Synthesis of nontoxic plasticizer tri-n-butyl citrate by using cerous methanesulfonate as catalyst

Cerous methanesulfonate was synthesized and used as the catalyst in the esterification of citric acid with butanol.The effects of amount of catalyst,alcohol/acid molar ratio and reaction temperature have been investigated.The products were analyzed by means of FT-IR spectroscopy.The optimum conditions for the synthesis of TBC over cerous methanesulfonate are : molar ratio of butanol to citric acid,4.50∶1;amount of catalyst,0.25%(molar percentage of citric acid) and reaction temperature,120～130℃.The yield can reach to 98.6%.The catalyst can be reused by simple phase-separation after reaction.It is used repeatedly for 5 times without obvious loss of activity and with the yield still over 90.0%.