蓖麻油基多元醇的制备及对环氧树脂的增韧改性

Preparation of castor oil-based polyol and its application in toughening epoxy resin

通过两步法制备得到了高官能度的蓖麻油基多元醇。蓖麻油首先与不对称的二异氰酸酯(2,4-TDI)反应得到-NCO封端的化合物,并通过在线红外光谱对反应进程进行了表征;然后与二乙醇胺反应,得到多羟基结构产物,GPC结果证明反应无交联现象。将此多元醇应用于环氧树脂增韧,通过拉伸剪切实验,DSC和SEM分析改性后材料的力学性能、热性质和断面形貌,发现在固化体系中引入具有柔性链段的蓖麻油分子,可以增强材料的拉伸剪切强度,同时材料出现屈服变形,显示出韧性断裂特征。

Multifunctional castor oil-based polyol was synthesized by two steps. First,castor oil reacted with asym- metric diisocyanate of 2,4-TDI and resulted in a -NCO terminated product. The course of reaction was analyzed by an on- line FTIR. The final polyhydroxy product could be obtained by a second reaction with a hydroxylation agent of diethano- lamine. No cross-linked phenomena could be found by the characterization of GPC. The polyol was applied in toughening ep- oxy resin and the mechanical property, the thermal property and the fracture surface of the modified materials were investi gated by shearing-tensile experiment,DSC and SEM. The results showed the flexible chains of castor oil can enhance the shear-tensile strength of materials and the modified epoxy resin exhibited ductile fracture with yield deformation.