Some study on esterification of maleic acid with 2-ethyl hexyl alcohol

Di-2-ethylhexyl maleate, as one of the synthetic aliphatic esters is considered as an example of the aliphatic plasticizers. It is prepared via the esterification of maleic acid with 2-ethyl hexyl alcohol at 170 degrees C using tetrabutyl titanate, and/or triisopropyl aluminate as catalyst. At the same temperature the esterification was conducted without catalyst and with other catalysts such as TICl4, SnCl4 and their prepared quaternary ammonium metallic salts for the purpose of comparison. The reaction was followed up by measuring the amounts of produced water, also by measuring the amount of unreacted acid in the reaction mixture. Imperical equation of reaction rate has indicated that esterification of this type is of apparent second order with respect to the acid.