高强度聚乙烯纤维绳索的制备研究

研究了纤维的捻度及浸胶处理对超高相对分子质量聚乙烯 (UHMWPE)纤维力学性能及摩擦磨损性能的影响。结果表明 ,UHMWPE纤维的断裂强力随着纤维捻度的增加而减小 ,纤维浸胶处理后的断裂强力增大 ;当UHMWPE纤维中改性氯丁胶粘剂或聚氨酯胶粘剂的含量为 6%时 ,其断裂强力分别增加 17.2 %或 13 .9% ,聚氨酯胶粘剂处理过的UHMWPE纤维的耐摩擦磨损性能最好。     

加工工艺对芳纶帘线性能的影响

研究加捻工艺和浸胶工艺对芳纶帘线性能的影响。结果表明：在一定捻度范围内,芳纶帘线的断裂强力随捻度的增大而降低,断裂伸长率随捻度的增大而提高;浸胶张力和浸胶温度对浸胶芳纶帘线的断裂强力没有明显影响;适当降低浸胶温度可提高浸胶芳纶帘线的粘合强度。     

干热处理对UHMWPE短纤维结构与性能的影响

采用电热恒温鼓风干燥箱对超高相对分子质量聚乙烯(UHMWPE)短纤维进行干热处理,研究了处理条件对纤维外观形态、分子结构、力学性能的变化及其影响规律。结果表明:UHMWPE纤维的熔融温度为147.7℃,随着热处理温度的升高,UHMWPE纤维的纵向表面裂纹逐渐增多,且温度越高表面裂纹越明显;纤维分子的扭曲变形和伸缩变形运动随处理温度的升高而变得较为剧烈;纤维的结晶结构随处理温度的升高较未处理纤维也发生了较小的变化;当温度高于100℃时,UHMWPE纤维的断裂强力随温度的升高有所下降,加热时间越长强力下降越多;而温度及时间对断裂伸长率的影响具有等效作用;干热处理UHMWPE纤维的温度宜控制在100℃以内,时间宜12 h以内。     

高性能纤维作为橡胶骨架材料的应用研究

研究聚酰亚胺纤维、芳纶纤维、玄武岩纤维、聚萘二甲酸乙二醇酯(PEN)纤维和聚亚苯基苯并二噁唑(PBO)纤维的工业丝性能及浸胶帘线的力学性能和粘合性能。结果表明:聚酰亚胺纤维和PBO纤维具有较高的强力和模量;聚酰亚胺纤维通过参考芳纶纤维的浸胶液配方进行浸胶处理,帘线与橡胶粘合性能良好;PEN纤维可以直接使用聚对苯二甲酸乙二酯(PET)纤维的浸胶方法进行处理;玄武岩纤维采用优化浸胶液配方进行浸胶处理,完全可以实现帘线与橡胶的良好粘合;PBO纤维采用目前现有浸胶方法较难进行表面接枝处理,与橡胶粘合性能较差。     

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%。     

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。     

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。     

结构设计对传动带用浸胶芳纶线绳性能的影响

分别采用1670dtex和1100dtex芳纶丝,研究结构设计对传动带用浸胶芳纶线绳性能的影响。结果表明：当原丝总纤度相同时,随着初复捻捻度的增大,捻度系数增大,线绳的初始断裂强力呈减小趋势,疲劳后断裂强力保持率呈增大趋势;当捻度相同时,增大原丝纤度,可提高线绳的耐疲劳性能;当直径和捻度相同时,通过改变捻线结构,增大初捻捻度系数,保持复捻捻度系数不变,可使线绳的耐疲劳性能得到提高。     

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℃。     

高模低收缩涤纶浸胶帘子布的开发研究

本研究开发出具有国外90年代先进水平的高模低收缩涤纶工业丝 研究了捻度对帘线断裂强力、断裂伸长、定负荷仲长的影响,并探讨了浸胶工艺对高模低收缩涤纶浸胶帘子布性能的影响。     

Tribological performance of self-lubricating polyurethane elastomer compounding with the modified ultra-high molecular weight polyethylene

Ultra-high molecular weight polyethylene (UHMWPE) powder was modified by surface treatment technology, then its wettability, dispersibility, mechanical, and tribological properties in polyurethane elastomer were studied. The testing results showed that after surface treatment, UHMWPE powder could infiltrate and disperse evenly in polyurethane, and build micro cross-link with the contact surface of polymer substrate, which is conducive to enhancing the internal stress of polymer and improving the mechanical properties. With a small amount of modified UHMWPE being added into the casting polyurethane (CPU) elastomer, the right-angled tearing strength increases and the abrasion loss decreases. Moreover, the elastomer surface self-lubricating performance of CPU compounding with modified UHMWPE is enhanced: compared with the neat CPU sample, the average friction coefficient of the CPU samples with 5%, 10%, and 15% of modified UHMWPE is reduced by 46.3%, 41.5%, and 39.0%, respectively, and the surface wear resistance is improved; under the high-load working condition, the CPU elastomer with 5% of modified UHMWPE has the optimal tribological performance.     

超高相对分子质量聚乙烯纤维的表面改性研究

选择乙烯-醋酸乙烯酯共聚物作表面改性剂,将其溶解在二甲苯中,对超高相对分子质量聚乙烯(UHMWPE)冻胶纤维进行萃取,然后经过多级热拉伸制得改性UHMWPE纤维。对冻胶纤维的萃取动力学、改性前后纤维的表面化学结构、表面粘结性能和力学性能进行了比较。结果表明:加入表面改性剂后,冻胶纤维的萃取除油速率变慢;纤维与树脂基体的粘结强度大大提高;纤维的力学性能略有下降。     

Polyphosphazene nanotube and modified waterborne polyurethane prepared by in situ polymerization

Novel hybrid inorganic/organic poly[cyclotriphosphazene-co-(hexafluoroisopropylidene)] nanotubes (PZTs) were synthesized through nucleophilic substitution using one-step method. The surface of PZTs contains hydroxyl and fluorine groups with a ratio of approximately 1:3, which imparts many functional properties to the nanotubes. The introduction of the active hydroxyl groups increased the chemical bond crosslinking between the nanotubes and the matrix resin. The introduction of fluorine atom provided the hydrophobicity and abrasion resistance properties. The water contact angle of PZTs is 140.3°. Chemical reaction occurred between WPU and PZTs to form covalent bonds through in situ polymerization. The water contact angle and thermal stability of waterborne polyurethane (WPU)/PZTs increased with the increasing nanotube content. When the nanotube content was 1.0 wt%, the maximum tensile strength of the composites was 3.36 MPa and the maximum elongation-at-break was 446.8%. The nanotubes showed toughening and strengthening characteristics. When 1.0 wt% PZTs were incorporated, the friction coefficient and abrasion loss of the composites reached a minimum value. The addition of nanotubes could increase surface hardness and crosslinking degree, absorb the coating heat of friction, and reduce the adhesive wear of polymer and the wear amount. The introduction of fluorine atoms could form a chemical transfer membrane and reduce the friction coefficient. Polyphosphazene nanotubes showed excellent modification properties in the waterborne polyurethane system.

     

超高分子量聚乙烯改性尼龙6复合材料的力学性能研究

通过挤出方法制备了尼龙6（PA6）／超高分子量聚乙烯（UHMWPE）复合材料,考察了复合材料摩擦学性能和力学性能。用光学显微镜观察分析了复合材料磨损表面形貌。结果表明：复合材料摩擦性能较纯尼龙有一定的提高,当UHMWPE含量为5％和10％时,复合材料耐磨减摩性较好。但随着UHM-WPE含量的增加,复合材料的硬度、拉伸强度、伸长率有所下降。     

超高相对分子质量聚乙烯纤维的表面改性研究

选择乙烯-醋酸乙烯酯共聚物作为表面改性剂,将其溶解在二甲苯中制成复合萃取液,对超高相对分子质量聚乙烯(UHMWPE)冻胶纤维进行萃取,经干燥和超倍拉伸制得表面改性UHMWPE纤维。对改性前后纤维的表面化学结构、结晶性能、表面粘接性能和力学性能进行了比较。结果表明:加入表面改性剂后,纤维表面引入了极性基团,结晶形态不变,纤维与树脂的抗界面剪切强度大大增加,纤维的力学性能变化不大。     

Adhesion of ultrahigh molecular weight polyethylene plates photografted with hydrophilic monomers and evaluation of failure location by X‐ray photoelectron spectroscopy

In this study, methacrylic acid (MAA) and acrylic acid (AA) were photografted onto the ultrahigh molecular weight polyethylene (UHMWPE) plates at different monomer concentrations and temperatures, and the grafted UHMWPE plates were bonded with aqueous polyvinyl alcohol (PVA) solutions. The tensile shear adhesive strength of both grafted UHMWPE plates was also discussed in relation to wettability and water absorptivity. The location of failure was also estimated by X‐ray photoelectron spectroscopy (XPS). Wettability of the MAA‐grafted UHMWPE plates became constant, when the UHMWPE surface was fully covered with grafted PMAA chains. Conversely, wettability of the AA‐grafted UHMWPE plates passed through the maximum value and then gradually decreased against the grafted amount probably due to aggregation of grafted PAA chains. Water absorptivity of the grafted layers formed at lower monomer concentrations or temperatures sharply increased at lower grafted amounts. The adhesive strength increased with the grafted amount and substrate breaking was observed at higher grafted amounts, indicating that a main factor to increase the adhesive strength is the formation of a grafted layer by shorter grafted polymer chains and/or the restriction of the location of photografting to the outer surface region. In addition, surface analysis by XPS showed that failure occurred in the boundary between the layer composed of grafted polymer chains and PVA chains and the ungrafted layer at a low adhesive strength, and the location of failure was shifted to the grafted layer containing PVA chains at the grafted amount increased. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40133.     

Enhanced wear resistance of ultra-high molecular weight polyethylene fibers by modified-graphite oxide

A simple and feasible method to enhance the wear resistance of ultra-high molecular weight polyethylene (UHMWPE) fibers was reported. The graphite oxide (GO) prepared using improved Hummer's method was surface modified with hexadecylamine to improve its compatibility with UHMWPE. Combined with well-dispersion of modified-GO (m-GO) in dichloromethane and the fact that the viscosity of UHMWPE suspension can be decreased by dichloromethane, the well dispersed m-GO/dichloromethane was added into UHMWPE suspension to improve m-GO dispersion in UHMWPE fibers. Finally, UHMWPE fibers with different m-GO concentration were prepared using gel spinning technology. The effect of m-GO concentration on the structure and properties of modified UHMWPE fibers were investigated. The results indicated that the melting temperature and crystallinity of m-GO modified UHMWPE fibers increased with increasing of m-GO concentration, while the fiber's crystal sizes and orientation increased, thus the tensile strength of m-GO modified UHMWPE fibers remained almost undamaged. The introduction of m-GO is beneficial to the formation of smooth transfer film on fiber's surface, which enhanced the self-lubrication of UHMWPE fibers. Compared with pure UHMWPE fiber, the UHMWPE fiber containing 1.5 wt% m-GO had enhanced wear resistance by 55.4% and still maintained high tensile strength of 29.98 cN dtex⁻¹.     

The Effect of Abrasion Surface Treatment on the Bonding Behavior of Various Carbon Fiber-Reinforced Composites

Abstract

In this paper we show that current abrasion surface preparation practices do not perform equally on all composite surfaces. The effect of abrasion on the adhesive bond strength of various carbon fiber (CF) composites was investigated. Cyanate ester composites were fabricated using a low, a high and an ultra high modulus carbon fiber (T300, M55J, K13C2U). XPS and contact angle measurements showed that the surface energy of all three composites increased due to the removal of contaminants as well as increased in surface roughness. However, the lap shear strength degraded sharply for a number of cases, irrespective of roughness, depending on the fiber used. Composites utilizing lower modulus carbon fibers increased in adhesive bond strength following abrasion in comparison to composites with higher modulus fibers. As the modulus of the fiber and the abrasive grit size increased, the degree of degradation caused by abrasion was shown to increase significantly. Scanning electron microscopy (SEM) and profilometry measurements showed the development of an abrasion-affected zone that was especially prevalent for higher stiffness composites. The failures for the higher modulus specimens were caused by subsurface damage located a few fiber diameters below the abraded surface. However, an alternate technique using atmospheric plasma surface treatment exhibited efficient removal of contaminants while showing no degradation of bond quality when treating these ultra high modulus composites.     

超高分子量聚乙烯阻燃抗静电改性

针对超高分子量聚乙烯(UHMWPE)阻燃、抗静电性能差,不能满足某些场合应用需求的现状,利用微胶囊化红磷和发黑作为改性剂,对UHMWPE进行改性,其氧指数达到24.2％～29.5％,表面电阻率降到1×10~9Ω以下,实现了阻燃、抗静电的目的,并且基本保持了UHMWPE原有的优异耐冲击与耐磨性能,提高了它的热变形温度与弯曲强度,从而拓宽了UHMWPE的应用范围。