Study of the effect of BDMA catalyst in the epoxy novolac curing process by isothermal DSC

Epoxy novolac/anhydride cure kinetics has been studied by differential scanning calorimetry under isothermal conditions. The system used in this study was an epoxy novolac resin (DEN431), with nadic methyl anhydride as hardener and benzyldimethylamine as accelerator. Kinetic parameters including the reaction order, activation energy and kinetic rate constants, were investigated. The cure reaction was described with the catalyst concentration, and a normalized kinetic model developed for it. It is shown that the cure reaction is dependent on the cure temperature and catalyst concentration, and that it proceeds through an autocatalytic kinetic mechanism. The curing kinetic constants and the cure activation energies were obtained using the Arrhenius kinetic model. A suggested kinetic model with a diffusion term was successfully used to describe and predict the cure kinetics of epoxy novolac resin compositions as a function of the catalyst content and temperature. Copyright © 2003 Society of Chemical Industry     

加快塑料技术中心建设提高新产品开发水平

对中国石油化工集团公司(简称中国石化)合成树脂生产及加工应用技术的现状进行了分析，指出中国石化应加快建设塑料加工应用技术中心，为塑料产品的加工用户提供高技术水平和快捷周到的技术服务，在合成树脂新产品开发和产品结构调整中发挥积极作用，以提高合成树脂产品的市场竞争力。     

Chemische Zusammensetzung und Mikrostruktur polymerabgeleiteter Gläser und Keramiken im System Si–C–O. Teil 2: Charakterisierung der Gefügeausbildung mittels hochauflösender Durchstrahlungselektronenmikroskopie und Feinbereichsbeugung

Chemical Composition and Microstructure of Polymer‐Derived Glasses and Ceramics in the Si–C–O System. Part 2: Characterization of microstructure formation by means of high‐resolution transmission electron microscopy and selected area diffraction Liquid or solid silicone resins represent the economically most interesting class of organic precursors for the pyrolytic production of glass and ceramics materials on silicon basis. As dense, dimensionally stable components can be cost‐effectively achieved by admixing reactive filler powders, chemical composition and microstructure development of the polymer‐derived residues must be exactly known during thermal decomposition. Thus, in the present work, glasses and ceramics produced by pyrolysis of the model precursor polymethylsiloxane at temperatures from 525 to 1550 °C are investigated. In part 1, by means of analytical electron microscopy, the bonding state of silicon was determined on a nanometre scale and the phase separation of the metastable Si–C–O matrix into SiO₂, C and SiC was proved. The in‐situ crystallization could be considerably accelerated by adding fine‐grained powder of inert fillers, such as Al₂O₃ or SiC, which permits effective process control. In part 2, the microstructure is characterized by high‐resolution transmission electron microscopy and selected area diffraction. Turbostratic carbon and cubic β‐SiC precipitate as crystallization products. Theses phases are embedded in an amorphous matrix. Inert fillers reduce the crystallization temperature by several hundred °C. In this case, the polymer‐derived Si–C–O material acts as a binding agent between the powder particles. Reaction layer formation does not occur. On the investigated pyrolysis conditions, no crystallization of SiO₂ was observed.     

国产延迟树脂在腈纶溶剂NaSCN除杂装置的应用

叙述了国产的延迟树脂与进口DOWEX-11-A8树脂在腈纶厂NaSCN回收模拟装置上的比较试验,由试验数据可得出;国产的延迟树脂NVI脱除率性能略优于美国DOWEX-11-A8树脂,并可替代DOWEX-11-A8树脂应用于腈纶厂延迟装置中。     

水溶性油墨用富马酸改性松香树脂的研制

介绍了一种水溶性富马酸改性松香树脂的制备方法 ,选取了较佳的工艺条件 ,本产品经国内几家油墨厂使用 ,结果表明适合水溶性油墨的应用要求     

硼酸铝晶须增强环氧树脂和双马来酰亚胺树脂体系的研究

本文以硼酸铝晶须为增强剂，以4，5-环氧环己烷-1，2-二甲酸二缩水甘油酯(TDE-85)，甲基纳狄克酸酐(MNA)、N，N’-二胺基二苯甲烷型双马来酰亚胺(BMI)/O，O′-二烯丙基双酚A(BA)体系分别作为基体制备晶须增强复合材料。研究了晶须对树脂的尺寸、表面处理方法、含量对树脂体系力学性能和热性能的影响；通过扫描电子显微镜(SEM)分析了浇注体的弯曲、冲击断口，研究晶须的增强机理。     

Structure and properties of CE/CTBN/EP blends: II. Effect of EP on the mechanical properties and thermostability of the CE/CTBN system

Carboxyl‐terminated butadiene‐acrylonitrile rubber (CTBN) has often been used to improve the toughness of cyanate ester (CE) resin while sacrificing modulus and thermostability. In this paper, the addition of the appropriate amount of epoxy resin (EP) to the CE/CTBN system is shown to not only increase the modulus and thermostability of the blend, but also improve the toughness. The values of impact strength showed a maximum for the CE/CTBN/EP 100/5/5 blend. The temperature of 10 % weight loss (T₁₀) improves from 376 °C for CE/CTBN 100/5 to 407 °C for the CE/CTBN/EP 100/5/2.5 blend. It is proposed that addition of the appropriate amount of EP can decrease the mobility and increase the stability of CTBN via the reaction between the terminal carboxyl group of CTBN and the hydroxyl group of EP. But a very high EP concentration will decrease the crosslinking density of CE, consequently reducing the mechanical properties and thermostability of the blends. Copyright © 2004 Society of Chemical Industry     

聚合物-金属界面相形貌的研究

环氧树脂在 Al 合金表面生成纤维状的界面相结构,其形成、发展和特征与树脂的体系、交联反应条件以及 Al 合金的表面状态有关。环氧树脂的基础相为颗粒状的超结构组织。聚合物界面相的力学破坏表现为纤维体的拉伸、变形和断裂,而基础相在纯剪切受力时出现在45°方向的裂纹,并发展导致连接层的破坏。     

一种环氧树脂阻尼灌封胶的热氧加速老化研究

研究了某种环氧树脂阻尼灌封胶在热氧老化的作用下分子结构、硬度、断面形貌以及动态力学性能随时间的变化．傅立叶红外光谱图表明，所制备的样品环氧基团反应比较完全，热氧老化后试样表面由仲胺和环氧基团形成的酯键发生了部分断裂和氧化；邵氏硬度的增加、瓦向高温区移动则表明在老化过程中复杂的固化反应仍然继续进行；最大损耗因子（tanδmax）波动较小表明试样老化后分子结构几乎保持不变；SEM图片显示试样的冲击断裂由老化前的韧性转变为老化后的脆性断裂．     

Fluorescence and IR characterization of epoxy cured with aliphatic amines

Cure reactions of the stoichiometric mixtures of diglycidyl ether of bisphenol A (DGEBA) and two very low molecular weight aliphatic polyether diamines (PED) were studied by using fluorescence and mid- and near-IR spectroscopic techniques. As the cure proceeded, the primary amine groups in PED are converted to the secondary and the tertiary amines. Near-IR spectral analysis was used to calculate the concentration of the three amine groups as a function of cure time. The decrease in the fluorescence intensity of DGEBA at about 307 nm was observed due to more effective quenching of the tertiary amine groups in PED, in comparison to the primary and the secondary amine groups. A large decrease in fluorescence intensity at 75 and 95 °C cure was observed. The amount of all the amine species was estimated from NIR spectra to shed light on the cure kinetics of PPO (polypropylene oxide) in comparison with PEO (polyethylene oxide) epoxy, as well as to explain their fluorescence behavior.The fluorescence intensity changes were correlated to the extent of epoxy reaction obtained by mid- and near-IR spectroscopy.