橡胶弹性体增韧环氧树脂的结构与性能研究

通过示差扫描量热仪、力学性能测试及电镜分析等研究了端羧基丁腈橡胶(CTBN)和核壳橡胶(CSR)增韧改性环氧树脂(EP)体系的结构与增韧改性效果,结果表明:CTBN和CSR都能显著提高环氧树脂的冲击强度,CSR增韧环氧体系的拉伸强度及弯曲强度增幅较大。CTBN的加入使环氧树脂的玻璃化温度大幅下降,EP/CSR体系的Tg也有所降低,但随CSR含量的增加又有回升的趋势。CTBN的加入对环氧体系的固化起到了抑制作用,体系的凝胶化时间明显变长;而CSR的加入对环氧体系的固化影响不大。比较而言,CSR增韧环氧体系的综合性能更佳。     

弹性体改性环氧树脂的新进展

本文就丁腈橡胶,丙烯酸酯橡胶,聚氨酯,聚硅氧烷等弹性体改性环氧树脂的研究在近些年取得的进展进行概述。     

橡胶增韧环氧树脂的研究进展

从增韧机理、增韧方法、协同改性和影响因素4个方面综述了橡胶增韧环氧树脂的研究进展及存在问题,并展望了其未来发展前景。     

端胺基聚氨酯液体橡胶增韧环氧树脂

本文合成了端胺基聚氨酯，研究了ＡＴＰＵ对环氧树脂的增韧作用。实验证明了１０ＰＨＲ ＡＴＰＵ对环氧树脂的增韧最佳，其断裂韧性ＧＴＲ由纯树脂的９．７６Ｊ／ｍ＾２增加到５１．５Ｊ／ｍ＾２，且其它性能未明显劣化。     

丙烯酸酯液体橡胶的合成及其增韧环氧树脂的研究进展

综述了反应性丙烯酸酯液体橡胶的合成方法及其用丙烯酸酯液体橡胶增韧环氧树脂的研究进展。其合成方法以溶液聚合为好,聚合产物以三元共聚物为好。增韧效果与体系的相态结构、化学键合和环氧基体的延展性有关。     

丙烯酸酯液体橡胶增韧环氧树脂的研究进展

综述了反应性丙烯酸液体橡胶的合成和增韧环氧树脂的研究进展。其合成方法以溶液聚合为好。增韧效果与体系相态结构、界面键合和环氧基体的延展性有关。     

橡胶增韧环氧树脂的新方法

本文讨论了液体端羧基丁腈橡胶增韧环氧树脂存在橡胶交联网络不完整问题,并进一步研究为克服此缺点而使用预制的橡胶微球(即活性微凝胶)作为环氧增韧剂的体系的表面化学性质、流变学性能、及以伯胺类固化剂固化的此体系的胶接强度及力学性能等。     

橡胶增韧环氧树脂的研究

以羧基丁腈橡胶、聚硫橡胶和羟基聚硅氧烷为增韧剂,以冲击强度、弯曲强度和拉伸剪切强度来评价环氧树脂的增韧效果。实验结果表明,加入增韧剂后的各配方韧性相对于对照组均有不同程度的提高;液态聚硫橡胶增韧的环氧树脂胶表现出良好的抗冲击性能和抗弯曲性能;羧基丁腈橡胶增韧的环氧树脂胶表现出良好的拉伸剪切性能。     

丁腈橡胶增韧环氧树脂研究进展

综述了近年来丁腈类橡胶增韧环氧树脂的研究进展,其中包括固体丁腈橡胶,液体丁腈橡胶(丁腈-40液体橡胶,无规端羧基液体丁腈橡胶(CRBN),端羧基液体丁腈橡胶(CTBN),改性端羟基丁腈橡胶(HTBN),改性端氨基液体丁腈橡胶(ATBN))以及改性液体丁腈橡胶与纳米SiO2共同增韧环氧树脂。     

橡胶增韧环氧树脂低温韧性的研究

以低分子量聚酰胺(PA300)为固化剂,以液体端羧基丁腈橡胶(CTBN)为增韧剂增韧改性双酚A型环氧树脂,考察了橡胶增韧剂、固化剂、稀释剂和无机填料对环氧树脂低温韧性的影响。通过对增韧体系应力应变特性和动态力学性能的研究表明,该体系具有优异的低温韧性。     

橡胶增韧环氧灌封料的研究

以液体羧基丁腈橡胶、液体聚硫橡胶为增韧剂制成环氧树脂灌封料,通过冲击强度、弯曲强度和拉伸剪切强度评价增韧环氧树脂灌封料的效果。实验结果表明,加入增韧剂的灌封料韧性与对照组相比均有不同程度的提高;液体聚硫橡胶增韧的环氧树脂灌封料表现出较好的抗冲击性能和抗弯曲性能;液体羧基丁腈橡胶增韧的环氧树脂灌封料表现出较好的拉伸剪切性能。     

Toughening epoxy resins with solid acrylonitrile–butadiene rubber

The feasibility of using solid acrylonitrile–butadiene rubbers (NBR) with 19 and 33% w/w acrylonitrile to toughen diglycidyl ether of bisphenol A (DGEBA) epoxy resins has been investigated. Thermal analysis experiments revealed a two‐phase morphology of these rubber‐modified epoxies. However, the higher content of acrylonitrile in the rubber caused better compatibility between NBR and the epoxy resin. The rubber with 33% acrylonitrile was found to be an effective toughening agent for DGEBA epoxy resins. Fracture surface studies and also the high tensile strength of crosslinked high molecular weight NBR suggest that the toughening effect should arise from rubber bridging and tearing mechanisms. © 2000 Society of Chemical Industry     

聚丙烯酸酯液体橡胶增韧环氧树脂体系研究

采用溶液聚合法合成了以丙烯酸丁酯、丙烯酸乙酯、丙烯酸缩水甘油酯为主链的液体橡胶,将其用于增韧改性环氧树脂/间苯二甲胺(EP 828/mXDA)体系,研究了聚丙烯酸酯液体橡胶用量对共混体系的微观形态、力学性能和玻璃化温度的影响。电镜观察显示液体橡胶改性EP828/mXDA的共混物呈海岛结构,连续相为环氧树脂,分散相为液体橡胶。随着丙烯酸酯液体橡胶用量增加,海岛相区的粒径和数量均呈增长趋势。当丙烯酸酯液体橡胶质量分数为15%时,共混物中海岛相区的尺寸为1μm左右,共混体系的冲击强度增加151.8%,玻璃化温度下降11.3℃。以丙烯酸液体橡胶改性EP828/mXDA环氧树脂体系,可以较大程度提高其韧性,同时其耐热性基本保持不变。     

热塑性树脂对环氧树脂的改性研究

回顾了国内外热塑性树脂改性环氧树脂的常用方法,详细介绍了一些最新的研究情况,列举了已被人们承认的环氧树脂改性的机理,并且对其机理进行了比较系统的总结。     

纳米丁腈橡胶改性环氧树脂的性能及其应用

简述了纳米硫化丁腈橡胶改性环氧树脂的性能特点;介绍了一种耐低温环氧电子灌封胶和一种常温固化耐高温胶的配方、性能及其应用.     

On hybrid toughened DGEBA epoxy resins

Considerable improvements in the fracture resistance of epoxy resins have recently been achieved by adding either rubbery or rigid second phase dispersions, or both, to an epoxy matrix. These multiphase epoxy systems are particularly useful as high performance adhesives and as matrix materials in advanced composites. This paper describes the development of new toughened epoxy hybrids, which contain both rubbery and rigid dispersions. The latter dispersions were either zirconia particles, short alumina fibres or glassy-metal ribbons. Micromechanisms of toughening and failure processes in these new materials are identified and discussed in the light of microstructures.     

Thermal and mechanical characterization of epoxy resins toughened using preformed particles

Preformed, multilayer particles have been used to toughen an epoxy resin. The particles were formed by emulsion polymerization and consist of alternate glassy and rubbery layers, the outer layer having glycidyl groups to give the possibility of chemical bonding of the particles in the cured resin. Two variants of this type of particle were used, termed GM(47/15) and GM(47/37); both types have an overall diameter of 0.5 µm, but the former have a thicker rubbery layer. For comparison, acrylic toughening particles (ATP) with no surface functionality and a liquid carboxyl‐terminated butadiene–acrylonitrile (CTBN) rubber were used as toughening agents. The epoxy resin system consisted of a commercial diglycidyl ether of bisphenol A (Shell Epon 828) with diamino‐3,5‐diethyl toluene as hardener, two commercial sources of which were used, namely Ethacure‐100 (Albemarle SA) and DX6509 (Shell Chemicals). These hardeners contain a mixture of two isomers, namely 2,6‐diamino‐3,5‐diethyltoluene and 2,4‐diamino‐3,5‐diethyltoluene Thermogravimetry in nitrogen shows that the preformed toughening particles begin to degrade at 230 °C, whereas the cured resin begins to degrade rapidly at 350 °C. Thus, even though the particles are less thermally stable than the cured resin, their degradation temperature is well above the glass transition temperature of the resin, and their use does not affect the thermal stability of the toughened materials at normal use temperatures. The performance of the toughening agents was compared using Ethacure‐100 as the hardener. The GM(47/15) and GM(47/37) toughening particles gave rise to a greater toughening effect than the ATP and the CTBN. For example, the fracture energies were: 0.26 kJ m^?2 for the unmodified resin; 0.60 kJ m^?2 for the resin toughened with CTBN; and 0.69 kJ m^?2 for the resin toughened with the GM(47/15) particles. The ultimate tensile stress of the unmodified epoxy resin was 43 MPa, which increased to 55 MPa when 20 wt% of GM(47/15) toughening particles were added. The toughness of resins cured with the DX6509 hardener were superior to those obtained with the Ethacure‐100 hardener, most probably due to DX6509 producing a less‐highly‐crosslinked network. This highlights the sensitivity of the toughening process to the hardener used, even for hardeners of a similar nature. © 2001 Society of Chemical Industry