Kevlar 49纤维与芳纶Ⅲ的结构与性能研究

借助傅立叶变换红外光谱仪、扫描电子显微镜、X射线光电子能谱仪和强力拉伸仪分析研究了Kevlar 49和芳纶Ⅲ的化学结构、表面特征及力学性能。结果表明:芳纶Ⅲ的红外谱图上多出了苯并咪唑环的吸收峰;芳纶Ⅲ的表面较粗糙,Kevlar 49表面较光滑,芳纶Ⅲ和Kevlar 49纤维表面的碳、氧元素均比化学式计算值有所增加,但氮元素含量下降;芳纶Ⅲ表面的极性基团种类比Kevlar 49多。芳纶Ⅲ的单纤维拉伸强度是Kevlar 49的1.5倍,断裂伸长率比Kevlar49提高了45%～65%;2种纤维的断裂方式均为劈裂断裂,具有皮芯结构,但芳纶Ⅲ分子间的作用力比Kevlar49纤维强。     

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...     

聚氨酯纤维表面预处理的研究

对聚氨酯纤维表面预处理各步骤进行了研究,制得了表面处理较好的聚氨酯纤维。采用化学法粗化聚氨酯纤维,粗化时间及粗化温度决定粗化效率的高低,粗化温度和时间应密切配合;聚氨酯纤维的敏化,使纤维表面吸附一层容易被还原的物质,通过氧化还原反应,使纤维表面附着一层金属层;活化处理后纤维表面有一定数量金属微粒沉积,这些金属微粒不仅具有催化作用,还可以为金属原子结晶提供晶核。     

脉冲激光改性聚氨酯表面无钯化学镀铜的实验研究

提出了一种在改性聚氨酯(PUR)材料表面进行金属化的方法。以掺杂了铜基金属复合物粉末的PUR浆料为基体,采用SPI光纤激光器(波长1 064 nm)对PUR表面进行刻蚀改性,达到传统化学镀铜中粗化和活化的目的,最后进行化学镀铜。对铜镀层进行了结合力、导电性以及延展性测试。结果表明,制备的铜镀层光亮、致密、结合力强、导电性好、延展性优良。通过扫描电子显微镜、X射线能谱仪、X射线光电子能谱(XPS)分析和俄歇电子能谱(XAES)分析对经过激光刻蚀改性的基体表面形貌和成分进行表征。探讨了激光刻蚀改性材料表面后,基体表面上铜元素的价态,分析XPS图谱和XAES图谱发现,激光刻蚀改性后的基体表面上铜元素以Cu+形式存在。研究了不同激光功率对刻蚀表面粗糙度的影响规律,通过胶带拉力实验验证了基体表面形貌与镀层结合强度的关系,实验结果表明,当用功率为7 W的激光刻蚀基体表面时,材料表面粗糙度值最大,并且其镀层结合力也最强。     

塑材电镀的两种粗化方法

化学镀之前,需要进行粗化处理,使塑料的表面形成均匀细致,无光泽的微观粗糙并具有亲水性。粗化分两种:一是机械粗化,另一是化学粗化。金属镀层与塑料的结合有两种方式;一种是机械结合,另一种是化学结合。化学粗化对两种结合方式都有利,机械粗化只对前一种结合方式有利。如以化学粗化所获得的结合力为100,机械粗化(液     

镁合金直接化学镀镍的研究

为了提高镁合金的耐蚀性,对表面进行化学镀镍.研究了硫脲、pH值、温度及时间等对化学镀镍层及镀速的影响.测定了镀层的显微硬度、结合力和耐蚀性.结果表明,镀层具有较高的硬度和较好的结合力,耐蚀性大大提高.X射线衍射表明,镀态下镀层为非晶态,热处理能使镀层晶化,当热处理温度达到400 ℃时,晶化效果尤为明显.     

通用ABS电镀性能研究

通过对ABS电镀机理的研究，探讨影响塑料金属镀层结合力的因素。同时通过使用不同的ABS粗化配方，研究最佳的粗化工艺。通过实际的实验对不同生产厂商的通用ABS之间电镀性能进行对比，为客户选料提供依据。     

可电镀聚甲醛镀层强度研究及其机理探讨

聚甲醛(POM)粗化处理后表面变脆,基体与镀层黏结强度低,很难单独用作电镀基体材料。通过在POM中加入丙烯腈-丁二烯-苯乙烯共聚物(ABS)和用表面处理剂对粗化后表面进一步处理来提高基体与镀层之间的黏结强度。结果表明,加入ABS能够使粗化后的表面粗糙度进一步提高,改善表面韧性;表面处理剂处理可以进一步增加表面极性基团含量,使基体与镀层黏结强度达到实际使用要求。     

不饱和聚酯树脂的粗化工艺

介绍了不饱和聚酯树脂的粗化工艺流程及各工艺规范通过正交试验确定了最佳粗化工艺条件：粗化液的体积分数为400ml／L温度为80～85℃,粗化时间为20min。讨论了粗化液用量、粗化温度和时间对粗化效果和镀层质量的影响经检测表明,该金属镀层与基体结合力良好目前该工艺已应用于生产中。     

新型金刚石/铜基复合材料粗化液的应用

对金刚石/铜基复合材料表面化学镀预处理过程中的粗化工艺进行了研究,开发了一种JG-01型粗化液,其组成为:亚硝酸钠5 g,氢氧化钠5 g,三乙醇胺0.3 g,过氧化碳酰胺0.4 g,高铁酸钾0.5 g,去离子水88.8 g。采用扫描电镜分析以及结合力、耐热性等测试方法对比研究了该新型粗化工艺和传统粗化工艺对金刚石/铜基复合材料化学镀镍层表面形貌和性能的影响。与传统粗化工艺相比,新工艺对金刚石/铜基复合材料表面具有更好的粗化效果,粗化后得到的镍镀层平整、光亮,结合力和耐热性好。新的粗化工艺有效地解决了传统粗化工艺存在的漏镀以及镀层光亮性、结合力和耐热性差等问题。     

玻璃纤维/环氧树脂复合材料表面金属化工艺研究

提出一种在玻璃纤维/环氧树脂复合材料表面化学镀镍的简化工艺,首先在复合材料表面引入含有镀镍短纤维的过渡层,复合材料与过渡层共固化成型。通过机械粗化、酸化、化学镀工艺成功地在玻璃纤维/环氧树脂复合材料表面沉积一层连续致密的Ni-P镀层。采用超景深显微镜观察化学镀后镀层的表面形貌,并采用SEM对镀层截面特征进行观测。系统地研究了化学镀时间、装载量对镀层表面形貌、镀层厚度与镀层沉积速度的影响规律,并测量了复合材料/镍镀层界面结合强度。试验结果表明,当化学镀时间为8 h、装载量为1.25 dm2/L时,镀层厚度能达到38.96μm,镀层结合强度达到8.45 MPa。     

Application of the microbond technique. IV. Improved fiber–matrix adhesion by RF plasma treatment of organic fibers

The microbond technique is a modification of the single-fiber pullout test for measuring interfacial shear strength. Briefly, a cured microdroplet of material is debonded in shear from a single fiber. Ultra-high modulus polyethylene (Spectra) fibers and aramid fibers (Kevlar) were treated using a radio frequency plasma in order to increase the interfacial bond between the fibers and an epoxy resin. The treated fiber surface was subsequently analyzed by X-ray photoelectron spectroscopy (XPS). Plasma treatment resulted in an increased concentration of oxygen containing functionalities on the fiber surface. The interfacial shear strength as determined by the microbond test increased by 118% for the Spectra fibers and by 45% for the Kevlar fibers with the same epoxy resin. Scanning electron microscopy indicated little change of the surface topography of either fiber following plasma treatment. Effects of friction and surface composition of the plasma-treated fibers is discussed. © 1993 John Wiley & Sons, Inc.     

Improvement of adhesion of Kevlar fiber to epoxy by chemical modification

Kevlar 149 fibers were surface-modified by chlorosulfonation and subsequent reaction of -SO₂O with some reagents (e.g. glycine, water, ethylenediamine, and 2-butanol) to improve the adhesion to epoxy resin. The mechanical properties and surface topography of the modified fibers were investigated at different reaction times and reagent concentrations. The surface functional groups introduced into the surface of the fibers were identified by X-ray photoelectron spectroscopy (XPS) and static secondary ion mass spectroscopy (SIMS). The interfacial shear strength (IFSS) between the fibers and epoxy resin was measured by the microbond test. The results showed that the IFSS was markedly improved (by a factor of 2.25) by the chlorosulfonation/glycine treatment and that the fiber strength was not affected. Scanning electron microscopy (SEM) was also used to study the surface topography of fibers pulled from the epoxy resin. Furthermore, energy dispersive X-ray (EDX) spectroscopy was used to qualitatively examine the amount of sulfur in the fiber surfaces and in the fracture surfaces of fibers from microbond pull-out specimens. The results of EDX examination were consistent with a change of the fracture mode from the interface between the fiber and the epoxy resin to a location within the fiber and/or epoxy resin as observed by SEM.     

Modification of the carbon fiber surface with a copper coating for composite materials with epoxy

Surface treatment of carbon fibers is essential to provide adequate interfacial interaction, and strength in carbon fiber/epoxy composites. The electrodeposition of a metallic copper coating on the carbon fiber surface has been examined as an alternative method to improve carbon fiber-epoxy interfacial properties. The wettability of the carbon fiber by the epoxy resin was improved as a result of copper electrodeposition. As a consequence, the adhesion between the carbon fiber and epoxy was also greatly improved by the surface electrolytic treatment used. The electrodeposition conditions affected significantly both wettability and adhesion phenomena. The electrolytic current had a strong effect on the interface performance. It was found that there was an intermediate electrolytic current, within the range used, which promoted better wetting and composite strength, compared with conventionally surface-oxidized carbon fibers.     

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     

磷酸表面改性Kevlar纤维及其复合材料性能的研究

采用磷酸溶液对芳纶纤维(Kevlar)进行了表面改性,通过考察其表面化学结构、元素组成、表面形貌及表面粗糙度的变化研究了磷酸对Kevlar纤维表面改性的效果.结果发现,改性后的纤维表面引入了含氧基团,并产生了明显的刻蚀作用.利用溶液预浸渍工艺和高温模压成型技术制备了Kevlar增强双马来酰亚胺树脂(BMI)复合材料,通...     

Functionalization of ceramic fibers by metallic sputter coating

Ceramic fibers were functionalized by the sputter coating of copper in this study. The surface and interface structures of the functionalized ceramic fibers were investigated by atomic force microscopy (AFM) and environmental scanning electron microscopy (ESEM). The observations by AFM revealed the formation of nanoclusters on the fiber surface. The coated layer of the sputtered copper was also confirmed by the ESEM examination, equipped with an energy-dispersive X-ray analysis. It was also found that the electrical resistance of the ceramic fibers decreased with increased coating thickness. The interfacial bonding between fibrous substrate and sputter-coated copper was investigated and discussed by peel-off tests in this study. The mechanism of the interfacial adhesion between copper and fiber substrate was also discussed.     

低温等离子体改性UHMWPE纤维的表面性能

采用空气低温等离子体改善超高相对分子质量聚乙烯(UHMWPE)短纤维的黏着性,设计正交试验对改性后纤维的黏着性进行测试与分析,确定出较优试验方案;然后对未处理和经较优方案改性后的UHMWPE短纤维的表面形貌、表面化学成分、表面润湿性和强伸性进行测试分析。结果表明:空气低温等离子体改性UHMWPE短纤维黏着性的较优处理条件为功率50 W、压强15 Pa、反应时间120 s,此时,纤维的剥离功是未处理的4.14倍,黏着性得到了大幅度的提升,且单纤维强力损失率仅为3.29%;经较优方案处理后,纤维表面的粗糙程度有所增加,表面润湿性有明显改善,纤维表面的C元素含量明显减少,O、N元素含量有所增加,且出现了相对含量为22.2%的C=O官能团,有利于UHMWPE短纤维黏着性的改善。