非平衡热力学在摩擦领域聚合物复合材料设计中的应用

以自润滑材料和摩擦材料为例,基于非平衡热力学原理从热量产生和传递的根本问题出发,研究摩擦系数和热导率对材料接触面温度的影响,指导聚合物基复合材料的设计。对于自润滑材料来说,将摩擦热量产生和传递过程假设成两个过程的串联,发现摩擦热产生是摩擦系统整体稳定运行的关键控制因素。对于摩擦材料来说,将摩擦热量传递过程假设成传递热量和分配热量两个过程的并联,发现需采用降低刹车片热导率的逆向思维降低接触面温度。     

碳纳米管在聚合物摩擦材料中的应用

综述了近年来碳纳米管(CNTs)在改善热固性树脂和热塑性树脂摩擦性能方面的研究进展,并展望了聚合物/CNTs摩擦材料今后的研究方向.     

工程用聚合物基复合材料摩擦行为研究进展

综述了复合改性聚合物材料摩擦磨损性能研究发展 ,主要分析了纤维、金属及其化合物、无机非金属化合物及聚合物填料对材料摩擦性能的影响和作用机理 ,以及工况条件及摩擦磨损形式对材料摩擦行为的影响 ,简述了复合材料摩擦行为模拟及预测的研究现状及研究中存在的问题 ,进一步探讨了材料摩擦行为模拟和预测的可能性。     

聚合物减摩自润滑材料在汽车中的应用

综述了聚合物减摩自润滑复合材料在汽车中的应用,对基体树脂的选择、减摩组分和抗摩增强组分的选择与匹配以及复合材料的摩擦机理进行了分述;提出了改善复合材料的减摩自润滑性能的几种途径,为正确设计减摩性聚合物基复合材料提供了依据。     

聚合物复合材料在汽车制造中的应用

国外的大公司,诸如通用发动机公司、Porchet 公司、菲亚特公司、杜邦公司、帝国化学工业公司(英)、拜耳公司和其他公司在苏联展出汽车,汽车的全部零件实际上是采用最新的聚合物复合材料制造。这种汽车比原型钢板汽车轻50～60%,具有油耗小(100km 路程油耗仅2～4L),较大的改进空气动力学性和寿命长的特点。此外汽车不需要防腐蚀的特殊的保护层。一般常用薄钢板制造汽车承受负荷最主要的零件是悬架零件(各种钢板弹簧)、万向轴、保险杠和传动零件。这些零件用的材料都是强度高、刚度硬、疲劳强度高、抗扭强度高,以连续玻璃纤维、碳纤维和芳香聚     

玻璃纤维在摩擦材料领域的应用

玻璃纤维在摩擦材料领域的应用东台玻璃纤维厂陶毕华朱瑞宏南京玻璃纤维研究设计院曾天卷１课题的提出石棉是一类经过机械加工后可以分解成矿物纤维的水化硅酸盐的总称。石棉具有优异的物理化学性能：不燃烧、不霉烂、具有很高抗拉强度、耐酸、酸碱、耐热性能优良，石棉纤...     

聚合物/纳米无机粒子摩擦复合材料研究进展

综述了纳米无机粒子聚合物摩擦材料的耐磨机理及其性能,讨论了影响复合材料摩擦性能的因素     

热力学及热力学参数状态图在SiAlON材料合成中的应用

热力学和热力学参数状态图在材料的合成和设计中起着重要的理论指导作用。文中对其基础理论知识进行了概述,重点讲述了它们在确定碳热还原氮化法合成O’SiAlON粉及热压烧结合成βSiAlON-15R复相材料的工艺条件和温度制度中的应用,并对其应用前景进行了展望。     

碳纤维/聚合物自润滑复合材料的机械及摩擦性能

采用以钢铁为基体高分子自润滑复合材料为衬层制作的传动件,兼有优良的减磨耐磨性能和高的承载能力。研究了组分对复合材料性能的影响,制备了机械和摩擦学性能好的碳纤维增强复合材料,其黏结强度和压缩强度分别达到16~18 MPa和85~91 MPa,冲击强度达19.67~23.45 kJ/m2;与锡青铜ZQSn6-6-3摩擦对比试验表明,复合材料在重载工况下具有更优良的摩擦性能,工作状况稳定,油摩擦因数为0.077,仅为ZQSn6-6-3的59%。试验还发现,轻载启动和在摩擦面开设润滑油槽有助于改善摩擦状况。     

Detailed thermodynamics for analysis and design of Ranque‐Hilsch vortex tubes

The Ranque‐Hilsch vortex tube is a device for continuously separating an inlet pressurized fluid stream into two outlet streams of warmer and cooler temperatures at lower pressures, with no moving parts and without any heat or work effects. It has been applied to cool or heat small systems where refrigeration is impractical. Studies of the fluid mechanics inside the tube have not fully established the flow structure that provides the separation. Thermodynamic energy and entropy balances giving relations among properties and the relative amounts of the three fluid streams have been examined to determine consistency among measured data along with sensitivity of the phenomena to tube configuration, measurement error, and properties. The strong response of the temperature separation to small variations in entropy generation is shown to limit the possibilities for generalized prediction of vortex tube behavior. © 2017 American Institute of Chemical Engineers AIChE J, 64: 1067–1074, 2018     

碳纳米管的制备及其聚合物基复合材料的研究进展

本文综述了单壁碳纳米管的制备方法,重点阐述了化学气相沉积法的合成运用,并对目前碳纳米管在聚合物基纳米复合材料方面的研究做了综合阐述。     

石墨烯复合材料的研究及其应用

综述了石墨烯复合材料的结构和分类,主要包括石墨烯-纳米粒子复合材料、石墨烯-聚合物复合材料和石墨烯-碳基材料复合材料,并简述石墨烯复合材料在催化领域、电化学领域、生物医药领域和含能材料领域的应用。     

Effect of silk fiber to the mechanical and thermal properties of its biodegradable composites

In recent years, natural fiber‐reinforced biodegradable thermoplastics are being recognized as an emerging new environmentally friendly material for industrial, commercial, and biomedical applications. Among different types of natural fibers, silk fiber is a common type of animal‐based fiber, has been used for biomedical engineering and surgical operation applications for many years because of its biocompatible and bioresorbable properties. On the basis of our previous study, a novel biodegradable biocomposite for biomedical applications was developed by mixing chopped silk fiber and polylactic acid (PLA) through the injection molding process. This article is aimed at studying the dynamic mechanical and thermal properties of the composite in relation to its biodegradation effect. At the beginning, it was found that the initial storage modulus of a silk fiber/PLA composite increased while its glass transition temperature decreased as compared with a pristine PLA sample. Besides, the coefficient of linear thermal expansions (CLTE) of the composite was reduced by 28%. This phenomenon was attributed to the fiber–matrix interaction that restricted the mobility of polymer chains adhered to the fiber surface, and consequently reduced the T_g and CLTE. It was found that the degraded composite exhibited lower initial storage modulus, loss modulus and tan delta (tan δ) but the T_g was higher than the silk fiber/PLA composite. This result was mainly due to the increase of crystallinity of the composite during its degradation process. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

聚合物/碳纳米管复合材料的研究现状及在纤维中的应用

对聚合物/碳纳米管复合材料的制备和性能研究现状及碳纳米管对聚合物的增强机理作了综述,并介绍了此纳米复合材料在复合纤维制备中的应用。     

介孔复合材料内界面热阻及热导率

界面广泛存在于复合材料中,对介孔复合材料热物性起着决定性的影响,研究界面的导热特性对于认识和理解介孔复合材料的导热机制十分重要。利用非平衡的分子动力学模拟方法计算介孔复合材料中基材与填充物间的界面热阻,考察界面热阻随温度、材料质量差异的变化,进一步用界面热阻修正介孔复合材料的有效热导率。结果表明,界面热阻的数量级为10^-11m²·K·W^-1,并随温度升高逐渐降低。界面两端材料质量差异越大,界面热阻越高。可通过减小孔径、减小纳米线长度、增大纳米线间距、降低纳米线填充率来降低介孔复合材料的有效热导率。界面热阻能降低材料的有效热导率。孔径越小、纳米线间距越小、纳米线长度越长、填充率越高,界面热阻降低热导率效果越显著。     

国内外高聚物基复合材料阻尼特性研究动态

综合讨论了国内外高聚物基复合材料阻尼特性的研究现状,重点介绍了聚合物组分、交联度、填料和阻尼材料使用条件对阻尼材料性能的相关性、高聚物基复合材料的阻尼机理及提高高聚物基复合材料阻尼的措施,并展望了高聚物阻尼在胶粘剂领域的应用前景。     

管内强化传热性能的熵产分析与性能评价

通过热力学第一、第二定律,对管内对流换热综合性能进行熵产分析和评价.建立了一种基于流动与传热过程熵增原理的统一分析方法,在等壁温边界条件下进行熵产分析.并以文献中内翅片管的强化传热作为应用,分别对相同流量、泵功、压降在等热负荷限制下进行强化传热性能评价.结果表明：对于给定的管道,量纲1熵产数只与流动Reynolds数和进口与壁面的温度差有关.利用该分析方法不仅可通过参数分析获得几种强化方式的能量综合利用效果,还可确定合理的流动工况参数、结构参数和合理的强化形式.     

Room temperature resistance relaxation behavior for carbon black filled conductive polymer composites

Room temperature resistance relaxation was studied with respect to carbon black (CB) volume fraction, the type of polymer matrix, and the environment. It was found that resistance of CB filled poly(methylvinylsiloxane) and polypropylene (PP) conductive composites changed at room temperature with different directions and amplitudes, depending on the filler volume fraction and the environment. The room temperature resistance relaxation was ascribed to the local Joule heat at the tunneling junction or the swelling effect of the solvents. On the other hand, CB filled immiscible PP/Nylon 1212 blends exhibited a stable electrical conduction due to the selective distribution of CB aggregates along the interface between polymer matrices. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

The mechanical and tribological properties of nitric acid‐treated carbon fiber‐reinforced polyoxymethylene composites

The carbon fibers have been exposed to nitric acid oxidation treatments and introduced into polyoxymethylene composites (POM/CF). The nitric acid treatment increases the number of the flaws, roughness of the surface, and disorder of carbon atoms on fiber, as well as introduces reactive functional groups, which could lead to a better mechanical bonding between fiber and the matrix. It is shown that the impact strength and fiber‐matrix adhesion in composites (POM/mCF) are superior to those for POM/CF composites. Simultaneously, the addition of mCF improves flexural strength and modulus relative to virgin POM significantly. Average friction coefficient values of POM/CF composites are lower than that of POM/mCF composites. As the percentage of fiber increases, the trend of wear ratio of the composites goes down initially and bumps up afterwards. The results indicate that the proper contents of CF and mCF in composites range from 5 wt % to 20 wt %. Scanning electron microscopy of worn surface morphology has revealed that the main wear mechanism of the composites were adhesive wear and ploughing wear. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41812.