芳纶混杂复合材料研究进展

对芳纶混杂复合材料的研究进展进行综述,包括芳纶/碳纤维、芳纶/玻璃纤维、芳纶/玄武岩纤维、芳纶/超高分子量聚乙烯纤维、芳纶/陶瓷纤维、芳纶/麻等二元混杂及多元混杂体系.     

芳纶纤维及其复合材料的研究进展

介绍芳纶纤维的性能和研究现状、芳纶纤维复合材料的应用以及芳纶复合帘线的开发和性能改进。芳纶纤维具有多种独特性能,国内外对芳纶纤维进行了广泛研究,芳纶纤维制备与应用技术难题不断被攻克,芳纶纤维的应用越来越广泛。芳纶纤维生产现主要集中在美国、日本和欧洲,近年来我国芳纶纤维的产业化发展迅速。芳纶纤维复合材料在军用和民用领域均得到广泛应用。芳纶复合帘线主要分为合股复合帘线和芯皮结构复合帘线。芳纶复合帘线改进的性能主要有耐压缩疲劳性能、拉伸性能和粘合性能。     

热分析技术在芳纶结构性能研究中的应用

介绍了热重分析法、差热分析法、动态热分析法、热力学分析法等热分析技术在芳纶结构和性能分析中的应用。指出国内对芳纶热性能研究应将各种热分析技术和其他结构分析技术联合使用,揭示芳纶结晶结构和无定形区链分子的运动规律,分析芳纶结构与芳纶制品性能之间的关系,为我国芳纶材料设计、芳纶结构性能的研究及芳纶制品的开发应用提供思路。     

俄罗斯芳纶发展概况及其制备、性能与应用

对俄罗斯芳纶做了全面的综述,详细介绍了其间位芳纶、对位芳纶和杂环芳纶的发展概况、化学结构、性能及应用等,重点介绍了对位杂环芳纶SVM、Armos和Rusar的发展及应用情况,最后展望了杂环芳纶的应用前景。     

对位芳纶的生产和应用技术进展(Ⅲ)

简介对位芳纶的供需和研发概况;着重叙述PPTA型芳纶、共聚型芳纶、俄罗斯芳纶等重要对位芳纶产品以及PBO纤维、M5纤维等相关高性能纤维的生产技术和主要性能,探讨了高性能纤维开发生产的通用技术;分析了对位芳纶的应用现状和技术;探讨对位芳纶生产技术和应用技术的发展趋势。     

对位芳纶生产和应用技术进展(Ⅱ)

简介对位芳纶的供需和研发概况;着重叙述PPTA型芳纶、共聚型芳纶、俄罗斯芳纶等重要对位芳纶产品以及PBO纤维、M5纤维等相关高性能纤维的生产技术和主要性能,探讨了开发生产高性能纤维的通用技术;分析了对位芳纶应用的现状和技术;探讨对位芳纶生产技术和应用技术的发展趋势。     

芳纶浆粕和芳纶纸的发展概况

介绍芳纶浆粕和芳纶纸的发展概况、应用领域及市场前景情况,对国产芳纶纸、NOMEX纸和对位芳纶纸进行简单比较,认为芳纶纸的关键技术是纤维原材料、分散流送技术、斜网成型技术和热轧技术,并对国内芳纶纸的发展提出一些看法。     

芳纶复合材料的制备及其在体育器械中的应用

芳纶作为一种新型高科技合成纤维,具有超高强度、高模量和耐高温性能,在体育器材领域中得到较为广泛的应用。该文在介绍芳纶性能的基础上,对不同类芳纶复合材料的制备方法进行了综述,主要包括全对位芳纶及其复合材料、间位芳纶及其复合材料、杂环芳纶及其复合材料等,并对芳纶复合材料在防护用具、运动服饰、运动绳索等体育器材中的应用进行了总结,同时展望了其未来的发展方向。可以预测,芳纶及其复合材料性能的进一步优化及其工业化生产,将成为芳纶材料未来的主要研究方向。     

芳纶Ⅱ与芳纶Ⅲ的热分解行为比较

利用热重分析研究了芳纶Ⅱ(Kevlar49)和芳纶Ⅲ(FanglunⅢ)在不同升温速率和氮气气氛下的热分解过程,用Kissinger方法、Flynn-Wall-Ozawa方法和Coats-Redfern方法研究了芳纶Ⅱ和芳纶Ⅲ的热分解动力学及热降解机理。结果表明:聚酰胺苯并咪唑嵌段使芳纶Ⅲ的热分解温度较芳纶Ⅱ稍有降低,但残炭率升高;芳纶Ⅱ和芳纶Ⅲ的起始热分解温度随升温速率加快而升高;芳纶II的热分解活化能(E)比芳纶Ⅲ稍高,用Kissinger方法、Flynn-Wall-Ozawa方法求得芳纶Ⅱ的E值分别为210.93,200.96 kJ/mol,芳纶Ⅲ的E值分别为208.35,196.98 kJ/mol,两种芳纶的固态热分解机理都为相边界反应,一维收缩,反应级数为1。     

石墨烯、碳纳米管改性芳纶Ⅱ及芳纶Ⅲ的研究进展

简要介绍了芳纶Ⅱ及芳纶Ⅲ的制备方法及性能提升途径,重点综述了石墨烯、碳纳米管改性芳纶Ⅱ及芳纶Ⅲ的研究进展。石墨烯、碳纳米管的引入能有效提升芳纶Ⅱ及芳纶Ⅲ的力学、电学、热学及抗紫外性能,并对其未来发展做出展望。     

杂环芳纶及其杂环单体（五）

介绍杂环芳纶Tverlon、SVM、Armos、Rusar和广东彩艳芳纶Ⅲ的一种共聚杂环单体一苯并单咪唑二胺的结构、性质及其合戍路线，并简要讨论其结构和性质对杂环芳纶聚合、戍纤过程和结构性能的一些影响。     

杂环芳纶及其杂环单体(五)

介绍杂环芳纶Tverlon、SVM、Armos、Rusar和广东彩艳芳纶Ⅲ的一种共聚杂环单体-苯并单咪唑二胺的结构、性质及其合成路线,并简要讨论其结构和性质对杂环芳纶聚合、成纤过程和结构性能的一些影响。     

脱羧反应研究进展

本文综述了关于脱羧反应研究的最新方法，包括光化学，电化学方法及用含氮杂环化合物，过渡金属催化脱羧法。     

俄罗斯杂环芳纶--大分子序列结构(三)

分析和讨论俄杂环芳纶大分子中二聚单体的序列结构,主要属于无规缩聚,其次是无规嵌段结构。     

Application of molecular topology for the prediction of reaction yields and anti-inflammatory activity of heterocyclic amidine derivatives

Topological-mathematical models based on multiple linear regression analyses have been built to predict the reaction yields and the anti-inflammatory activity of a set of heterocylic amidine derivatives, synthesized under environmental friendly conditions, using microwave irradiation. Two models with three variables each were selected. The models were validated by cross-validation and randomization tests. The final outcome demonstrates a good agreement between the predicted and experimental results, confirming the robustness of the method. These models also enabled the screening of virtual libraries for new amidine derivatives predicted to show higher values of reaction yields and anti-inflammatory activity.     

杂环表面活性剂的合成及杀菌性能研究

以吡啶与1-溴代烷(溴代辛烷、溴代癸烷、溴代十二烷和溴代十四烷)为原料,合成了一系列杂环表面活性剂。用正交试验确定合成目标产物的较佳工艺条件为:反应温度90℃,反应时间5h,溴代烷与吡啶的摩尔比1∶1。利用IR,1 H NMR对杂环表面活性剂进行结构表征。测定了目标产物对大肠杆菌、金黄色葡萄球菌和枯草芽孢杆菌的杀菌性能。结果表明:所合成的杂环表面活性剂对上述三种细菌具有良好的杀菌性能。     

Chemical modification of poly(2,6-dimethyl-1,4-phenylene oxide) via phase transfer catalysis

The chemical modification of poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) has been performed under phase transfer catalyzed (PTC) conditions. Four types of reactions: Williamson etherification, cyanide displacement, esterification, and heterocyclic group transfer have been identified as positive reactions involving the nucleophilic displacement on PPO. In reaction with alcohols, under PTC conditions, functional yields as high as 100% were obtained while for the esterification reaction functional yields of 92% were reached. Low conversions were found in reactions with cyanides and heterocylic compounds. Possible interactions of the reactive sites leading to additional crosslinking are being suggested. Minor changes in thermal stability of substituted PPO compared with the parent polymer were recorded. The modification of their permeation properties to gases was attributed to changes in polymer chain mobility and packing as well as to changes in polymer side chain polarity.     

Stabilization of acrylic fibers by sulfur atoms mechanism of stabilization

The conventional process for making carbon fibers from PAN fibers includes a preliminary step of oxidizing the fibers in order to stabilize the polymer prior to pyrolysis where oxygen atoms are incorporated into the polymer. We have found that the introduction of sulfur atoms can also stabilize the PAN fibers. It was concluded that the essential step of the stabilization of acrylic fibers is the formation of active sites by the incorporation of hetero atoms into the polymer to initiate polymerization of nitrile groups to form the condensed heterocylic ring structure. The kinetics of stabilization reaction were studied and it was found that stabilization is a first order reaction with activation energy of 30 kcal · mol^?1. The chemistry and the mechanism of the stabilization is proposed.     

A simple and versatile protocol for the preparation of functionalized heterocycles utilizing 4-benzoyl-5-phenylamino-2,3-dihydrothiophene-2,3-dione

The reaction of ethyl benzoylpyruvate with phenyl isothiocyanate in alkaline medium yields 4-benzoyl-5-phenylamino-2,3-dihydrothiophene-2,3-dione (1). Reaction of the intermediate 1 with primary aromatic amines such as aniline derivatives, benzidine and secondary aliphatic amines, namely diethylamine, piperidine, morpholine and piperazine afforded the corresponding thiophene 2a–2g and amide 3a–3d derivatives. Compound 1 reacts with N,N′- and N,O-dinucleophiles such as 1,2-diaminoalkanes, 2-aminoethanol, 1-aminoguanidine, guanidine, urea, 1,2-phenylenediamine and 2-amino-4-methylphenol to form the heterocylic compounds 4–10.     

Water‐Soluble Gold–N‐Heterocyclic Carbene Complexes for the Catalytic Homogeneous Acid‐ and Silver‐Free Hydration of Hydrophilic Alkynes

Water‐soluble gold(III/I) N‐heterocylic carbene complexes behave as efficient catalysts for the hydration of terminal alkynes in neat water. The transformation proceeds in the absence of Brønsted acids or halide scavengers and is suitable for sensitive substrates. Kinetic profiles and DFT studies provide a clear picture of intermediates present during catalysis.