环己二醇二缩水甘油醚/环氧树脂固化动力学

对E-44环氧树脂,1,2-环己二醇二缩水甘油醚与E-44环氧树脂的混合物,1,2-环己二醇二缩水甘油醚分别与二氨基二苯基甲烷的固化反应应用示差扫描量热仪(DSC)进行了研究。在E-44环氧树脂中加入1,2-环己二醇二缩水甘油醚后,不但对环氧树脂有较好的稀释作用,降低了环氧体系固化反应的表观活化能,增加了环氧树脂的固化反应活性和固化反应速度,还提高了环氧固化物的力学性能。测定了反应热焓,计算出固化反应的表观活化能分别为46.08 kJ/mol,39.50 kJ/mol,35.58 kJ/mol,相应的固化反应级数分别为0.86,0.84,0.83。     

液体成型用环氧树脂体系与碳纤维表面浸润性能研究

采用1,4-丁二醇二缩水甘油醚(BDDGE)、聚乙二醇二缩水甘油醚(PEGDGE)、双酚A聚氧乙烯醚06(BPE-06)3种活性环氧树脂稀释剂,分别制备了低黏度适合复合材料液体成型工艺(LCM)的环氧树脂体系,研究了体系与国产碳纤维(HF10)的表面浸润性。首先,研究了稀释剂结构、用量对环氧树脂体系与碳纤维湿润性的影响;其次,研究了稀释剂/树脂/固化剂体系的湿润温度、反应程度对树脂与碳纤维表面的浸润性影响。采用DCAT21表面/界面张力仪分析了树脂与碳纤维界面的前进接触角;采用Young-Dupre法,计算了树脂与碳纤维的热力学粘附功。结果表明,采用稀释剂降低黏度,可以有效改善树脂体系与碳纤维的浸润性;相同黏度时,不同结构稀释剂提高浸润性效果顺序为:PEGDGEBPE-06BDDGE;升高温度可以提高环氧树脂与碳纤维的浸润性;随着反应程度的提高,树脂体系与碳纤维的湿润性变好。     

松香基环氧树脂的合成及性能研究

通过丙烯酸松香(AR)分别与1,4-丁二醇二缩水甘油醚(BDGE)、1,6-己二醇二缩水甘油醚(HDGE)酯化反应合成出松香基环氧树脂预聚体ARBDGE和ARHDGE,丙烯酸松香分别与二乙烯三胺(DETA)、四乙烯五胺(TEPA)酰胺化反应合成出松香基聚酰胺固化剂ARDETA和ARTEPA,测试了理论配比下反应生成固化物的玻璃化转变温度(Tg)及性能;结果表明,松香基固化物硬度中等、划格实验≤3级、T-弯均为0级、耐冲击性能≥5.88 J,耐化学腐蚀合格,紫外加速老化30 d无任何变化。     

活性稀释剂苄基缩水甘油醚丙烯酸酯的合成及性能表征

本文以苄基缩水甘油醚和丙烯酸为原料合成活性稀释剂苄基缩水甘油醚丙烯酸酯(BGEA),研究了反应温度、催化剂和阻聚剂用量对反应的影响.结果表明最佳的反应条件为:反应温度110℃左右,催化剂N,N’-二甲基苄胺质量分数为0.9%,阻聚剂对甲氧基苯酚质量分数为0.2%.后将BGEA作为稀释剂加入到双酚A型环氧丙烯酸树脂中配制成光固化涂料,利用TG、AFM等表征手段对光固化膜的热性能、表面形貌及物理机械性能进行研究.     

活性稀释剂种类对环氧树脂体系性能的影响研究

采用丁基缩水甘油醚(660)、乙二醇二缩水甘油醚(669)和苯基缩水甘油醚(690)三种活性稀释剂对环氧树脂/甲基四氢邻苯二甲酸酐(MeTHPA)固化体系进行改性,研究了稀释剂对树脂胶液粘度及其固化物力学性能和电性能的影响。结果表明,当加入669和690稀释剂后,体系的介电性能基本不变,耐电弧性能提高,而660的加入会降低体系的介质损耗,对耐电弧性能影响很小。其中,当690的添加量为3%时,耐电弧达到94s,比纯树脂提高了22%;当添加量为3%～12%时,树脂固化物的拉伸强度稳定在45～55MPa之间。     

双官能团稀释剂对TGDDM/MeTHPA体系固化行为及固化性能的影响研究

研究了双官能团稀释剂1,4-丁二醇二缩水甘油醚(BUDGE)的含量对N,N,N',N'-四缩水甘油基-4,4'-二氨基二苯基甲烷/甲基四氢苯酐(TGDDM/Me THPA)环氧体系的影响。分别采用旋转黏度计、差示扫描量热仪、电子万能试验机和冲击试验机对体系的黏度、固化行为和力学性能进行了研究。实验结果表明,BUDGE可大幅降低TGDDM及TGDDM/Me THPA体系的黏度;BUDGE的加入会导致体系中环氧基团的表观活性降低,从而降低体系的反应速率;BUDGE的加入可以提高TGDDM/Me THPA体系固化物的拉伸强度、弯曲强度、伸长率及冲击强度;当BUDGE与TGDDM的质量份数比为25∶75时,体系的力学性能达到最大值。     

2-乙基-4-甲基咪唑固化环氧树脂的研究

本文对2-乙基-4-甲基咪唑固化双酚A二缩水甘油醚型、缩水甘油酯和脂环型环氧树脂体系的固化反应特征、动力学及其反应活性进行了研究.     

稀释剂的选择对环氧树脂性能的影响探究

研究了两种活性稀释剂丁基缩水甘油醚、C₁₂-C₁₄烷基缩水甘油醚的添加量对环氧树脂黏度、固化时间、吸水性、耐热性能的影响。实验结果表明：丁基缩水甘油醚和C₁₂-C₁₄烷基缩水甘油醚的加入，可以使环氧树脂黏度分别降低75%和73%,并且随着添加量的增大，黏度降低更明显。环氧树脂固化物的吸水率会随稀释剂的添加量增多呈现先增后降趋势，环氧树脂固化物的耐分解温度均有提升。     

用DTA研究环氧树脂固化反应动力学

本文用DTA和FIR研究双酚A二缩水甘油醚型环氧树脂与2-乙基-4-甲基咪唑固化反应动力学,探讨了固化反应的机理。结果表明,此固化反应是分步进行的。第一步是加成反应,第二步是催化聚合反应,由此确定适宜采用分段固化工艺。通过DTA曲线推得固化工艺温度,并计算固化反应各步活化能：E1＝36．8kJ．mol-1,E2＝53．gkJ·mol-1。     

基于正交试验的E51/T31清漆的制备及其综合性能优化

以E51环氧树脂为基料,添加适量的稀释剂丁酮和1,4-丁二醇二缩水甘油醚,增韧剂端羧基液体丁腈橡胶(CTBN-15)和T31固化剂,制备了环氧树脂清漆。以漆膜附着力、抗弯曲性和冲击强度为指标,结合正交试验,分析了丁酮、1,4-丁二醇二缩水甘油醚、CTBN-15和T31的添加量对清漆综合性能的影响,获得了3个指标各自的最优条件,然后利用综合平衡法,优选出兼顾3个指标的清漆配方:丁酮10%,1,4-丁二醇二缩水甘油醚20%,CTBN-15 10%,T31固化剂35%。优化后制得的清漆漆膜附着力为26.86 MPa,抗弯曲性0 cm,冲击强度40 kg·cm,硬度2H、耐中性盐雾腐蚀时间144 h。经过多目标优化后得到的清漆漆膜不仅附着力和抗弯曲性最佳,而且有效地减少了漆膜冲击强度的下降。     

Thermal and mechanical properties of aminopropoxylate-cured epoxy matrices

Bisphenol A diglycidyl ether–aminopropoxylate mixtures have been characterized with respect to their viscosities in the presence and absence of butanediol diglycidyl ether (reactive diluent), and their curing patterns have been studied at room temperature with or without 2,4,6-tris(dimethylaminomethyl)phenol (initiator/accelerator). A priori, these mixtures are expected to provide low connectivities to infinite networks at gelation, a prediction supported by the multiple glass-transition-temperature (T_g) behaviour of their cured forms. The effect of the aminopropoxylate curing agent chemistry/functionality, and the presence or absence of accelerator and reactive diluent on the tensile and impact behaviour of cured materials, is reported. An expectation of increased importance of polymerization with increases in the initiator/accelerator levels, alongside epoxy–amine addition reactions, has not been evidenced by the mechanical measurements. For diglycidyl ether bisphenol A–aminopropoxylate epoxy systems, in the glycidyl ether/reactive hydrogen molar ratio range 0·80 (set A) to 1·95 (set B), the tensile failure mode is brittle fracture. For the set A formulations, this mode of failure persists up to reactive diluent loadings of 1·01wt% based on the weight of bisphenol A diglycidyl ether. Beyond 1·01wt% reactive diluent loadings, the set A formulations show ductile failure with yielding; the tensile toughness increases with increases in reactive diluent levels. For the set B formulations, and for all reported loading levels of reactive diluent, the castings failed in brittle fashion with pronounced cavitation and stress whitening. © 1998 Society of Chemical Industry     

快速固化型环氧树脂灌浆材料的制备及性能

利用腰果酚、多聚甲醛、二乙烯三胺曼尼西反应合成的酚醛胺与聚丙二醇二缩水甘油醚反应制备了环氧树脂固化剂,与环氧树脂E-51、F-51、稀释剂692制备了双组分环氧树脂灌浆材料。研究了固化剂的合成工艺以及环氧树脂灌浆材料的固化行为和固结体的性能。结果表明,合成固化剂的最佳投料比为n(醛)∶n(酚)∶n(胺)∶n(醚)=1∶1. 1∶1. 2∶0. 4,固化剂组分与环氧树脂组分的体积比为100∶(80～120)时,浆液的初始黏度为400～500 mPa·s,凝胶时间为25～45 min,固结体性能都符合JC/T 1041-2007的要求;在浆液发生凝胶前,浆液黏度先随着时间逐渐降低后快速上升,凝胶时间随着使用温度的降低逐渐增加。     

低粘度中温固化环氧树脂基体的研究

采用环氧树脂E-51,稀释剂1,4-丁二醇二缩水甘油醚(622)和四氢邻苯二甲酸二缩水甘油酯(711),固化剂3-氨甲基-3,5,5-三甲基环己基胺(固化剂A)和α-(2-氨甲基乙基)-ω-(2-氨甲基乙氧基)聚[氧(甲基-1,2-亚乙基)](固化剂B)制备了4种环氧体系,通过粘度和力学性能测试及示差扫描量热分析对其加工性能、固化特性、耐热性及拉伸性能进行了研究。结果表明,当E-51,711,固化剂A和B的质量配比为95∶5∶12.05∶17.10时,环氧体系综合性能最佳,30℃下初始粘度为0.4 Pa.s,适用期为40 min,固化后的拉伸强度为70 MPa,断裂伸长率为6.1%,可用于湿法缠绕成型或液体模塑成型。     

糠醇缩水甘油醚稀释的环氧体系的性能研究

通过力学性能和热性能测试研究了糠醇缩水甘油醚(FGE)稀释的双酚A环氧树脂(DGEBA)体系的固化性能和固化反应动力学。通过Málek自催化机理模型求得添加10%FGE的DGEBA与脂肪族聚酰胺固化剂的固化反应平均活化能为64.66kJ/mol,低于苄基缩水甘油醚(BGE)稀释体系。以FGE稀释的固化产物的拉伸强度达到62.93MPa,比BGE体系高出20%左右。拉伸伸长率达4.66%,是BGE体系的4倍左右。添加FGE的固化物冲击强度达36.17MPa,比BGE体系高出约70%左右。使用FGE和BGE的环氧固化物的玻璃化转变温度分别为46.32℃和52.36℃。FGE和BGE体系固化物的5%的热失重温度分别为260.79℃和194.59℃。FGE是1种良好的环氧树脂稀释剂。     

Experimental modeling of the cure behavior of a formulated blend of DGEBA epoxy and C12‐C14 glycidyl ether as a reactive diluent

Microwave curing of polymer matrix composites has been suggested as an attractive substitute for conventional thermal curing. Formulations of epoxy and reactive diluents have the advantage of better wettability and uniform fiber impregnation. However, higher peak exotherms in large masses, and thus thermal overshoot, presents a challenge for cure cycle optimization. Therefore, building a reliable curing model will not only predict the behavior of these materials during actual processing, but also facilitate numerical modeling of the process and comparison of other resin formulations. In this study the effect of the reactive diluent on the isothermal cure kinetics of low viscosity epoxy was investigated using differential scanning calorimetry (DSC). A formulated blend of diglycidyl ether of bisphenol A (DGEBA) and C₁₂–C₁₄ aliphatic glycidyl was cured using diethylene triamine as the curing agent. Using a standardized procedure, ISO 113571‐5, the epoxy formulation was isothermally cured at several temperatures and the heat flow monitored and recorded. Using the heat flow data from DSC, the rate of cure was determined experimentally and a proper autocatalytic model with a total order of about 2.3 was fit to describe the process. Least‐square regression and isoconversion methods were used to find the model parameters and the activation energy, respectively. The accuracy of the model shows fine correlation with experimental data. By comparison to other epoxy resin without diluents, the analysis of the data shows that the reactive diluent increased the curing rate, while the values of activation energy and process parameters remained within the typical values of epoxy formulations. Based on these data, the future use of these types of resins in nonthermal curing of epoxy matrix composites is discussed. POLYM. COMPOS., 26:593–603, 2005. © 2005 Society of Plastics Engineers     

Studies on Cure Kinetics of Diglycidyl Ether of 4,4′-Bisphenol/4,4′-Diaminobiphenyl Using the Advanced Isoconversional Method

The cure kinetics of a rigid-rod epoxy monomer, diglycidyl ether of 4,4′-bisphenol (DGEBP), and the curing agent with the similar rigid-rod group, 4,4′-diaminebiphenyl (DABP), was studied using an advanced isoconversional method (AICM). DGEBP/DABP curing system was carried out by means of differential scanning calorimetry (DSC). Three exothermic peaks were depicted by nonisothermal DSC studies: the first two peaks were attributed to the curing reaction, and the last peak was attributed to the decomposition of the cured epoxy resin. The LC phase transformation of the curing process was observed by PLM. Using AICM, the largest activation energy of the curing reaction of DGEBP/DABP system was obtained as 108 kJ/mol. It can also be learned that LC phase transformation of the curing process affects the reaction significantly.     

用DTA研究环氧树脂固化反应动力学

本文用ＤＴＡ和ＦＩＲ研究双酚Ａ二缩水甘油醚型环氧树脂与２－乙基－４－甲基咪唑固化反应动力学,探讨了固化反应的机理。结果表明：此固化反应是分步进行的。第一步是加成反应,第二步是催化聚合反应,由此确定适宜采用分段固化工艺。通过ＤＴＡ曲线推得固化工艺温度,并计算固化反应各步活化能：Ｅ１＝３６８ｋＪ．ｍｏｌ－１,Ｅ２＝５３９ｋＪ．ｍｏｌ－１     

Effect of various epoxy fortifiers on the reactivity in curing of epoxy resins

Diglycidyl ether of ethylene glycol was prepared and used as a reactive diluent in the curing of an epoxy resin, based on diglycidyl ether of bisphenol A. Effect of different fortifiers on the curing reaction of the resin-diluent system has been investigated using differential scanning calorimetry. The dynamic scans were analyzed using four different relations to evaluate the kinetic parameters, the activation energy and the order of the reaction. The reactions are found to follow first order kinetics with an activation energy in the range of 36 – 84 kJ mol^-1.