Abstracto

Advanced synthesis of dioctyl phthalate (DOP) and dibutyl phthalate (DBP) plasticizers: I. Comparison between aluminum oxide(Al2O3)and tetra-n-butyltitanate (TnBT) as esterification catalysts, II. Successful scaling up the bench scale to a semi-pilot scale

Usama F.Kandil, Nevien O.Shaker, Nahed M.Amer, Maher A.El-Sockary

Esterification of phthalic anhydride with 2-ethylhexanol and 1-butanol has been investigated using aluminum oxide/sodium hydroxide catalyst system and tetra-n-butyltitanate (TnBT) catalyst for comparison. TnBT catalyst shows higher activity in esterification. A complete conversion of phthalic anhydride to dioctyl phthalate and dibutyl phthalate are achieved in 2 hrs in presence of TnBT.While in case of using aluminumoxide/sodium hydroxide catalyst system, it requires at least 3 hrs. In addition, at the end of the reaction, TnBT is easily hydrolysable to a polymeric titanium dioxide; an easily filtered solid.An addition of filter aid can help achieve a good, rapid filtration of this polymeric titaniumdioxide.An improved purification method has been performed to the synthesized DBP plasticizer, which is then identified by FT-IR, 1H-NMRandGC. Details of a laboratory scale pilot plant in standard steel components have been designed to produce 50 litres of ester product.