Solvent-free thermal decomposition of methylenediphenyl di(phenylcarbamate) catalyzed by nano-Cu2O

Methylene di(phenylisocyanate) (MDI) was prepared by thermal decomposition of methylenediphenyl di(phenylcarbamate) (MDPC) under solvent-free conditions with a nano-Cu2O catalyst. The preparation of nano-Cu2O was investigated in detail to obtain the optimal catalytic performance. The thermal decomposition reaction conditions, including reaction temperature, reaction pressure, and reaction time, were studied in the presence of nano-Cu2O. The results show that Cu2O prepared using a hydrolysis method and then calcined at 300 °C in Ar atmosphere for 2 h exhibited the optimal catalytic activity. The optimal reaction conditions were as follows: mass ratio of catalyst to MDPC 6.0 × 10−4, reaction temperature 220°C, reaction time 12 min, and reaction pressure 0.6 kPa. Under these conditions, the conversion of MDPC reached 99.8% and 86.2% MDI selectivity was achieved.

摘要研究了无溶剂条件下纳米Cu2O催化二苯甲烷二氨基甲酸苯酯(MDPC)热分解制备二苯甲烷二异氰酸酯(MDI), 考察了纳米Cu2O的制备条件与反应条件对MDPC热分解反应性能的影响. 结果表明, 水解法制备的纳米Cu2O在Ar中于300 °C焙烧2 h, 其催化性能最佳; 最佳的反应条件为Cu2O用量为原料总重的0.06%, 反应温度220 °C, 反应压力0.6 kPa, 反应时间12 min, 此时MDPC转化率达到99.8%, MDI选择性86.2%.

Graphical AbstractNano-Cu2O shows high catalytic activity for the thermal decomposition of methylenediphenyl di(phenylcarbamate) under solvent-free conditions. Solvent-free thermal decomposition is a green synthetic route to methylene di(phenylisocyanate).Figure optionsDownload as PowerPoint slide