聚醚砜和二氧化硅纳米粒子协同增韧三官能团环氧树脂的研究

与传统的双官能团环氧树脂相比,多官能团环氧树脂具有更高的交联密度,这赋予其更好的力学性能和耐热性,但却降低了环氧树脂的韧性。本文研究发现,同时加入热塑性树脂聚醚砜(PES)和亲水性二氧化硅纳米粒子(A200)可以显著提高TDE85环氧树脂的强度和韧性。当TDE85∶PES∶A200质量比=100∶5∶0.3时,复合材料的增强和增韧效果最佳,改性环氧树脂的拉伸强度和断裂伸长率分别提高了38.1%和29.4%,并且没有明显牺牲基体树脂的模量和耐热性。扫描电子显微镜(SEM)结果表明,改性后的环氧树脂呈现韧性断裂行为,其增韧机理可以解释为PES树脂和二氧化硅纳米粒子不同增韧机理的协同作用。     

使用纳米粒子增强环氧树脂

在环氧树脂中填充纳米粒子可以同时提高其强度和韧性。断裂韧性和弯曲模量随纳米填料含量的增加呈线性增加。而且,其耐磨性也得到提高。     

胺基修饰二氧化硅改性环氧树脂胶粘剂

以Stober法制备球形纳米二氧化硅,并用氨丙基三乙氧基硅烷（APTES）对其进行发面修饰。将修饰后的二氧化硅分散到环氧树脂胶黏剂中,进一步测试粘接的冲击和拉伸剪切强度,表征断面形貌。结果表明,修饰后的二氧化硅粒子在环氰树脂胶黏剂中具有较好的分散性,其拉伸剪切强度提高了约31％,剪切冲击强度提高了约66．7％。     

拉挤纤维／环氧树脂复合材料用内脱模剂研究

本文介绍了环氧树脂拉挤专用内脱模剂的合成,阐述了作为环氧树脂拉挤内脱模剂的选择及作用原理,并通过拉挤绝缘子芯棒对该内脱模剂性能进行了评估,结果表明,利用环氧树脂添加内脱模剂所拉出的绝缘子世棒表面光滑,机电性能优良,是环氧树脂拉挤理想的专用内脱模剂。     

纳米粒子改性环氧树脂的研究进展

环氧树脂是一类具有优异性能的热固性材料,广泛应用于航空航天、车辆工程等领域,但由于其交联结构,环氧树脂韧性较差。其中纳米粒子改性环氧树脂在增韧环氧树脂的同时,其力学性能也有所提升。对三种纳米粒子改性环氧树脂的研究进展进行了综述,包括纳米二氧化硅、石墨烯及衍生物和碳纳米管,对改性效果进行了详细的阐述分析,讨论了增韧机理。     

汽车工程用聚乙烯复合材料的改性处理及研究

通过在聚乙烯塑料中同时加入二氧化硅和滑石粉两种填充剂制备了可用于汽车工程的聚乙烯复合材料,并比较了不同含量的二氧化硅和滑石粉的综合作用以及其对聚乙烯复合材料性能的影响。结果表明:拉伸强度和断裂伸长率均随着二氧化硅含量的增加而减小,而弯曲强度随着二氧化硅含量增加而增加。相比于纯聚乙烯,二氧化硅和滑石粉的综合作用可以有效提高其热稳定性。并且随着二氧化硅含量的增加,材料的冲击强度、硬度均先增加后下降,并在50%含量时达到了最大值。与某汽车品牌材料的性能指标相比,制备的聚乙烯复合材料性能指标均具有一定的优异性,并且相比于纯聚乙烯具有较好的抗老化性。制备的聚乙烯复合材料可以应用于汽车工程材料之中。     

乙烯基纳米二氧化硅的制备及其对聚丙烯熔体强度的影响

利用乙烯基硅烷偶联剂对纳米二氧化硅进行表面进行改性,制备出乙烯基纳米二氧化硅,将其与聚丙烯（PP）熔融共混,并采用红外光谱仪、热失重分析仪、哈克流变仪、高级扩展流变仪及熔体强度测定仪研究了乙烯基纳米二氧化硅粒子对PP熔体强度的影响。结果表明,与未改性纳米二氧化硅填充的PP和纯PP相比,乙烯基二氧化硅填充的PP熔体强度显著提高,并且随着其含量的增加,PP的熔体强度逐渐升高。     

耐水型环氧树脂增韧剂的制备及应用

用乳液聚合法合成了烷基化纳米二氧化硅/甲基丙烯酸甲酯/丙烯腈核壳型复合弹性粒子,并用于增韧环氧树脂。核壳粒子的形态由透射电镜观测,改性试样的断裂表面由扫描电镜观测,并对该增韧剂进行了实际应用的研究。结果表明:在复合粒子的添加量为10phr时,能大幅度提高环氧树脂的韧性及耐水性。     

高性能环氧树脂粘合剂的改性方法及结构与性能的关系

从结构与性能的关系着手,综述了近年国内外高性能环氧树脂粘合剂改性研究的最新进展,主要包括环氧树脂粘合剂的二氧化硅纳米粒子改性、环氧树脂粘合剂的石墨烯改性、环氧树脂粘合剂的纤维和碳纳米管改性、环氧树脂粘合剂的橡胶改性以及环氧树脂粘合剂的其他改性。同时对高性能环氧树脂粘合剂今后的发展趋势进行了分析与展望。研制开发绿色无污染的高性能和功能性的新型环氧树脂粘合剂将是今后该领域的主攻方向。     

高性能环氧树脂粘合剂的改性方法及结构与性能的关系

从结构与性能的关系着手,综述了近年国内外高性能环氧树脂粘合剂改性研究的最新进展,主要包括环氧树脂粘合剂的二氧化硅纳米粒子改性、环氧树脂粘合剂的石墨烯改性、环氧树脂粘合剂的纤维和碳纳米管改性、环氧树脂粘合剂的橡胶改性以及环氧树脂粘合剂的其他改性。同时对高性能环氧树脂粘合剂今后的发展趋势进行了分析与展望。研制开发绿色无污染的高性能和功能性的新型环氧树脂粘合剂将是今后该领域的主攻方向。     

环氧树脂/CaCO_3纳米复合材料的力学及光学性能研究

采用CaCO3 纳米颗粒均匀溶混于环氧树脂中 ,制得环氧树脂 /CaCO3 纳米复合材料 ,并对该复合材料进行了宏观力学性能测试 ,微观断口分析及光弹实验测试。结果表明 ,掺杂纳米粉后 ,实现了材料的增强增韧 ,同时对材料的光透性没有明显影响     

端脂肪氨基聚醚改性环氧树脂的性能研究

用自制的一种既含聚醚柔性链段又含苯脂肪氨基刚性链段的端脂肪氨基聚醚(APPEG)作为固化剂对环氧树脂进行增韧改性。扫描电子显微镜和力学性能测试结果表明,固化剂对环氧树脂具有明显的增强、增韧效果,且改性的环氧树脂胶粘剂具有很好的填充性能,填充比高达50%。与羰基铁粉组成的涂层材料具有优异的力学性能和热稳定性能。     

Preparation of Poly(N-butyl methacrylate-co-glycidyl methacrylate) and Toughness Improvement for Powder Epoxy Resin E663

Copolymers of poly(n-butyl methacrylate-co-glycidyl methacrylate) were prepared by a free radical polymerization. The structures of the copolymers were characterized. The copolymers could be added to a powder epoxy resin (E663) to form modified epoxy resins. It was found that toughness of the cured modified epoxy resins were greatly improved, impact strength increased 3 times and fracture elongation increased 20% compared to the cured unmodified E663 resin. This is because that the copolymers had epoxy groups and flexible butyl groups, the former were involved in cross-linking reaction of the E663, and the latter made contribution to the toughness improvement.     

高性能室温固化环氧结构胶的制备与研究

为了改善环氧固化物的韧性,又保持其热稳定性及提高其抗冲击性能,采用超细全硫化羧基丁腈橡胶粒子改性环氧树指技术,并辅以玻璃微珠,球型硅微粉,ACR丙烯酸酯橡胶微球等抗冲剂填充,制备出一款高性能室温固化环氧结构胶.实验中采用高速搅拌球磨法在环氧树脂中分散超细全硫化羧基丁腈橡胶粒子,辅以填充物,制备的环氧树脂结构胶剪切冲击强...     

Modification of epoxy resins with acrylic rubbers containing a pendant epoxy group

New acrylic rubbers with a pendant epoxy group were prepared by copolymerization of butyl acrylate (BA) with vinylbenzyl glycidyl ether (VBGE). The modification of an epoxy system (bisphenol-A diglycidyl ether/p,p′-diaminodiphenyl sulfone) with the acrylic rubbers was carried out in order to increase the toughness of the cured epoxy resin. The addition of 20 wt.-% of the copolymer containing 74% of BA and 26% of VBGE units resulted in a 30% increase in the fracture toughness (K_IC) of the cured resin at minimal expenses of strength and modulus of the resin. The modified epoxy resin had two-phase morphology in which the rubber particles with average diameter of 2 μm are dispersed in the epoxy matrix. The copolymer without the pendant epoxy group, prepared from BA and vinylbenzyl methoxyethyl ether, was ineffective as a modifier, indicating that the reaction of the pendant epoxide with the epoxy matrix resulted in good interfacial adhesion between the rubber particles and the matrix, and in the increased toughness. The epoxide-containing copolymers with 55 or 86% of BA units were also insufficient modifiers. The addition of the former yielded cured resins with homogeneous structure, whereas that of the latter resulted in macroscopic phase separation between the rubber and the epoxy resin.     

羟基化结合硅烷偶联剂改性对光固化Si3N4膏料性能的影响

采用羟基化结合硅烷偶联剂(KH560)对氮化硅(Si₃N₄)粉体进行表面功能化改性,配制出高固含量、高固化深度的Si₃N₄膏料,并基于立体光固化(SL)工艺制备了高强度的Si₃N₄复杂结构件。结果表明:Si₃N₄表面的KH560改善了粉体与树脂的相容性,降低了Si₃N₄膏料的粘度;同时,KH560的环氧基团(—CH(O)CH₂)与环氧树脂(EA)通过化学键等方式相结合,形成了EA核壳结构,降低了树脂与陶瓷颗粒之间的折射率差,从而提高了Si₃N₄膏料的固化深度。表面羟基化处理后Si₃N₄表面吸附了更多的KH560,从而进一步降低了Si₃N₄膏料的粘度,提高了Si₃N₄膏料的固化深度。最终,用羟基化和KH560改性后的Si₃N₄粉体配制出的Si₃N₄膏料固含量达到50%(体积分数),固化深度达到64 μm。烧结后Si₃N₄试样致密度为83%,断裂韧性为(4.38±0.45) MPa·m^1/2,抗弯强度达到(407.95±10.50) MPa。     

环氧树脂/碳化硅复合材料的热性能及韧性

采用碳化硅作为增强剂制备了环氧树脂/碳化硅复合材料,考察了复合材料的热学及力学性能。实验结果表明,碳化硅的添加使环氧树脂的玻璃化温度提高。当碳化硅添加质量分数为3%时,复合材料的韧性与纯环氧树脂相比提高了35%。     

Toughening of epoxy resin by functional‐terminated polyurethanes and/or semicrystalline polymer powders

Hydroxyl‐, amine‐, and anhydride‐terminated polyurethane (PU) prepolymers, which were synthesized from polyether [poly(tetramethylene glycol)] diol, 4,4′‐diphenylmethane diisocyanate, and a coupling agent, bisphenol‐A (Bis‐A), 4,4′‐diaminodiphenyl sulphone (DDS), or benzophenonetetracarboxylic dianhydride, were used to modify the toughness of Bis‐A diglycidyl ether epoxy resin cured with DDS. Besides the crystalline polymers, poly(butylene terephthalate) (PBT) and poly(hexamethylene adipamide) (nylon 6,6), with particle sizes under 40 μm were employed to further enhance the toughness of PU‐modified epoxy at a low particle content. As shown by the experimental results, the modified resin displayed a significant improvement in fracture energy and also its interfacial shear strength with polyaramid fiber. The hydroxyl‐terminated PU was the most effective among the three prepolymers. The toughening mechanism is discussed based on the morphological and the dynamic mechanical behavior of the modified epoxy resin. Fractography of the specimen observed by the scanning electron microscopy revealed that the modified resin had a two‐phase structure. The fracture properties of PBT‐particle‐filled epoxy were better than those of nylon 6,6‐particle‐filled epoxy. Nevertheless, the toughening effect of these crystalline polymer particles was much less efficient than that of PU modification. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2903–2912, 2001     

Toughening epoxies with halloysite nanotubes

An experimental attempt was made to characterize the fracture behaviour of epoxies modified by halloysite nanotubes and to investigate toughening mechanisms with nanoparticles other than carbon nanotubes (CNTs) and montmorillonite particles (MMTs). Halloysite-epoxy nanocomposites were prepared by mixing epoxy resin with halloysite particles (5 wt% and 10 wt%, respectively). It was found that halloysite nanoparticles, mainly nanotubes, are effective additives in increasing the fracture toughness of epoxy resins without sacrificing other properties such as strength, modulus and glass transition temperature. Indeed, there were also noticeable enhancements in strength and modulus for halloysite-epoxy nanocomposites because of the reinforcing effect of the halloysite nanotubes due to their large aspect ratios. Fracture toughness of the halloysite particle modified epoxies was markedly increased with the greatest improvement up to 50% in K_IC and 127% in G_IC. Increases in fracture toughness are mainly due to mechanisms such as crack bridging, crack deflection and plastic deformation of the epoxy around the halloysite particle clusters. Halloysite particle clusters can interact with cracks at the crack front, resisting the advance of the crack and resulting in an increase in fracture toughness.