脲衍生物对环氧树脂/双氰胺体系促进作用的研究

Accelerating Effect of Urea Derivatives on Epoxy/Dicyandiamide System

对比了不同结构的脲衍生物[3-(3-氯-4-甲基苯基)-1,1-二甲基脲(A)、3-(3,4-二氯苯基)-1,1-二甲基脲(B)、3-(4-氯苯基)-1,1-二甲基脲(C)]对环氧树脂/双氰胺体系的促进作用。利用差示扫描量热仪和傅里叶变换红外光谱研究了3种环氧树脂/双氰胺/脲体系的反应活性和固化反应动力学。结果表明,体系A的最佳配比为:环氧∶双氰胺∶脲A=100∶6∶4(质量比,下同),130℃时40min就可以完全固化,其表观活化能(Ea)=64.66kJ/mol,反应级数(n)=0.897;体系B的Ea=71.68kJ/mol,n=0.930;体系C的Ea=71.03kJ/mol,n=0.928;3种体系配制的胶液的室温剪切强度均大于20MPa,体系A的粘接强度达到24.98MPa。

The accelerating effect of different ureas E3-（3-chloro-4-methyl-phenyl）-1, 1- dimethylurea （A） ; 3-（3, 4-dichlorophenyl）-l, 1-dimethylurea （B） ; 3-（4-chlorophenyl）-l, 1- dimethylurea （C）-] on the epoxy/dicyandiamide system were compared. Differential scanning calorimetry （DSC） and Fourier transformlinfrared spectroscopy （FTIR） were utilized to study the reactivity and curing reaction kinetics of three epoxy/icyandiamide/urea systems. It was showed that the best ratio for system A was 100 ： 6 ： 4 （Epoxy dicyandiamide ： urea A）. The system needed 40 rain to be cured completely at 130 ℃. The activation energy （Ea） for system A, B and C was 64. 66, 71.68 and 71.03 kJ/mol and the reaction order for the three systems was 0. 897, 0. 930 and 0. 928, respectively. All the shear strengths of the three adhesive systems at room temperature were higher than 20 MPa, in which the system A provided the highest value of 24. 98 MPa. Key words： epoxy resin; dicyandiamide; urea derivative; curing reaction kinetics