蓖麻油基水性环氧固化剂的合成及性能

Preparation and Properties of Waterborne Epoxy Curing Agents Based on Castor Oil

以液化的二苯基甲烷二异氰酸酯(MDI)、蓖麻油酸(RA)为原料,先经MDI-RA加成后,再与乙二醇二缩水甘油醚经酯化反应得到蓖麻油基环氧活性中间体(RAE),RAE经二乙烯三胺(DETA)扩链得到RAE-DETA加成物,最后经缩水甘油封端制备得到蓖麻油基水性环氧固化剂(RAWCA)。当n(MDI)∶n(RA)为1∶3和1∶4时分别制得RAWCA-1和RAWCA-2,利用红外光谱(FT-IR)、核磁共振氢谱(1 H NMR)和凝胶色谱(GPC)表征了目标产物的结构,结果表明:制备的目标产物结构参数与设计的分子结构基本吻合,目标化合物的Mn和M w分别为1 832和1 983。对RAWCA产物性能考察可知,目标产物均具有乳化液体环氧树脂E-51的功能,选择n(MDI)∶n(RA)为1∶3制备的RAWCA-1与E-51固化,漆膜的耐水性较佳,且漆膜柔韧性达1 mm、铅笔硬度达3H、抗冲击性达50 kg/cm,性能可与市售水性环氧固化剂产品相媲美。

The adducts MDI-RA were firstly synthesized from liquified diphenylmethane diisocyanate(MDI)and ricinoleic acid(RA).Then esterification reaction between ethylene diglycidyl ether and MDI-RA was carried out for the preparation of the castor oil based epoxy active intermediates(RAE).Finally,the chain reaction of RAE with diethylenetriamine(DETA)and glycidol was performed to obtained the waterborne epoxy curing agents based on castor oil.By this way,two kinds of target products(RAWCA-1 and RAWCA-2)were obtained from feeding ratio of the n(MDI)∶n(RA)of 1∶3 and 1∶4,respectively.The chemical structures of the intermediates and the target products were confirmed by Fourier transform infrared spectroscopy(FT-IR),proton nuclear magnetic resonance(1 H NMR)and gel permeation chromatography(GPC).The results showed that the structure parameters of target products were basically agreed with the designed molecular structure and the M n and M w of target products were 1 832 g/mol and 1 983 g/mol.The property study showed that the target products could emulsify liquid epoxy resin E-51.The properties of the two-component film obtained from the curing reaction of RAWCA-1 and liquid epoxy resin E-51 were as follows:flexibility 1 mm,pencil hardness 3H,impact resistance 50 kg/cm,good water resistance,which could meet a requirement with commercial waterborne epoxy curing agent products.