Esterification reaction using solid heterogeneous acid catalysts under solvent-less condition

The preparation of di-2-ethylhexylphthalate (DOP) via esterification reaction of phthalic anhydride by 2-ethylhexanol in the presence of solid acidic catalysts such as natural and synthetic zeolites, H4Si(W3O10)4, and sulfated ZrO2 has been investigated. Important plasticizers and ester base oils have prepared from anhydrides/acids and alcohols in the presence of sulfated zirconia under solvent-free condition.