高性能纤维及其他合成纤维

20115125高性能芳族聚酰胺纤维的光降解Liu Xiao Yan…;Chemical Fibers International,2008,58(1),p.46(英)用氙弧光和碳弧光模拟阳光老化,比较了3种高性能纤维Kevlar-PBO-Kermel纤维的拉伸性能。在这些试样中,Kevlar129纤维具有最好的力学性能保持性,一般来说,Kermel纤维的力学性能保持性最差。发现,PBO的抗日晒性最差,虽然它原有的强度最高,但在光辐照处理下,强度迅速下降。同时,     

埃克森美孚化工推出三种新的VISTAMAXX~弹性体,应用于薄膜和聚合物改性

近日,埃克森美孚化工推出了三种新的Vistamaxx~特种弹性体牌号,这些牌号具有很低的凝胶数值,是高性能膜和纤维应用方面的理想材料。和其它Vistamaxx特种弹性体一样,这些牌号可与聚乙烯(PE)和聚丙     

苯并三唑/纳米TiO_2改性PPS纤维的制备及性能

为了改善聚苯硫醚(PPS)纤维的光稳定性能,将苯并三唑与纳米二氧化钛(Ti O2)按一定比例复配与PPS切片进行共混熔融纺丝,制得改性PPS纤维,研究了改性PPS纤维的可纺性及其性能。结果表明:苯并三唑/纳米Ti O2复配物的质量分数大于1.5%时,改性PPS纤维的可纺性变差;当复配物质量分数小于等于1.5%时,改性PPS纤维的表观形貌和可纺性满足工业生产要求;随着苯并三唑/纳米Ti O2的添加量增加,改性PPS纤维的断裂强度有所降低,断裂伸长率和热性能变化不大;当苯并三唑质量分数为1.5%,Ti O2为0时,PPS的结晶速率最大,改性PPS纤维的光稳定性能最好,光照前后的色度变化值为14.02。     

新纤维提供更好的防护性和舒适性

(1)最新Kermel(克梅尔)纤维的机械性能提高30％ 最新的Kermel纤维是世界上第一种也是迄今为止唯一的第三代芳酰胺纤维。这是1992年成立的国际Kermel公司于1993年达成并提出的在防火纤维技术方面的主要进展的直接成果。该公司是罗纳普朗纤维公司与阿莫科织物与纤维公司的世界合资公司,这样就把两个主要集团的技术和商业化能力结合在一起。 第三代Kermel是通过将重要的进展导入纤维的制造方法中而达成的,这样就导致     

Kevlar纤维复合材料在土木工程结构加固中的应用

简要介绍了用于纤维增强复合材料(FRP)的碳纤维(CF)、对位芳纶(AF)、玻璃纤维(GF)、玄武岩纤维(BF)的特性。用图表介绍了Kevlar49布的规格、技术参数、特点、应用及加固工艺,并对FRP市场需求作了详细分析。结果表明:Kevlar49布具有较强的市场竞争力;中国土木工程结构加固的潜在市场非常巨大,将为高性能纤维及其FRP生产商带来无限商机。     

阿科玛在2013 Techtextil展出用于纺织品的热熔胶及PVDF

阿科玛最近参展位于德国法兰克福展览中心的国际产业用纺织品及非织造布展览会(2013 Techtextil)。展出了PLATAMID高性能共聚酰胺热熔胶,用于超耐磨纤维纺纱、无纺布和纺织涂料的新KynarPVDF。     

高性能橡胶助剂Sulfron®3000对载重轮胎和工程机械轮胎胎面胶性能的影响

探讨高性能橡胶助剂Sulfron~3000对载重轮胎和工程机械轮胎胎面胶性能的影响。结果表明,在载重轮胎和工程机械轮胎胎面胶中添加1~3份Sulfron~3000,可以改善胶料的拉伸应力-应变性能、撕裂强度、耐磨性能、耐疲劳性能和耐热老化性能,显著降低生热。     

有机高性能纤维

1芳香族聚酰胺纤维1.1 PMIA纤维Nomex是DuPont公司于1960年研制出的一种间位型芳香族聚酰胺纤维。学术名为聚间苯二甲酰间苯二胺(PMIA)纤维。自1972年开始,日本Teijin(帝人)公司也开始生产商品名为Conex的PMIA纤维。PMIA纤维具有良好的防火、耐热、耐化学试剂性能,可用于航天飞行员的宇航服、赛车运动服、防火工作服、耐高温滤布、烘干机衬布、传送带基布以及复合材料等。     

溶胶—凝胶法SiO_2涂复膜

<正> 溶胶—凝胶法是将烃氧基金属等的化合物在溶液中加水分解,使之聚合制成凝胶,再将凝胶加热调制成玻璃或结晶体,许多人大力试验用凝胶化时的凝胶在基板(棒或板)纤维上涂膜直接成形,然后加热试图保持玻璃成形体。这涂复膜由于只用少量的原料就赋予基板高性能或赋予基板具有光,电子,磁性,热,化学或生体特性等各种机能,正在进行很多的实用化。     

轶纶~特性及其在烟尘滤料的应用

主要介绍了轶纶(聚酰亚胺纤维)的综合性能及在滤料行业中的应用,阐述了轶纶的主要理化特性,如长度、细度、断裂强度、断裂伸长率、耐热性、耐腐蚀性、阻燃性、耐候性、防霉性能和可纺性。综述表明,轶纶综合性能优异,能适应和满足生产加工成滤料的要求,是一种非常适合烟尘过滤用的纤维。     

轶纶~聚酰亚胺短纤维的性能及其应用

轶纶短纤维是国内首个工业化生产的聚酰亚胺纤维,其具有多方面的优良性能：热分解温度〉500℃;280℃热空气处理100 h后抗拉伸强度保持率〉80%;热导率4.58 W/（K m2）,低温保暖性能优越;耐化学酸碱性优于其他同类产品,极限氧指数〉38%,阻燃性能好;耐高温过滤性绝佳。因此,轶纶短纤维可于苛刻的高温环境中应用。     

聚酰亚胺——轶纶~的热稳定性研究

轶纶是长春高琦聚酰亚胺材料有限公司生产的一种聚酰亚胺纤维。从热失重分析、动态力学分析、静态力学分析以及耐热性对比等4个方面讨论了轶纶的热稳定性。由试验数据得知:轶纶R的玻璃化转变温度为380℃左右,并且在500℃之前不发生热分解反应。通过对比可以发现,轶纶R的热稳定性优于奥地利产聚酰亚胺纤维P84、聚四氟乙烯、聚苯硫醚等现有的高性能合成纤维。     

芳砜纶水洗丝在不同热拉伸温度下的结构性能变化

设计了多级多倍连续热拉伸工艺对芳砜纶水洗丝进行热拉伸,研究了从350～390℃的热拉伸温度对纤维结构和性能的影响.通过力学性能、动态热力学分析和热失重分析研究了不同热拉伸温度下纤维的性能变化,结合光学显微镜、同步辐射广角X-射线衍射仪研究了不同温度热拉伸下纤维形态结构和超分子结构的变化.研究发现:纤维热拉伸前后热分解温度(Td)变化不明显,玻璃化转变温度(Tg)有所提高,纤维的断裂强度和模量显著提高;但断裂强度和伸长率对温度的依赖性出现了先增大后减小的变化趋势,过高的拉伸温度导致纤维脆性增加,断裂强度和伸长率减小;随着热拉伸温度的升高,纤维的晶态结构趋于完善,结晶度、取向度和晶粒尺寸随之增大,但密度变化并不显著.     

热处理温度对PBO纤维性能的影响

PBO纤维因其具有高强度、高模量、高耐热性以及高化学稳定性等性能而被公认为目前综合性能最好的有机纤维。对自制的初生PBO纤维分别在500℃、550℃、600℃、650℃和700℃进行高温热处理,并对处理后纤维的力学性能、耐热性能、表面形貌以及界面性能进行测试。结果表明,500℃下热处理后PBO纤维拉伸强度最大为4.72GPa,随着热处理温度升高,纤维的力学性能下降;600℃下热处理后PBO纤维的初始分解温度最高为641.3℃;随着热处理温度的提高,PBO纤维的表面粗糙度在增加,同时其界面剪切强度(IFSS)也随着温度的升高而增大。     

Preparation and properties of successive alkali treated completely biodegradable short jute fiber reinforced PLA composites

The natural fiber reinforced biodegradable polymer composites were prepared with short jute fiber as reinforcement in PLA (Poly lactic acid) matrix. The short jute fiber is successively treated with NaOH at various concentrations (5%, 10%, and 15%) and H₂O₂. The composites were prepared with untreated and treated short jute fibers at different weight proportions (up to 25%) in PLA and investigated for mechanical properties. The results showed that the composite with successive alkali treated jute fiber at 10% NaOH and H₂O₂ with 20% fiber loading has shown 18% higher flexural strength than neat PLA and untreated jute/PLA composite. The flexural modulus of the composite at 25% fiber loading was 125% and 110% higher than that of composites with untreated fibers and neat PLA, respectively. The impact strength of composite with untreated fibers at higher fiber weight fraction was 23% high as compared to neat PLA and 26% high compared to composite with treated fibers. The water absorption was more for untreated jute/PLA composite at 25% fiber loading than all other composites. The composite with untreated fibers has high thermal degradation compared with treated fibers but lower than that of pure PLA matrix. The enzymatic environment has increased the rate of degradation of composites as compared to soil burial. Surface morphology of biodegraded surfaces of the composites were studied using SEM method. POLYM. COMPOS., 37:2160–2170, 2016. © 2015 Society of Plastics Engineers     

Electrospun fabrication,excellent high-temperature thermal insulation and alkali resistance performance of calcium zirconate fiber

CaZrO₃ (CZO) precursor fibers were prepared by sol-gel method and electrospinning technique from solutions which contained aqueous precursors of calcium and zirconium ions and polyethylene oxide. The crystallization of CZO fibers was a concurrent process with the decomposition of organics. The evolution process was characterized by Fourier transform infrared (FT-IR) and Raman spectra, thermogravimetry and differential scanning calorimetry (TG/DSC), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The heat-conducting property and high temperature stability of fibers were characterized by the measurements of thermal conductivity and heating permanent linear change, respectively. The fibers were treated in NaOH solution at 80?°C to characterize the alkali resistance. The results showed that CZO fibers had the lower thermal conductivity than the other reported forms of CZO materials, and they possessed excellent stability up to 1100?°C with thermal shrinkage less than 1.2% and excellent corrosion resistance to alkalis. Hence, CZO fiber could be used as a suitable corrosion resistant refractory material for high-temperature thermal insulation.     

Mechanical properties of carbon fiber composites modified with nano-SiO2 in the interphase

The performance of carbon fibers-reinforced composites is dependent to a great extent on the properties of fiber–matrix interface. To improve the interfacial properties in carbon fibers/epoxy composites, nano-SiO₂ particles were introduced to the surface of carbon fibers by sizing treatment. Atomic force microscope (AFM) results showed that nano-SiO₂ particles had been introduced on the surface of carbon fibers and increase the surface roughness of carbon fibers. X-ray photoelectron spectroscopy (XPS) showed that nano-SiO₂ particles increased the content of oxygen-containing groups on carbon fibers surface. Single fiber pull-out test (IFSS) and short-beam bending test (ILSS) results showed that the IFSS and ILSS of carbon fibers/epoxy composites could obtain 30.8 and 10.6% improvement compared with the composites without nano-SiO₂, respectively, when the nano-SiO₂ content was 1 wt % in sizing agents. Impact test of carbon fibers/epoxy composites treated by nano-SiO₂ containing sizing showed higher absorption energy than that of carbon fibers/epoxy composites treated by sizing agent without nano-SiO₂. Scanning electron microscopy (SEM) of impact fracture surface showed that the interfacial adhesion between fibers and matrix was improved after nano-SiO₂-modified sizing treatment. Dynamic mechanical thermal analysis (DMTA) showed that the introduction of nano-SiO₂ to carbon fibers surface effectively improved the storage modulus of carbon fibers/epoxy.     

Preparation of TiO2 Nanoparticles Coated Cotton Fibers at Low Temperature and Their Photocatalytic Activity

TiO_2 nanoparticles coated cotton fiber composite was successfully prepared by using a sol-gel method at low temperature(about 100℃) using tetrabutyl-titanate [Ti(OBu)_4] as raw material.The preparation of the TiO_2 colloid and the composite were described.The properties of resulting materials were characterized by SEM and XRD,the photocatalytic degradation performance was tested using methylene blue(MB) as the target pollutant in aqueous solution.The results showed that the amorphous TiO_2 nanoparticles were distributed evenly on the outer surfaces of cotton fibers,which shows efficient photocatalytic properties when exposed to UV light,the degradation rate of MB reached 95.35% under the conditions of catalyst dosage 2.5 g/L,MB concentration 50 mg/L,irradiation time 120 min,and pH 10,and the photocatalytic activity of TiO_2/cotton fibers remained above 90% of its activity as-prepared after being used four times,the degradation rate of MB could reach 88.78% when irradiation time was 120 min.The photocatalytic degradation of MB could be properly described by the first-order kinetic law.By comparison of the removal rates of MB with and without UV light,it could be affirmed that the disappearance of MB was due to photodegradation rather than adsorption on cotton fibers.     

The use of Isocyanate as a Bonding Agent to Improve the Mechanical Properties of Polyethylene-Wood Fiber Composites

Abstract

Chemithermomechanical pulp (CTMP) of aspen was used as a filler in high density (HDPE) and linear low density (LLDPE) polyethylenes. To improve the bonding between the fiber and polymer, different chemical treatments of the fiber a) treatment with different isocyanates b) coating with maleic anhydride was carried out. Composites with isocyanate treated wood fibers produced higher tensile strength compared to untreated fiber composites. But when compared to diisocyanate, the polyisocyanate treated fibers produced higher gain in strength. HDPE or LLDPE filled with maleic anhydride coated CTMP aspen fibers showed a slight decrease in strength with the increase in filler concentration. Tensile modulus generally increased with filler loading and was not much affected by fiber treatment.     

Selective decomposition of isopropanol using as prepared and oxidized graphite nanofibers

Three types of as prepared and treated graphite nanofibers (GNFs) were used as catalysts in the decomposition of isopropanol to propene and acetone in the presence of oxygen to evaluate the surface chemistry of the fibers. As prepared herringbone fibers were found to produce higher selectivity for propene compared to the as prepared platelet and ribbon fibers at all temperatures explored. Herringbone fibers that had undergone oxidative treatment with nitric acid, phosphoric acid, ruthenium tetroxide or potassium permanganate were also evaluated at a 290 °C. Effects of oxidation treatments on fiber structure were evaluated using a host of analytical techniques including BET, SEM/EDS, TGA, XPS, and fluorescence labeling of surface species. Selectivity for acetone dehydrogenation product or propene dehydration product could be achieved by the appropriate surface treatment. Nitric acid was the mildest treatment and the treated fibers showed minimal changes. (Potassium permanganate was a harsh treatment that almost completely degraded fiber structure, creating amorphous carbon.) Phosphoric acid treated fibers were found to produce very high conversions and almost pure selectivity for propene. Ruthenium tetroxide did not appear to have a large affect on fiber morphology; however, selectivity for acetone was much higher when GNFs were treated with ruthenium tetroxide.