Manufacturing of Ultra-high Molecular Weight Polyethylene Fiber Reinforced Tape and the Loss of Strength

Due to the low density and excellent mechanical proper-ties,high performance fiber reinforced materials have aconsiderable application in the area of high technologyand dally usage.In this paper,the Ultra-high Molecu-lar Weight Polyethylene(UHMWPE)fiber reinforcedPE tape prepared with the method of powder impregnat-ion was studied.The effect of impregnate length and thetensile force of the yarn on the fiber content as well as on the strength and modulus of the tape were discussed.Calculation shows that the strength and the modulus ofthe ULMWPE fiber can keep about 85％ after it undergothe process.

Reattachment of the Osteotomized Greater Trochanter in Hip Surgery Using an Ultrahigh Molecular Weight Polyethylene Fiber Cable: A Multi-Institutional Study

The purpose of this multicenter study was to evaluate the clinical performance of an ultrahigh molecular weight polyethylene (UHMWPE) fiber cable for re-attachment of the osteotomized greater trochanter in hip surgery. Included in the study were 85 hips that had undergone surgery with greater trochanter osteotomy, including 50 hip arthroplasty procedures and 35 hip osteotomies. The osteotomized greater trochanter was reattached using one or more UHMWPE fiber cables. The bone union and displacement of the greater trochanter were assessed in radiographs for up to 12 months after surgery. Non-union of the osteotomy site occurred in 4.7% of the cases. In approximately 90% of the cases, displacement was less than 2 mm at up to 12 months after surgery. The UHMWPE fiber cable was a good biomaterial for reattaching the osteotomized greater trochanter and may also be an option for osteosynthesis procedures.

Ultra-High Molecular Weight Polyethylene Tape Applied for Distal Humeral Condyle Fracture around Total Elbow Arthroplasty in Patients with Rheumatoid Arthritis: Report of Two Cases

Managing fractures of distal humerus in patients with rheumatoid arthritis (RA) is technically challenging. Total elbow arthroplasty (TEA) is one of the treatment options for these fractures. While elbow motion is largely regained by TEA, comminuted condyle fragments are often ignored. Although numerous approaches for repair of condylar fragments around TEA are described, any universal fixation strategy for these fractures has not been established. This report describes, for the first time, application of an ultra-high molecular weight polyethylene (UHMWPE) tape for the treatment of distal humerus fracture in 2 patients with rheumatic elbow arthropathy. The post-operative clinical courses were good. Radiographs showed bony union of the condylar fragments without loosening in two cases. Because of its flat configuration, softness, and flexibility, UHMWPE tape is a promising material for stabilizing fracture of the distal humerus associated with TEA.

Temperature Effect on the Conformation Transition of Ultra-high Molecular Weight Polyethylene/Polypropylene Blends Undergoing Continuous Volume Extensional Flow:A Mesoscopic Simulation

Due to the multiformity and complexity of chain conformation under external flow and the challenge of systematically investigating the transient conformation and dynamic evolution process of polymer chains at the molecular level by means of present experimental techniques,a universal description of both chain conformation and dynamics with respect to continuous volume extensional flow(CVEF)is still absent.Taking into account the temperature effect,we performed dissipative particle dynamics(DPD)simulations with the particles corresponding to the repeat units of polymers over a wide temperature range and analyzed the correlation with the conformational properties of ultra-high molecular weight polyethylene/polypropylene(UHMWPE/PP)blend in response to the CVEF.With time evolution,the polymer chains become highly oriented parallel to the flow direction instead of the initial random coiling and self-aggregation.It is found that a high temperature is necessary for more substantial compactness to take place than low temperature.The low-k plateau and low-k peak in structure factor S(k)curves suggest a low degree of conformational diversity and a high degree of chain stretching.It is also concluded that the intra-molecular C-C bond interaction is the main driving force for the dynamics process of the chain conformations undergoing CVEF,where the motion of the alkyl chains is seriously restricted owing to the increase in bond interaction potential,resulting in a reduction of the difference in diffusion rates among alkyl chains.

捻度对渔用UHMWPE裂膜纤维线股拉伸性能与耐磨性能的影响研究

为促进超高分子量聚乙烯裂膜纤维(简称UHMWPE裂膜纤维)在渔用绳网中的应用,以膜裂法制备渔用UHMWPE裂膜纤维为原料,通过加捻制备渔用UHMWPE裂膜纤维线股,在此基础上,考察了加捻对UHMWPE裂膜线股的线密度、直径、拉伸性能和耐磨性能的影响。结果显示:UHMWPE裂膜纤维线股随捻度的增加表现出直径逐渐减小、实际线密度先增大后减小以及捻回角逐渐增加等特征;对于不同线密度规格的UHMWPE裂膜纤维线股,随着捻度的增加,其断裂强力均呈现降低的趋势,且纤维线密度越低,加捻对线股断裂强度的影响越小;1600 D的UHMWPE裂膜纤维线股的磨损次数随捻度的增加而降低,而3200和4800 D线股的磨损次数随捻度的增加呈现先降低后升高的变化趋势,且4800 D的不同捻度的线股之间的磨损次数无显著性差异(P<0.05),显示出纤维线密度越大,加捻对其耐磨性能的影响越小。1600、3200和4800 D的UHMWPE裂膜纤维线股的结节强力随捻度的增大呈现先升高后降低的变化趋势,当预加捻度为120 T·m^(-1)时,3种线密度线股的结节强力达到最大值,分别为204.15、373.5、562.41 N,较未加捻UHMWPE裂膜纤维分别提高了50.14%、37.13%和30.22%。在本实验捻度设置范围内,1600 D裂膜线股的结节强度随捻度的增加而增大,较未加捻裂膜纤维结节强度提高了32.49%。研究表明,无捻或低捻度、低线密度UHMWPE裂膜纤维线股可用于UHMWPE裂膜纤维无结网的制备;无捻或低捻度的高线密度UHMWPE裂膜纤维线股则具有较好的耐磨性能;中高捻度、低线密度UHMWPE裂膜纤维线股可用于UHMWPE裂膜纤维有结网的制备。研究结果可为渔用UHMWPE裂膜纤维绳网材料的加工、开发与应用提供参考。

Ballistic Penetration Damage of Hybrid Thermoplastic Composites Reinforced with Kevlar and UHMWPE Fabrics

Polymer matrix types of fiber hybrid composites are key factors to improve ballistic impact damage tolerances.Here we report ballistic penetration damages of Kevlar/ultra-high molecular weight polyethylene(UHMWPE)hybrid composites with thermoplastic polyurethane(PU)matrix.The hybrid composites were penetrated by fragment-simulating projectiles(FSPs)using an air gun impact system.The effects of stacking sequences on the ballistic performance of hybrid composites were analyzed.Two types of specific energy absorption(the energy absorption per unit area density and the energy absorption per unit thickness)were investigated.It was found that the main damage modes of PU hybrid composites were fiber breakage,matrix damage,fiber pullout and interlayer delamination.The instantaneous deformation could not be used as a reference index for evaluating the ballistic performance of the target plate.The energy absorption process of the PU hybrid composites showed a nonlinear pattern.The hybrid structure affected the specific energy absorption of the materials.

乙烯-丙烯酸共聚物改性环氧树脂/UHMWPE纤维复合材料的制备与性能研究

使用乙烯-丙烯酸共聚物(EAA)与环氧树脂复配作为基体,利用水基乳液浸渍超高分子量聚乙烯(UHMWPE)纤维制备了复合材料,通过在树脂浸润性、树脂耐热性能、复合材料力学性能、界面结合情况以及微观形貌等方面的测试表征,对比了不同EAA含量的基体树脂对UHMWPE纤维复合材料性能的影响。结果表明,EAA与环氧树脂质量比为25∶75的共混体系一方面可发挥EAA组分与UHMWPE纤维间亲和力强的优势,另一方面还能凭借环氧树脂的刚性交联网络保持较高的耐热性能,体系的层间剪切强度达到8.7 MPa,在60℃下弯曲强度保持率接近80%,表现出优异的综合性能。

碳化硼陶瓷/UHMWPE纤维复合靶板防弹性能仿真与实弹验证

目的:为实现防弹靶板的轻量化和高防护性,对碳化硼陶瓷/超高分子量聚乙烯(ultra-high molecular weight polyethylene,UHMWPE)纤维复合靶板的防弹性能进行仿真优化与实弹验证。方法:首先,基于ANSYS/LS-DYNA建立碳化硼陶瓷/UHMWPE纤维复合靶板的有限元模型。其次,对子弹侵彻不同厚度搭配的防弹靶板过程进行仿真,分析防弹靶板对100 m处56式7.62 mm普通枪弹的防护效果。最后,基于仿真结果,以靶板的防护性和质量作为主要指标,对靶板进行优化设计,并通过实弹射击验证设计靶板的防弹性能。结果:仿真结果表明,不同厚度搭配的防弹靶板都可以实现对100 m处56式7.62 mm普通枪弹的有效防护;实弹验证结果表明,仿真结果准确,设计的防弹靶板具有较好的防护性。结论:对碳化硼陶瓷和UHMWPE纤维设置合理的配比可以满足防弹靶板的高防护性和轻量化需求,该研究可为轻质、高防护性防弹靶板的研发提供参考。

PREPARATION AND CHARACTERIZATION OF ULTRA-HIGH MOLECULAR WEIGHT POLY(ETHYLENE TEREPHTHALATE)(PET)FIBER

This paper reports the spinning and drawing behavior of Ultra-high Molecular Weight polyethylene Terephthalate) (UHMW-PET) fibers. The as-spun fibers were produced by dry-jet wet spinning of a 15%-17% solution in 50:50(v:v) trifluroroacetic acid and dichloromethane. Both molecular weight and polymer solution concentration have marked effect on the drawability of the as-spun-fibers. The maximum extension drawing ratio (EDRmax) of as-spun fiber increases with increasing molecular weight, whereas optimal concentration to achieve the EDRmax of as-spun fibers decreases with increasing molecular weight. Drawing speed and temperature during the first step have remarkable effect on the drawability of these fiber during the second step. Relatively lower drawing temperature and drawing speed (19 ℃ , 60 mm/min) during the first drawing step was beneficial to mechanical properties of ultimate fibers. At the range of 210 ℃ to 230 ℃, the draw ratio (DR) during the second step increases with increasing temperature.

Hot-Drawing of Ultrahigh-Molecular-Weight Polyethylene Gel Films

The three stages in the hot-drawing process of ultrahigh-molecular-weight polyethylene gel films can be detected by x-ray diffraction, infrared spectroscopy, birefringence and scanning electron microscopy. In the first stage of the drawing process, the lamellae in the gel films rotate and/or slip with the b-axis preferentially perpendicular to the drawing direction. With increased drawing, the c-axis of the lamellae become parallel to the stretching direction while unfolding of the chain begins, and the chains of the amorphous phase also orient along the drawing direction in the strain-chain domain. When the draw ratio is large enough, the lamellar structure is transformed into a fibrillar structure in a two-dimensional fashion.

Cyclic Pulsating Pressure Enhanced Segregating Structuration of Ultra-High Molecular Weight Polyethylene/Graphene Composites as High-performance Light-Weight EMI Shields

Currently,the enhancement in electromagnetic interference(EMI)performance of polymeric composite generally relies on either improving electrical conductivity(σ)for stronger electromagnetic(EM)reflections or tailoring structure for higher EM resonances.Herein,we proposed a novel technique called cyclic pulsating pressure enhanced segregating structuration(CPP-SS),which can reinforce these two factors simultaneously.The structural information was supplied by optical microscopy(OM)and scanning electron microscopy(SEM),both of which confirmed the formation and evolution of segregate structured ultra-high molecular weight polyethylene(UHMWPE)/graphene composites.Then,the result showed that CPP-SS can significantly improve theσof samples.Ultimately,advanced specific EMI shielding efficiency of 31.1 d B/mm was achieved for UHMWPE/graphene composite at 1-mm thickness and a low graphene loading of 5 wt%.Meanwhile,it also confirmed that the intrinsic disadvantage of poor mechanical properties of conventional segregated structure composites can be surpassed.This work is believed to provide a fundamental understanding of the structural and performance evolutions of segregated structured composites prepared under CPPSS,and to bring us a simple and efficient approach for fabricating high-performance,strong and light-weight polymeric EMI shields.

UHMWPE的应变率效应及其对超高速碰撞特性的影响

为分析超高分子量聚乙烯(ultra-high molecular weight polyethylene,UHMWPE)的应变率效应及其对超高速碰撞特性的影响规律,采用万能材料试验机和分离式霍普金森拉杆对UHMWPE纤维束进行静、动态拉伸实验,获得了不同应变率下材料的应力-应变关系,并进一步开展了UHMWPE纤维织物的超高速碰撞数值模拟。结果表明,UHMWPE的拉伸模量和强度均随应变率的升高而逐渐增大。随着材料应变率敏感系数的增大,防护结构对弹丸动能的吸收率呈现先减小后增大的趋势。

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/m 2、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。

UHMWPE防弹复合材料正交试验设计与分析

铺层结构和成型工艺是影响超高分子量聚乙烯(ultra-high molecular weight Polyethylene,UHMWPE)纤维复合材料弹道防护性能的重要因素。为评估各因素对UHMWPE纤维复合材料防弹性能的影响程度,基于正交试验设计建立了铺层角度以及包括温度、压强、时间三个热压成型工艺条件下的4因素3水平正交表并进行了9组弹道极限试验。通过对试验结果进行极差和方差分析表明,各试验因素对弹道防护影响程度由大到小依次为铺层角度、成型时间、成型压强和成型温度。此外,研究发现:[(0°/90°)_(2)]_(2n)和[(-45°/45°)_(2)]_(2n)铺层复合材料弹道冲击吸能体现为多破坏模式协同耗能,而[(0°/90°)_(2)/(-45°/45°)_(2)]n准各向铺层复合材料的弹道冲击吸能体现为单一破坏模式耗能;综合考虑防弹性能和成本确定的最优组合为成型温度120℃、压强25 MPa、时间20 min,铺层角度[(0°/90°)_(2)]_(2n)。

Optimization of the Production Process of Flash-Spinning UHMWPE Superfine Fiber by Response Surface Methodology

In this paper, statistical optimization method was used to optimize the flash-spinning process conditions. Ultra-high molecular weight polyethylene （UHMWPE） superfine fiber was fabricated by flash-spinning method using UHMWPE as the fiberforming polymer, 1, 2-dichloroethane as the main solvent. The important parameters of the flash-spinning were filtered by Plackett-Burman experimental design based on the single factor experiments. After determining the best regions of the fiber properties, the optimum level of the important parameters were determined by Box-Behnken design. The results of the design showed that the important parameters influencing on the properties of the flash.spinning fiber were spinning temperature, spinning pressure, and spinning solution concentration. The optimum technical parameters were： spinning temperature 186. 4 ~C, spinning pressure 6. 16 MPa, spinning solution concentration 3.06 %. The highest combination property of the flash-spinning fiber was 86.39 under this condition.

Surface Treatment of UHMWPE Fibers for Adhesion Promotion in Epoxy Polymers

Surface of Ultra-high molecular weight polyethylene （UHMWPE） fiber were treated by chromic acid chemical etching, pyrrole chemical vapour phase deposition and the complex of these two methods, respectively. The change of surface properties and structure of fibers were discussed by Fiour Transform Infrared Spectroscope （FTIR）, Dynamic Mechanical Analysis （DMA） and Scanning Electron Microscope （SEM）. The results show that some new oxygenous groups could be found on surface of UHMWPE fiber after chromic acid chemical etching, which enhanced intemolecular interaction with polypyrrcle. The adhesion of the fiber and resin natrix increased after pyrrole chemical vapour deposition. When chromic acid etching combined with pyrrole chemical vapor deposition, the treated fiber not only has the same properties as original fiber bat also outstanding adhesion to epoxy resin matrix, and its composites have better mechanic properties shear strength）, resulting from intemolecular interaction treated fiber and polypyrrole.

固态牵伸工艺对UHMWPE纤维性能的影响

文中采用凝胶纺丝法,以十氢萘为溶剂,制备得到两种干态超高分子量聚乙烯纤维原丝,在后续的固态牵伸(多级牵伸)阶段,系统研究了牵伸倍率、牵伸温度及倍率分配对纤维力学性能的影响。结果表明:牵伸温度与牵伸倍率适配时,较高的牵伸倍率有利于得到更高性能的纤维,制得的纤维强度最高为39.3 cN/dtex,模量最高为1570 cN/dtex;在相同牵伸倍率及分配的情况下,相比于强度,弹性模量对工艺的变化更敏感,在一定范围内提高温度,纤维模量会下降;在相同总牵伸倍率的情况下,牵伸倍率较大的分配差异更有利于获得高性能纤维。

高岭土/四针状ZnO晶须填充UHMWPE的研究

采用超细高岭土和四针状ZnO晶须对超高分子量聚乙烯 (UHMWPE)进行物理填充改性 ,研究了这 2种填料对于UHMWPE摩擦磨损性能的影响。结果表明 ,四针状ZnO晶须和高岭土都可以降低UHMWPE摩擦系数和磨损率 ,同时二者具有的协同效应 ,在 4 .5 %四针状ZnO晶须和 4 .5 %高岭土的用量时 ,摩擦系数最低 ;在 6 %四针状ZnO晶须和3%高岭土的用量时 ,磨损率最小。SEM表明 2种填料的磨损机理存在差异。复合填充时 ,四针状ZnO晶须可以限制高岭土磨屑的产生 ,进一步降低材料的磨损率。

UHMWPE／纳米SiO2复合弹性材料的摩擦磨损性能研究

以纳米SiO2作为填料制备UHMWPE/纳米SiO2复合材料,采用MRH-5A型摩擦磨损试验机研究纳米含量与载荷等因素对复合材料摩擦磨损性能的影响;利用扫描电子显微镜观察复合材料磨损表面形貌并分析其磨损机理。结果表明,填充纳米SiO2,UHMWPE的摩擦系数减小约40%;SiO2含量为10%左右时,复合材料的摩擦系数最小,磨损性能最好;随着载荷的增大,复合材料的摩擦系数随之增大,尔后趋于平稳;复合材料磨损量随着载荷的增大而增加;摩擦过程中存在短暂的摩擦跑合期。纯UHM-WPE的磨损机理是粘附,而复合材料的磨损机理主要表现为疲劳剥层。

辐射接枝改性对UHMWPE纤维性能的影响

采用预辐射接枝聚合方法制备了丙烯酸甲酯(MA)接枝改性的超高分子量聚乙烯(UHMWPE-g-PMA)纤维。研究了接枝率对UHMWPE纤维结构和力学性能的影响。红外光谱(FT-IR)和扫描电镜(SEM)测试显示,UHMWPE纤维上接枝了PMA分子链。UHMWPE-g-PMA纤维结晶度随接枝率增大而降低;PMA接枝链对UHMWPE纤维的正交晶相无影响,但对单斜晶相和中间相影响明显。UHMWPE-g-PMA纤维的拉伸断裂强度随吸收剂量增大而减小,但不随接枝率变化;拉伸断裂伸长率随吸收剂量增大而减小,随接枝率升高而增大。接枝前后UHMWPE纤维的水接触角测试结果显示,随着接枝率的增加,UHMWPE-g-PMA纤维与水的接触角减小。