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.

Surface Modification of Polyethylene Terephthalate(PET) Fiber by Roll-to-Roll Treatment in Atmospheric Ar/O_2 Dielectric Barrier Discharge(DBD) Plasma

In this work,polyethylene terephthalate(PET) fibers were continuously treated by atmospheric dielectric barrier discharge(DBD) in Ar mixed O2 plasma,and the discharge was characterized by electrical function and optical diagnostics.It is found that the interfacial adhesion strength between treated PET fiber and resorcinol formaldehyde latex(RFL)(little)-rubber was improved(about 50%) by the measurement of interfacial shear strength(IFSS) and peel test.The wettability was improved rapidly in the initial treatment time.It is considered that oxidation chemical reaction as the major role of PET fiber surface modification is ahead of the physical etching effect.The high density of atomic oxygen in the plasma by optical emission spectroscopy supports the purpose.According to the scanning electron micrograph(SEM) image in the work,the longer treatment time obviously caused physical etching effect,which shall be less responsible for the improvement of the wettability.

Characterization and Comparison of Rheological Properties of Agro Fiber Filled High-Density Polyethylene Bio-Composites

The rheological behavior of composites made with high-density polyethylene (HDPE) and different agro fiber by-products such as corncob (CCF), Rice hull (RHF), Flax shives (FSF) and Walnut shell (WSF) flour of 60 - 100 mesh were studied. The experimental results were obtained from samples containing 65 vol.% agro fiber and 3 wt.% lubricant. Particle sizes distribution of the agro fibers was in the range of 0.295 mm to ?0.125 mm. SEM showed evidence of complete matrix/fiber impregnation or wetting. The melt rheological data in terms of complex viscosity (η*), storage modulus (G'), loss modulus (G"), and loss tangent (tanδ) were evaluated and compared for different samples. Due to higher probability of agglomeration formation in the samples containing 65 vol.% of agro fillers, the storage modulus, loss modulus and complex viscosity of these samples were high. The unique change in all the samples is due to the particle size distribution of the agro fibers. The storage and loss modulus increased with increasing shear rates for all the composites, except for Walnut shell composite which exhibited unusual decrease in storage modulus with increasing shear rate. Damping factor (tanδ) decreased with increasing shear rate for all the composites at 65 vol.% filler load although there were differences among the composites. Maximum torque tended to increase at the 65 vol.% agro fiber load for all composites. Corncob and Walnut shell composites gave higher torque and steady state torque values in comparison with Flax shives and Rice hull composites due to differences in particle sizes distribution of the agro fibers.

THE EFFECTS OF ULTRA DRAWING ON THE CRYSTAL STRUCTURE OF GEL SPUN POLYETHYLENE FIBERS

It is believed that gel spun polyethylene(PE)fibers have a somewhat extended chain crystalstructure,because of the disentangling of the chains which takes place in semi-dilute solutionand the ultra high draw ratio used.Ten years ago,PE shish-kebabs grown from dilute solutionwere proved to have extended chain backbone which causes the raising of its melting point.These crystals were found to have a triclinic crystal phase,This study shows a different result forgel spun ultra high drawn PE fiber.The unit cell remains orthorhombic even if the draw ratioreaches 50;as the draw ratio increases,the length in a and b axes are shortened while that in c ax-is changes quite insignificantly.When the draw ratio is over 10,two endothermic melting peakscan be seen in the DSC curves with corresponding peak temperature of 136.7-145.3℃.The lat-ter peak is attributed to the amount of extended chain crystal.

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.

Improvement of Mechanical,Dynamic-Mechanical and Thermal Properties for Noil Ramie Fiber Reinforced Polyethylene Composites

Noil discarded fibers from fiber production for textile industry have short length and are always considered less valuable.Here,noil ramie fibers/HDPE composite is prepared using twin-screw extruder and the dynamic mechanical and thermal properties are studied.The influence of ramie fiber and maleic anhydride-grafted polyolefin(MA-g-PO)on mechanical,dynamic mechanical and thermal properties is investigated.It is observed that the tensile,flexural and impact properties of the composites treated with MA-g-PO are all improved in comparison to the untreated composites.Dynamic mechanical properties of the composite with MA-g-PO show an increase in the storage modulus with a higherαrelaxation peak,together with the micromorphology analysis,indicating an improved interfacial bonding between fiber and matrix by the MA-g-PO addition.Furthermore,the change in TGA thermograms of composite caused by MA-g-PO exhibits that the addition of MA-g-PO is also helpful to increase the thermal stability of noil ramie fiber/HDPE composites.

Decorative Wood Fiber/High-Density Polyethylene Composite with Canvas or Polyester Fabric

Wood-plastic composite is an environmentally friendly material,due to its use of recycled thermoplastics and plant fibers.However,its surface lacks attractive aesthetic qualities.In this paper,a method of decorating wood fiber/high-density polyethylene(WF/HDPE)without adding adhesive was explored.Canvas or polyester fabrics were selected as the surface decoration materials.The influence of hot-pressing temperature and WF/HDPE ratio on the adhesion was studied.The surface bonding strength,water resistance,and surface color were evaluated,and observation within the infrared spectrum and under scanning electron microscopy was used to analyze the bonding process.The results showed that the fabric and WF/HDPE substrate could be closely laminated together depending on the HDPE layer accumulated on the WF/HDPE surface.The molten HDPE matrix penetrates canvas more easily than polyester fabric,and the canvasveneered composite shows a greater bonding strength than does the polyester fabric-veneered composite.A higher proportion of the thermoplastic component in the substrate improved the bonding.When the hot-pressing temperature exceeded 160°C,the fabric-veneered WF/HDPE panels had greater water resistance,although the canvas fabric changed more obviously in terms of fiber shape and color,compared with the polyester fabric.For the canvas fabric,140°C–160°C was a suitable hot-pressing temperature,whereas 160°C–180°C was more suitable for polyester fabric.The proportion of the thermoplastic component in the composite should be not less than 30%to achieve adequate bonding strength.

Structural Changes of Polyethylene Terephthalate Fibers Grafted by Acrylamide

A group of grafted PET fibers with different graft yield are formed by grafting acrylamide onto the PET main chains. The structure of grafted fibers are studied by scanning electronic microscope ( SEM ), infra-red spectrophotometer ( IR ), and differential scanning calorimetry(DSC). At the same time, the moisture regain, dyeability, strength, and elongation at break of the samples are measured and their relations with structural changes are discussed. Compared with ungrafted fiber, shape of the fiber cross-section, IR characteristic absorption peaks, and melting behavior of the grafted fibers have been changed, causing the fiber dyeability and moisture regain to be increased, and mechanical properties to be changed.

Low Density Linear Polyethylene Reinforced with Alkali and MAPE Treated Fibers from Coffee Pulp

In this work fibers derived from coffee, hulls have been incorporated into Linear Low Density Polyethylene (LLDPE). The influence of the filler content on the thermal and physicomechanical properties of the composites obtained was assessed. The results showed that the incorporation of fibers was able to improve the thermostability of LLDPE/Coffee hulls fibers;comparing the treated fiber composite with untreated fiber composites, the chemical treatment reduces by 58.3% the water absorption, while increasing the elongation and tensile strength by about 48% and 17% respectively. Moreover, due to better interfacial interaction induced by MAPE, the corresponding composite exhibited better properties compared to the untreated fiber composite. Results are indicative of the fact that both mercerization and MAPE (coupling agent) have significant positive effects on the fiber-matrix interaction in terms of adhesion, wetting and dispersion, this treatment produced a better fiber distribution and consequently a more uniform composite morphology without voids and gaps between the fibers and the matrix, allowing the possibility to use higher fiber contents (up to 30% wt.) with acceptable mechanical properties.

Experimental and Numerical Analysis of High-Strength Concrete Beams Including Steel Fibers and Large-Particle Recycled Coarse Aggregates

In order to study the performances of high-strength concrete beams including steel fibers and large-particle recycled aggregates,four different beams have been designed,tested experimentally and simulated numerically.As varying parameters,the replacement rates of recycled coarse aggregates and CFRP(carbon fiber reinforced polymer)sheets have been considered.The failure mode of these beams,related load deflection curves,stirrup strain and shear capacity have been determined through monotonic loading tests.The simulations have been conducted using the ABAQUS finite element software.The results show that the shear failure mode of recycled concrete beams is similar to that of ordinary concrete beams.The shear carrying capacity of high-strength concrete beams including steel fibers and large-particle recycled coarse aggregates grows with an increase in the replacement rate of recycled coarse aggregates.Reinforcement with CFRP sheets can significantly improve the beam’s shear carrying capacity and overall resistance to deformation.

CT Image-based Analysis on the Defect of Polypropylene Fiber Reinforced High-Strength Concrete at High Temperatures

With the application of X-ray computed tomography（CT） technology of C80 high-strength concrete with polypropylene fiber at elevated temperatures, the microscopic damage evolution process observation and image building could be obtained, based on the statistics theory and numerical analysis of the combination of concrete internal defects extension and evolution regularity of microscopic structure. The expermental results show that the defect rate has changed at different temperatures and can determine the concrete degradation threshold temperatures. Also, data analysis can help to establish the evolution equation between the defect rate and the effect of temperature damage, and identify that the addition of polypropylene fibers in the high strength concrete at high temperature can improve cracking resistance.

Effect of Groundnut Shell Powder on the Mechanical Properties of Recycled Polyethylene and Its Biodegradability

Natural fiber reinforced composites have gained considerable attention particularly in the manufacturing industry owing to their light weight, corrosion resistance, abundance, and biodegradability. In this work, alkaline treated and untreated groundnut shell powder (GSP) was used to reinforce recycled polyethylene to produce GSP-recycled polyethylene composites with improved mechanical properties and biodegradability. GSP with particle sizes of 0 - 300 μm and 300 - 600 μm was used in different proportions: 5%, 10%, 15%, 20%, 25%, and 30% wt. The fiber was immersed for 5 hours in a 10 wt% NaOH solution. Tensile and hardness test data showed an improvement in mechanical properties of the treated fiber composites. Results of water absorption test also showed that treated GSP-recycled polyethylene composites had a lower rate of water absorption than the untreated GSP-recycled polyethylene composites. Through Fourier transform infrared spectroscopy, disappearance of characteristics peaks of hemicellulose and lignin was observed. Growth of fungi on the fiber-reinforced composites was observed, which was evidence that GSP-recycled polyethylene composite was biodegradable. Finally, SEM micrographs showed uniform distribution of treated fibers in the polymer matrix;this explained the observed improvement in the mechanical properties of treated GSP-recycled polyethylene composites.

Elasto-plastic Analysis of High-strength Concrete Shear Wall with Boundary Columns Using Fiber Model

In this study,an experimental study and numerical calculations using fiber model were conducted for four high-strength concrete shear walls with boundary columns under low cyclic load.The boundary column and shear wall were divided into fiber elements,and PERFORM-3D finite element analysis software was used to carry out push-over analysis on the test specimens.The results show that the finite element analysis results were in good agreement with the experimental results.The proposed analysis method could perform elasto-plastic analysis on the high-strength concrete shear wall with boundary columns without distinguishing the categories of frame column and shear wall.The seismic performance of high-strength concrete shear wall with boundary columns was analyzed using the following parameters:axis compression ratio,height to width ratio,ratio of vertical reinforcement,and ratio of longitudinal reinforcement in the boundary column.The results show that the increase in the axial compression ratio causes the bearing capacity of the shear wall to increase at first and then to decrease and causes the ductility to decrease.The increase in the height to width ratio causes the bearing capacity of the shear wall to decrease and its ductility to increase.The ratio of vertical reinforcement was found to have little effect on the bearing capacity and ductility.The increase in the ratio of longitudinal reinforcement in boundary column resulted in a significant increase in the bearing capacity and caused the ductility to decrease at first and then to slowly increase.

树枝状磺化聚醚砜纤维基复合固态电解质的制备及其性能

为解决应用于全固态锂金属电池中固态有机电解质离子电导率较低和力学性能较弱的问题,采用静电纺丝技术制备了树枝状磺化聚醚砜(SPES)纳米纤维膜,将其与聚氧化乙烯(PEO)结合制备复合固态电解质,并应用于全固态锂金属电池中。探讨了纺丝工艺对纳米纤维形貌的影响,在最佳的静电纺丝工艺参数下,研究了SPES纳米纤维膜对复合固态电解质结晶度、离子电导率、力学性能以及电化学性能的影响。结果表明:在四丁基六氟磷酸铵质量分数为2%,静电纺丝电压为30 kV,接收距离为15 cm时,制备的树枝状SPES纳米纤维膜具有最好的形貌,将PEO浇筑在该纳米纤维膜上获得的复合固态电解质其离子电导率为8.13×10^(-5)S/cm(30℃),断裂强度为5.1 MPa,且可使对称电池在0.1 mA·h/cm^(2)下稳定循环198 h,使LiFePO_(4)/Li电池在循环400圈后仍保持着128.6 mA·h/g的放电比容量;SPES纳米纤维膜因破坏PEO的结晶区且能构成三维离子传输路径,不仅提高了复合固态电解质的离子电导率,还使复合固态电解质具有优异的力学强度,可满足高性能全固态锂金属电池的应用需求。

高强度玻璃纤维对阻燃增强PET性能的影响

研究了高强度玻璃纤维对阻燃增强聚对苯二甲酸乙二酯(PET)材料性能的影响,并制备了综合性能优良的高性能阻燃增强PET材料,同时分析了高强度玻璃纤维和普通无碱玻璃纤维在PET材料中的尺寸分布。结果表明:高强度玻璃纤维的表面处理可以有效提高阻燃增强PET材料的性能;阻燃增强PET的性能随着玻璃纤维含量的增加而提高,高强度玻璃纤维比普通无碱玻璃纤维能更好地改善PET材料的综合性能。

LLDPE/碳纤维网复合膜的制备及性能

为了提高线型低密度聚乙烯(LLDPE)的拉伸强度和模量,将碳纤维(CF)梳理成均匀的碳纤维网,将其作为增强材料与LLDPE复合制备LLDPE/CF复合膜,综合利用热失重分析(TG)、扫描示差量热分析(DSC)、扫描电子显微镜(SEM)及拉伸测试等手段分析碳纤维网含量对复合膜结构及性能的影响。结果表明:与LLDPE膜相比,LLDPE/CF复合膜的拉伸强度和杨氏模量显著提高并随碳纤维网含量增加而增大,当碳纤维网质量分数仅为1%时,拉伸强度从10.6MPa提高到28.7MPa,提高了171%,杨氏模量由75MPa增大到1119MPa,约提高到原来的15倍;碳纤维网的引入有利于LLDPE/CF复合膜热稳定性能的提高,当碳纤维网含量仅为1%时,LLDPE/CF的初始热分解温度和最大热分解速率温度与LLDPE相比分别提高了21℃和11℃;碳纤维网的引入促进了LLDPE分子链的结晶,使LLDPE/CF复合膜的结晶度增大,有利于拉伸强度和模量提高;SEM结果显示碳纤维网与LLDPE基体间的界面结合较强,有利于力学性能的提高。研究成果可为高性能聚合物/碳纤维复合材料的制备提供实验依据和理论指导价值。

高密度聚乙烯三维网状纳微米纤维的强伸性能

为实现高密度聚乙烯三维网状纳微米纤维(PENFs)的自主化规模化生产,以高密度聚乙烯和二氯甲烷为原料,通过高压闪喷纺丝设备成功制备了性能优异的PENFs,采用响应面法对纺丝过程中各工艺参数进行优化,并对其力学性能和耐候性能进行分析。结果表明:PENFs的最佳制备工艺条件为纺丝温度176.3℃、纺丝压力8.6 MPa、纺丝溶液质量分数8.0%,此时制得的PENFs的断裂强度和断裂伸长率分别可达到29.1 cN/dtex和99.9%,优于芳纶和涤纶等常规纤维;定伸长和定载荷条件下,PENFs的弹性回复能力随着拉伸次数和载荷的增加而逐渐降低,拉伸伸长为5%时PENFs纤维的弹性回复率可达到92.8%且拉伸10次后降低至75.5%,拉伸载荷为1.2 N时PENFs纤维的弹性回复率为84.6%;放置在室外20 d内PENFs纤维的强伸性能损失较小,30 d后断裂强度和断裂伸长率明显降低,但纤维外貌并无明显变化。

聚乙烯纤维在混凝土中的应用研究进展

综述了超高相对分子质量聚乙烯纤维及其他聚乙烯纤维对混凝土性能的影响,以及在混凝土开发中的应用研究进展。聚乙烯纤维的桥接作用可阻止混凝土裂纹的产生及扩展,提高混凝土的力学性能和耐腐蚀性能,一方面为聚乙烯纤维在建筑领域的应用提供了可能,另一方面也为超高性能混凝土的开发提供了机遇。应加强聚乙烯纤维增强混凝土的系列化、标准化研究,尽快实现工业化。

长玻纤/高密度聚乙烯复合材料的制备

以N406作为偶联剂,向双螺杆挤出机中连续加入玻璃纤维(玻纤GF),再经剪切、混合工艺,共混制备了长玻纤增强高密度聚乙烯(HDPE)复合材料。采用万能拉伸测试仪、冲击强度测试仪和熔体流动速率(MFR)测试仪,测试了复合材料的力学性能和流动性能;采用差式扫描量热仪(DSC)表征了复合材料的结晶温度、熔融温度;用热失重分析仪(TG)测量了复合材料的玻纤含量。研究结果表明,N406的用量对HDPE的拉伸强度的影响不大,但对冲击强度和MFR的影响较明显。偶联剂用量为8%时,相较未用偶联剂的长玻纤,增强HDPE复合材料的冲击强度提高了64.34%,MFR降低了40.07%。随着玻纤含量增加,拉伸强度、冲击强度升高,MFR降低;HDPE的结晶温度降低,熔融温度增加。玻纤含量为31.26%的复合材料,拉伸强度达到62.88MPa,较纯HDPE提高了180.97%。

过滤吸油用PP/PE双组分熔喷非织造布的性能测试研究

以不同质量比的聚丙烯(PP)、聚乙烯(PE)为原料制得PP/PE双组分熔喷非织造布,测试分析了PP/PE双组分熔喷非织造布的性能。结果表明:PP/PE双组分熔喷非织造布的纤网呈现蓬松杂乱的三维结构,纤维直径较细,孔隙率较高;随着PE添加比例增大,PP/PE双组分熔喷非织造布的面密度和厚度增大,拉伸断裂强力、顶破强力略有下降,硬挺度下降,透气性增大;当PP/PE质量比为73时,PP/PE双组分熔喷非织造布的水接触角在129°左右,吸油倍数为18.75,20 s内吸油高度为1.7 mm,空气过滤效率为56.82%,综合性能较好,可应用于过滤、吸油等领域。