以二聚酸(DA)和三乙烯四胺(TETA)为起始原料合成聚酰胺预聚物(PA),并以PA和TETA为基础胺,聚乙二醇二缩水甘油醚(PEGDGE)为亲水链段,双酚A型环氧树脂E51为疏水链段,正丁基缩水甘油醚(BGE)与γ-缩水甘油醚氧丙基三甲氧基硅烷(KH560)的混合物为封端剂,制备了一种自乳化型水性环氧固化剂(Si-WECA)。通过傅里叶变换红外光谱(FT-IR)对固化剂的结构进行表征。研究了KH560添加量对乳液流变性能、固化膜微观形貌、热稳定性、力学性能、疏水性以及耐盐雾性能的影响。结果表明:当KH560添加量为8%时,所制固化剂Si-WECA-4表现出良好的稳定性,且固化所得环氧树脂涂膜表现出最佳的综合性能:拉伸强度为44.75MPa,断裂伸长率为12.35%,水接触角为101.8°,热失重10%对应温度为290℃,同时具有良好的耐盐雾性能。

A self-emulsifying waterborne epoxy curing agent (Si-WECA) was prepared by first preparing a polyamide prepolymer (PA) from dimer acid (DA) and triethylenetetramine (TETA),then combining PA and TETA as base amines with polyethylene glycol diglycidyl ether (PEGDGE) as the hydrophilic segment,bisphenol A-type epoxy resin E51 as the hydrophobic segment,and a mixture of n-butyl glycidyl ether (BGE) and γ-glycidoxypropyltrimethoxysilane (KH560) as the capping agent.The structure of the curing agent was characterized by Fourier transform infrared spectroscopy (FT-IR).The influence of KH560 content on emulsion rheology,cured film micromorphology,thermal stability,mechanical properties,hydrophobicity,and salt spray resistance was systematically investigated.Results indicated that when KH560 addition reached an 8%,the prepared curing agent Si-WECA-4 achieved excellent stability and the cured epoxy coating exhibited optimal comprehensive properties,with a tensile strength of 44.75MPa,an elongation at break of 12.35%,a water contact angle of 101.8°,and a 10% thermal decomposition temperature of 290℃,while also demonstrating excellent salt spray resistance.