STUDIES ON THE SYNTHESIS OF DIPENTYL PHTH ALATE USING HYDROTALCITE-CONTAINING RARE-EARTH AS A CATALYST

Synthesis of dipentyl phthalate using hydrotalcite-containing rare ear th as a catalyst is studied in detail, involved influence of amount of the catalyst, mole ratio of phthalic anhydride to n-pentanol, reactio n temperature and time on the conversion of phthalic anhydride to dipe ntyl phthalate. The results show that the catalyst has a high catalyti c activity and high selectivity, and the conversion is up to 95%. La c ontent in the catalyst may change in a certain range and the conversio n of phthalic anhydride increases with increasing of La content. The s urface area of the catalyst calcined at 400 degrees C is about 120 m(2 )/g(BET/N-2 technique). It has Lewis and Bronsted acid sites and the a mount of Lewis acid is far more than that of Bronsted acid. The mole r atio of chemical composition of the catalyst is Mg : Al : La = 6: (2-x ) : x, where 0 less than or equal to x less than or equal to 0.