共查询到19条相似文献,搜索用时 140 毫秒
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本文研究了双酚A对多官能度环氧基和羧基聚丙烯酸正丁酯橡胶增韧环氧树脂的影响。结果表明,加入双酚A,拉伸断裂能有大幅度提高,同时不降低弹性模量。这可能是由椽胶提高断裂伸长与双酚A提高屈服应力产生协同效应的结果。对羧基橡胶增韧的三元共混体系,拉伸断裂能随羧基官能度上升而增加。断裂面的形态研究表明,由于羧基橡胶与双酚A的酯化反应,大大减少了羧基橡胶聚集对增韧的不利影响。 相似文献
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以松节油为原料合成出新型TEG - 99环氧树脂 ,研究了它分别与典型胺类、聚酰胺类及酸酐类固化剂的固化反应和固化产物的性能。结果表明 ,以松节油为原料合成TEG - 99环氧树脂的过程简单、稳定 ,产物具有与双酚A型环氧树脂相似的外观、理化性能、固化特征等 ,是松节油综合利用的一个有前景的途径 相似文献
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酚酞聚醚醚砜(PES-c)同未交联的双酚A二缩水甘油醚(DGEBA)环氧树脂的共混物呈单一的玻璃化转变温度,其相容性主要归因于混合熵的贡献。PES-C同交联的环氧树脂之间的相容性与所用的固化剂有关。以胺类作DGEBA的固化剂时,共混物不发生相分离;以酸酐作固化剂时,共混物发生相分离。 相似文献
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本文针对聚二甲基硅氧烷改性环氧树脂相溶性太差,性能不够理想等问题,提出用氰丙基替代部分甲基以减小聚硅氧烷与环氧树脂的溶度参数差,改善两相的相溶性。采用氨丙基封端的聚氰丙基甲基硅氧烷低聚体(表1)单独或与二乙烯三胺(固化剂)一同与双酚A环氧树脂反应,合成了一系列不同聚硅氧烷分子量和重量百分比的样品(表2)。并用示差扫描量热计(DSC)、动态力学谱(DMA)、光电子能谱(XPS)、接触角仪、扫描电子显微镜(SEM)、电子拉力试验机对其进行研究。结果表明在聚硅氧烷软段中引入氰丙基可提高两相的相溶性并使增韧效果明显改善。 相似文献
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采用分子动力学方法建立了二乙基甲苯二胺/双酚A缩水甘油醚环氧树脂体系(DETDA/DGEBA体系)和间苯二胺/双酚A缩水甘油醚环氧树脂体系(mPDA/DGEBA体系)的交联模型,在此基础上,分析了固化剂分子结构的差异对树脂性能的影响,研究发现mPDA/DGEBA体系的玻璃化转变温度、模量以及阻碍水分子的扩散性能均高于DETDA/DGEBA体系。为了进一步揭示交联环氧树脂分子结构与性能之间的关系,研究了上述两体系的自由体积和内聚能密度。结果表明,与DETDA/DGEBA体系相比,mPDA/DGEBA体系具有较小的自由体积和较高的内聚能密度。较小的自由体积和较高的内聚能密度是造成mPDA/DGEBA体系玻璃化转变温度、模量以及阻碍水分子的扩散性能均高于DETDA/DGEBA体系的原因。 相似文献
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通过 DSC法研究了 LEPB、双酚 A型环氧树脂 E-51和 TDE-85型环氧树脂与四种芳基碘钅翁盐的热固化行为及反应活化能。结果发现 ,双酚 A型环氧树脂固化反应的活化能较高 ,而 TDE-85的放热较集中。同时发现与酸酐固化剂相对照 ,本文中使用的 LEPB—固化剂体系的活化能 (78.66~ 1 0 2 .5k J· mol-1)普遍高于LEPB酸酐体系的活化能 (69.0 4~ 75.1 0 k J·mol-1)。 相似文献
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Toughened epoxy resin with excellent properties was obtained by adding organic acid anhydride curing agent and hydroxy-terminated butadiene-acrylonitrile copolymer (HTBN), which is cheaper than CTBN. The anhydride reacts with both epoxy groups on epoxy resin and hydroxyl groups on HTBN. As a result the soft long chains of HTBN and the rigid chain of epoxy resin form one network, giving the resin toughness. Two-phase structure of the toughened resin was observed by SEM and TEM. 相似文献
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一种液晶环氧增韧环氧树脂的研究 总被引:16,自引:0,他引:16
环氧树脂具有优异的机械性能 ,耐高温以及良好的加工工艺性 .被广泛用于机械、航天、船舶等领域 .由于环氧树脂固化后断裂延伸率小 ,脆性大 ,使其应用受到了一定的限制 .为此 ,国内外学者对环氧树脂进行了大量的改性研究工作 .用含有“柔性链段”的固化剂固化环氧 ,在交联网络中引入柔性链段[1] ;在环氧基体中加入橡胶弹性体[2 ] 、热塑性树脂[3 ,4] 、液晶聚合物[5,6] 等分散相或用热固性树脂连续贯穿于环氧树脂网络中形成互穿、半互穿网络结构[7] ,以改善环氧树脂的韧性 .本文采用液晶环氧化合物原位复合增韧环氧树脂 ,考察了液晶环氧对环… 相似文献
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L. Calabrese 《European Polymer Journal》2003,39(7):1355-1363
The curing kinetics of an epoxy resin matrix, based on diglycil ether of bisphenol A and F (DGEBA-DGEBF), associated with an anhydride hardener, at different carboxyl-terminated copolymer of butadiene and acrylonitrile liquid rubber (CTBN) concentration (0-10 phr) are studied using a differential scanning calorimetry (DSC) and a stress-controlled rheometer in isothermal and dynamic conditions. The aim of this work is to correlate the presence of the rubber phase with the transition phenomena that occur during the curing process. The CTBN rubber induces a catalytic effect on the polymerization of the pure resin clearly observed by a significant enhancement of the curing rate. Calorimetric and rheological analysis also evidences that gelation and vitrification times take place not punctually but in a wide range of time. Rheological data show that the presence of rubbery phase induces a higher rate of gel formation during the early stages of the reactions, confirming the calorimetric results. Finally the results are compared with theoretical models evidencing a good fitting between experimental and predictive data. 相似文献
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咪唑固化不同类型环氧树脂的固化特征、固化动力学及其反应活性 总被引:2,自引:0,他引:2
以咪唑为固化剂,对缩水甘油醚型、缩水甘油酯型环氧树脂(简称链型环氧树脂)及脂环环氧树脂的固化特征、固化动力学及反应活性进行了研究.DSC实验结果表明,固化过程均分两阶段进行,链型环氧树脂固化反应表观活化能低于脂环环氧树脂.各树脂第一阶段的表观反应活化能均低于第二阶段活化能.当脂环环氧树脂中混入不同比例的链型环氧树脂后,固化反应速率均较脂环环氧树脂单独固化时快,当链型环氧树脂量大于50%时,更为明显. 相似文献
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A novet toughened epoxy resin was obtained by using aprecopotymer of epoxy resin and hydroxy-terminated butadiene-acrylonitrilecopolymer(HTBN)and amine curing agent.The cured toughened resin hasexcellent mechanical properties due to the two-phase structure,which has beenobserved from SEM and TEM. 相似文献
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Miyuki Harada Mitsuhiko Morimoto Mitsukazu Ochi 《Journal of Polymer Science.Polymer Physics》2003,41(11):1198-1209
A biphenol‐type epoxy resin, which had a mesogenic group in the backbone moiety, was modified with carboxy‐terminated butadiene acrylonitrile copolymer (CTBN) as a reactive elastomer, and its fracture toughness was measured. With the addition of CTBN, the fracture toughness of the biphenol‐type epoxy resin significantly increased and became significantly higher than that of a bisphenol A‐type epoxy resin modified with CTBN. The network chain orientation in the cured biphenol‐type epoxy resin system was clearly observed during the fracture process with polarized microscopy Fourier transform infrared measurements, although such a phenomenon was not observed in the bisphenol A‐type epoxy resin system. The high toughness of the cured biphenol‐type system was clearly due to the consumption of the mechanical energy by a large deformation of the matrix resin due to the orientation of the network chains during the fracture process. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 1198–1209, 2003 相似文献
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电子束作用下双酚A型环氧树脂体系的固化特征 总被引:1,自引:0,他引:1
当前 ,先进树脂基复合材料基本上都是采用加热固化成型的 ,由于其工艺周期长 ,造成复合材料的制造成本较高 ,同时 ,热固化采用的固化剂和有机溶剂往往会对操作人员及环境造成危害 .为顺应复合材料低成本化和无公害化的发展趋势 ,树脂基复合材料的电子束辐射固化技术逐渐发展起来 .复合材料的电子束固化技术是在 2 0世纪 80年代初 ,由法国Aeropaticle的研究人员首先进行的[1] .近年来 ,美国、日本、加拿大及欧洲的许多国家都在积极从事于研究和利用此项技术 ,并且已经取得了可观的成果[2 ] .我国在这方面的研究工作也开始起步 .作… 相似文献
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Two kinds of tough ductile heatresisting thermoplastic, namely bisphenol A polysulfone (PSF) and polyethersulfone (PES) were used to toughen thermoset epoxy resin. A systematic study on the relationship between the molecular weight and the terminal group of the thermoplastic modifier and the fracture toughness of the modified resin was carried out. The morphology of PSF modified epoxy resin was surveyed. With the same kind of PSF the structure of the epoxy resin and the toughening effect of PSF was also investigated. The fractography of PSF, particle modified epoxy was examined in detail with SEM. The contribution of every possible energy absorption process has been discussed. Crack pinning mechanism seems to be the most important toughening mechanism for tough ductile thermoplastic PSF particle modified epoxy system. 相似文献
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升温与等温法非模型动力学研究环氧树脂固化反应 总被引:2,自引:0,他引:2
基于DSC数据,采用以Vyazovkin积分法为基础的升温法非模型动力学和等温法非模型动力学对双酚A型环氧树脂E51/4,4′-二氨基二苯基砜(DDS)体系及多官能度环氧树脂AG80/DDS体系的固化过程进行了研究,并结合玻璃化转变温度的变化和原位红外测试技术,对比分析了升温与等温条件下的固化反应规律.结果表明,与传统的模型拟合法相比,非模型动力学更适合定量预测树脂固化反应过程,并能为固化过程中反应机理变化的研究提供重要依据;等温法非模型动力学能够更好地预测两种树脂体系在不同恒温条件下的固化反应历程,并且升温法与等温法非模型动力学所得到的反应活化能-固化度之间的变化关系不同,表明不同温度条件下树脂的反应机理不同,这与升温和恒温条件下玻璃化效应及环氧官能团的变化规律相吻合. 相似文献