桥梁加固用腰果酚改性胺类低温固化剂分子的空间位阻效应研究

Study on steric hindrance of cardanol modified amines as low temperature curing agents for bridge reinforcing

以腰果酚、多聚甲醛和3种不同分子链长度的多胺(二乙烯三胺、三乙烯四胺和四乙烯五胺)等为原料,通过曼尼希反应合成了3种桥梁加固用空间位阻不同的腰果酚改性胺类低温固化剂。采用傅里叶红外光谱对其进行了表征,同时分析了胺值,研究了其对环氧树脂(E-51)胶粘剂低温固化性能的影响。结果表明,随着胺类固化剂空间位阻的减小,固化剂胺值逐渐减小,黏稠度增加,其固化的E-51胶粘剂低温固化物的弯曲强度、拉伸强度、压缩强度和钢-钢拉伸剪切强度逐渐增大,断裂伸长率逐渐减小,但受拉弹性模量变化趋势不明显,从分子结构水平研究了腰果酚改性低温固化剂性能及固化物性能的影响。揭示了腰果酚改性胺类低温固化剂空间位阻效应与固化性能之间存在的内在联系及基本规律,从而对腰果酚改性胺类固化剂的研究提供了理论依据。

In this paper, three cardanol modified amines with different steric hindrance as the low temperature curing agents for bridge reinforcing were prepared by Mannich reaction using cardanol, paraformaldehyde and three amines with different molecular chain length(diethylenetriamine, triethylenetetramine and tetraethylenepentamine). The products were characterized by Fourier infrared spectra. The amine value of the products were analysed and the effect of them on curing properties of epoxy resin(E-51) adhesives at low temperature were investigated. The results showed that the amine value of the curing agents decreased, their viscosity increased, the bending, tensile, compression and steel-steel tensile-shearing strengths increased, the elongation at break decreased for the cured epoxy resins and their change of tesile modulus was not obvious with increasing the steric hindrance of the amine curing agents. So the curing properties and the performance of the cured for cardanol modification were studed from the molecular structure level and the theoretical basis was provided for the research of cardanol modified amine curing agents.