由碳酸二甲酯合成异氰酸酯

SYNTHESIS OF ISOCYANATES FROM DIMETHYLCARBONATE

异氰酸酯是一种重要的有机中间体,是生产聚氨酯的主要原料。碳酸二甲酯法合成异氰酸酯是采用碳酸二甲酯(DMC)代替光气与胺类发生甲氧羰基化反应合成氨基甲酸酯,氨基甲酸酯再分解生成异氰酸酯的工艺方法。该法具有无毒、无污染、原子经济性高的优点,符合绿色化工的发展趋势,是一条极具发展前景的非光气法合成异氰酸酯的工艺路线。笔者着重介绍了利用碳酸二甲酯为原料合成二苯甲烷二异氰酸酯(MDI)、2,4-甲苯二异氰酸酯(TDI)、1,6-六亚甲基二异氰酸酯(HDI)等几种重要异氰酸酯的工艺研究与技术进展。

Isocyanate,as an important organic intermediate,is the primary material of producing polyurethane.Utilizing dimethyl carbonate as the substitute of phosgene,the synthesis of isocyanate includes two steps,which are the methoxycarbonylation of amines with dimethyl carbonate to produce carbamates and the decomposition of carbamates to obtain isocyanate.Due to non-toxicity,non-pollution and high-atom economy,this method is a well promising route to synthesize isocyanate,which greatly accorded with the development trend of green chemical industry.In this paper the process research and technological progress of synthesis of several important isocyanates from dimethyl carbonate,such as methylene diphenyl diisocyanate,2,4-toluene diisocyanate,1,6-hexamethylene diisocyanate and so on are emphatically introduced.