Study On The Reaction Of α-Pinene Over Acid Ionic Liquids

Eight kinds of Bnpnsted acidic ionic liquids:1-(3-sulfonic group) propyl-3-methyl-imidazole dihydro-phosphate [(HSO₃^-pmim)]⁺[H₂PO₄]^-, l-(3-sulfonicgroup)propyl-3-methylimidazole hydro-sulfate [(HSO₃^-pmim)]⁺[ HSO₄]^-, n-(3-sulfonicgroup)-propyl-pyridine hydro-sulfate [HSO₃ppy]⁺[ HSO₄]^-, n-(3-sulfonic group)-propylpyridine dihy-drophosphate [HSO₃ppy]⁺[H₂PO₄]^-,(3-sulfonic group)-propyl-triethylammonium hydro-sulfate [N(Et)₃(CH₂)₃SO₃H]⁺[HSO₄]^-, (3-sulfonic group)propyl-triethyl ammonium dihydro-phosphate [N(Et)₃(CH₂)₃SO₃H]⁺[H₂PO₄]^-,l-n-butyl-3-methyl-imidazole hydro-sulfate [C₄mim]⁺[HSO₄]^-,l-n-butyl-3-methylimidazole dihydro-phosphate [C₄mim]⁺[ H₂PO₄]^-were synthesized by two-step, and nine kinds of Lewis acidic ionic liquids:AlCl₃-n-methylimidazoliumchloride[Hmim]Cl-AlCl₃,AlCl₃-l-n-ethyl-3-methyl-imidazole bromide[C₂mim]Br- AlCl₃, AlCl₃-1-n-Butyl-3 -methylimidazolechloride [C₄mim]Cl-AlCl₃,AlCl₃-triethyl-ammonium chloride [(Et)₃NH3]Cl-AlCl₃, AlCl₃-tetra-ethyl-ammonium bromide [(Et)₃NC₂H₅]Br-AlCl₃, AlCl₃-butyl-triethyl-ammonium chloride [(Et)₃NC₄H₉]Cl- AlCl₃, AlCl₃-pyridinium chloride [C₅H₅NH]C1- AlCl₃, AlCl₃-ethyl-pyridinium bromide[C₅H₅NC₅H₅]Br- AlCl₃,AlCl₃-butyl-pyridinium chloride [C₅H₅NC₄H₉]C1- AlCl₃were synthesized. Their structure and acidity were characterized and tested.In the hydration of a-pinene to prepare terpineol, the catalytic effect and the repeated use of the traditional catalyst phosphoric acid and 6 composite catalysts of ionic liquids and CICH₂COOH were studied. The result showed that composite catalyst of [HSO₃^-pmim]⁺[ H₂PO₄]^- and CICH₂COOH which can be reused and easy to be separated with the product was a better catalyst. Under the optimum conditions, conversion rate of a-pinene reached 97.1 %, selectivity of terpineol 52.4 %, and the composite catalyst can be reused without any treat, after used 5 times, conversion rate of a-pinene keeps over 83.7 %, selectivity of terpineol 51.6 %.In the esterification reaction of a-pinene to prepare terpinyl acetate and bornyl acetate, the catalytic effect and the repeated use of traditional catalysts sulphuric acid, phosphoric acid and eight composite catalysts were studied. The result showed that composite catalyst of [HSO₃^-pN(Et)₃]⁺[ HSO₄]^- and CICH₂COOH revealed high selectivity to bornyl acetate, conversion rate of a-pinene 95.9 %, and after used 5 times, conversion rate of a-pinene keeps 87.4 %; composite catalyst of [HSO₃^-pmim]⁺[ H₂PO₄]^-and CICH₂COOH revealed high selectivity to terpinyl acetate, it was over 36.0 %, conversion rate of a-pinene 85.7 %, and the catalytic can be used 6 times. At the same time, the influences of reaction conditions of above reactions, such as materials molar ratio, reaction time, reaction temperature and amount of catalyst were investigated, and the optimum conditions were obtained.At the same time, the effects of AlCl₃-alkylimidazole, AlCl₃-alkyltriethylamine and AlCl₃-alkylpyridine on the polymerization of a-pinene were preliminary studied, [C₄mim]Cl- AlCl₃ has the best effect, and the softening point of terpene resin is 104℃The use of acid ionic liquids in the field of turpentine solved many disadvantages in traditional technology, such as one-time large amount of catalyst, difficult separation and environmental pollution. It showed that the studies was a good guidance to the application of acid ionic liquids in correlative fields.