对位芳纶及其复合材料综述并产业化发展思考

对位芳纶由于其出色的性能,在宇宙探索、航空航天、国防军工、民用建筑等领域有大量的应用,尤其是芳纶复合材料已成为高科技领域必不可少的基础材料。对位芳纶复合材料具有轻质高强等突出特点,因此在节约减排方面具有显著效果,随着全球低碳经济的到来,芳纶及其复合材料的发展前景会越来越好。本文根据对位芳纶发展及应用的最新情况,详细介绍了对位芳纶的种类、性能、应用以及发展概况,并结合多年的对位芳纶研发及产业化经验,分析探讨了我国现有对位芳纶及其复合材料产业化发展方面存在的问题,指出我国在技术、生产效率、生产能力、设备、市场等方面与国外的差距,并据此提出对位芳纶及其复合材料今后的发展方向和研究重点。最后从科学发展观和低碳经济的角度,指出我国对位芳纶及其复合材料产业化发展的必要性和紧迫性。     

对位芳纶应用技术发展水平比较研究

对位芳纶纤维是最重要的有机高性能纤维。"十一五"期间,国产对位芳纶纤维技术实现了历史性突破。基本型对位芳纶纤维已批量生产,并在军需民用领域得到了初步应用。本文分析了国内外对位芳纶制品技术的发展现状,提出了促进我国对位芳纶产业发展的建议。一、对位芳纶及制品简介1.对位芳纶简介对位芳纶由聚对苯二甲酰对苯     

对位芳纶浆粕的制造及其应用

2006年全世界芳纶浆粕的需求量已达1万多吨,对位芳纶产能5.5万吨还在不断增加.上海依极科技有限公司建成50T/a芳纶浆粕生产厂,本文介绍芳纶浆粕专利技术、制备和性能及其应用,而芳纶浆粕的产业化成功,将开辟广阔的新应用领域.     

芳纶树脂基复合材料的应用与发展

<正>1概述芳纶树脂基复合材料是以合成树脂为基体,以芳纶为增强材料经复合而制成的一种新型工程材料。芳纶具有低密度、高比强度、高比模量、耐冲击、耐腐蚀、阻燃等优异性能,是理想的有机纤维增强材料。芳纶主要分为3类:对位芳纶、间位芳纶和芳纶Ⅲ。对位芳纶是对位芳香族聚酰胺纤维的简称,即聚对苯二甲酰对苯二胺(PPTA)纤维,国内称其为     

高性能纤维及其复合材料在防护装备上的应用

介绍了高性能纤维及其复合材料在防护装备上的应用及发展历程,包括芳纶纤维、超高分子量聚乙烯纤维、杂环类纤维及其复合材料在防护装备上目前的应用状况和各自优缺点,以及防护装备上用的高性能纤维及其复合材料的发展方向,也介绍了高性能纤维及其复合材料应用技术的发展趋势。     

芳纶Ⅲ纤维及其复合材料制品研究进展

介绍了国产芳纶Ⅲ纤维的制作过程、力学性能和表面状态,复合材料性能采用NOL环、单向板及其复合材料容器进行试验。结果表明,芳纶Ⅲ纤维复合材料压力容器性能水平已达到国外同类纤维性能水平。芳纶Ⅲ纤维复合材料可以应用于高性能的航天产品,是我国目前可以开展工程应用的最高水平的国产纤维复合材料。     

对位芳纶纤维的研究与应用进展

介绍了对位芳纶的结构和性能,以及当前其应用的各种领域,通过对位芳纶纤维表面改性研究,使其产品性能不断改善,材料成本降低,对位芳纶纤维必将在更广阔的领域中得到应用。     

芳纶1313纤维纸基复合材料及其研究进展

高性能芳纶1313纤维纸基复合材料是航空航天、船舶、电子、绝缘等领域的重要材料,目前在国内还没有厂家正式投产,在国际上也被美国杜邦公司和日本帝人公司垄断生产.重点论述了芳纶1313纤维纸基复合材料的纤维组成、性能以及应用前景,并评述了国内外芳纶1313纤维和芳纶1313纤维纸的研究进展.近年来国内该材料的发展较为迅速,该课题组成功实施产业化项目后,有望打破杜邦公司的垄断地位.     

对位芳纶产业化溶剂精制装置工艺路线研究

由于对位芳纶具有高强度、高模量、热收缩低、尺寸稳定性好、耐化学腐蚀及节约能源等优异性能,被广泛应用于航天航空、耐高温复合材料、橡胶制品等领域,是目前受人们关注的高性能纤维之一,对位芳纶工业化生产由PPTA树脂合成、纺丝、溶剂精制与回收关键工艺技术构成,本文主要通过溶剂NMP精制工艺选择及关键技术研究,介绍溶剂NMP精制装置工艺路线研究。     

改性芳纶浆粕增强橡胶基复合材料的性能研究

采用戊二醛、二甲基乙酰胺(DMAC)/氯化锂(LiCl)/磷酸溶液对对位芳纶浆粕纤维表面改性,形成了交联网状结构。以硅橡胶生胶为主要原料,加入各类填料经过混炼、硫化后制得对位芳纶浆粕/硅橡胶混炼胶复合材料。研究结果表明,以2%戊二醛为交联剂,芳纶浆粕含量为10份条件下,制得的硅橡胶复合材料性能较好。硅橡胶复合材料的邵尔A型硬度达到86度,拉伸强度达到8.9MPa,伸长率达到128%,撕裂强度达到12.8kN/m,压缩永久变形为55%。制得的硅橡胶复合材料比普通硅橡胶具有优异的力学性能,在密封材料领域有广泛的应用前景。     

玻璃/苎麻纤维混杂复合材料力学性能研究

混杂纤维增强复合材料由于可以综合利用各种纤维的优点,极大的提高了复合材料的性能,拓展了复合材料的适用范围。本文采用玻璃纤维和苎麻纤维混杂酚醛树脂制备复合材料,研究了复合材料混杂比和铺层顺序对混杂纤维复合材料力学性能的影响。从结果可以看出,玻璃纤维和苎麻纤维的不同比例对混杂复合材料的力学性能有着显著的影响,而采用玻璃纤维作为芯层的时候可以获得较好的拉伸性能,采用苎麻纤维作为芯层的时候可以获得较好的弯曲和剪切性能。     

导电玻璃纤维及其功能复合材料研究进展

玻璃纤维增强聚合物基复合材料因其成本低、力学性能好等优点被广泛应用,而导电玻璃纤维增强复合材料将进一步拓展玻璃纤维复合材料的应用领域,也是其未来发展的重要方向。本文综述了国内外导电玻璃纤维的种类、构建结构及特征性能等,同时介绍了不同导电玻璃纤维对玻璃纤维功能复合材料的性能影响;最后,结合目前导电玻璃纤维及其复合材料的应用和限制,阐述了聚合物基导电玻璃纤维功能复合材料的发展趋势。      

Biocomposites from Musa textilis and polypropylene: Evaluation of flexural properties and impact strength

Abaca (Musa textilis)-reinforced polypropylene composites have been prepared and their flexural mechanical properties studied. Due to their characteristic properties, M. textilis has a great economic importance and its fibers are used for specialty papers. Due to its high price and despite possessing very distinctive mechanical properties, to date abaca fibers had not been tested in fiber-reinforced composites. Analysis of materials prepared showed that, in spite of reduced interface adhesion, flexural properties of the PP composites increased linearly with fiber content up to 50 wt.%. Addition of a maleated polypropylene coupling agent still enhanced the stress transfer from the matrix to the reinforcement fiber. As a result, composites with improved flexural properties were obtained. The mechanical properties of matrix and reinforcing fiber were evaluated and used for modelling both the flexural strength and modulus of its composites. In addition, the impact strength of materials was evaluated. Comparison with mechanical properties of composites reinforced with fiberglass points out the potentiality of abaca-reinforced polypropylene composites as suitable substitutes in applications with low impact strength demands.     

Comparative study of high temperature composites

Two classes of composite made using either ceramic matrix with high temperature fibers or carbon/carbon have been used for various applications that require high temperature resistance, over three decades. However, their use has been limited to special applications because of the high costs associated with fabrication. Typically the composites are cured at more than 1000°C, and in most instances the heating has also to be carried out in controlled environments. In addition, because of the high processing temperature, only certain type of expensive fibers can be used with the ceramic matrices. A recently developed inorganic matrix, called polysialate can be cured at temperatures less than 150°C, making it possible to use carbon and glass fibers. Composites made using carbon, glass and combinations of carbon and glass fibers have been tested in bending and tension. This paper presents the comparison of processing requirements and mechanical properties of carbon/carbon composites, ceramic matrix composites made with silicon carbide, silicon nitride and alumina fibers and carbon/polysialate composites. The results indicate that carbon/polysialate composite has mechanical properties comparable to both carbon/carbon and ceramic matrix composites at room and high temperatures. Since the polysialate composites are much less expensive, the authors believe that it has excellent potential for more applications in aerospace, automobile and naval structures.     

无机纤维增强SiO2气凝胶隔热复合材料的研究进展

SiO_2气凝胶因其独特的纳米孔结构而具有低密度、低热导率等特点,具备成为高效隔热材料的潜力,然而SiO_2气凝胶的力学性能较差,极大地限制了其在隔热领域的应用。采用无机纤维作为增强体,制备的SiO_2气凝胶复合材料同时具有较好的力学和隔热性能,是目前国内外高性能隔热材料的研究热点之一。综述了无机纤维增强SiO_2气凝胶隔热复合材料的制备方法及其研究进展,并展望了其未来发展方向。     

Studies on Mechanical, Friction, and Wear Characteristics of Kevlar and Glass Fiber-Reinforced Friction Materials

Asbestos possesses properties that are ideally suitable for use as a friction material in automotive and a number of other applications. Animal and human studies carried out since the early 1900s have established that asbestos is carcinogenic and that exposure to especially asbestos dust causes a large number of diseases. Realizing the health hazards posed by asbestos, many countries started phasing out asbestos from all asbestos-containing products since the 1980s. Some of them imposed a total ban in the 1990s on the use of asbestos-containing friction products. This situation forced many manufacturers to look for alternatives to asbestos. But the efforts have only been partly successful. The search is, therefore, still on to find suitable substitutes for asbestos. Though steel wool, Kevlar, glass, and a number of other mineral fibers have been tried out on an experimental basis over the last two decades, glass and Kevlar fibers, in particular, have shown promise as potential substitutes for asbestos. These days, therefore, studies on polymer-based friction materials reinforced with glass, Kevlar, and ceramic fibers are being pursued with much fervor. However, conflicting views are prevailing even today as to the suitability of asbestos-free composites for automotive applications and freedom from the concomitant health risks posed by them. In the present work, therefore, phenolic resin matrix samples reinforced with different amounts of glass and Kevlar fibers were produced and characterized for their mechanical, physical, friction, and wear properties to assess their suitability for light passenger car applications. The study establishes that composites based on glass and Kevlar fibers show good mechanical, physical, friction, and wear characteristics, enhancing thereby their suitability for automotive applications. The property improvements achieved are correlated to the composition, microstructure, and the changes taking place on the surface of the friction composites.     

Critical review of recent publications on use of natural composites in infrastructure

Compared to most synthetic fibers, natural fibers are low-cost, are easier to handle, have good specific mechanical properties, and require only around 20–40% of the production energy. Using natural materials and modern construction techniques reduces construction waste and increases energy efficiency while promoting the concept of sustainability. Several drawbacks of natural composites which would be even more pronounced in their use in infrastructure include their higher moisture absorption, inferior fire resistance, lower mechanical properties and durability, variation in quality and price, and difficulty using established manufacturing practices when compared to synthetic composites. Many researchers have been working to address these issues, with particular attention paid to the surface treatment of fibers and improving the fiber/matrix interface. Because of their positive economic and environmental outlook, as well as their ability to uniquely meet human needs worldwide, natural composites are showing a good potential for use in infrastructure applications.     

Investigations on NiAl composites fabricated by matrix coated single crystalline AlO-fibers with and without hBN interlayer

The intermetallic compound NiAl has excellent potential for high temperature structural applications but suffers from low temperature brittleness and insufficient high temperature strength. One way to remove these deficiencies is the reinforcement by high strength ceramic fibers. Such intermetallic matrix composites can be conveniently fabricated by the hot pressing of matrix coated fibers. Al₂O₃ single crystal fibers show excellent chemical stability with the NiAl matrix, but the residual thermal compressive stresses during cool down dramatically degrades the fiber strength and thus, renders the composite useless for structural applications. We report on an experimental and computational study to mitigate this problem and to fabricate Al₂O₃/NiAl composites with sufficient high temperature strength. Analytical TEM, mechanical testing and push-out tests were employed to characterize chemistry, microstructure and mechanical properties of the composites. It will be shown that a processing window exists that allows producing intermetallic matrix composites with promising mechanical properties.     

Fabrication of advanced “green” composites using potassium hydroxide (KOH) treated liquid crystalline (LC) cellulose fibers

Advanced green composites having excellent strength and stiffness were fabricated using liquid crystalline (LC) cellulose fibers and soy protein isolate (SPI) resin. Further, LC cellulose fibers were treated with potassium hydroxide (KOH) to improve their tensile strength and Young’s modulus by increase the crystallinity of cellulose. The improvements were significant when the treatment was carried out while keeping the fibers under tension. The Young’s modulus (stiffness) of the LC cellulose fibers increased by about 33 % from 47.8 to 63.7 GPa and the strength increased by about 18 % from 1483 MPa to 1749 MPa. X-ray diffraction (XRD) study of the LC cellulose fibers showed over 50 % increase in crystallinity after the KOH treatment. The mechanical properties of the LC cellulose fiber-reinforced composites were also high and improved further when the KOH treated fibers were used. With 65 % fiber volume it should be possible to obtain composites with strength above 1020 MPa and modulus of over 37 GPa, making them truly advanced green composites that could be used for structural applications.