热固性树脂的微波固化

本文介绍了热固性树脂用微波加热固化的原理,并报导了环氧树脂微波固化的实验研究。实验结果表明,与常温固化相比,环氧树脂微波固化的速度远比常温固化快,而其浇铸体的拉伸强度则基本相同。     

微波固化热固性树脂研究最新进展

综述近年来热固性树脂及其复合材料的微波固化最新研究进展,介绍微波热效应原理,重点讨论热固性树脂微波固化与加热固化的不同、热固性树脂微波固化工艺及颗粒增强热固性树脂基复合材料的微波固化。并指出目前微波固化研究中的不足及今后的发展方向。     

介电分析法在热固性树脂固化研究中的应用

本文介绍了介电分析法在热固性树脂及以其为基体的涂料和纤维增强复合材料固化研究中的应用。     

热固性树脂半固化片树脂流动度研究

采用聚丁二烯、丙酮、陶瓷粉填料和其他助剂,制得胶液,用偶联剂处理过的玻璃布在胶液中浸渍后,在70℃干燥脱溶剂,在140℃继续烘烤10 min,得到半固化状态的预浸片.将浸渍片按固定的尺寸裁切后即得到所需的热固性树脂半固化片.对半固化片关键指标之一的树脂流动度的影响因素及调控方法进行了较为详细的讨论.结果表明,在良好界面...     

热固性树脂及其固化剂的研究进展

介绍了环氧树脂、不饱和聚酯、酚醛树脂以及脲醛树脂的化学结构、特点及应用,综述了这几种热固性树脂固化剂的研究进展,并简要介绍了相关固化机理。     

热固性聚酯粉末涂料及其固化

本文概述了聚酯粉末涂料的组成及环氧固化体系。着重介绍环氧化合物异氰脲酸三缩水甘油酯(TGIC)固化的羧基聚酯粉末涂料。     

热固性树脂的化学流变性

本文讨论了热固性树脂固化时化学流变性问题,并通过两种途径模拟了热固性树脂的化学粘度.     

生物质热固性树脂的研究进展

综述了近5年来生物质热固性树脂,包括环氧树脂、酚醛树脂和聚氨酯等研究进展。概述了几种生物质热固性树脂的制备方法、合成条件和反应原理,分析了生物质热固性树脂的性能如玻璃化转变温度(T_g)、热分解温度、拉伸强度、弯曲强度、断裂伸长率、弹性模量、硬度、溶胀率、残炭率、可降解温度、游离酚含量和游离甲醛含量等,并与非生物质热固性树脂(双酚A环氧树脂、酚醛树脂和聚氨酯等)进行了比较。展望了生物质热固性树脂的发展前景。     

Thermoset Matrices for Structural Adhesives: Imidazole-Catalysed Curing of Epoxy Resins

The thermoset epoxy systems of diglycidyl ether of bisphenol-A (DGEBA) and different imidazoles (unsubstituted imidazole, N-methyl-im., 2-methyl-im., 4(5)-methyl-im., 2-ethyl,4-methyl-im., 2-ethyl-im., 2-phenyl-im.) as catalytical curing agents were characterized. From microcalorimetric experiments it was deduced that each molecule of imidazole induces more than 20 epoxy groups to undergo polyaddition. Therefore, optimum glass transition temperature-ranges can be obtained with 0.025 to 0.05 mol of catalyst/equivalent of epoxy. The different alkyl-and aryl-substituted imidazoles show rather similar catalytic effects, with the kinetics differing by a factor of 3 at most. Mechanical properties (flexural modulus and strength, ultimate strain and fracture toughness) at ambient temperature do not correlate with the crosslinking density of the polymer network.     

微波技术在环氧树脂及其复合材料中的应用

论述了近年来微波固化技术在环氧树脂及其复合材料固化中的应用,重点比较了微波固化与传统热固化后环氧树脂及其复合材料的力学性能、热性能和粘结强度的变化,并对环氧树脂复合材料微波固化的研究进行了展望。     

Loss of Curing Agent During Thin Film (Droplet) Curing of Thermoset Material

Recently, it has been reported by our group and others^1.2 that loss of curing agent is encountered during the curing of small droplets or thin films of amine cured epoxies. In our earlier study³ results were reported on loss of curing agent in small droplets used in conducting the rnicrobond, single fiber test for determination of interfacial shear strength (ISS). It was reported that use of a volatile curing agent (meta-phenylene diamine (m-PDA) with DGEBA resin) resulted in increasing amounts of curing agent being lost (as measured by T₈ of the cured droplets) with decreasing droplet size during the processing procedure. Droplets smaller than 150 micrometers were seen to lose up to 40% of the curing agent leading to alteration of the mechanical properties of the droplet and, therefore, causing measured values of ISS to be exceedingly low. Use of a less volatile curing agent (Jeffamine 700, a polyether diamine, Texaco Specialty Chemicals) in combination with DGEBA resin produced results which indicated that loss of curing agent was not occuring. This study was undertaken to show the relationships between film (or droplet) size and the amount of curing agent lost (during the processing) for three different aminecured epoxy systems.     

水性环氧树脂固化剂的研究进展

从水性环氧树脂固化剂的改性原理出发,介绍了现有制备胺类水性环氧树脂固化剂技术的三种改性方法,比较了酰胺化多胺、聚酰胺、多胺-环氧加成物等用作水性环氧树脂固化剂的优势与不足之处,并简单地归纳了水性环氧树脂固化剂研究与发展进程。     

Ortho-Substituted Ortho-Cresol Novolac Resins as an Epoxy Resin Curing Agent

A series of ortho-substituted ortho-cresol novolac resins were synthesized and used as curing agents for epoxy resins. The chemical structures of different ortho-substituted ortho-cresol novolac resins were investigated by many measurements, such as FT-IR, ¹H NMR, and ¹³C NMR. The results indicated that the ortho-cresol novolac resin with the needed proportion of ortho-substitution was synthesized through the adjustment of the reaction conditions. The studies on the curing kinetics of ortho-cresol novolac epoxy resin cured by different ortho-cresol novolac resins showed that the activation energy was reduced with an increase in the proportion of ortho-ortho methylene bridges.     

波导对橡胶微波加热硫化的影响

采用ANSYS有限元分析软件分别模拟橡胶在圆波导和同轴波导两种模式下的微波加热硫化过程。结果表明:同轴波导模式下胶料的微波加热效率低于圆波导模式,但同轴波导模式下胶料经微波加热后,胶料的最高和最低温度的差值较小,即同轴波导模式下加热胶料内的温度分布较均匀。     

用微波连续硫化技术生产汽车橡胶密封条

详细介绍了汽车用橡胶密封条的微波连续硫化生产技术,包括生产装备、胶料配合、胶料混炼、生产工艺等,并对国内生产现状及发展前景进行了分析。     

Compressive Properties and Curing Behaviour of Unsaturated Polyester Resins in the Presence of Vinyl Ester Resins Derived from Recycled Poly(ethylene terephthalate)

Poly(ethylene terephthalate) waste was depolymerised in the presence of tetraethylene glycol and manganese acetate as a catalyst, so as to produce oligomers. An epoxy resin was then prepared by the reaction of these oligomers with epichlorohydrin in presence of NaOH as a catalyst. New diacrylate and dimethacrylate vinylester resins were then synthesized by reaction of the terminal epoxy groups with acrylic and methacrylic acid in the presence of triphenyl phosphite as a catalyst. The chemical structures of the resulting vinyl ester resins were confirmed by ¹HNMR. The vinyl ester resins were used as crosslinking agents for unsaturated polyester resin diluted with styrene, using free radical initiator and accelerator. The curing behaviour of the unsaturated polyester resin, vinyl ester resins and styrene was evaluated at temperatures from 25 to 55 ^○C. The compression properties of the cured resins, having different vinyl ester contents and different cure temperatures, were evaluated. Increasing the cure temperature and the vinyl ester content led to a pronounced improvement in the compression strength and Young’s modulus.     

松香合成环氧树脂及其固化剂的研究进展

综述了松香制备特种环氧树脂及固化剂的研究进展,分析了以松香为原料合成缩水甘油酯、缩水甘油醚型环氧树脂、松香基固化剂的反应机理及产品性能,分析了以松香为原料制备环氧树脂及固化剂的优势,展望了此领域的发展趋势和前景。