固定化脂肪酶合成二元酸酯

Synthesis of Dicarboxylic Esters by Lipase

二元脂肪酸酯可作高质量的溶剂、润滑剂,又可作为燃料和多种轻工业产品的添加剂,主要用作润滑剂的基础油和塑料增塑剂。二元酸酯基合成润滑剂产品,具有闪点高,适用温度范围宽、润滑性好的特点。二元酸酯挥发性小,稳定性和挠曲性良好,适用于食品包装和户外用塑料制品[1]。?..

The syntheses of dicarboxylic esters by immobilized lipase from Candida sp. -1619 were investigated.The reaction system was composed of 1 mmol dicarboxylic acid,2 mmol alcohol,3 mL hexane and 15 mg celite adsorbed immobilized lipase(300 u),in a closed 100 mL Erlenmeyer flask,shaken at 40℃ for 5h.Sebacic acid was the best substrate among nine dicarboxylic acids selected.Among the 18 saturated fatty n-alcohols,the alcohols with carbon chain length rangin from C4～C18 had good reactivity.The primary alcohols had much better reactivities than corresponding secondary alcohols and multihydroxy alcohols.Tertiary alcohols showed no reactivity.Hydrocarbons,benzene,toluene,xylene and tetrachloride were favorite reactants among 15 organic solvents selected.in none solvent stationary system,(5 mmol sebacic acid,10 mmol dodecanol,150 mg immobilized lipase(3000 u))reacted without plug for 3.5h,the optimum temperature was 60℃.The conversion degree was over 92% when reaction carried out at 50～90℃ for 17h.The suitable reaction pH ranged from 6～8.The reactant was developed on GF 254 plate(hexane:ethyl ether:acetic acid=30:20:1( V:V:V ).There were three spots with different Rf value at 0.96,0.55 and 0 corresponding to product,oleyl alcohol and sebacic acids,respectively.