芳纶平纹布表面预处理及其与天然橡胶的界面粘合性能

研究了自制芳纶表面改性剂A和胶粘剂类型对芳纶布/天然橡胶复合材料界面粘合性能的影响,并利用SEM分析了芳纶纤维改性前后的表面形貌和复合材料剥离界面形貌。结果表明,使用改性剂A处理的芳纶布、开姆洛克胶粘剂和天然橡胶制成的复合材料粘合强度达到了13.9kN/m,与未处理芳纶布相比提高了162%,较间苯二酚/甲醛/胶乳胶粘剂(RFL)的提高了61%;复合材料剥离界面微观形貌为橡胶撕裂和芳纶纤维劈裂共存;改性剂A对芳纶表面浸润良好,二者有一定程度的化学反应。     

磷酸酯偶联剂改性芳纶纤维增强聚丙烯复合材料的性能研究

采用磷酸酯偶联剂对芳纶纤维表面进行接枝改性,研究了实验条件和纤维含量对芳纶纤维增强聚丙烯(PP)复合材料力学性能的影响,并用电子扫描显微镜观察了PP复合材料的微观形态结构。结果表明:磷酸酯偶联剂成功接枝到芳纶纤维表面上,使芳纶纤维和PP的界面黏结性能得以明显改善。芳纶纤维可以显著地提高PP复合材料的力学性能当,其含量为20%时复,合材料的综合性能最优。     

芳纶涂敷物及其对芳纶复合材料性能的影响

使用三种不同的有机溶剂萃取芳纶,对获得的萃取物进行了分析,结果表明:萃取物中包含多种成分,其中的醚类和硅油类物质是影响纤维复合材料性能的重要因素;对萃取处理前后芳纶增强环氧树脂复合材料的层间剪切性能进行了研究,初步探讨了纤维表面涂敷物对纤维表面能、纤维复合材料力学性能的影响。     

低温氨气等离子体对芳纶表面的改性

采用氨气等离子体对芳纶表面进行改性,用X-射线光电子能谱、场发射扫描电子显微镜、力学性能测试等手段对改性前后纤维表面的元素组成、形貌及其拉伸强度进行表征,并进一步通过微脱黏方法分析了等离子体处理条件对芳纶/环氧树脂复合材料界面黏结强度的影响。结果表明:芳纶经表面改性后,其表面极性官能团、表面粗糙度均有所增加,同时与环氧树脂基体的界面黏结强度明显增加。     

芳纶纤维增强丁腈橡胶的摩擦性能

研究了芳纶纤维增强丁腈橡胶(NBR)复合材料的物理机械性能和摩擦性能,并用扫描电子显微镜分析了芳纶纤维增强NBR复合材料的磨损表面和磨屑形貌。结果表明,芳纶的加入提高了NBR的拉伸强度;随着芳纶用量的增大,复合材料的扯断伸长率降低;芳纶的加入降低了NBR的摩擦系数和磨损率;当芳纶用量为20份时,复合材料的综合性能最佳。加入芳纶对NBR摩擦磨损形式的改变是NBR摩擦性能提高的重要原因。     

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。     

短芳纶纤维增强聚苯硫醚复合材料的性能

研究了短芳纶纤维增强ＰＰＳ／ＰＥＫ－Ｃ复合材料树脂体系的力学性能。主要讨论了短芳纶纤维的长度、含量及芳纶纤维的表面处理方法和压制温度对复合材料体系力学性能的影响。结果表明：纤维的长度和含量对力学性能有显著影响,在相同纤维含量下,纤维长度增加可使纤维末端数减少,减少了应力集中点,有利于拉伸强度和冲击强度的提高。芳纶纤维不需经过表面化学处理即与ＰＰＳ有良好的界面特性。随加工温度升高,复合材料冲击强度降低,拉伸强度提高     

芳纶/环氧复合材料性能研究

对国产芳纶Ⅲ/环氧及F-12/环氧复合材料的力学性能,与绝热层材料的相容性、3个热常数、微观断裂形貌等进行了系统地测试、比对和分析.结果表明,芳纶Ⅲ复合材料的抗弯曲、压缩、剪切和横向拉伸性能均低于相应的F-12复合材料,但具有优越的抗纵向拉伸强度,其抗纵向拉伸强度比F-12复合材料高约13.9%;芳纶复合材料与丁腈橡胶的抗两板剪切性能略高于芳纶复合材料与三元乙丙橡胶的抗两板剪切性能.总体上来说,芳纶复合材料属于隔热性能较好的材料,但其抗剪性能、纵向抗压性能较差.SEM可观察到芳纶复合材料破坏断口呈"皮芯"抽离和纤维撕裂的破坏特征.     

三种间位芳纶纸蜂窝力学性能及断口形貌分析

通过压缩性能、剪切性能和平面拉伸性能试验,对两种规格、三种牌号国产间位芳纶纸蜂窝与美国杜邦Nomex蜂窝的主要力学性能进行了对比分析;通过芳纶纸抗张强度试验,分析了芳纶纸性能对纸蜂窝主要力学性能的影响;通过微观下观察平面拉伸试样断口形貌,分析了纸蜂窝拉断时纤维和基体的破坏模式与其拉伸性能的关系。芳纶纸蜂窝主要力学性能试验表明,同种规格国产间位芳纶纸蜂窝的主要力学性能已基本达到Nomex蜂窝水平并且可满足目前国产大型客机选材要求。     

洋麻/芳纶混纺织物增强复合材料的力学性能研究

为了探究四种洋麻/芳纶不同混纺比对其混纺织物增强复合材料力学性能的影响,对以环氧树脂为基体,精细化处理的洋麻和对位芳纶不同混纺比机织物为增强体的复合材料进行力学性能测试,并对洋麻纤维扫描电子显微镜(SEM)及傅里叶红外光谱(FTIR)测试分析纤维表面粗糙度及极性变化,从而来分析力学测试结果。结果表明,洋麻/芳纶30/70混纺织物增强复合材料弯曲强度最高,为248.81MPa,弯曲模量为12.91GPa,与纯芳纶织物增强复合材料相比,分别提高4.9%和7.1%;而洋麻/芳纶20/80混纺织物增强复合材料剪切强度最高,为24.58MPa,与纯芳纶织物增强复合材料相比,提高18.6%。SEM及FTIR表明洋麻纤维精细化处理后,纤维表面粗糙度增加,极性降低,提高了增强体与树脂的界面结合力,从而改善了复合材料的弯曲、剪切性能。     

Surface Characterization of Differently Pretreated Flax Fibers and Their Application in Fiber-Reinforced Composites

Strong natural bast fibers, especially flax fibers, can be used to replace glass fibers in reinforced composites. The properties of natural fibers depend largely on maturity, retting and processing. Two chemical treatments were applied to retted and semiretted flax fibers to create better fiber to resin bonding and to show the effect of retting degree and successive purification processes on the mechanical properties of natural composite materials. Retted and semiretted flax fibers have been scoured and bleached with the objective of removing surface impurities and developing finer structure. To investigate the effect of adhesion promoter on the mechanical properties of natural fiber composite, a composite sample was prepared from bleached retted flax pretreated with adhesion promoter Isostearoyltitanate (ISTT).

After treatments the fibers got cleaner and the measurements showed that the fiber fineness as well as the surface free energy increased. The treatments were accompanied by decrease in the fiber tenacity but it has been found not to be reflected to the final mechanical properties of the composite. No improvement was remarked by using Isostearoyltitanate for surface modification.     

Effect of fiber treatment on the mechanical properties of LDPE-henequen cellulosic fiber composites

The degree of mechanical reinforcement that could be obtained by the introduction of henequen cellulosic fibers in a low-density polyethylene, LDPE, matrix was assessed experimentally. Composite materials of LDPE-henequen cellulosic fibers were prepared by mechanical mixing. The concentration of randomly oriented fibers in the composite ranged between 0 and 30% by volume. The tensile strength of these composite materials increased up to 50% compared to that of LDPE. There is also a noticeable increase in Young's modulus for the composite materials that compares favorably with that of LDPE. As expected, the addition of the fibers decreases the ultimate strain values for the composite materials. The thermal behavior of the LDPE-henequen cellulosic fibers materials, studied by differential scanning calorimetry, DSC, showed that the presence of the fibers does not affect the thermal behavior of the LDPE matrix; thus, the interaction between fiber and matrix is probably not very intimate. Preimpregnation of the cellulosic fibers in a LDPE-xylene solution and the use of a silane coupling agent results in a small increment in the mechanical properties of the composites, which is attributed to an improvement in the interface between the fibers and the matrix. The shear properties of the composites also increased with increasing fiber content and fiber surface treatment. It was also noted that the fiber surface treatment improves fiber dispersion in the matrix. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 197–207, 1997     

Surface modification of textile fibers for improvement of adhesion to polymeric matrices: a review

Surface treatments have long been utilized to modify the chemical and physical structures of the surface layers of textile fibers, thus improving the properties of fibers in many applications. This review discusses the feasibility and characteristics of different methods of surface modification of polymeric textile fibers, focusing on tailoring fiber-matrix bond strength in fiber-reinforced composite materials. The influence of various treatments on the chemical and mechanical properties of different fibers is discussed. Some very recent developments in surface modification of textile fibers are highlighted.     

Modification of Low-surface Energy Fibers used as Reinforcement in Cementitious Composites: A Review

This paper provides a review on the surface modification of low-surface energy fibers (polypropylene, polyethylene, and nylon) and discusses on the effects of these treatments toward the physical/mechanical properties of cement-based composite materials. These properties include the tensile, flexural, compressive strength and toughness, stress–strain behavior, modulus of elasticity, and workability. The effects of these treatments on the changes in the fiber/cement matrix interfacial properties are also presented. Studies have shown that various surface treatments have been used to improve the efficiency of the low-surface energy synthetic fibers in the cementitious composites. The modifications are on the basis of physical, chemical, and mechanical methods. The main achievements found have been the development of fibers with modified surface to optimize fiber–matrix adhesion. Moreover, the recently developed surface modifications will allow obtaining high-performance cementitious materials reinforced with the synthetic fibers.     

Production and characterisation of vapour grown carbon fiber/polypropylene composites

Polymeric composites are widely used in the aircraft and automotive industries. Their high strength-to-weight ratio makes significant weight reduction possible. Beside this advantage, the polymer materials also offer a good corrosion resistance but the mechanical and electrical properties are not satisfactory. In order to increase these properties, vapour grown carbon fibers (VGCF) with high strength and metal-like electrical conductivity can be embedded in the polymeric matrix. To ensure a good adhesion between the fibers and the polymer matrix a functionalization of the chemically inert surface of the fibers is necessary.In the present research work oxygen-containing functional groups were introduced on the fiber surface through cold plasma treatment. Measurements of the fiber surface energy after plasma functionalization showed an enhancement of at least 50% of the initial value. The VGCF/PP composites with different amounts of VGCF were made through extrusion and injection molding. The results show that the degree of fiber surface functionalization and the fiber distribution and orientation in the polypropylene (PP) matrix may strongly influence the mechanical properties of the composite.     

Properties of Recycled Polycarbonate/Waste Silk and Cotton Fiber Polymer Composites

Polymer-based composite structures have advantages over many other materials. The most important advantage is the higher mechanical properties obtained from the composites when supported by fiber reinforcement. The mechanical and thermal properties of fiber-reinforced composite structures are affected by the amount of fibers in the structures, orientation of the fibers and fiber length. Silk and cotton fibers are used in many fields but especially in clothing and textiles. However, there is not enough research on their usage as reinforcement fibers in composite structures. Silk fibers as a textile material have better physical and mechanical properties than other animal fibers. The improvement of the mechanical and physical properties of the composite structures allows them to be used in many areas. From economical, technological and environmental points of view, the improvement of mechanical and physical properties of polymeric materials are receiving much attention in recent studies.

In this study, different application areas were chosen to evaluate the waste silk and waste cotton rather than classic textile applications. Waste silk and cotton and recycled polycarbonate polymer were mixed and as a result composite structures were obtained. Silk and cotton waste fiber dimensions were in between 1 mm, 2.5 mm and 5 mm. The recycled PC/silk and cotton wastes were mixed in the rates of 97%/3%. Mixtures were prepared by twin-screw extruder. Tensile strength, % elongation, yield strength, elasticity modulus, Izod impact strength, melt flow index (MFI), heat deflection temperature (HDT) and Vicat softening temperature properties were determined. To determine the materials' thermal transition and microstructure properties, differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) were used.     

优化螺杆组合提高CFRPA性能的影响

通过优化螺杆组合，研究了ＣＦＲＰＡ复合材料中碳纤维的长度分布对其力学性能的影响，用ＭＭ－２００磨损试验机测试了ＣＦＲＰＡ复合材料的磨损性能。结果表明：通过适当的螺杆组合，复合材料的力学性能显著提高，合适的螺杆组合可以使树脂中长碳纤维的比例增大，改善增强效果，使ＣＦＲＰＡ的耐磨性提高，摩擦系数下降。     

碳纳米材料接枝碳纤维的复合材料界面增效研究进展

界面作为复合材料的重要组成部分,起着传递载荷的作用,影响复合材料的整体性能。碳纤维表面属于石墨乱层结构,微晶有序取向,惰性大,不易与树脂基体结合。对碳纤维进行适当的表面改性,增加纤维的比表面积、粗糙度和引入活性官能团,都能改善表面润湿情况,实现机械结合和化学结合,提高复合材料的界面性能。碳纳米材料接枝到碳纤维表面,是提高界面性能的有效方法之一。因此,对碳纳米管、氧化石墨烯接枝碳纤维的制备方法、界面增效设计以及界面增强机制的国内外研究现状进行综述和分析,在此基础上,展望了碳纳米材料接枝碳纤维表面和界面性能评价方法的研究趋势和前景。     

环氧改性聚碳酸酯单向纤维复合材料研究

采用Ｅ－５１环氧树脂改性聚碳酸酯，研究其单向Ｅ－玻璃纤维、单向碳纤维Ｔ３００、Ｍ４０复合材料。结果表明，改性后的聚碳酸酯复合材料（ＰＣＣＭ）的层间剪切强度等性能明显提高，玻纤复合材料提高幅度最大。纤维－基体界面粘接良好。     

基于NOL环的高性能纤维与环氧树脂的匹配性研究

纤维与树脂的界面对复合材料的整体力学性能有着显著的影响。基于NOL环的宏观力学测试一般被用来反映复合材料的界面粘结性能,因此适用于评价纤维与树脂之间的宏观力学性能匹配性。为了探究高性能碳纤维T700SC、T800HB及高强玻璃纤维与环氧树脂的宏观力学性能匹配性,本研究首先根据GB/T 1458—2008国家标准制备NOL环试样,再借助NOL环的拉伸和层间剪切强度测试分析了高性能纤维与环氧树脂不同匹配组合宏观力学性能差异的原因,并寻找出最佳匹配组合。结果表明:玻璃纤维与环氧树脂的界面存在最佳的粘结强度,而且不同粘结强度导致拉伸强度和破坏机理不同,而碳纤维复合材料界面性能较差,容易分层破坏;T800HB与环氧树脂的宏观力学匹配性优于T700SC,环氧树脂力学性能、碳纤维的表面微观结构与性质以及环氧树脂与碳纤维之间的相互作用关系是影响界面粘结性能的根本原因。该研究在高性能纤维单向复合材料的材料选择与设计方面具有现实意义。