熔喷/纺粘复合非织造布过滤材料的研究

本文研究了熔喷/纺粘复合非织造布过滤材料的形态结构,物理机械性能和过滤性能。讨论了熔喷和纺粘工艺对聚丙烯纤维结构特性的影响。结果表明:熔喷纤维直径直方图呈对数正态分布,分子取向随纤维直径减小而增大。纺粘法纤维取向度比熔喷纤维高,纤维均匀。不同牵伸工艺对聚丙烯纤维的结晶变体有较大影响,复合材料具有独特的物理机械性能和过滤双重作用。     

改性二氧化钛/纺黏-熔喷非织造抗菌复合滤材的制备及性能

改性二氧化钛(TiO_2)纳米颗粒通过在线和离线法分别负载到聚丙烯熔喷和聚乙烯/聚酯皮芯型双组分纺黏非织造材料上,再将两种材料复合后可制备成高效抗菌的室内空气过滤材料。借助扫描电子显微镜和X射线衍射仪来表征其微观形貌和组成成分,并利用自动滤料仪、电子织物强力仪以及振荡法分别测试复合滤材的滤效和压降、力学性能以及抗菌性能。结果表明:改性TiO_2纳米颗粒被成功沉积在纤维表面,且不同TiO_2负载量会对纤维的形貌产生影响;复合滤材的纺黏层在强力拉伸中起主要作用;当纺黏材料和熔喷材料的TiO_2负载质量分数分别为20%和15%时,复合滤材的综合空气过滤性能较好,其在紫外光照条件下对大肠杆菌(E.Coli)和金黄色葡萄球菌(S.aureus)的抑菌率高达99.07%和99.27%。     

工艺温度对超临界CO_2发泡聚丙烯泡孔结构的影响

以自制的高熔体强度聚丙烯为原料,利用超临界流体技术制备了聚丙烯发泡材料。重点考察了发泡温度对所得聚丙烯泡孔结构的影响。结果表明:155~170℃为适宜发泡的温度区间,随着温度的降低,泡孔密度增加,平均泡孔直径减小;当发泡温度为160℃时,泡孔密度、平均泡孔直径和表观密度依次分别为1.03×107cell/cm3、73.86μm和0.016 g/cm3,此时发泡倍率最大,达到55倍;温度通过影响聚丙烯的结晶速率、熔体的黏弹性以及发泡剂在聚丙烯熔体中的溶解度和扩散系数等来控制泡孔结构和发泡倍率。     

聚丙烯/乙烯-乙烯醇共聚物/聚丙烯接枝马来酸酐共混体系的流变性能

以聚丙烯接枝马来酸酐(PP-g-MAH)为相容剂,采用双螺杆共混法制备聚丙烯/乙烯-乙烯醇共聚物(PP/EVOH)共混物.利用毛细管流变仪研究PP/EVOH共混物的流变行为,研究了共混物配比、剪切速率和温度对流体的剪切应力、表观黏度、非牛顿指数和黏流活化能等方面的影响.结果表明,EVOH的加入降低了共混体系的剪切应力和表观黏度,温度在低剪切速率时对表观黏度的影响较大.     

基于人工神经网络的超稠油表观黏度预测

对辽河超稠油表观黏度与温度、剪切速率的关系进行了全面的研究,结果表明超稠油的表观黏度是温度与剪切速率的函数,表观黏度随温度的升高而减小,随剪切速率的增大而减小.运用人工神经网络的方法来模拟各种影响因素与超稠油表观黏度之间的映射关系,建立了超稠油表观黏度的预测模型.这种方法综合考虑了温度、剪切速率对超稠油表观黏度的影响,模型所需参数少、计算简单、预测精度较高,为原油管道工艺计算和管道运行提供了较精确的黏度参数.     

锦涤纶复合丝的工艺研究 第一部分:纺丝和拉伸工艺研究

本文叙述了锦涤纶皮芯型复合长丝纺丝、拉伸工艺的试验结果。实验以16孔同心皮芯型锦涤纶复合长丝为主,通过多次试纺,找到了比较合理的纺丝、拉伸工艺条件,并对工艺条件与纤维结构性能之间的关系进行了初步探讨。     

熔体微分静电纺丝聚丙烯纤维的吸油性能研究

利用自制熔体微分静电纺丝装置制备不同纺丝温度条件的聚丙烯纤维。获得纤维的平均直径为810 nm,单个喷头产量达13 g/h;电纺纤维接触角分布在140°~150°,对比数据发现接触角与纤维直径无明显关系;聚丙烯纤维棉相对机油的最大初始吸油率、吸油倍率和保油率分别为235、158和62 g/g。初步探究吸油机理表明,吸油倍率随纤维直径的减小、孔隙率的增加、油品黏度的增加有增大的趋势,纤维样本重复吸/放油7次后,其吸油倍率为原来的59%~78%。     

β晶相聚丙烯成纤性能的研究

作者研究了β晶相聚丙烯的成纤性能。研究表明,在一定的温度范围内,熔体温度对聚丙烯初生纤维的β晶含量影响甚微,而纺丝的冷却速率和冷却介质对其有较显著的影响。含β晶相聚丙烯初生纤维经拉伸后,在纤维的表面呈现许多微孔及裂缝。与普通聚丙烯纤维比较,制得的纤维有较小的表观密度,其吸湿性有明显的提高。     

稠油蒸汽泡沫共混体系的流变性能研究

为了进一步加强对稠油蒸汽泡沫驱油过程中流体力学性能的认识,在油藏压力7.60 MPa下,利用高温高压流变仪测得了不同条件下稠油蒸汽泡沫共混体系的流变曲线.实验结果表明:稠油蒸汽泡沫驱油体系均为假塑性流体,其流变方程能很好地关联幂律模型;随蒸汽相饱和度和泡沫剂浓度升高,体系表观黏度增大;随蒸汽干度和温度升高,体系表观黏度降低;在低剪切速率时,表观黏度和温度关系满足Arrhenius方程,随着剪切速率增大,表观黏度和温度关系逐渐偏离Arrhenius方程;黏流活化能的绝对值随剪切速率增大而降低,在低剪切速率时,表观黏度对于温度变化更敏感.     

玻璃纤维毡(GMT)浸渍过程中的表面张力作用

采用带有热台的显微镜研究了200℃下聚丙烯树脂熔体沿玻璃纤维(束)的流动过程。实验结果表明:高黏的聚丙烯熔体能够在表面张力的作用下沿纤维束间的微观缝隙自发地流动,并且缝隙的间距越小,树脂的流动速率就越快;树脂熔体在经过一段时间的缓慢自发流动以后会加速流动。通过测试交叉纤维间熔体的间距,间接计算了聚丙烯树脂在该状态下自发流动的临界毛细管直径和自发流动的最低压力。     

制备长玻纤增强聚丙烯复合材料的熔融浸渍过程分析

以玻璃纤维/聚丙烯为研究对象,建立热塑性熔融树脂浸渍纤维的理论模型,模型表征在实验过程中不同加工工艺条件、熔体黏度以及纤维结构对树脂完全浸渍纤维束所需时间的影响,同时探讨了相关机理。树脂浸渍纤维的程度通过所制试样的层间剪切强度来表征,并通过扫描电镜对预浸带界面进行研究,结果表明：纤维束在浸渍机头中的停留时间、浸渍机头的温度、纤维束展宽以及选择不同的树脂基体,均将影响树脂与纤维两相间的界面结合,并最终影响材料的力学性能;树脂基体中添加相容剂马来酸酐接枝聚丙烯（PP-g-MAH）在玻璃纤维和树脂基体两相间能够起到交联作用,明显提高两相间的界面结合强度,使得复合材料的力学性能优于未添加PP-g-MAH的试样,但在基体中添加过多的PP-g-MAH,试样的力学性能则表现出下降的趋势。     

Preparation of Acid Dyeable Polypropylene Fiber

A series of basic copolyamides has been synthesized withadipic acid(AA),hexamethylene diamine(HMDA)anddiethylenetriamine(DETA).Intrinsic viscosity determi-nation,thermal analysis and infrared spectrum analysisof the copolyamide indicates that molecular weight,ther-mal stability reduce whereas alkalinity increase with theincreasing fraction of DETA.Then acid dyeable polypro-pylene fibers are prepared by admixing polypropylene(PP)with those copolyamides prior to extrusion.Lowconcentration of the additive affects slightly on the crys-tallinity and the mechanical property of PP fiber.Themodified PP fibers have a nice acidic dyeability.     

Preparation of High Shrinkage Polypropylene

The common PP chips have been used to prepare high shrinkage PP fibers with shrinkage in boiling water higher than 50%. Meanwhile, the process conditions on fiber structure and properties have been discussed in detail. With the increase of drawing temperature, the shrinkage in boiling water of the fiber increases at first, and then decreases in the temperature range from 70℃to lOO℃. The better drawing temperature is from 75℃ to 85℃ according to the melt index of the PP material. The shrinkage in boiling water of PP fiber increases with the increase of pump delivery. The orientation factor and crystallinity increase with the increase of drawing temperature. With an increase in drawing temperature, unit-cell numbers and monomer unit numbers in every crystal nucleus tend to increase, but unit volume crystal nucleus tend to reduce.     

直线式双组分熔体微分电纺“月牙状”聚丙烯纤维制备

搭建直线式熔体微分电纺设备，制备了聚丙烯（PP）和聚乳酸（PLA）双组分纤维，将所制样品放入丙酮水溶液中作浸泡处理，溶解PLA组分获得PP单组分异形纤维；然后对PLA添加增塑剂乙酰柠檬酸三丁酯（ATBC）进行降黏处理，以达到改变PLA熔体流动速率（MFRs）的目的，探究不同MFRs差异所产生的不同包裹现象。研究结果表明，两种组分的MFRs差异对双组分纤维的包裹现象产生显著影响，且通过实验可知，当ATBC质量分数为6%的PLA与PP共纺时，可得到形貌最佳的PP组分异形纤维。     

聚丙烯与聚酯共混物的流变性能研究

本文对聚丙烯(PP)与阳离子可染聚酯(CDPET)在组成为97/3,95/5,90/10、85/15和80/20以及与对苯二甲酸丁二酯(PBT)组成为90/10共混物的流变行为、共混物形态结构与流变性质的关系作了研究。结果表明,PP与CDPET、PBT的共混物熔体均为切力变稀的幂律流体。共混物PP/CDPET熔体表观粘度对剪切速率的依赖性比PP/PBT小,而对温度的依赖性则比PP/PBT大。PP/CDPET共混物随着第二组分含量的变化其表现粘度在5(质量)％时出现极大值,这与共混物熔体中分散相的形态结构物有关;CDPET百分含量越大,PP/CDPET共混物熔体粘度对温度越敏感。     

连续玻纤增强聚丙烯熔融浸渍过程降黏研究

将不同配比的高黏度聚丙烯与低黏度聚丙烯共混制备高低黏度树脂混配基体,旋转流变测试结果显示低黏度聚丙烯的加入显著降低了共混体系的黏度。以高低黏度聚丙烯共混物为热塑树脂基体,采用熔融浸渍方法制备连续玻纤增强聚丙烯热塑预浸带。研究发现随着低黏度聚丙烯含量的增加,热塑树脂基体的加工性能明显提高,预浸带制品的孔隙率及纤维断裂率逐渐降低。将各组预浸带模压成型后进行力学测试,结果显示低黏度聚丙烯的加入使层压板层间剪切强度、弯曲强度、拉伸强度均出现小幅度下降,而对冲击强度基本无影响。结合加工性能及力学性能,低黏度聚丙烯质量分数10%时共混物的综合性能最佳。     

Influence of alkaline treatment and fiber loading on the physical and mechanical properties of kenaf/polypropylene composites for variety of applications

Due to current trend and increasing interest towards natural based fiber products, Kenaf (Hibiscus cannabinus) fibers have been used for the developments of many products. Therefore, Kenaf fiber-reinforced composites have been widely used in engineering and industrial applications. The present work deals with the fabricating and characterization of untreated and treated kenaf/polypropylene (PP)-reinforced composites. Composites of PP reinforced with treated and untreated kenaf fibers were fabricated using the injection molding technique. Different fiber loadings of 10, 20, 30, 40, 50 wt% treated and untreated kenaf composites were also prepared. X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and thermo gravimetric analysis (TGA) were performed on the treated, untreated kenaf fibers and kenaf/PP composites. Moreover, the alkaline-treated kenaf composites exhibit better physical, morphological, and mechanical properties because of the compatibility of kenaf with PP. However, variations in tensile and flexural properties depend on treatment and kenaf fiber contents. The percentage increase in the mechanical properties of the treated kenaf/PP composites relative to that of PP was also measured. In addition, 40 wt% kenaf fiber loading resulted in higher mechanical properties. By contrast, kenaf/PP composite with 50% fiber loading was not successfully prepared because of improper mixing and the burning of kenaf fibers in the PP matrix. To conclude, 40% kenaf/PP composites with superior physical and mechanical properties may be used in variety of applications such as automotive, sports, construction, animal bedding, and mass production industries.     

The Manufacture of Structured Flax/Hemp Fiber Thermoplastic Composites and Its Flexural Properties

Flax and hemp fibers were used as reinforcing materials to commingle with polypropylene (PP) fiber to realize the mixture of two materials at the stage of yarn.Meanwhile,PP filaments were introduced to produce a corespun yarn with flax/PP as core and PP filament as outer sheath.The commingled yarns were woven into 2D fabric which was used as the prefabricated material.The composite laminates were prepared by hot press technology.The effects of manufacture technology, yam structure,and fiber weight fraction on flexural properties of composites were investigated.     

Influence of Spinning Technology on Dye Uptake of Modified Polypropylene Fiber

By adding small amount of olefin polymer additive, the dyeability of polypropylene fiber can be improved. Research results show that the improvement of dyeing performance of modified PP fiber is mainly due to the formation of looser structure of PP matrix and the micro-channels among additive particles in blended fiber. The dye uptake of drawn fibers decreases with drawing ratios obviously and changes with temperature of heat plate and heat roller a little.