常压等离子体改善高性能纤维粘结性的研究

以氦气为载气,氧气为反应气体,对高强度聚乙烯和Twaron 1000芳纶两种高性能纤维进行常压等离子体处理,来改善纤维的粘结性能;采用单纤维抽拔实验测定等离子体处理前后纤维与环氧树脂之间的界面剪切力;利用原子力显微镜和X射线光电子能谱仪分析等离子体处理前后纤维表面形态和化学成分的变化。结果表明:高强度聚乙烯纤维和芳纶经常压等离子体处理后,纤维表面粗糙度增加,纤维表面碳元素含量下降,羟基、羧基等含氧或氮的极性基团增加,纤维粘结性能得到提高,但其强度无明显变化。     

低温等离子处理对玄武岩纤维表面及复合材料性能的影响

对玄武岩纤维表面进行低温等离子处理,研究了低温等离子处理纤维对其表面性能、偶联剂吸附量及纤维增强树脂层间胶合强度和力学性能的影响。结果表明,纤维表面经低温等离子处理后,玄武岩纤维表面接触角由未处理时的132.23°降为75.22°,润湿性大大改善;纤维表面偶联剂吸附量在低温等离子处理10遍时达到最大;低温等离子及偶联剂处理纤维表面,处理10遍时,玄武岩纤维增强环氧树脂(BFRP)的拉伸性能、弯曲性能达到最优,而其剪切强度在处理2到10遍范围增加较快,10遍以后几乎不变。     

UHMWPE纤维的表面改性及其在网式阻车器中的应用

本文简要介绍了超高分子量聚乙烯(UHMWPE)纤维的性能,总结了超高分子量聚乙烯纤维等离子处理法、氧化处理法、电晕放电处理法、辐射引发表面接枝处理等多种表面处理方法,讨论了这些表面处理方法对纤维增强复合材料粘结性能和本体力学性能的影响,分析了这些方法的处理效果、处理工艺等对实现连续化、工业化可行性的影响,并介绍了由UHMWPE纤维为原料制成的特种纤维网片在网式阻车器这个反恐领域的特殊应用。     

常压等离子体处理芳砜纶的结构与性能研究

分别采用氦气和氦气/氧气对芳砜纶进行常压等离子体处理。采用滴水吸收实验测定处理前后纤维表面的润湿性,利用扫描电子显微镜和X射线光电子能谱仪分析处理前后纤维表面形态和化学成分的变化。结果表明:经常压等离子体处理后芳砜纶表面粗糙度增加,纤维表面碳元素含量下降,羟基、羧基等含氧或氮的极性基团增加,芳砜纶纱线的润湿性能提高,纱线强度没有明显变化,氦气/氧气等离子体处理比氦气等离子体处理效果更好。     

碳纤维及无机纤维

20034243等离子氧化处理对超高模量碳纤维的表面和界面性能的影响Montes一Moran M.A.…:ComPosites,PavtAZOOI,32A,(3一4),P.361一371(英) 一种超高模量(uHM)碳纤维受到等离子氧化作用的处理,采用表面特殊技术,研究该处理对碳表面的物理和化学性能的影响。由SEM和STM研究完成确定表面形态的变化,纳米级的观察,推份出的结论是氧等离子体清洁了碳杂质的有机表面。XPS分析已处理的纤维显示出非常明显的氧含量增加。按来样计算和等离子处理纤维配制单根纤维的环氧组份,同时完成破碎试验,以表征纤维/基质分界面粘合的特征用拉曼光谱绘…     

常压等离子体改善合成纤维吸湿性的研究

用氦气作为等离子体的气体源、对涤纶、锦纶6、高强度聚乙烯纤维,Twaron 1000芳纶4种合成纤维进行常压等离子体处理,改善纤维的吸湿性能。结果表明:常压等离子体处理,对涤纶和锦纶6的表面有一定的刻蚀作用,但对高强度聚乙烯纤维、Twaron 1000芳纶的表面没有明显影响;经常压等离子体处理后,合成纤维表面氧、氮有所增加,吸湿性能得到提高,强度没有显著变化。     

等离子体技术对高性能有机纤维表面改性的研究

本文简要介绍了几种高性能有机纤维(芳纶、PBO、UHMWPE、PPS等)的性能及其应用,并阐述了低温等离子体技术对这些纤维表面性能的改性研究情况,发现等离子体处理可以对纤维表面产生物理刻蚀和化学改性作用,不仅能显著增加纤维的表面粗糙度,还能在纤维表面引入一些极性基团,降低纤维的表面能,从而提高了纤维与树脂基体的粘结性能;同时,等离子体技术操作简单,对环境污染少,因而是一种很有效的环境友好型改性技术,很适合运用在高性能有机纤维表面改性领域.     

PBO纤维及其改性的研究进展

简述了聚对苯撑苯并双噁唑(PBO)纤维的结构与性能;详述了PBO纤维的改性研究进展。PBO纤维的改性主要是改善其抗压性能和表面粘结性能。提高微纤间相互作用或交联等方法可提高PBO纤维的压缩强度;通过酸处理、偶联剂处理、等离子体处理及电晕处理等方法可提高PBO纤维的表面粘结性能。指出表面改性仍将是PBO纤维改性研究的重点。     

气体等离子处理提高塑料部件的粘结力

冷态气体等离子表面处理,可以显著增加塑料部件的粘结强度。这种加工处理可用于由标准的环氧树脂和聚氨酯粘结的装饰部件。等离子处理可作为一种通用的处理方法,它适用于各种塑料制品,甚至适用于由工程树脂制造的制品。     

淀粉纳米晶对玻璃纤维的表面改性研究

采用自制的淀粉纳米晶(SNC)对玻璃纤维进行表面处理,增加其与环氧树脂基体的界面剪切强度(IFSS)。研究了处理方式、处理时间、SNC乙醇分散液浓度、热处理温度等工艺参数对SNC在玻璃纤维表面沉积情况的影响,以及对改性玻璃纤维与环氧树脂的界面性能的影响规律。采用扫描电子显微镜、单纤维强力仪对处理前后玻璃纤维进行表征,并采用微脱粘法测试玻璃纤维与环氧树脂的界面粘结情况。结果表明,当重力静置处理时间24 h,SNC乙醇分散液浓度为1 g/100 m L时,SNC在玻璃纤维表面均匀沉积,且能显著提高玻璃纤维与环氧树脂的IFSS,为27.29 MPa,较未处理的纤维增加29.3%。150℃热处理4 h后,X射线光电子能谱结果显示SNC与玻璃纤维形成化学键合,进一步增加纤维与环氧树脂的界面粘结,IFSS值达到32.30 MPa,较未处理的纤维增加53%,且纤维的拉伸强度得到较好的维持。     

Surface modification of ultra high modulus polyethylene fibers by an atmospheric pressure plasma jet

To improve their adhesion properties, ultra high modulus polyethylene (UHMPE) fibers were treated by an atmospheric pressure helium plasma jet (APPJ), which was operated at radio frequency (13.56 MHz). The surface properties of the fibers were investigated by X‐ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and contact angle measurement. The surface dyeability improvement after plasma treatments was investigated using laser scanning confocal microscopy (LSCM). The adhesion strengths of the fibers with epoxy were evaluated by microbond tests. In addition, the influence of operational parameters of the plasma treatment including power input and treatment temperature was studied. XPS analysis showed a significant increase in the surface oxygen content. LSCM results showed that the plasma treatments greatly increased fluorescence dye concentrations on the surface and higher diffusion rate to the fiber center. The tensile strength of UHMPE fiber either remained unchanged or decreased by 10–13.6% after plasma treatment. The contact angle exhibited a characteristic increase in wettability, due to the polar groups introduced by plasma treatment. The microbond test showed that the interfacial shear strengths (IFSS) increase significantly (57–139%) after plasma treatment for all groups and the optimum activation is obtained at 100°C and 5 W power input. SEM analysis showed roughened surfaces after the plasma treatments. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008     

Influence of temperature and relative humidity on aging of atmospheric plasma jet treatment effect on ultrahigh-modulus polyethylene fibers

The aging effects of atmospheric pressure plasma treated fiber surfaces are important for storage and processing of the fibers. One of the high-performance fibers, ultrahigh modulus polyethylene (UHMPE) fiber, was chosen as a model system to investigate the aging process of atmospheric pressure plasma jet (APPJ) treated fibers surfaces 0, 7, 15 and 30 days after initial plasma treatment. The fiber was first plasma-treated and then stored at temperatures varying from ?80 to 80°C on the same relative humidity (RH, 0%) and on RH of 0%, 65% and 100% at the same temperature of 20°C. Immediately after the plasma treatment, scanning electron microscope (SEM) showed the roughened fiber surface. X-ray photoelectron spectroscopy analysis showed changed surface chemical compositions. Contact-angle measurement showed increased surface wettability and microbond test showed an increase in IFSS. With increasing relative humidity or decreasing temperature, the IFSS value decreased and the contact angle increased more slowly. However, after 30 days, the IFSS values and contact angles reached a similar level for all groups. Moisture showed no effect on the single fiber tensile strengths during aging. The reasons for the observed aging behavior could be that decreasing temperature or increasing relative humidity hindered the surface rearrangement of polymer chains after plasma treatment.     

Influence of environmental moisture on atmospheric pressure plasma jet treatment of ultrahigh-modulus polyethylene fibers

One of the main differences between low-pressure and atmospheric-pressure plasma treatments is that there is little moisture involved in the low-pressure plasma treatment, although moisture could exist at the wall of the vacuum chamber or react with the substrate after plasma treatment, while in the atmospheric-pressure plasma treatment moisture exists not only in the environment but also in any hygroscopic substrate. In order to investigate the influence of environmental moisture on the effect of atmospheric pressure plasma treatment, ultra-high-modulus polyethylene (UHMPE) fibers were treated using an atmospheric-pressure plasma jet (APPJ) with 10 l/min helium gas-flow rate, treatment nozzle temperature of 100°C and 5 W output power. The plasma treatments were carried out at three different relative humidity levels, namely 5, 59 and 100%. After the plasma treatments, the surface roughness increased while the water-contact angle decreased with increasing relative humidity. The number of oxygen containing groups increased as the environmental moisture content increased. The interfacial shear strength of the UHMPE fiber/epoxy system was significantly increased after the plasma treatments, but the moisture level in the APPJ environment did not have a significant influence on the adhesion properties. In addition, no significant difference in single fiber tensile strength was observed after the plasma treatments at all moisture levels. Therefore, it was concluded that the environmental moisture did not significantly influence the effect of atmospheric-pressure plasma treatment in improving interfacial bonding between the fiber and epoxy. The improvement of the interfacial shear strength for the plasma-treated samples at all moisture levels was mainly due to the increased surface roughness and increased surface oxygen and nitrogen contents due to the plasma etching and surface modification effect.     

Surface characterization method of oxygen plasma-treated UHMPE fiber using DRIFT spectroscopy

The surface treatment and characterization of ultrahigh modulus polyethylene (UHMPE) fiber has been an important research subject. In this study, in order to investigate the oxygen plasma-treated UHMPE fiber according to the treatment time, diffuse reflectance Fourier transform infrared (DRIFT) spectroscopy was used as an analysis tool. The UHMPE fiber in a plain fabric was used for the surface analysis. The KBr overlay technique was efficient for enhancing the characteristic peaks from the UHMPE fiber surface. However, the KBr overlay made the comparison of the spectra among the UHMPE fiber samples difficult due to the different KBr overlay amount of each sample. In order to compare the relative peak areas of the oxygen plasma-treated UHMPE fiber according to the treatment time, DRIFT analysis was performed without KBr overlay under constant fiber orientation to remove the fiber orientation effect. The spectral subtraction was useful for investigating the minute change of the UHMPE fiber after the oxygen plasma treatment under the constant fiber orientation. The peak at 1896 cm⁻¹ was assigned to the crystalline combination mode of the UHMPE fiber and remained almost the same after the oxygen plasma treatment. This peak was used as an internal standard peak for the spectral subtraction and the peak area normalization. The relative peak areas in the DRIFT spectra of the UHMPE fiber were compared according to the oxygen plasma treatment time. The C=O group increases and the C—O group decreases as the oxygen plasma treatment time increases. The DRIFT analysis data of the oxygen plasma-treated UHMPE fiber correlated well with the electron spectroscopy for chemical analysis data and DRIFT spectroscopy is known to be useful for investigating the UHMPE fiber surface. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 1117–1124, 1998     

The role of additional silane coupling agent treatment in oxygen plasma-treated UHMPE fiber/vinylester composites

Ultra-high modulus polyethylene (UHMPE) fiber was treated with oxygen plasma and a silane coupling agent in order to improve the interfacial adhesion between the UHMPE fiber and vinylester resin. The oxygen plasma and γ-methylmethacryloxypropyltrimethoxysilane (γ-MPS)-treated UHMPE fiber/vinylester composites showed a slightly higher interlaminar shear strength than the oxygen plasma-treated UHMPE fiber/vinylester composites. The interfacial adhesion of the oxygen plasma-treated UHMPE fiber/vinylester composites in this study is mainly due to mechanical interlocking between the micropits formed by the oxygen plasma treatment and the vinylester resin. The γ-MPS molecules adsorbed onto the UHMPE fiber surface neither affected the morphology of the UHMPE fiber surface, nor reduced the extent of mechanical interlocking. The improved interfacial adhesion by the γ-MPS treatment is due to enhanced wettability and chemical interaction through the chemically adsorbed γ-MPS molecules, as detected by Fourier-transform infrared (FT-IR) spectroscopy. The γ-MPS molecules adsorbed onto the ultra-high molecular weight polyethylene (UHMWPE) plate surface also reduced the aging effect of the oxygen plasma-treated UHMWPE surface.     

Catalytic grafting: A new technique for polymer/fiber composites. II. Plasma treated UHMPE fibers/polyethylene composites

In this paper, the catalytic grafting technique for preparation of polymer/fiber composites is extended to plasma treated ultra-high modulus polyethylene (UHMPE) fiber/high density polyethylene (HDPE) system. The OH groups introduced on the UHMPE fiber surface by oxygen plasma treatment were used to chemically anchor Ziegler-Natta catalyst which then was followed by ethylene polymerization on the fiber surface. The morphology and interfacial behavior, as well as the mechanical properties, of the HDPE composites reinforced by catalytic grafted or ungrafted UHMPE fibers were investigated by SEM, DSC, polarized light optical microscopy, and tensile testing. The experimental results show that the polyethylene grafted on the fibers acted as a transition layer between the reinforcing UHMPE fibers and a commercial HDPE matrix. The interfacial adhesion was also significantly improved. Compared with the composite reinforced by ungrafted UHMPE fibers, the composite reinforced by catalytic grafted UHMPE fibers exhibits much better mechanical properties.     

Effect of plasma pretreatment on enhancing wrinkle resistant property of cotton fiber treated with BTCA and TiO2 System

1,2,3,4‐butanetetracarboxylic acid (BTCA) with titanium dioxide as a catalyst, was used to crosslink cotton fibers for the purpose of enhancing wrinkle recovery angle (WRA). To enhance the BTCA treatment with TiO₂, surface modification of cotton fiber is required; atmospheric pressure plasma jet pretreatment was used in experiments reported in this article. In this study, optimum conditions for plasma pretreatment were analyzed using orthogonal array testing strategy (OATS) technique, on the basis of WRAs achieved after BTCA treatment with and without TiO₂ as catalyst. It was found that (i) longer duration of plasma pretreatment provides enough time for the substrate to be impacted by the concentrated active species produced in plasma gas and therefore, modifies the material surface effectively and offers the best balance between enhancement of WRA and minimization of fiber damage, (ii) high oxygen flow rate producing a severe etching effect that alters the material's surface characteristics. However, when concentration of O₂ increased during the plasma pretreatment, the active species might react with the oxygen also, besides the cotton surface, and (iii) when the distance between the plasma jet nozzle and the substrate surface is too large, plasma gas from the nozzle is unable to hit the fabric surface, which means no surface modification is achieved. As a result, plasma treatment with 2 mm/s treatment speed, 0.1 L/min oxygen flow rate, and 2 mm jet‐to‐substrate distance was the most effective plasma pretreatment. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Effect of Atmospheric Plasma Treatment on Carbon Fiber/Epoxy Interfacial Adhesion

In this work the effect of atmospheric plasma treatment on carbon fiber has been studied. The carbon fibers were treated for 1, 3 and 5 min with a He/O₂ dielectric barrier discharge atmospheric pressure plasma. The fiber surface morphology, surface chemical composition and interfacial shear strength between the carbon fiber and epoxy resin were investigated using atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and the single fiber composite fragmentation test. Compared to untreated carbon fibers, the plasma treated fiber surfaces exhibited surface morphological and surface composition changes. The fiber surfaces were found to be roughened, the oxygen content on the fiber surfaces increased, and the interfacial shear strength (IFSS) improved after the atmospheric pressure plasma treatment. The fiber strength showed no significant changes after the plasma treatment.     

Polyurethane paint adhesion improvement on aluminium alloy treated by plasma jet and dielectric barrier discharge

The effect of atmospheric pressure plasma treatment on the adhesion between a protective coating and AA1100 alloy was investigated. Two plasma sources were used for surface modifications: atmospheric pressure plasma jet and dielectric barrier discharge. The surface roughness and water contact angle measurements were conducted in order to evaluate the changes on the aluminium surface after plasma processing. The paint coating was tested using the adhesion tape test (ASTM D3359). A significant improvement of surface wettability and adhesion was obtained after plasma treatments.