the interfacial properties between aramid fibers and epoxy matrix. Scanning electron microscopy (SEM), X‐ray photoelectron spectroscopy (XPS), dynamic contact angle analysis (DCA), interfacial shear strength (IFSS), and single fiber tensile testing were carried out to investigate the functionalization process of aramid fibers and the interfacial properties of the composites. Experimental results showed that the fiber surface elements content changed obviously as well as the roughness through the radiation and chemical reaction. The surface energy and IFSS of aramid fibers increased distinctly after the ammonification, respectively. The amino groups generated by ammonification enhanced the interfacial adhesion of composites effectively by participating in the epoxy resin curing. Moreover, benefited by the appropriate radiation, the tensile strength of aramid fibers was not affected at all. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44924.     

Interfacial studies on the surface modified aramid fiber reinforced epoxy composites

In this work, solutions of rare earth modifier (RES) and epoxy chloropropane (ECP) grafting modification method were used for the surface treatment of aramid fiber. The effect of chemical treatment on aramid fiber has been studied in a composite system. The surface characteristics of aramid fibers were characterized by Fourier transform infrared spectroscopy (FTIR). The interfacial properties of aramid/epoxy composites were investigated by means of the single fiber pull‐out tests. The mechanical properties of the aramid/epoxy composites were studied by interlaminar shear strength (ILSS). As a result, it was found that RES surface treatment is superior to ECP grafting treatment in promoting the interfacial adhesion between aramid fiber and epoxy matrix, resulting in the improved mechanical properties of the composites. Meanwhile, the tensile strengths of single fibers were almost not affected by RES treatment. This was probably due to the presence of reactive functional groups on the aramid fiber surface, leading to an increment of interfacial binding force between fibers and matrix in a composite system. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:4165–4170, 2006     

Formation of a carbon fiber/polyhedral oligomeric silsesquioxane/carbon nanotube hybrid reinforcement and its effect on the interfacial properties of carbon fiber/epoxy composites

A carbon fiber/polyhedral oligomeric silsesquioxane/carbon nanotube (CF–POSS–CNT) hybrid reinforcement was prepared by grafting CNTs onto the carbon fiber surface using octaglycidyldimethylsilyl POSS as the linkage in an attempt to improve the interfacial properties between carbon fibers and an epoxy matrix. X-ray photoelectron spectroscopy, scanning electron microscopy, dynamic contact angle analysis and single fiber tensile testing were performed to characterize the hybrid reinforcements. Interlaminar shear strength (ILSS), impact toughness, dynamic mechanical analysis and force modulation atomic force microscopy were carried out to investigate the interfacial properties of the composites. Experimental results show that POSS and CNTs are grafted uniformly on the fiber surface and significantly increase the fiber surface roughness. The polar functional groups and surface energy of carbon fibers are obviously increased after the modification. Single fiber tensile testing results demonstrate that the functionalization does not lead to any discernable decrease in the fiber tensile strength. Mechanical property test results indicate the ILSS and impact toughness are enhanced. The storage modulus and service temperature increase by 11 GPa and 17 °C, respectively. POSS and CNTs effectively enhance the interfacial adhesion of the composites by improving resin wettability, increasing chemical bonding and mechanical interlocking.     

Wetting and adhesion behavior of armos fibers after dielectric barrier discharge plasma treatment

To investigate the influence of atmospheric plasma treatment on aramid fiber wetting and adhesion behavior, an air dielectric barrier discharge (DBD) was applied to the Armos aramid fiber surface at different discharge power densities. Dynamic contact angle analysis indicated that the total surface free energy was increased from 49.6 to 68.3 mJ/m 2 , an increment of 37.7%, whereas the single-fiber tensile strength testing showed that the mechanical properties of the Armos fibers were almost unaffected. With the enhancement of fiber surface wettability, the interlaminar shear strength, which was used to determine the interfacial adhesion in Armos-fiber-reinforced thermoplastic poly(phthalazinone ether sulfone ketone) composites, increased by 17.2% to 71.4 MPa. Scanning electron microscopy photos showed that the predominant failure mode of the composites changed from interface failure to matrix and/or fiber failure after the plasma treatment. Taken together, these results suggest that the air DBD plasma was an effective technique for improving the surface and interfacial performance of the Armos fibers without damaging their bulk properties. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Influence of oxygen plasma treatment parameters on the properties of carbon fiber

This study is focused on the impact of oxygen plasma treatment on properties of carbon fibers and interfacial adhesion behavior between the carbon fibers and epoxy resin. The influences of the main parameters of plasma treatment process, including duration, power, and flow rate of oxygen gas were studied in detail using interlaminar shear strength (ILSS) of carbon fiber composites. The ILSS of composites made of carbon fibers treated by oxygen plasma for 1 min, at power of 125 W, and oxygen flow rate of 100 sccm presented a maximum increase of 28% compared to composites made of untreated carbon fibers. Furthermore, carbon fibers were characterized by scanning electron microscopy (SEM), tensile strength test, attenuated total reflectance Fourier transform infrared (ATR-FTIR), and Raman spectroscopy analyses. It was found that the concentration of reactive functional groups on the fiber surface was increased after the plasma modification, as well the surface roughness, which finally improved the interfacial adhesion between carbon fibers and epoxy resin. However, high power and long exposure times could partly damage the surface of carbon fibers and decrease the tensile strength of filaments and ILSS of treated fiber composites.     

Ultrasonic modification of aramid fiber–epoxy interface

An ultrasonic irradiation technique is used during the process of fabricating aramid fiber–epoxy resin reinforced composites to improve the interfacial adhesion performance. Under the ultrasonic treatment, the change of the resin viscosity is studied. The results of a microbond test show obvious improvement in the interfacial shear strength after ultrasonic treatment. The mechanical properties of the composites, such as the interlaminar shear strength and tensile strength, are measured. Combined with the SEM results, these show it is the mechanical properties that are improved and the fracture modes are varied from the interface between the fibers and resin to the fibrillation of fibers and resin. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2764–2768, 2001     

Experimental characterization of contact angle and surface energy on aramid fibers

In this paper, both contact angles and surface energy of aramid fibers are investigated using the liquid droplet method. First, the contact angles between matrix resin and aramid fibers are measured at different degrees of cure, which indicate that the contact angles increased initially and then decreased after the consolidation. Second, surface energy components of aramid fibers are determined from the contact angle using the geometric-mean equations. Finally, the influences of various surface treatments on the surface energy of aramid fibers are analyzed. These results play an important role for designing and evaluating the fiber/matrix interfacial strength of aramid fiber-reinforced composites.     

界面结合对GF/PDCPD复合材料性能的影响

界面结合性能对制备性能优异的复合材料具有重要意义。通过对双环戊二烯（DCPD）与玻璃纤维（GF）的浸润性进行研究，将其与等效环氧树脂比较，开发了一种与玻璃纤维具有较好结合性的DCPD树脂，用其制备出一种综合性能优异的玻璃纤维增强PDCPD基复合材料。通过动态接触角、90?拉伸强度和层间剪切强度实验，测定了不同树脂与玻璃纤维之间的粘附力，提供了玻璃纤维与不同树脂界面性能差异。结果表明，SCB-600 DCPD树脂与玻璃纤维的结合性较优，动态接触角为60.35??0.3?，90?拉伸强度为(42.3?1.6) MPa，层间剪切强度为(61.3?3.2) MPa，与1564环氧树脂相当。进一步优化了DCPD树脂质量分数，当树脂质量分数为30%?2%时，SCB-600 DCPD复合材料具有相对最优的力学性能，材料拉伸强度为(1180.1?4.1) MPa，弯曲强度为(1060.4?4.6) MPa，缺口冲击强度为(145.3?4.8) KJ/m2。其弯曲和拉伸强度与玻璃纤维增强环氧树脂基复合材料的性能基本相当，但缺口冲击强度优于1564环氧树脂。