干法纺丝用UHMWPE的性能剖析

从相对分子质量、颗粒分布、热分析和溶胀溶解等方面对干法纺丝用超高相对分子质量聚乙烯(UHMWPE)的性能进行分析,探讨了各因素对干法纺丝UHMWPE纤维的影响。结果表明:相对分子质量是决定UHMWPE纤维质量的关键因素,应控制在(4~5)×106;UHMWPE粒径小及分布窄,可加快纺丝溶解溶胀;当UHMWPE的相对分子质量接近时,其初始结晶度越高,纤维性能越好。     

超高相对分子质量聚乙烯的性能与纺丝研究

研究了超高相对分子质量聚乙烯(UHMWPE)的性能,采用冻胶纺丝-超倍拉伸技术,对不同UHM-WPE进行纺丝.制得UHMEPW纤维;通过扫描电镜、广角X射线衍射、声速法、强力仪,对UHMWPE纤维的结构与性能进行研究.结果表明:不同UHMWPE的相对分子质量、粒径分布等物理性能对其的溶胀溶解、以及纺制纤维的性能有较大影...     

多级拉伸中超高相对分子质量聚乙烯纤维的结构与性能研究

采用凝胶纺丝-超拉伸技术纺制了超高相对分子质量聚乙烯(UHMWPE)纤维。采用双折射法、DSC热分析法对不同拉伸级数的纤维进行了结构分析并测试了其力学性能和抗蠕变性能。研究结果表明:随着拉伸倍数的增加,纤维的取向度、结晶度及热性能得到了提高,力学性能和抗蠕变性得到改善,可得到纤维强度大于30cN/dtex,模量超过1200cN/dtex的高性能纤维。     

超高相对分子质量聚乙烯纤维用原料的性能研究

研究了不同厂家纺丝用超高相对分子质量聚乙烯(UHMWPE)树脂的性能,并进行了UHMWPE的纺丝试验,发现它们之间存在着一定差异,而且树脂性能的差异对纤维力学性能造成一定影响,从而建立UHMWPE原料性能与纺丝性能之间的对应关系。     

UHMWPE冻胶纺丝中的降解行为及其对纤维性能的影响

采用双螺杆混炼挤出机溶胀、溶解和挤出纺丝技术制备超高相对分子质量聚乙烯(UHMWPE)冻胶纤维,经热管拉伸得到UHMWPE纤维,研究了冻胶纺丝工艺及后续热拉伸对UHMWPE纤维黏均相对分子质量(M_η)的影响,以及M_η与UHMWPE成品纤维力学性能、热性能、抗蠕变性能及耐磨性能的关系。结果表明:螺杆转速、溶解温度及溶液浓度变化引起的物料高温停留时间和受剪切强度变化对UHMWPE分子降解程度有很大的影响,超倍热拉伸工艺对UHMWPE分子降解影响不大;在UHMWPE溶解均匀的情况下,纤维强度、抗蠕变及耐磨性能随冻胶纤维M_η的增大而增大,且纤维结晶度增加,熔点升高;而UHMWPE溶解条件不佳时,冻胶纤维M_η最高,但纤维表面呈现不均匀凸起,纤维综合性能也变差。     

超高相对分子质量聚乙烯纤维树脂基复合材料性能研究

风电行业进入平价上网时代，风电叶片需要一种介于玻璃纤维和碳纤维之间性价比高的新型纤维。超高相对分子质量聚乙烯（UHMWPE）纤维具有比强度高和比模量高的优势，相同性能下其价格为碳纤维的30%，因此超高相对分子质量聚乙烯纤维具有极大的性价比优势。对超高相对分子质量聚乙烯纤维的拉伸性能、疲劳性能、纤维与树脂的结合能力和抗蠕变能力进行了系统的研究，研究结果表明，超高相对分子质量聚乙烯纤维浸胶纱拉伸模量100 GPa，上浆剂0.5%的含量性能最佳。并对超高相对分子质量聚乙烯纤维基复合材料在抗蠕变型、高表面粘合型方面提出了改进方向。     

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...     

UHMWPE纤维蠕变性能及其数学模型拟合

测试分析了超高相对分子质量聚乙烯 (UHMWPE)纤维的蠕变性能 ,研究了蠕变与温度、外加应力之间的关系。随环境温度的升高 ,纤维的恒蠕变速率增大 ,抗蠕变断裂时间变小 ,蠕变断裂伸长变大 ;随施加应力的增大 ,纤维的恒蠕变速率增大 ,抗蠕变断裂时间变小 ,蠕变断裂伸长变小。通过计算机编程拟合的蠕变曲线与实测蠕变曲线十分吻合 ,拟合出的材料相关参数与实际测量值相近。     

超高相对分子质量聚乙烯树脂的溶胀性能研究

通过自行设计的溶胀性能测试方法,讨论了超高相对分子质量聚乙烯(UHMWPE)树脂的生产工艺、相对分子质量、树脂质量分数、粒径分布以及溶剂等因素对溶胀性能的影响。结果表明,不同厂家生产的UHMWPE树脂的溶胀性能有区别,随着相对分子质量增大,树脂的溶胀温度升高,溶胀时间变长;树脂质量分数提高,不利于树脂的充分溶胀;适当的粒径范围,能使树脂具有良好的溶胀性能;溶剂溶解性能的差异,对树脂的溶胀有较大的影响。     

超临界CO_2预处理对UHMWPE纤维电子束辐照效果的影响

采用正交试验,研究了超临界CO_2预处理工艺(压力、温度、时间)对辐敏剂三羟甲基丙烷三甲基丙烯酸酯(TMPTMA)渗入率及超高相对分子质量聚乙烯(UHMWPE)纤维凝胶含量和蠕变率的影响,并利用Minitab软件分析UHMWPE纤维凝胶含量和蠕变率与TMPTMA渗入率之间的关系,最后通过对UHMWPE纤维各项性能的测定,进一步优化超临界CO_2预处理工艺。研究结果表明:处理温度对TMPTMA的渗入率及UHMWPE纤维凝胶含量和蠕变率影响最大,其次为压力,时间的影响最小;确定了最佳工艺为处理压力30 MPa、温度80℃、时间50 min;TMPTMA渗入率是引起各个影响因素不同水平之间凝胶含量和蠕变率出现差别的重要因素;超临界CO_2预处理对UHMWPE纤维的辐照交联起到了重要的促进作用,使其抗蠕变性能得到很大程度的改善。     

纤维级超高分子量聚乙烯的制备及性能研究

采用自制新型高效负载型QTE-1催化剂,合成了用于纺丝的纤维级超高分子量聚乙烯(UHM-WPE),进行了中试以及工业化生产;考察了反应温度、反应压力等工艺条件对UHMWPE性能的影响,并考察了其纺丝性能。结果表明:QTE-1催化剂体系聚合活性较高,可达5×104g/(g.h)以上,反应动力学平稳,UHMWPE黏均分子量可达4×106以上;UHMWPE黏均分子量随反应温度的升高而降低,随反应压力的增大而增高;UHMWPE堆密度随反应温度和反应压力升高而增高;UHMWPE中试和工业化生产工艺平稳,产品性能优异,能够较好地满足纺丝要求。UHMWPE纤维断裂强度达28.44 cN/dtex,模量达1 400 cN/dtex。     

Size effect of charcoal particles on the properties of bamboo charcoal/ultra‐high molecular weight polyethylene composites

This study was aimed at examining the size effect of charcoal particles on the properties of bamboo charcoal (BC)/ultra‐high molecular weight polyethylene (UHMWPE) composites. Four types of BC with various particle sizes were mixed with UHMWPE using a twin‐screw extruder. It was found that the melting temperature and crystallinity of the composites were slightly decreased with the addition of BC. The incorporation of BC remarkably improved the tensile properties and creep resistance of UHMWPE, and the particle size of BC strongly affected the properties of BC/UHMWPE composites. The BC with lowest particle size exhibited best reinforcement, where the tensile strength and Young's modulus were increased by 385% and 517% compared with neat UHMWPE. The composites with 70 wt % BC possessed conductivities of 16.8, 14.1, 13.5, and 10.9 S/m. The storage modulus and glass transition temperature of the composites also increased with the addition of BC. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45530.     

超高分子量聚乙烯纤维性能及应用概述

超高分子量聚乙烯纤维有着高取向度,高结晶度,强力、模量高,抗冲击,耐腐蚀,耐光照,耐挠曲,耐磨损等优点。它的密度比水小,介电性能好。超高分子量聚乙烯纤维的缺点是使用温度不高,耐氧化性能差,抗蠕变性能差,表面加工困难。正是超高分子量聚乙烯纤维自身所具有的这些特点,它在抗冲击防护,低温,耐压,海洋工程,渔业等领域有着广泛地使用。     

UHMWPE/CNTs复合体系及其纤维的研究进展

综述了超高分子量聚乙烯(UHMWPE)、碳纳米管(CNTs)、UHMWPE/CNTs复合体系及其纤维的研究现状,以及CNTs的添加对UHMWPE/CNTs复合体系及其纤维性能的影响;添加CNTs可有效提高UHM-WPE的耐磨性、电学性能、力学性能以及UHMWPE纤维的抗蠕变性能和热稳定性能;指出CNTs对UHM-WPE改性过程中存在的主要问题是CNTs分散性差,CNTs的生产成本高,UHMWPE/CNTs的改性机理有待进一步深入,并进一步拓宽UHMWPE/CNTs复合体系及其纤维的应用领域。     

正交试验优化挤干辊用非织造基布的制备工艺

为优化挤干辊用高强聚丙烯/超高分子质量聚乙烯(UHMWPE)纤维非织造基布的制备工艺及性能,以高强聚丙烯纤维、UHMWPE纤维为原料,选取纤维质量比、针刺密度及针刺深度为影响因素,设计三因素三水平正交试验,利用非织造技术制备了9种高强聚丙烯/UHMWPE纤维非织造基布样品.测试9种样品的单位面积质量、厚度、透气率、断裂...     

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.     

水性聚氨酯基氧化铟锡蚀刻油墨的制备与性能

以聚乙二醇(PEG)和异佛尔酮二异氰酸酯(IPDI)为基本原料,2,2-二羟甲基丙酸(DMPA)作为亲水扩链剂,经1,2-丙二醇(PDO)扩链后,甲基丙烯酸羟乙酯(HEA)封端,三乙胺(TEA)中和乳化,合成了水性聚氨酯(WPU)乳液;通过热重分析仪、粒径分析仪对树脂性能进行了表征。结果表明,DMPA用量在3%～6%时,可得到分子量低、水溶性好、耐热性能好、粒径合适、乳液均匀稳定的产品。以自制的水性聚氨酯树脂为油墨连结料,磷酸或磷酸与硫酸复合作为蚀刻剂,白陶土作为填充料,添加消泡剂和流平剂,制备了水性ITO蚀刻油墨,得出了油墨的最佳配方,并对油墨进行了一系列的表征。结果表明,最佳的油墨配方是蚀刻剂含量25%～30%、水性连结料含量30%～45%、填充料含量30%～45%、助剂1%。最佳蚀刻工艺为ITO薄膜蚀刻温度为120℃,蚀刻时间20 min,油墨清洗时间50 s;ITO玻璃蚀刻温度为150℃,蚀刻时间20 min,油墨清洗时间40 s。油墨粒径主要分布在10～50 μm之间,其在使用3 h后失水率仅在1.12%～3.68%,且存放60 d后黏度和pH基本无变化,蚀刻能力不随时间推移而降低,且丝网印刷的线路图像解析度明显好于市售的水性油墨。     

超高相对分子质量聚乙烯长丝蠕变性能的研究

通过悬挂重物一定时间后测试纤维蠕变伸长和用蠕变仪直接测量的方法分别测试了超高相对分子质量聚乙烯长丝和高强涤纶工业丝这两种高强纤维的蠕变性能。从试验中得出超高相对分子质量聚乙烯长丝具有比高强涤纶工业丝更高的断裂强度和弹性模量。两种纤维随悬挂重物时间的延长及重物重量的增加,其断裂强力总体上呈下降趋势,但程度不同。悬挂重物相同时间下,超高相对分子质量聚乙烯长丝伸长较高强涤纶工业丝小,且其形变在外力撤除后难以恢复,产生较大塑性变形,大大影响其力学性能。     

浆粕性质对离子液体法再生竹浆纤维性能的影响

以6种不同性质的竹浆粕为原料,选用1-乙基-3-甲基咪唑醋酸盐{[EMIM] Ac]为溶剂,采用干喷湿纺的方式制备了再生竹浆纤维,探讨了竹浆粕性质对再生竹浆纤维制备过程中溶解、流变行为以及纤维性能的影响.结果表明:离子液体对竹浆粕具有非常强的溶解能力;6种竹浆粕/[EMIM] Ac纺丝液都属于切力变稀流体;高聚合度和高α纤维素的竹浆粕制备的纤维的断裂强度和模量较高,但是纺丝过程不连续,发生断头较多.     

Refractories containing fused and sintered alumina aggregates: Investigations on processing,particle size distribution and particle morphology

The present study investigated pressed high-purity alumina refractories containing either white fused or tabular (sintered) alumina aggregates under comparable conditions. Using factorial experiments especially the effects of the pressing pressure, the particle size distribution model and the particle morphology were evaluated. White fused alumina exhibited a higher refractoriness under load as well as a lower total compression and creep rate in creep in compression experiments. However, tabular alumina had a higher cold crushing strength and Young's modulus before and after thermal shock. Yet, no significant effect regarding the relative loss of the Young's modulus due to thermal shock was determined. Generally, a higher pressing pressure reduced the apparent porosity and increased the cold crushing strength, the Young's modulus and the refractoriness under load. The batches according to a recently suggested modified Andreasen particle size distribution model contained a considerably higher amount of the coarsest particle fraction, while the medium particle size fractions were reduced. Surprisingly, for both alumina raw materials the modified Andreasen model resulted in a virtually identical apparent density and a slightly lower apparent porosity compared to the conventional Andreasen model. Furthermore, the thermomechanical properties were essentially unaffected, while the cold crushing strength and the Young's modulus were somewhat lower. For both raw materials the addition of blocky coarse grain fractions yielded a lower apparent porosity and higher apparent density compared to angular grains due to improved particle packing. Remarkably, the creep in compression and the creep rate were reduced as well. Consequently, the modified Andreasen model together with a designed particle morphology might allow the fabrication of shaped alumina products with a much higher content of coarse grained particles resulting in at least similar or even improved physical, mechanical and thermomechanical properties irrespective of the used alumina raw material.