摘要
本文用DSC、TBA、旋转粘度计等手段对一系列不同结构及不同取代基取代的脲衍生物对环氧树脂/双氰双胺固化体系的潜伏性促进作用作了考察。结果表明,其促进效果随脲的α位取代烷基碳原子数增加而减弱,而其β、γ位上的取代基团变换时对促进作用无明显影响。由此得出4,4-二(N,N-二甲基)脲二苯甲烷(简称M-二甲)和2,4-二(N,N-二甲基)脲甲苯(简称T-二甲)二种脲衍生物在本丈所考察的28种化合物中具有最显著的促进效果,其中T-二甲的促进活性略高于M-二甲,它们均可使上述固化体系的固化温度降至130℃左右,含有此促进剂的固化体系即使在30℃下贮存,其粘度保持基本不变的时间仍可达三个月以上。
A series of different substituted ureas were evaluated as latent accelerators in the curing of dicyandiamide-cured epoxy resin by DSC, TBA and rotation viscometer techniques. Experimental work revealed that the accelerating effect of the substituted ureas was promoted with the decrease of the magnitude of the a substituents, whereas the nature of the substitu-tents on the β and γ locations has no disturbance on the accelerating level. Comparis on of varionus ureas shows 4, 4'-bi(N, N-dimethyl) urea diphenyl methane and 2, 4-bi(N,N-dime-thyl) urea toluene to be the most effective among the accelerators evaluated in this work. The temperature required for cure completion of dicyanidimide-cured bisphenol A epoxy resin was decreased from 170℃ to 130℃ using these optimized accelerators. The storage life of epoxy formulation with 3phr accelerators at 30℃ might be delayed to over three months based on the extrapolation from Arrhenius plots and viscosity-storage time curves.
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
1989年第3期329-336,共8页
Acta Polymerica Sinica
关键词
脲衍生物
潜伏性促进剂
固化体系
Dicyandiamide-Epoxy resin, Latent accelerator, Urea derivative
