Green synthesis of plasticizer dibutyl phthalate

The dibutyl phthalate was synthesized with NaHSO 4 ·H 2 O as catalyst by esterification of phthalic anhydride and n-butanol. The optimal reaction parameters for the process were obtained as follows: the molar ratio of n-butanol to phthalic anhydride was 2. 5 ∶ 1,and that of the catalyst to phthalic anhydride was 1 ∶ 500,the reaction temperature was 195 ℃ and the reaction time was 2 h,esterification rate was up to 98. 5%. The yield for dibutyl phthalate was 96%,the fineness for dibutyl phthalate was 99. 8%. The consumption quota of phthalic anhydride was 0. 6 and that of n-butanol was 0. 7. The catalyst was safe,economic and no environmental pollution,which agrees with the principles of green synthesis chemistry.