摘要
以甲苯-2,4-二异氰酸酯作标准化合物,用在线红外光谱研究了取代苯酚的氨酯化反应。研究发现,苯环上的取代基对反应速率影响较大,吸电基能够加速其氨酯化反应,取代苯酚的反应速率依次为对硝基苯酚>苯酚>对甲基苯酚。而且,在不同极性溶剂中进行两者的反应,均得到相同的反应规律。溶剂对反应速率影响也较大,极性溶剂可增大反应速率(二甲基亚砜>环己酮>1,4-二氧六环>二甲苯),呈现出与醇-异氰酸酯相反的反应规律,这可能是反应机理不同所致。
With toluene-2,4-diisocyanate as the standard compound, in-situ FT-IR was used to research the urethane reaction of substituted phenols. It showed that the substitutent in benzene ring greatly affected the reaction rate and electron with drawing group could accelerate the urethane reaction. The reaction rates of different substitu- ted phenols followed the order of p-nitrophenol 〉 phenol 〉 paracresol. Similar result was obtained when different solvents were used. Moreover, solvent polarity also greatly affected the reaction rate and the reaction was largely accelerated in polar solvents （dimethyl sulfoxide 〉 cyclohexanone 〉 1,4-dioxane 〉 xylene）. It was opposite to the reacting rule of aleohol-isocyanate reaction. It was caused by different reaction mechanism.
出处
《聚氨酯工业》
2012年第1期20-22,共3页
Polyurethane Industry
