Activities of clays and ion exchange resins in the synthesis of phthalate esters

Abstract

Phthalate esters are used as plasticisers, solvents and perfumery compounds. Usually homogenous polluting and corrosive acids are used as catalysts for esterification which leave traces of inorganic impurities in the final product and they also impart coloration. This paper evaluates the activities of acid treated clays and ion exchange resins in the esterification of phthalic anhydride using methanol as the model alcohol. Amberlyst - 36 > Amberlyst - 15 > Indion - 130 > Deloxane > Filrol - 24 Clay > K - 10 Clay. The effects of various parameters with Amberlyst-36 were studied to find that the reaction was intrinsically kinetically controlled. It was observed that the catalyst chosen had excellent reusability and was not deactivated. A kinetic model was developed from the experimental data. Phthalate esters of ethanol, n-propanol and n-butanol were also synthesized.