芳砜纶增强的新型摩擦材料研究

研究了芳砜纶纤维增强新型摩擦材料。采用分步干式开松法解决了芳砜纶的散问题，应用正交设计法优化芳砜纶磨擦材料的配方。研究表明该摩擦材料性能优于半金属摩擦材料和石棉摩擦材料。     

多孔酚醛树脂热解碳材料的制备与结构

用苯酚和甲醛在氨水催化下合成了可溶性酚醛树脂, 经掺杂不同质量比发泡剂(氯化锌)后在惰性气氛下进行热裂解(500～900 ℃), 制备了多孔热解碳导电材料(PPAS); 用FTIR, XRD, TG, SEM, BET等方法对所制备材料进行了结构表征, 详细讨论了发泡剂的加入对热解碳导电材料结构和性能的影响. 研究发现: 酚醛树脂经掺杂一定量发泡剂后再进行热裂解, 一方面加快了酚醛树脂分子间的脱水速度, 降低了热裂解温度范围; 另一方面, 裂解产物内部结构的微晶尺寸和层间距发生了明显变化, 未掺杂发泡剂的裂解产物呈现尖锐棱角的无定形结构, 而掺杂发泡剂的裂解产物则为多孔的球形和椭球形结构; 表面吸附实验测试结果表明, 当酚醛树脂与发泡剂的质量比为1∶3, 升温速率为30 ℃/h, 热裂解温度为600 ℃时, 热裂解产物的比表面积可达2150 m2•g－1, 平均孔径在11 Å左右.     

润滑材料摩擦化学

外界机械能能够引发的化学反应称为摩擦化学反应。当两个接触的表面进行相对运动时,在界面发生物理和化学变化或反应。润滑材料在服役过程中发生的摩擦化学反应对于其性能的具有正面或负面的影响。通过了解摩擦化学反应机理和反应产物结构及组成,对于理解润滑材料失效机制、性能调控原理具有指导意义。本文针对润滑材料的主要类型：润滑添加剂、纳米添加剂、离子液体、稀土、陶瓷、类金刚石薄膜、有机薄膜、聚合物,综述了近几十年来在相关润滑材料方面开展和取得的摩擦化学研究结果。     

摩阻材料用亚麻油改性酚醛树脂的制备及耐热性研究

利用亚麻油改性酚醛树脂,得到高性能的摩阻材料用树脂基体.推导了改性机理和结构特征,并进行了耐热试验和分析.结果表明,亚麻油参与了反应并成为聚合物的一部分,亚麻油改性酚醛树脂固化后的结构特征是互穿聚合物网络(IPN),与普通酚醛树脂相比,亚麻油改性酚醛树脂的耐热性能显著提高,可望用作耐高温磨阻材料树脂基体.     

酚醛树脂包覆氧化天然石墨作为锂离子电池负极材料

天然石墨经过浓硫酸氧化处理,酚醛树脂包覆并高温碳化后形成具有核壳结构的碳包覆氧化天然石墨复合材料.采用扫描电子显微镜(SEM),透射电子显微镜(TEM),X射线衍射(XRD),激光显微拉曼光谱(Raman)等检测技术对氧化处理以及酚醛树脂热解碳包覆前后天然石墨材料的结构与形貌进行分析与表征.结果表明,氧化处理与适量的酚醛树脂热解碳包覆有效修复了天然石墨表面的一些缺陷结构,使其表面更为光滑.电化学测试结果显示,经过氧化处理与酚醛树脂热解碳包覆后天然石墨材料电化学性能得到明显提高.酚醛树脂包覆量为9%时,复合材料表现出最好的电化学性能,其首次放电比容量为434.0mAh·g-1,40次循环后,放电比容量保持在361.6mAh·g-1,而未经处理的天然石墨放电比容量仅为332.3mAh·g-1.该改性方法有效提高了天然石墨材料的比容量,对其进一步应用具有重要意义.     

掺杂ZnCl2对酚醛树脂热解炭材料结构与性能的影响

采用比表面吸附(BET)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线衍射光谱(XRD)、激光拉曼光谱(Raman)等手段,对掺杂ZnCl2的酚醛树脂热裂解炭材料进行了表征.结果表明该材料的微粒及孔径均为纳米级,平均微粒径在40～60nm,平均孔径为3.86nm.用该材料做电极,经过30次充放电循环,可逆容量为360mA·h·g-1.     

X射线光电子能谱技术在高分子材料摩擦化学研究中的应用

X射线光电子能谱技术(XPS)是材料表面分析的重要手段,其近年的快速发展促进了表面化学领域研究的深入.高分子及其复合材料在摩擦学性能方面具有普遍的优势,通过XPS对高分子及其复合材料摩擦表面的分析,可以确定摩擦过程的化学变化,并对改进材料的摩擦学性能起到理论的指导作用.作者主要介绍XPS技术的基本原理,及其在高分子与复合材料摩擦学性能研究中的应用.     

静电纺丝技术制备聚合物基中空结构材料

静电纺丝是一种制备纳米尺度连续长丝的技术, 采用静电纺丝技术高效可控地构筑微纳米中空结构材料备受关注. 本文综述了通过静电纺丝技术制备聚合物中空纤维和中空微球的研究进展, 展望了其在不同功能材料领域的发展前景.     

基于甘油三酸酯的高分子材料Ⅱ.乙烯基聚合物等及复合材料、杂化材料

甘油三酸酯是一种可再生资源,可以从向日葵、棉花、亚麻籽等植物中提取得到。基于甘油三酸酯制造高分子材料可通过许多方法,如缩合反应、自由基反应、阳离子聚合反应等。文章是基于甘油三酸酯的高分子材料Ⅰ.聚酯和聚氨酯的续篇,综述乙烯基聚合物等及复合材料、杂化材料的研究进展。     

γ-射线辐照接枝制备几种功能性高分子材料

概述了近几年来本研究组在高分子材料辐照接枝制备功能性高分子材料方面的研究进展.分别以丙烯酸、顺丁烯二酸、苯乙烯接枝聚四氟乙烯纤维,制备了不同酸性的聚四氟乙烯功能纤维.以N-异丙基丙烯酰胺接枝壳聚糖制备温度及pH敏感材料,获得了性能特异的新型功能性高分子材料.报道了该类新型功能高分子材料的各种特异性能,如对金属离子优异的分离、吸附和解吸性能、超强酸性和一系列潜在用途.     

Braking Performance of an Organic Brake Pad Based on a Chemically Modified Phenolic Resin Binder

An organic brake pad for railroad passenger-coach braking was prepared using a chemically modified phenolic resin (PF), that was designed and manufactured in our laboratory. The braking performance of the pad was investigated on a full-scale test bench. For comparison, a brake pad based on straight PF was also prepared and investigated. The results showed that the modified PF pad possessed much higher impact strength, and better braking stability and wear resistance than the straight PF pad. It is thought that the better overall properties of the modified PF pad resulted from the changes in chemical structure of the resin during the frictional process and the strong interreaction of the modified resin binder with the hybrid fibers.     

醇酸树脂固化过程的FTIR跟踪

本文用FTIR内标法跟踪观察了醇酸树脂的固化过程,选取1600cm~(-1)处的苯环振动峰作内标峰。结果表明,随着固化的进行,不饱和键递减,涂膜的羧基、羟基等含氧基团递增。固化过程的快慢同涂膜厚度有关,它是受氧扩散作用控制的。     

Molecular Relaxations in Hybrid Organic–Inorganic Materials Prepared by a Sol–Gel Process

Organic–inorganic hybrid materials based on alkoxy-silane-terminated macromonomers synthesised from a hydroxy-terminated hydrogenated polybutadiene, H-PBD, have been investigated. Different morphologies of the hybrid materials are obtained according to the conditions of the synthesis and to the non compatibility between the organic and the inorganic components. In order to establish the relationships between the structure and the properties of the organic–inorganic (O/I) materials, infrared, small-angle X ray scattering, transmission electron microscopy, dynamical mechanical spectroscopy and dielectric measurements have been performed. This paper focuses especially on the analysis of the dielectrical relaxations in a large range of frequencies and temperatures compared with the dynamic mechanical one to propose a model of morphology of the final O/I materials. It is found in particular that a distinct interfacial region between the organic-rich phase and the silicate clusters is developed in the case of the low acid-to-alkoxide ratio for hybrids (based on γ-amino propyl triethoxysilane) (i.e. for the long periods of gelation). © 1997 John Wiley & Sons, Ltd.     

溶胶-凝胶法制备光固化聚氨酯丙烯酸酯杂化材料的研究

以溶胶-凝肢法制备的硅溶胶为无机相,聚氨酯丙烯酸酯为有机相,以γ-甲基丙烽酰氧丙基三甲氧基硅烷(TMSPM)为两相间的偶联剂,制得了光固化杂化材料。研究了未固化的杂化体系的稳定性问题,并对其进行了结构表征和性能研究。无机相与有机相通过共价键相连。使得杂化体系光固化膜高硬度的获得并没有以柔韧性的损失为代价。在无机物含量较低时,聚氨酯丙烯酸酯／二氧化硅杂化体系先固化膜的耐磨性略有提高。     

Core/Shell Structured PCM Nanocapsules Obtained by Resin Fortified Emulsion Process

Phase change material (PCM, octadecane) nanocapsules were successfully prepared by resin fortified emulsion (RFE) polymerization using the alkali soluble resin (ASR) of poly(ethylene‐co‐acrylic acid) (EAA) and poly(styrene‐co‐acrylic acid) (SAA). Stable PCM nanocapsules were obtained by resin fortified emulsion polymerization, which could be attributed to the prevention of Ostwald ripening due to PCM being hydrophobic. Analysis of online FTIR measurements throughout the reaction confirmed that the nanocapsules contained octadecane as a PCM. TEM imaging of the PCM nanocapsules showed spherical and core/shell morphology. The characteristics of PCM nanocapsules can be controlled by process parameters. As a result, the particle size and particle size distribution (i.e., polydispersity index (Dw/Dn)) of the PCM nanocapsules were created by adjusting manufacturing conditions. The PCM nanocapsules exhibited thermal energy storage (～49.8 J/g) and release (～47.9 J/g) behavior.     

溶胶-凝胶法合成杂化材料中的增容剂的应用

讨论了溶胶 -凝胶法合成有机 /无机杂化聚合物材料中的增容剂的应用 ,并详细介绍了三类增容剂的结构、增容机理和性能。     

Identification and Capture of Phenolic Compounds from a Rapeseed Meal Protein Isolate Production Process By-Product by Macroporous Resin and Valorization Their Antioxidant Properties

In this study, phenolic compounds from an aqueous protein by-product from rapeseed meal (RSM) were identified by HPLC-DAD and HPLC-ESI-MS, including sinapine, sinapic acid, sinapoyl glucose, and 1,2-di-sinapoyl gentibiose. The main phenolic compound in this by-product was sinapine. We also performed acid hydrolysis to convert sinapine, and sinapic acid derivatives present in the permeate, to sinapic acid. The adsorption of phenolic compounds was investigated using five macroporous resins, including XAD4, XAD7, XAD16, XAD1180, and HP20. Among them, XAD16 showed the highest total phenolic contents adsorption capacities. The adsorption behavior of phenolic compounds was described by pseudo-second-order and Langmuir models. Moreover, thermodynamics tests demonstrated that the adsorption process of phenolic compounds was exothermic and spontaneous. The highest desorption ratio was obtained with 30% (v/v) and 70% (v/v) ethanol for sinapine and sinapic acid, respectively, with a desorption ratio of 63.19 ± 0.03% and 94.68 ± 0.013%. DPPH and ABTS tests revealed that the antioxidant activity of the hydrolyzed fraction was higher than the non-hydrolyzed fraction and higher than the one of vitamin C. Antioxidant tests demonstrated that these phenolic compounds could be used as natural antioxidants, which can be applied in the food industry.     

GDX树脂富集－反相高效液相色谱法分离测定酚类化合物

用ＧＤＸ－５０２树脂富集的酚类化合物，经反相高效液相色谱法分离和检测，具有较好的准确度和精密度。     

Redox Active Mesoporous Hybrid Materials by In situ Syntheses with Urea‐linked Triethoxysilylated Phenothiazines

Triethoxysilyl functionalized phenothiazinyl ureas were synthesized and immobilized by in situ synthesis into mesoporous hybrid materials. The designed precursor molecules influence the structure of the final materials and the intermolecular distance of the phenothiazines. XRD and N₂ adsorption measurements indicate the presence of highly ordered two‐dimensional hexagonally structured functional materials, while the incorporation of the organic compounds in the solid materials was proved by means of ¹³C and ²⁹Si solid state NMR spectroscopy as well as by FT‐IR spectroscopy. Upon oxidation with (NO)BF₄ or SbCl₅, stable phenothiazine radical cations were generated in the pores of the materials, which was detected by means of UV/Vis, emission, and EPR spectroscopies.     

Mechanical properties of phenol/formaldehyde resin composites reinforced by cellulose microcrystal with different aspect ratio extracted from sisal fiber

Sisal cellulose fiber (SCF) and sisal fiber cellulose microcrystal (SFCM), produced with sulfate pulping method and ball‐milling approach separately, were in‐situ polymerized and dispersed into phenol/formaldehyde (PF) resin, to manufacture SCF/PF and SFCM/PF composites via rolling and molding method and investigate the effect of SCF and SFCM on the impact, flexural, and dynamic mechanical properties of the SCF/PF and SFCM/PF composites. As a result, under the condition of same content, SFCM could preferably enhance these properties maybe resulting from the better dispersion in resin matrix than SCF. In particular, when SFCM content was 7%, the impact strength and equilibrium relaxation modulus of the SFCM/PF composite were increased by 26.5% and 37.7%, while the creep deformation was decreased by 26.5%. In addition, when SFCM content was 5%, the flexural strength, initial storage modulus and glass transition temperature of SFCM/PF composite were increased by 8.5%, 22.6%, and 13°C. Copyright © 2016 John Wiley & Sons, Ltd.