Synthesis of Nontoxic Plasticizer Tri-n-butyl Citrate Using Lanthanum Methanesulfonate as Catalyst

Lanthanum methanesulfonate was synthesized and used as a catalyst in the esterification of citric acid with butanol.The effects of amount of catalyst,alcohol/acid molar ratio and reaction temperature were investigated.The products were analyzed by means of FT IR spectroscopy.The optimum conditions for the synthesis of TBC over lanthanum 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°C.The yield can be over 98.5% under optimum conditions.The catalyst can be reused by simple phase-separation after reaction.It was used repeatedly for 5 times without obvious loss of activity and with the yield still over 90.0%.