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。     

超高相对分子质量聚乙烯纤维的低温等离子体处理

利用低温等离子体技术对超高相对分子质量聚乙烯(UHMWPE)纤维进行表面改性,用单因素试验和正交试验对改性后的UHMWPE纤维的静摩擦因数和断裂强力进行测试与分析,最终确定最优的等离子体改性工艺为压强50 Pa、功率100 W、时间180 s。对处理前后的UHMWPE纤维的毛细效应、表面形貌、红外光谱进行了测试和对比,结果发现:改性后的UHMWPE纤维的吸水性能明显增强,纤维表面变得凹凸不平,粗糙度和比表面积增大,纤维表面起伏数量增多,幅度变大,且出现了新的含氧官能团,有利于提高UHMWPE纤维表面的黏结性。     

低温等离子体技术在超高相对分子质量聚乙烯纤维表面改性中的应用

介绍了低温等离子体的概念、分类及其在超高相对分子质量聚乙烯纤维(UHMWP E)表面改性方面的特点;阐述了国内外在低温等离子体对UHMWPE纤维表面改性前后纤维本身及其复合材料性能的影响情况;简介了用自行研制的低温等离子体设备对UHMWPE纤维进行表面改性的研究结果和低温等离子体处理UHMWPE纤维表面改性的发展前景。实验表明,UHMWPE纤维经过等离子体处理后表面产生刻蚀和交联,其与树脂间的粘结性能改善;该低温等离子体设备能满足UHMWPE纤维表面改性连续化生产需要。     

低温等离子体对UHMWPE纤维的表面改性

运用自行研制的常压低温等离子体设备对超高相对分子质量聚乙烯(UHMWPE)纤维进行了表面处理,选用正交试验法通过润湿性测试优化出不同工作气氛下的工艺条件,采用强力测试、扫描电镜(SEM)和光电子能谱仪(XPS)分析了等离子体处理前后UHMWPE纤维的性能变化。结果表明,常压低温等离子体在Ar携带丙烯酸和Ar／O2的气氛下处理UHMWPE纤维,表面改性效果良好。特别是选用Ar／O2流量比100:1,处理速度为5．8 m／min,输出功率189 W,可满足连续化生产。     

等离子体处理对芳纶性能的影响

芳纶作为增强材料在复合材料中有广泛的应用,其界面性能是影响其复合材料界面粘结性能的重要因素。分别采用H2、空气低温等离子体对芳纶表面进行了处理。研究了等离子体表面改性后芳纶性能的变化。结果表明:经低温等离子体处理后纤维表面张力增大,由46.0mN·m-1增加到63.2mN·m-1;表面极性增强,极性分数由58.0%提高到69.9%,而纤维单丝断裂强度未有明显变化。     

UHMWPE纤维的表面处理技术进展

详细介绍了超高相对分子质量聚乙烯(UHMWPE)纤维的表面改性方法、改性原理及改性效果,并提出了UHMWPE纤维的表面处理技术的新进展及展望。UHMWPE纤维的表面改性方法主要有氧化处理法、化学交联法、电晕放电法、辐照引发表面接枝法、等离子体处理法等;目前,电晕放电法已经应用于工业化生产,其他方法难以实现工业化;今后,硅烷偶联剂化学交联法有较好的工业化应用前景,采用两种或多种方法并用对UHMWPE纤维进行表面改性将会得到较好的发展。     

低温等离子体与马来酸酐对UHMWPE纤维表面改性

用低温等离子体技术和接枝反应对超高分子量聚乙烯（UHMWPE）纤维进行表面处理.纤维进行低温等离子体后接枝处理的最佳工艺条件是：在80℃的1.0 mol/L的马来酸酐水溶液中加热1.5 h在维持整体形貌的前提下,在纤维长链表面引入了活性基团,增大了纤维与其他基质材料之间的化学键合能力和咬合能力,提高纤维的表面性能,从而达到表面改性的目的。     

空气冷等离子体处理对UHMWPE纤维性能与结构的影响

采用不同功率、压力和时间的空气冷等离子体对超高相对分子质量聚乙烯(UHMWPE)纤维进行处理,测试其力学性能和摩擦性能,并对处理前后纤维的形貌进行观察。结果表明,经空气冷等离子体处理后,纤维的断裂强力有所降低,静摩擦系数和动摩擦系数均得到大幅度提升,纤维表面出现横向均匀刻蚀层,粗糙度增加。     

超高分子质量聚乙烯纤维黏结强度增强方法研究

为提高超高分子质量聚乙烯(UHMWPE)纤维复合材料中纤维与树脂基体之间的界面黏结强度,提出通过不同质量分数的硅烷偶联剂KH-570处理纳米SiO_2对UHMWPE纤维进行表面改性。对改性处理后的纤维与乙烯基酯树脂进行黏结强度试验,发现硅烷偶联剂处理纳米SiO_2能有效提高纤维的界面黏结强度,同时使纤维保持一定的断裂强度。     

低温等离子体处理对高强聚乙烯纤维表面影响的研究

采用空气低温等离子体处理高强聚乙烯纤维,测试处理前后纤维表面摩擦系数的变化,并采用电子扫描显微镜（SEM）和原子力显微镜（AFM）对纤维表面形貌进行观察分析。结果发现,空气低温等离子体处理的刻蚀作用会在纤维表面形成致密的＂小坑群＂,使得纤维表面产生剥落、联结,造成纤维表面的粗糙程度有所增加,其处理后的纤维表面静、动摩擦系数有所提高。     

Mechanical properties of surface‐modified ultra‐high molecular weight polyethylene fiber reinforced natural rubber composites

The mechanical properties of ultra‐high molecular weight polyethylene (UHMWPE) fibers reinforced natural rubber (NR) composites were determined, and the effects of fiber surface treatment and fiber mass fraction on the mechanical properties of the composites were investigated. Chromic acid was used to modify the UHMWPE fibers, and the results showed that the surface roughness and the oxygen‐containing groups on the surface of the fibers could be effectively increased. The NR matrix composites were prepared with as‐received and chromic acid treated UHMWPE fibers added 0–6 wt%. The treated UHMWPE fibers increased the elongation at break, tear strength, and hardness of the NR composites, especially the tensile stress at a given elongation, but reduced the tensile strength. The elongation at break increased markedly with increasing fiber mass fraction, attained maximum values at 3.0 wt%, and then decreased. The tear strength and hardness exhibited continuous increase with increasing the fiber content. Several microfibrillations between the fiber and NR matrix were observed from SEM images of the fractured surfaces of the treated UHMWPE fibers/NR composites, which meant that the interfacial adhesion strength was improved. POLYM. COMPOS., 38:1215–1220, 2017. © 2015 Society of Plastics Engineers     

Evaluation of Adhesion Property of UHMWPE Fibers/Nano-epoxy by a Pullout Test

Ultrahigh-molecular-weight polyethylene (UHMWPE) fibers have poor wetting and adhesion properties to polymer resins because of the inert surface of the fibers. In our previous study, a reactive nano-epoxy matrix, developed by making a modification on the matrix with reactive graphitic nanofibers (r-GNFs), showed improved wettability to UHMWPE fibers. In this work, fiber bundle pullout tests were conducted to evaluate the adhesion property between the UHMWPE fibers and the nano-epoxy matrices. Analysis of load-displacement curves from pullout tests shows that debonding initiation load and ultimate debonding load increased considerably, because of effective improvement of adhesion between the UHMWPE fibers and nano-epoxy matrix. Stress-controlled and energy-controlled models of interfacial debonding were applied for theoretical analyses. Results from ultimate IFSS, frictional shear stress, and critical energy-release rate are in good agreement with experimental results. Nano-epoxy matrix with 0.3 wt% r-GNFs shows effective improvement in terms of adhesion property between UHMWPE fiber and epoxy.     

Surface modification and physical properties of various UHMWPE‐fiber‐reinforced modified epoxy composites

Two surface modification methods—plasma surface treatment and chemical agent treatment—were used to investigate their effects on the surface properties of ultrahigh‐molecular‐weight polyethylene (UHMWPE) fibers. In the analyses, performed using electron spectroscopy for chemical analysis, changes in weight, and scanning electron microscope observations, demonstrated that the two fiber‐surface‐modified composites formed between UHMWPE fiber and epoxy matrix exhibited improved interfacial adhesion and slight improvements in tensile strengths, but notable decreases in elongation, relative to those properties of the composites reinforced with the untreated UHMWPE fibers. In addition, three kinds of epoxy resins—neat DGEBA, polyurethane‐crosslinked DGEBA, and BHHBP‐DGEBA—were used as resin matrices to examine the tensile and elongation properties of their UHMWPE fiber‐reinforced composites. From stress/strain measurements and scanning electron microscope observations, the resin matrix improved the tensile strength apparently, but did not affect the elongation. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 655–665, 2007     

UHMWPE纤维针织物-环氧树脂复合材料的制备与性能

将等离子体处理前后的超高相对分子质量聚乙烯(UHMWPE)纤维针织物分别与环氧树脂在平板硫化机上进行复合,制作出UHMWPE纤维针织物复合材料,对其进行裁样,测试UHMWPE纤维针织物复合材料的拉伸、弯曲和压缩性能。结果表明:经等离子体处理后,复合材料的拉伸强度、弯曲强度均有较大提高,压缩强度有小幅增加。     

Surface modification of ultra‐high molecular weight polyethylene fiber by different kinds of SiO2 nanoparticles

We successfully improved the interfacial adhesion strength between ultra‐high molecular weight polyethylene (UHMWPE) fiber and resin by the surface modification of UHMWPE fiber with two kinds of SiO₂ nanoparticles through gel spinning process. Modified effect of treated SiO₂ nanoparticles by coupling agent was superior to original SiO₂ nanoparticles. Compared with unmodified fibers, pull‐out tests of modified UHMWPE/treated SiO₂ fibers revealed that interfacial adhesion strength increased by the maximum of 10.95%, but corresponding breaking strength decreased by 8.51%. In addition, the interfacial adhesion strength and breaking strength could continue to enhance with increasing the additive amount of treated SiO₂ nanoparticles. The results of Differential Scanning Calorimetry (DSC), X‐ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and Scanning Electron Microscopy (SEM) indicated that the crystallinity of all modified fibers decreased while crystallite dimension increased, and the surface of modified fibers by treated SiO₂ nanoparticles exhibited polar functional group (C=O). The superiority of this modified technology was that it realized the bulk industrial production and maneuverability, low cost, and no pollution. POLYM. COMPOS., 38:1928–1936, 2017. © 2015 Society of Plastics Engineers     

Charaterization of UHMWPE fiber/matrix adhesion by dynamic mechanical spectrometry

The tensile and dynamic mechanical properties of polystyrene and a poly(styrene-co-buty1 acrylate-co-cyclohexy1 methacrylate) statistical terpolymer (terpolymer) reinforced by randomly oriented, discontinuous ultra-high molecular weight polyethylene (UHMWPE) fibers are presented in terms of the fiber/matrix interfacial properties. Using a thermomechanical block model based on the parallel rule of mixtures, the adhesion characteristics of poly(butyl acrylate) (PBA) and poly(cyclohexyl methacrylate) (PCHM) grafted, plasma treated, and untreated fibers were determined. The model successfully predicts the tan δ response of the composites including peak height variations and the development of additional loss dispersions associated with the interphase. Moreover, the model yields a fiber reinforcement efficiency factor, K, which gives a quantitative measure of adhesion. The contact angle of PBA and PCHM grafted high density polyethylene (HDPE) films are also included and are compared to the contact angle of plasma treated fibers. The results indicate that PBA and PCHM grafts enhance adhesion through polymer graft/matrix interactions, not simply by improved wetting.     

Interfacial evaluation of epoxy/carbon nanofiber nanocomposite reinforced with glycidyl methacrylate treated UHMWPE fiber

Interface interactions of fiber–matrix play a crucial role in final performance of polymer composites. Herein, in situ polymerization of glycidyl methacrylate (GMA) on the ultrahigh molecular weight polyethylene (UHMWPE) fibers surface was proposed for improving the surface activity and adhesion property of UHMWPE fibers towards carbon nanofibers (CNF)‐epoxy nanocomposites. Chemical treatment of UHMWPE fibers was characterized by FTIR, XPS analysis, SEM, and microdroplet tests, confirming that the grafting of poly (GMA) chains on the surface alongside a significant synergy in the interfacial properties. SEM evaluations also exhibited cohesive type of failure for the samples when both GMA‐treated UHMWPE fiber and CNF were used to reinforce epoxy matrix. Compared with unmodified composite, a ～319% increase in interfacial shear strength was observed for the samples reinforced with both 5 wt % GMA‐grafted UHMWPE and 0.5 wt % of CNF. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43751.     

Measurement of Adhesion Between Carbon Fibers and Bismaleimide Resins

The adhesion between carbon fibers and bismaleimide resins was evaluated using the microbond single fiber pull-out test. A commercially-available, methylene dianiline-based bismaleimide resin and a novel phosphorus-containing bismaleimide were tested with as-received and plasma-treated polyacrylonitrile-based carbon fibers. The surface chemical composition, topography, tensile strength, and surface free energy of the carbon fibers were studied using x-ray photoelectron spectroscopy, scanning electron microscopy, single fiber tensile tests, and dynamic contact angle analysis. The carbon fiber-bismaleimide adhesion improved when the carbon fiber received an oxidative commercial surface treatment or was exposed to an air or ammonia plasma prior to bonding.