胺化酰胺胺固化的环氧树脂体系的特性及其固化机理

能热分解成异氰酸酯和叔胺的胺化酰亚胺是很好的潜伏性环氧树脂固化剂和环氧－酸酐体系的固化促进剂，它固化的环氧树脂有许多优异的性能，特别是高的韧性和粘接强度。由胺化酰胺热分解速度控制的、高温下相对慢的、独特的固化机理是韧性的起因。     

环氧树脂/胺化酰亚胺潜伏性固化体系的制备

为了深入了解新型环氧树脂/胺化酰亚胺潜伏性固化体系的使用条件,采用差示扫描量热（DSC）技术考察了E–51型环氧树脂/脂肪族胺化酰亚胺体系的非等温固化反应过程,研究了体系的固化条件及固化物性能。结果表明：E–51与固化剂的物质的量比为1∶0.1;体系的固化条件为固化150℃/2 h,后固化180℃/1 h。树脂试样制备工艺简单,无挥发性有机溶剂,树脂混合物贮存稳定性好。体系固化反应平稳且放热量较少,完全固化后的树脂试样具有良好的耐水性、耐热性和物理机械性能。     

固化温度对环氧树脂固化物性能的影响

制备了以叔胺为末端基的超支化聚酯为主要成分的潜伏型环氧树脂固化剂,用于双酚A型环氧树脂的固化.通过差示扫描量热仪(DSC)研究不同固化温度下的固化情况,确定了合理的固化工艺.研究了不同固化温度条件下环氧树脂固化物的拉伸强度、弯曲强度、冲击强度、动态力学性能和样品断面的形貌.结果表明,低温固化的材料具有更好的综合性能.80℃固化物具有最优异的各项性能,含超支化结构的固化剂具有一定的潜伏性,同时显著提高了环氧树脂固化物的韧性.     

聚醚酰亚胺/环氧树脂体系的固化及相分离行为研究

环氧树脂固化物本征的低韧性是限制其在复合材料应用的主要缺点之一。利用高性能热塑性树脂聚醚酰亚胺(PEI)与环氧树脂共混,系统研究了PEI在环氧树脂中的溶解行为、固化行为以及相分离行为。溶解试验表明:PEI与环氧齐聚物具有良好的相互溶解性;同时,PEI的加入降低了环氧树脂固化反应的活化能,但并没有改变其固化反应的机制。扫描电镜结果显示:随着PEI含量的增加,环氧/PEI浇铸体的相形貌从明显的分散颗粒相结构演变为双连续相结构和反转相结构。     

酶解木质素胺的合成及其固化环氧树脂的研究

以玉米秸秆酶解木质素为原料和二乙烯三胺进行Mannich反应制备了木质素胺,探讨了单因素反应条件对胺化反应的影响,并将木质素胺参与环氧树脂的固化反应,对其固化物性能进行了分析。结果表明反应温度为90℃、反应时间为3h、Na OH与木质素的质量比为0.07∶100、二乙烯三胺与木质素的质量比为3∶10、甲醛与木质素的质量比为1∶1时胺化效果最好,所制备的木质素胺的氮含量为68.6mg/g。DMA测试表明,聚酰胺/环氧树脂固化体系中木质素胺的加入会提高环氧树脂固化物的储能模量及玻璃化转变温度。TG分析表明,木质素胺的加入使得聚酰胺/环氧树脂固化物的分解温度降低,但体系的最终残余量增加。     

有机硅改性环氧树脂及其室温固化的性能研究

采用二苯基硅二醇(DSPD)改性双酚A型环氧树脂(E-51)制备了有机硅改性的环氧树脂,采用硫脲改性聚酰胺650制备了室温快速固化的环氧固化剂。合成产物通过红外进行表征,用盐酸-丙酮法测定改性环氧树脂的环氧值,通过指干时间确定聚酰胺650和改性聚酰胺650与E-51的较优配比。通过差示扫描量热分析法(DSC)和热重分析法(TG)表征改性环氧树脂固化物的耐热性,通过拉伸性能和扫描电镜测试(SEM)表征改性环氧树脂固化物的韧性。实验结果表明,环氧树脂经改性后,其玻璃化温度升高了27℃,与聚酰胺650固化后,固化产物的起始热分解温度明显增加,失重50%的分解温度升高了180℃,固化物的断裂伸长率增加了3.41%,断裂面呈现明显韧性断裂特征。     

新型潜伏性环氧树脂固化剂ADI的合成及性能研究

以偏二甲肼、环氧丙烷和正癸酸甲酯为原料,合成新型热潜伏性环氧树脂固化剂1,1–二甲基–1–(2–羟丙基)胺–2–癸酰亚胺(ADI),并采用傅里叶变换红外光谱、核磁共振波谱和元素分析,确定了产物的结构,借助热重同步差热分析仪,研究了产物的热分解特性以及ADI/E–44双酚A环氧树脂体系固化反应热行为。结果表明:ADI/E–44双酚A环氧树脂固化温度为100℃,固化时放热平稳,常温下潜伏期在60 d以上。     

液晶双马来酰亚胺改性环氧树脂的研究

采用一种含芳酯键的液晶双马来酰亚胺单体(BM I)改性环氧树脂/芳香胺固化体系,对比了改性前后环氧树脂的性能。发现BM I可以显著提高环氧树脂的韧性,并且对环氧树脂的耐热性有一定改善作用。同时,BM I对环氧树脂/芳香胺固化体系的凝胶化反应存在明显的催化作用。     

聚硫醚改性环氧树脂室温固化耐高温结构胶粘剂

目前室温固化耐高温环氧树脂结构胶粘剂主要采用液体端羧基丁腈橡胶增韧环氧树脂为主体,以改性液体端胺基丁腈橡胶或聚醚胺为韧性固化剂,其最高使用温度仅120℃。聚硫橡胶作为环氧树脂增韧剂和固化剂则由于耐热性能和增韧效果差,很少用于室温固化耐热环氧树脂结构胶粘剂。通过改进聚硫橡胶的内聚强度和耐热性能,作为增韧剂,克服了聚硫橡胶耐热性能和增韧效果差的缺点,大大地提高了室温固化环氧树脂结构胶粘剂的剥离强度,通过BMI与脂肪胺加成反应,并加入叔胺固化剂,合成具有BMI结构和叔胺的固化剂,以及加入有机硅改性石棉,使室温固化环氧树脂结构胶粘剂的耐热性能达到177℃,瞬间使用温度达300℃,达到室温固化高温使用的目的。     

环氧树脂/有机脲体系的固化反应动力学

研究了环氧树脂/有机脲体系的固化行为,探讨了固化反应机理。结果表明:有机脲是一种能有效固化环氧树脂的潜伏性固化剂;固化反应机理为有机脲与环氧树脂首先反应生成噁唑酮和仲胺,在环氧树脂过量的情况下,仲胺与环氧树脂反应生成叔胺,叔胺进一步反应产生阴离子活性中心,最终引发阴离子开环聚合。反应初期固化反应速率受有机脲分解产生仲胺浓度的影响,反应中期有机脲分解完毕,阴离子活性中心浓度为常数。     

Aminimide as hardener/curing promotor for one part epoxy resin composition

Three kinds of aminimide compounds were examined as latent hardeners/promotors for epoxy resins. Since aminimides are thermolyzed to generate tertiary amine and isocyanate, the compounds are useful as polymerization initiators for the epoxy group as well as promotors for epoxy–acid anhydride reaction. The pot life was over 30 days at 40°C for a formulated one-part epoxy resin system. In comparison with epoxy resins cured with conventional hardeners, several interesting characteristics of the mechanical and electrical properties were observed. In particular, the epoxy resins cured by aminimides exhibited high tensile strength and high impact strength, which make them excellent curing agents for adhesive applications. The reasons for these unique properties are discussed.     

油酸对环氧树脂的改性研究

研究了油酸对环氧树脂酸酐固化物性能的影响。用简支梁冲击试验机研究了油酸对固化物耐冲击性的影响,并用热变形仪和热重分析仪研究了固化物热稳定性的变化。结果表明,适量的油酸可以提高环氧树脂固化物的韧性,对其硬度影响不大,而且当固化剂适量时则对固化物的耐热性影响很小。     

几种胺类固化剂对环氧树脂固化行为及固化物性能的影响

固化剂结构对环氧树脂的固化行为和固化物性能具有重要影响,本文研究了聚醚胺(D-230)、异佛尔酮二胺(IPDA)和3,3'-二甲基-4,4'-二氨基-二环己基甲烷(DMDC) 3种胺类固化剂与实验室自制的低翻度环氧树脂A进行固化反应.通过薪度分析、红外(FTIR)光谱分析、DSC分析等手段研究了环氧树脂与固化剂反应程度...     

Physicochemical properties and fracture behavior of soy‐based resin

A soy‐based resin was prepared by the process of transesterfication and epoxidation of regular food‐grade soybean oil. The soy‐based resin was used as a reactive diluent and also as a replacement of bisA epoxy resin in an anhydride‐cured polymer. The curing efficiency of soy epoxy resin was studied using differential scanning calorimetry. Physicochemical properties and fracture behavior of soy‐based resin polymers were studied using dynamic mechanical analysis and fracture toughness measurements, respectively. Toughness measurements were carried out using the compact tension geometry following the principles of linear elastic fracture mechanics. Tests showed that the addition of soy‐based epoxy resin to the base epon resin improved the toughness of the blend. Morphology of the fractured specimens has been analyzed by scanning electron microscopy. The soy‐based resins hold great potential for environmentally friendly, renewable resource based, and low cost materials for structural applications. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

次中温环氧树脂固化剂(8104)的性能研究

本文研究了一种次中温环氧树脂固化剂（８１０４）的工艺性及其固化物的性能。试验结果表明：８１０４固化剂可在５０－８０℃下固化环氧树脂;与环氧树脂的混合物在室温下的适用期大于１０ 小时;固化物具有极好的韧性、良好的耐湿热性能和力学性能。因此,８１０４可用于大面积和大体积的环氧树脂固化施工,也可作为模具树脂、涂料及结构材料的固化剂。     

Synthesis and characterization of diphenylsilanediol modified epoxy resin and curing agent

A series of diphenylsilanediol modified epoxy resins and novel curing agents were synthesized. The modified epoxy resins were cured with regular curing agent diethylenetriamine (DETA); the curing agents were applied to cure unmodified diglycidyl ether of bisphenol A epoxy resin (DGEBA). The heat resistance, mechanical property, and toughness of all the curing products were investigated. The results showed that the application of modified resin and newly synthesized curing agents leads to curing products with lower thermal decomposition rate and only slightly decreased glass transition temperature (T_g), as well as improved tensile modulus and tensile strength. In particular, products cured with newly synthesized curing agents showed higher corresponding temperature to the maximum thermal decomposition rate, comparing with products of DGEBA cured by DETA. Scanning electron microscopy micro images proved that a ductile fracture happened on the cross sections of curing products obtained from modified epoxy resins and newly synthesized curing agents, indicating an effective toughening effect of silicon–oxygen bond.     

Toughening of Diglycidyl Ether of Bisphenol-A Epoxy Resin Using Poly (Ether Ether Ketone) with Pendent Ditert-Butyl Groups

Poly(ether ether ketone) (PEEKDT), hydroxyl terminated poly(ether ether ketone) (PEEKDTOH) and fluorine terminated poly (ether ether ketone) (PEEKDTF) with pendent ditert-butyl groups were synthesized by the nucleophilic substitution reaction of 4,4′-difluorobenzophenone with 2,5-ditert-butylhydroquinone in N-methyl-2-pyrrolidone medium using anhydrous potassium carbonate as catalyst. Diglycidyl ether of bisphenol-A epoxy resin was blended with PEEKDT, PEEKDTOH, and PEEKDTF, and cured with 4,4′-diaminodiphenylsulfone (DDS). The polymers formed heterogeneous blends before curing, and upon curing the polymers got dispersed in the epoxy matrix. The mechanical properties of the cured blends were slightly lower than that of the unmodified resin. The fracture toughness increased with the addition of ditert-butyl PEEK into epoxy resin and the extent of improvement was dependent on the type of modifier used. Hydroxyl terminated polymers gave up to 40% increase in fracture toughness. The dynamic mechanical spectrum of the blends showed only a single T_g due to the proximity of the glass transition temperature of modified PEEK and DDS cured epoxy resin.     

环氧树脂/胺基酰亚胺潜伏性固化体系非等温固化动力学研究

分别采用Kissinger模型和Flnn-Wall-Ozawa(FWO)模型研究了E-51型环氧树脂/胺基酰亚胺潜伏性固化体系的非等温固化动力学,得到了该体系在这2种模型下的固化反应活化能.分析了不同动力学模型对该体系固化反应动力学研究的影响.结果表明,由2种模型得到的固化动力学参数基本相近.E-51/胺基酰亚胺体系的固化反应具有变活化能特征,固化反应起始阶段的活化能较高,约为103～112 kJ/mol;当固化度为0.9时,活化能约为63～82 kJ/mol.