The Catalytic Synthesis Of Dual-alkyl Dimaleates And Its Applied Research Of Esterification Reaction With Titanate Agent

Dimaleats, applied in industrial water conditioning, medicine, agriculture etc, was unsaturated dual-alkyl dimaleates. Recently dimaleates was applied to prepare 1,4-butanediol by catalytic hydrogenation, it was a new applied range for dimaleates. This subject is to study the process of synthesizing dimaleats using isooctanol and maleic anhydride as the crude material,under the catalyst of titanate. First several catalysts were tested under a given condition to determine the best one according to the selectivity of dimaleats;Second the effects of the factors was discussed such as operational reaction temperature, catalysis use level, reaction time, the type of dehydrant, the amount of dehydrant and optimize the technological conditions. Structures of the dimaleats were characterized with IR and element analysis. Then titanate catalyst was study in the application of other esterification.The experimental result show: when synthesizing the di-2-ethylexyl maleate, the reaction temperature should be refluxing, the reaction time should be 0.5h, the amount of the catalyst should be 0.1~1.5%, methybenzent, the amount of dehydrant should be 10~20%,and the ratio of mole of maleic anhydride and isooctanol should be l:2.0~3.0. The optimal technological conditions were:0.5% catalyst(A), 1:3.0 maleic anhydride and isooctanol(B), 10% dehydrant(C) by orthogonal experiment. Under the these conditions and purification, the colourless or light di-2-ethylexyl maleate was obtained. The purification of synthesized di-2-ethylexyl maleate proved that the end of reaction decompression was required to remove retained isooctanol and dehydrant, and then joined with the absorber for the formation of precipitation remained catalyst, after filtering, and then obtained colourless or light-coloured di-2-ethylexyl maleate. The techniques was operated easily.Furthermore, the synthetic reaction of other esterification with titanate catalyst wasdiscussed, the results was proved that : titanate catalyst in the esterification reaction was a great potential esterification catalyst, this catalytic reactivity was higher than other catalyst's in the same conditions .