Kevlar纤维的表面改性研究

采用甲苯-2,4-二异氰酸酯(TDI)和环氧树脂(EP)混合制得的表面改性剂对Kevlar纤维进行表面接枝处理,利用扫描电子显微镜观察Kevlar纤维改性前后的表面形貌及改性Kevlar纤维与弹性体间剥离界面的破坏形貌,用衰减全反射傅里叶变换红外光谱仪分析Kevlar纤维改性前后表面化学基团的变化,研究了改性效果和机理。结果表明,TDI和EP发生了化学反应,改性剂可在Kevlar纤维表面引入活性基团,从而显著改善了Kevlar纤维与聚合物基体之间的界面粘合状态。     

Kevlar纤维表面改性及用于绝热层材料制备

为改善Kevlar纤维在三元乙丙橡胶中的使用性能,用化学方法对Kevlar纤维进行键合C=C的表面处理.通过傅里叶变换红外光谱、扫描电镜和X射线光电子能谱对表面改性进行鉴定,并进行纤维处理前后纤维抗拉伸强度和绝热层配方试验.实验结果表明,纤维经过表面改性,拉伸强度下降15%,其与三元乙丙橡胶制得的绝热层力学性能有显著提...     

改性Kevlar纳米纤维对羧基丁腈橡胶/丁苯橡胶共混胶力学性能的影响

采用环氧氯丙烷对Kevlar纳米纤维(KNFs)表面进行改性,制备了表面改性KNFs(m-KNFs),考察了m-KNFs对羧基丁腈橡胶(XNBR)/丁苯橡胶(SBR)共混胶力学性能的影响.结果表明,m-KNFs可以增强XNBR/SBR共混胶的拉伸性能及撕裂性能,提高硫化胶的热稳定性和耐溶剂性能.添加5份m-KNFs后,...     

Kevlar纤维的表面改性

Kevlar(K)纤维的表面改性是近年来国内外复合材料界关注的一个重要课题。本文评述了K纤维的几种表面处理方法。并提出了改善K纤维复合材料性能的三种可能途径。     

硅烷改性PPTA纤维的表面粘结性能研究

采用未干燥的聚对苯二甲酰对苯二胺(PPTA)纤维,以乙烯基三甲氧基硅烷(VTMS)溶液对其进行表面改性,分析了改性前后PPTA纤维的表面元素、形貌结构以及力学性能的变化,并通过微脱胶法和激光拉曼光谱法研究了PPTA纤维/环氧树脂复合材料的界面剪切强度。结果表明:经VTMS溶液改性后,PPTA纤维表面产生了新的极性官能团,表面粗糙度增加;随着VTMS溶液浓度增大或处理时间增加,PPTA纤维/环氧树脂界面剪切强度逐渐增大,PPTA纤维的力学性能略为降低;较佳改性处理条件为VTMS溶液质量分数6%,处理时间5 min;经VTMS溶液改性处理后,PPTA纤维与树脂间的粘接性能提高,延缓了纤维轴向应力的传递。     

特种纤维及其他合成纤维

944185芳纶纤维的表面改性及其性能Briaeoe B.J…,.:^dhes.,90,int.,conf一1990,56/1~56/6(英)通过用烷基和二醇基团的接枝以及涂覆水溶胶粒子在Kevlar纤维表面进行改性的研究,从润湿的数据中已表明纤维表面的接枝相当成功,并且说明wilhelmy技术对改性纤维的表面能的特征是有用的。(汪兴华) 列礴186能进行织造的全伸展聚四氟乙烯纤维High perfonanee Textiles,1995,(6),p:4(英)Gore公司的100多全伸展Rastex聚四氟乙烯纤维具有强力不低于o.265N/tex,模量为4.IN/tex以及极佳的耐磨和耐挠曲性能,该纤维能在一212。护288℃的温度范围内连续…     

短切芳纶纤维增强PC/ABS合金的拉伸性能

以磷酸协同偶联剂改性对位芳纶纤维(PPTA)为增强材料,采用熔融共混法制备了 PPTA/PC/ABS复合材料,研究了 PPTA的含量与长度对复合材料拉伸性能的影响.研究结果表明,经过改性的PPTA表面变得粗糙,纤维与基体材料的接触面积明显增大.采用傅里叶红外光谱分析了 PPTA改性前后表面化学基团的变化,结果表明,磷酸...     

EVA共混改性UHMWPE纤维的表面性能

以乙烯-醋酸乙烯酯共聚物(EVA)作为共混改性剂,将其溶解在超高相对分子质量聚乙烯(UHMWPE)纺丝溶液中,制得共混改性UHMWPE冻胶纤维;对改性UHMWPE冻胶纤维进行萃取,干燥和热拉伸制得改性UHMWPE纤维;研究了改性前后纤维的结构与性能.结果表明:共混改性后UHMWPE纤维表面引入了极性基团,纤维与树脂基体...     

基于聚乙烯纤维表面改性的超高性能混凝土应变硬化机理EI北大核心CSCD

采用不同浓度硅烷偶联剂(SCA)溶液对憎水的聚乙烯纤维(PE纤维)进行表面改性处理,用表面改性后的PE纤维制备超高性能混凝土(UHPC),测定其直拉应变硬化与开裂行为。结果表明:对于低水胶比(0.18)UHPC,掺有3%浓度SCA溶液改性PE纤维得到了较好的应变硬化效果,多缝开裂效果更为显著。改性PE纤维影响UHPC应变硬化的机理是,附着在PE纤维表面的硅烷偶联剂官能团与基体之间建立较强的化学粘结力,其中的自由羟基(—OH)与基体中水化产物C-S-H发生缩合反应,羟基(—OH)与Ca(OH)_(2)中的Ca^(2+)之间发生配位化合作用。     

高疏水PAN的制备及其性能

以磷酸和环氧树脂E20制备了水性的磷酸改性环氧树脂(PAER),考察了反应温度、反应时间、投料比等因素对环氧树脂转化率的影响,得到了制备PAER的最佳条件。采用傅里叶变换红外光谱和核磁共振波谱对PAER结构进行了表征。用KOH中和PAER得到磷酸改性环氧树脂的钾盐(PAERK),测试了PAERK乳液的性质。使用含氟表面活性剂(FP?6812)与PAERK复配制得了含氟改性环氧树脂钾盐(PAERKF),测试了PAERKF乳液施覆改性前后聚丙烯腈纤维(PAN)与水的接触角及纤维在环氧树脂中的分散性,并通过场发射扫描电子显微镜对纤维的表面形貌进行了观察。结果表明,PAERKF的最佳上浆浓度为0.6 %(质量分数,下同),最佳施覆量为5.0 mg/g;经PAERKF施覆改性后的PAN纤维与水的接触角可达146.94°,纤维具备了高疏水特性;经PAERKF施覆改性后的PAN在环氧树脂基体中的分散系数(β)可达0.89,纤维在树脂基体中的分散性得到改善。     

Surface modification of Kevlar by grafting carbon nanotubes

A novel and efficient method was developed for surface‐modification of Kevlar fibers by multi‐wall carbon nanotubes (MWCNTs). Kevlar fibers were immersed in a solution mixed with Hexamethylene diisocyanate, 1,4‐diazabi‐cyclo [2,2,2] octane (DABCO), and toluene to introduce pendant amine groups before the COCl‐functionalized carbon nanotubes were chemically grafted onto the surface of modified fibers under ultrasonic condition. The characterization of resulting fiber involved in SEM, infrared spectroscopy, and tensile measurement. Results indicated over 20% of the fiber surface were coated by MWCNTs even after washing, which indicated a good adhesion. Furthermore, the mean value of tensile strength of Kevlar fiber was improved by 12% compared with original one. And the interlaminar shear strength (ILSS) of the fiber‐reinforced bismaleimides composite was increased by 30%. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Kevlar织物的Ar等离子体表面改性工艺优化研究

本文采用正交试验设计的方法优化了Ar冷等离子体对Kevlar49 S500织物的表面改性工艺。研究了Ar冷等离子体处理工艺的气压、功率和处理时间等参数对Kevlar49 S500织物表面性质的影响,通过测定改性前后织物与环氧树脂复合的界面剪切强度,对处理效果进行评价。结果表明：工作气体压力的影响最显著,时间和功率的影响次之。最终获得了等离子体改性的最佳工艺条件70Pa、300W、2min,经该工艺处理后的Kevlar织物／环氧复合材料的层间剪切强度为40.8MPa,较未处理的34.6MPa提高了18％。     

燃气流作用时间对玻璃钢层间剪切强度的影响

研究了不同燃气流作用时间对玻璃钢层间剪切强度的影响。研究结果表明:随着燃气流作用时间的延长,玻璃钢表面碳化失效层数呈增加趋势;未烧蚀部分复合材料层间剪切强度虽有降低,但是降低幅度不大,说明表面的玻璃布层碳化失效对深层复合材料层间剪切强度影响不大;烧蚀后复合材料断裂模式由韧性转变为脆性。该研究结果为玻璃钢在燃气流环境中的应用提供了重要的数据支撑。     

Properties of cyanate ester-cured epoxy/polyphenylene oxide blends as a matrix material for Kevlar fiber composites

Epoxy/polyphenylene oxide (PPO) blends were cured with multifunctional cyanate ester resin. The effects of the PPO content on the cure behavior in the cyanate ester-cured epoxy were investigated with Fourier transform infrared spectroscopy (FTIR). The cure reaction in the epoxy/PPO blends was faster than that of the neat epoxy system. FTIR analysis revealed that the cyanate functional group reactions were accelerated by adding PPO and that several co-reactions had occurred, such as cyanate-hydroxyl addition and epoxy-cyanate addition. This was caused by the reaction of cyanate ester with the PPO phenolic end-group and water yielding imidocarbonate and carbamate intermediate which can react with cyanate ester to form cyanurate. Then the cyanurate can react further with the epoxy resin. Thermal mechanical analysis showed that the thermal stability of the epoxy/PPO blends is improved by adding PPO. The morphology of the fiber-rich areas in the composite is different from that of the epoxy/PPO blend without Kevlar fiber. In the pure polymer blends with high PPO content (30 and 50 phr), phase separation and phase inversion were observed. In the composites, the majority of the epoxy resin migrates to the polar fiber surface, resulting in epoxy-coated fibers. So the interfacial shear strength (IFSS) between Kevlar fiber and the epoxy/PPO blends is almost the same as that between Kevlar fiber and neat epoxy. The presence of PPO does not affect the interfacial property in the epoxy/PPO/fiber composite. So the interlaminar shear strength (ILSS) increase with the PPO content is due to an increase in the composite's ductility or toughness.     

Effect of calcium chloride on the surface properties of Kevlar fiber

In this study, we present a new approach to modify the surface of Kevlar‐29 fiber by the complexation. The surface of Kevlar‐29 fiber was treated by calcium chloride (CaCl₂) ethanol solution. The structure and morphology of the modified Kevlar‐29 fiber were characterized by Fourier transform infrared spectroscopy, X‐ray photoelectron spectroscopy, X‐ray diffraction instrument, atomic force microscopy, and scanning electron microscopy. The results showed that CaCl₂ treatment's method can cause changes of the chemical groups of Kevlar‐29 fiber. The amino‐groups of Kevlar‐29 fiber were freed and the contents of ‐C‐N‐ increased. The changes can improve the surface roughness of Kevlar‐29 fibers. This can increase the adhesive of Kevlar fiber/epoxy composites. From the ILSS and mechanical properties values, it can be concluded that treatment with 5 wt % CaCl₂ for 5 h is the optimum complexation condition. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41358.     

透波性混杂纤维复合材料性能与应用

研究了透波性混杂纤维复合材料的性能,结果表明,芳纶纤维和玻璃纤维按一定混杂比和混杂方式与力学性能和电性能优良的乙烯基酯树脂体系制成的混杂纤维复合材料,可作为频率选择反射器用的功能和结构材料。     

Effect of various methods of pre-treatment of carbon fibers on the mechanical properties of PIP-based ceramics/carbon composites

The purpose of the work was to determine the conditions of CF preparation to obtain carbide composites with favorable mechanical response. The relationships between the interfacial properties of fiber/polymethylsiloxane composite, and mechanical properties of the resulting fiber/carbide composites were investigated. The CF/resin interfacial strength was modified by oxidation of CF surface with nitric acid, silanization, and depositing CNT or a pyrolytic carbon layer (PyC). The study of composite interphases (ILSS and SEM) and surface tests of the modified CF (XPS, FT-IR, wettability measurements) showed different nature of the bonding occurring at the fiber/resin and fiber/ceramics boundary. The CF silanization significantly improved the ILSS between CFs and resin by 38.5%, while reduced flexural properties of carbide composites. The most promising treatment method of CF for PIP-based ceramic composites was modification with PyC, which provided 2 times higher ILSS, 1.5 times higher flexural strength and improved work to fracture (WF) as compared to unmodified CF.     

CHARACTERIZATION, PROPERTIES, AND PROCESSING OF LARC PETI-5® AS A HIGH-TEMPERATURE SIZING MATERIAL: III. ADHESION ENHANCEMENT OF CARBON/BMI COMPOSITES

A phenylethynyl-terminated imide oligomer (LaRC PETI-5®) with a number average molecular weight of 2500 g/mol has been applied onto the surfaces of PAN-based carbon fiber tows and woven carbon fabrics as a sizing material to introduce an interphase between the fiber and matrix in carbon/BMI composites. The adhesion between the fiber and matrix was enhanced by the presence of a properly processed LaRC PETI-5® interphase. The results showed that when LaRC PETI-5® was sized and processed at 150°C, the interfacial shear strength (IFSS) of unidirectional IM7/BMI composite measured by using a microindentation technique and the interlaminar shear strength (ILSS) of a carbon/BMI composite measured by short beam shear test were markedly improved by about 35% and 66%, respectively, in comparison with the unsized counterparts. The adhesion enhancement strongly depends not only on the presence or absence of LaRC PETI-5® sizing interphase but also on the temperature profile applied to the sizing before composite fabrication. Both of these factors critically influence the physical and chemical state of the sizing material. Scanning electron microscopic observations of the composite fracture surfaces support the improved interfacial property of carbon/BMI composites.     

The Friction and Wear Properties of ECP Surface-Treated Kevlar Fiber-Reinforced Thermoplastic Polymide Composites

Epoxy chloropropane (ECP) grafting modification method was used for the surface treatment of Kevlar fiber to improve the interfacial adhesion of the Kevlar fiber-reinforced polyimide (PI) composite. The surface characteristics of untreated and treated Kevlar fiber were characterized by Fourier transform infrared (FT-IR) spectroscope. The friction and wear properties of the polyimide (PI) composites filled with differently surface treated Kevlar fibers (20 vol%), sliding against GCr15 steel, were investigated on a ball-on-block reciprocating UMT-2MT tribometer. Experimental results revealed that ECP treatment largely reduced the friction and wear of Kevlar/PI composites. Scanning electron microscope (SEM) investigation of worn surfaces of PI composites showed that ECP treated Kevlar/PI composite had the strongest interfacial adhesion and the smoothest worn surface under given load and reciprocating sliding frequency.     

加工条件对芳纶纤维增强PPS／PEK—C性能的影响

研究了短芳纶纤维增强ＰＰＳ／ＰＥＫ－Ｃ复合材料的力学性能。主要讨论了混合工艺、压制温度及冷方式等加工条件对材料力学性能的影响。