超高分子量聚乙烯纤维液相氧化改性及其橡胶基复合材料制备

为了增强超高分子量聚乙烯(UHMWPE)纤维与橡胶基体之间的界面粘结强度,采用高锰酸钾溶液对UHMWPE纤维进行表面处理,并将处理后的纤维加入到天然橡胶中制备短切UHMWPE纤维/橡胶复合材料。结果表明,高锰酸钾溶液处理可有效增加纤维表面粗糙度及表面含氧官能团含量,最佳改性工艺条件是:按照m(高锰酸钾)∶m(浓硝酸)=1∶30配置高锰酸钾溶液,在室温下将UHMWPE纤维放入上述溶液中处理1 min。与纯橡胶样品相比,在m(UHMWPE纤维)∶m(天然橡胶)=0~6∶100范围内,随着处理后短纤维质量分数的增加,复合材料的硬度不断增大,最大增加量达到94%;复合材料的撕裂强度先增大后减小,在m(UHMWPE纤维)∶m(天然橡胶)=4∶100时达到最大值,最大增加量达到43%。     

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。     

硅烷偶联剂表面改性UHMWPE纤维的工艺优化

以硅烷偶联剂KH-550在不同条件下处理超高相对分子质量聚乙烯(UHMWPE)纤维,采用正交实验方法,以硅烷偶联剂KH-550的浓度(A)、处理温度(B)、处理时间(C)为因素,以UHMWPE纤维的断裂强力、界面剪切强度(τ)为实验指标,研究了硅烷偶联剂KH-550处理UHMWPE纤维的最佳工艺条件。结果表明:UHMWPE纤维断裂强力的影响因素主次顺序为A,B,C,τ的影响因素主次顺序为B,A,C;硅烷偶联剂KH-550处理UHMWPE纤维的最优工艺为硅烷偶联剂KH-550质量分数17.5%,处理温度55℃,处理时间7 h,在此条件下得到的UHMWPE纤维的断裂强力为41.15 cN,断裂强力损失率为2.44%,τ为1.359MPa,τ的增加率为35.22%。     

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。     

紫外辐射接枝改性UHMWPE纤维表面的研究

采用紫外辐射接枝方法对超高相对分子质量聚乙烯(UHMWPE)纤维表面进行改性。探讨了单体种类及浓度、引发剂、抗氧剂、接枝方法等对UHMWPE纤维表面处理效果的影响,测试了以其作为增强材料的复合材料的层间剪切强度。结果表明:在有氧开放体系下,气相接枝效果好于液相接枝;丙烯酰胺单体的接枝效果优于其它单体;接枝率随接枝单体浓度和接枝时间的增加而增加。采用丙烯酰胺为接枝单体,在光强度为86μW/cm~2条件下,对UHMWPE纤维进行紫外辐射接枝改性,按照一定铺层方式制备的环氧基复合材料的层间剪切强度从未处理的14.59MPa提高到17.36MPa。     

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。     

偶联剂改性UHMWPE纤维表面性能的研究

选用硅烷偶联剂KH-550,KH-560和钛酸酯偶联剂NDZ-201作为表面改性剂,对超高相对分子质量聚乙烯(UHMWPE)冻胶纤维在萃取阶段进行表面处理,经干燥、超拉伸制得表面改性UHMWPE纤维。采用红外光谱仪、接触角测量仪测定了纤维的表面化学结构和表面润湿性能,采用单纤维树脂包埋-拔出法测定了纤维与树脂基体的界面剪切强度,比较了改性前后纤维的力学性能变化。结果表明:改性后纤维表面引入了极性基团,硅烷偶联剂KH-550对UHMWPE纤维的表面改性效果最好。采用质量分数为1%的硅烷偶联剂KH-550溶液处理后,纤维与环氧树脂间的界面剪切强度提高了87.8%,纤维的断裂强度和模量分别提高了6.9%和32.6%。     

铬酸处理液对UHMWPE纤维性能的影响

利用自行研制的铬酸处理液对超高相对分子质量聚乙烯(UHMWPE)纤维进行表面改性,并利用扫描电镜(SEM)、红外光谱(FITR)和接触角、单丝强力试验对纤维的表面性能和强度的变化进行表征。结果表明,表面处理时间和表面处理温度是影响纤维处理后性能的重要因素,UHMWPE纤维的最佳表面处理时间为3mim,最佳表面处理温度为80～85℃。     

基于UHMWPE纤维低度交联与表面改性制备高模量、高强度UHMWPE/EP复合材料

从工业化生产应用角度研究电晕处理直接作用于超高分子量聚乙烯(UHMWPE)纤维编织布织布表面，探究纤维表面交联和界面改性对复合材料力学性能的影响。利用X射线光电子能谱(XPS)、傅里叶变换红外光谱(ATR-FTIR)和扫描电镜(SEM)对UHMWPE纤维表面物理性质和化学组成进行表征。采用差示扫描量热仪(DSC)对电晕处理前后纤维结晶度和热稳定性进行表征。当电晕处理功率达到3.0 kW时，UHMWPE-C3.0kW/EP复合材料的冲击强度、弯曲强度和弯曲模量达到了167.4 kJ/m²、121.3 MPa和9.3 GPa,相较于未处理UHMWPE/EP复合材料分别增加了31.5%、64.8%和190.6%。结果表明，通过电晕处理强化了纤维表面与树脂界面黏接强度，有利于复合材料对外力的传递分散，并通过强界面破坏吸收能量及UHMWPE纤维的断裂和形变提高了复合材料的抗冲击和抗弯性能。     

铬酸处理的超高分子量聚乙烯纤维粘接性研究

本文采用不同浓度和温度下的铬酸溶液对超高分子量聚乙烯纤维进行表面处理。通过DSC、DMA、X-衍射和SEM分析纤维的结构,测试了纤维接触角、断裂强度和层间剪切强度。实验结果表明,随着处理液酸浓度的增加,纤维表面刻蚀程度增加,层间剪切强度增大,而纤维表面极性不变;处理时间和溶液温度须控制在一个合适的水平。     

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     

表面改性超高相对分子质量聚乙烯纤维的热性能研究

采用铬酸刻蚀和化学气相沉积聚吡咯处理了超高相对分子质量聚乙烯(UHMWPE)纤维。用DSC、DMA、X-射线衍射及SEM分析了纤维的热力学性能、结晶情况及纤维的表观形貌。结果表明,铬酸处理及化学气相沉积聚吡咯处理后,纤维的耐热性均有所提高,纤维表面变得更加粗糙,其中化学气相沉积聚吡咯处理的纤维变化更明显。     

PE—UHMW纤维／环氧树脂复合材料研究

对超高相对分子质量聚乙烯(PE-UHMW)纤维进行了铬酸液相氧化和纳米二氧化硅溶胶表面涂覆的复合化表面处理，并对PE-UHMW纤维／环氧树脂复合材料进行了界面性能研究。结果表明，单纯的液相氧化和表面涂覆均可以提高复合材料的界面性能，但液相氧化处理时间过长会使纤维强度降低，而复合化处理则具有协同效应，可以不降低纤维强度而大幅度提高复合材料的层间剪切强度，是一种有效的表面处理方法。     

Radiation‐induced graft copolymerization of MMA monomer onto UHMWPE: Adhesion improvement

Graft copolymerization of methyl methacrylate monomer onto ultra high molecular weight polyethylene (UHMWPE) and acid‐etched UHMWPE was conducted using preirradiation method in air in the presence of a Mohr salt and sulfuric acid to improve adhesion to the bone cement. The grafted samples were characterized by Fourier transform infrared (FTIR) spectroscopy, gravimetric method, goniometry, and interfacial bonding strength measurements. The FTIR results showed the presence of ether, carbonyl, and hydroxyl groups for grafted films. The gravimetric results showed that the chromic acid etching and graft copolymerization had a synergetic effect so, the irradiated, then chromic acid etched at room temperature and grafted sample (Rad etch25) had the highest grafting degree. The interfacial bonding strength between UHMWPE and poly methyl methacrylate bone cement was considerably improved by graft copolymerization and chromic acid etching. The surface morphology was studied by scanning electron microscopy. The substitution of polar groups into the backbone of UHMWPE by chromic acid etching and graft copolymerization changed its contact angles with water and methylene iodide and increased its surface energy, as evidenced by contact angle measurements. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Irradiation grafting of methyl methacrylate monomer onto ultra‐high‐molecular‐weight polyethylene: An experimental design approach for improving adhesion to bone cement

The grafting of methyl methacrylate (MMA) onto ultra‐high‐molecular‐weight polyethylene (UHMWPE) and chromic acid etched UHMWPE was conducted with a preirradiation method in air in the presence of a Mohr salt and sulfuric acid. The grafted samples were characterized by Fourier transform infrared (FTIR) spectroscopy, a gravimetric method, differential scanning calorimetry, scanning electron microscopy (SEM), and interfacial bonding strength measurements. The FTIR results showed the presence of ether and carbonyl groups in the MMA‐grafted UHMWPE (MMA‐g‐UHMWPE) samples. The Taguchi experimental design method was used to find the best degree of grafting (DG) and bonding strength. The efficient levels for different variables were calculated with an analysis of variance of the results. SEM micrographs of MMA‐g‐UHMWPE samples showed that with increasing DG and chromic acid etching, the MMA‐g‐UHMWPE rich phase increased on the surface; this confirmed the high interfacial bonding strength of the grafted samples with bone cement. The grafting of the MMA units onto UHMWPE resulted in a lower crystallinity, and the crystallization process proceeded at a higher rate for the MMA‐g‐UHMWPE samples compared to the initial UHMWPE; this suggested that the MMA grafted units acted as nucleating agents for the crystallization of UHMWPE. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

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...