| In the high utilization of turpentine in natural biomass resources,the reaction of ?-pinene hydrate preparation of ?-terpineol has important industrial value and significance.In order to abandon the traditional protonic acid to produce large amount of waste acid/water,the harsh control conditions and other defects.Based on the concept of "green chemistry" and "environmentally friendly catalysis",the carboxyl functionalized ionic liquids were synthesized by combining the catalysts applied in the hydration of ?-pinene.The ionic liquid structure was modified to optimize its catalytic performance in the hydration of ?-pinene.Simultaneously,the acidity of heteropoly acid anion was changed,and a variety of carboxyl groups with ionic acid and heteropoly acid salt were designed and synthesized.And it was applied to the synthesis of ?-terpineol by ?-pinene one-step hydration.Three new green catalytic systems have been developed to achieve the goal of environment-friendly catalysis and had achieved good catalytic performence.In this thesis,the structure of carboxyl functionalized ionic liquid catalysts was characterized by 1HNMR and FT-IR.The thermogravimetric analysis?TGA?was used to test its thermal stability.Furthermore,n-butylamine?n-Bu NH2?was used to test the acid strength and total acid amount of the ionic liquid catalysts.The solubility of various catalysts in water/?-pinene was tested.The effects of the anionic/cationic part of the catalyst on the acidity and the solubility and other chemical properties were explored.A series of alkyl imidazolyl functionalized ionic liquid catalysts were designed and synthesized in order to catalyze the hydration of ?-pinene.The experimental results show that the functionalized heteropoly acid salt catalyst [N-C14,N'-?CO2H?2-C2H2-Im-Br]2HPW12O40 with high acid strength is better,the introduction of carboxyl and halogen groups improves the selectivity of terpineol.Under the condition of 0.25 mmol of catalyst,0.30 mol of water,0.06 mol of ?-pinene,react 8 h at 70 °C,the conversion of ?-pinene reached 89.4%,the selectivity of ?-terpineol was 30.1%.The total selectivity of the hydrated products was 38.7%.And at the end of hydration,the catalyst was insoluble in the aqueous phase and the oil phase,and the catalyst can be recovered and reused by simple decantation separation,and a certain re-use performance is exhibited.Benzimidazole is a kind of heterocyclic compound with special structure,try to introduce the carboxyl functional group into the ionic liquid structure with benzimidazole as the organic cationic ring to synthesize the carboxyl functionalized ionic liquids.And the catalytic performance is controlled by regulating the alkyl chain length and structure on the parent ring.A variety of benzimidazole-based carboxyl functionalized ionic liquids were designed and synthesized from haloalkanes and used in the hydration of ?-pinene.The results show that the catalyst of [C6H4-CH?Et?-N2-C2H3-?CO2H?2]H2PW12O40 with short alkyl chain has a good catalytic effect,the conversion of ?-pinene was 95.2%,the selectivity of ?-terpineol was 24.8%,and the total selectivity of hydrated products was 31.6%.In addition,the catalyst has a good reusability,in the recycling after 5 times to maintain a high activity,is a novel environmentally friendly catalytic process.Based on the characteristics of water and oil immiscibility in the hydration of ?-pinene,the octylamine polyether carboxyl functionalized ionic liquid catalyst with both surface activity and acidity was also designed and synthesized.A series of carboxyl functionalized ionic liquids with different degree of polymerization n?number of ethyleneoxy units in ionic liquid structure?were synthesized by using halogenated carboxylic acid as carboxyl donor,phosphotungstic/sulfuric acid as anionic group catalyst.It was indicated that the catalyst showed a certain surface activity,the reaction system was microemulsion under the reaction temperature?80 °C?,and the effective collision probability was increased.However,after the end of the reaction,the catalyst and the products tend to form colloidal inclusions which were difficult to be separated.The separation of the catalyst and the products can be achieved by heating,adding the saturated electrolyte,high-power centrifugating,etc.Evidently,the self-separation of the catalyst was poor.The catalyst [AC1870-CH2COOH]H2PW12O40 achieved 68.1% conversion of ?-pinene and 25.5% selectivity of ?-terpineol without auxiliary catalyst.This study is a polyether type carboxylic acid functionalized ionic liquid catalyzed ?-pinene and provides a theoretical basis in related areas.The aim of this dissertation is to explore a new catalytic system for the hydration of ?-pinene without the support of organic acids such as chloroacetic acid,which provides a new pattern for the environmentally friendly catalytic process of biomass turpentine resources. |
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