考察了不同有机溶剂对松脂的酸性组分(左旋海松酸、枞酸、硬脂酸)、不皂化物和松节油的溶解性能,研究了采用溶剂沉淀分离松脂树脂酸和松节油的加工新方法;分析沉淀分离条件对松脂树脂酸沉淀产率的影响,探讨沉淀分离法松脂加工工艺条件;运用气相色谱/质谱分析树脂酸沉淀的化学组成,并进行理化性能测试。结果表明:以二氯甲烷为良性溶剂溶解松脂,与松脂酸性组分的非良性溶剂乙腈混合,可以沉淀分离松脂树脂酸;滤液中二氯甲烷和乙腈可通过分馏方法分离回收、重复利用,而松节油则通过水蒸气蒸馏法分离回收;在松脂、二氯甲烷和乙腈的质量比为1∶1.3∶2的条件下,松脂树脂酸的产率为71%、酸值为183 mg/g、不皂化物质量分数为2%;该溶剂沉淀分离方法适用于马尾松松脂等松节油含量不高的松脂原料,无需特殊设备,操作工艺简单,不改变天然松脂树脂酸的化学组成,有利于天然松脂资源的综合利用。
A technology for processing pine oleoresin into rosin and turpentine by using solvent precipitation separation was examined based on analysis of the solubility of representative acid compounds(abietic acid,levopimaric acid and stearic acid),turpentine and unsaponifiable matters in different organic solvents.Effects of the precipitation separation conditions on the yield of resin acids precipitate were investigated for developing the technological processing of oleoresin.The composition of resin acids precipitates was analyzed by GC/MS,and tests for their physical and chemical properties were done.The results showed that when CH2Cl2 was used as a good solvent to dissolve pine oleoresin and CH3CN was used as a poor solvent of resin acids to mix with pine oleoresin solutions,resin acids could be precipitated from pine oleoresin solutions and collected by filtration.CH2Cl2 and CH3CN could be recycled and reused from the filtered solutions by fractional distillation,and then turpentine was separated by steam distillation.Under the optimum processing conditions when the optimum oleoresin,CH2Cl2,CH3CN mass ratio was 1∶1.3∶2,the yield,acid value and unsaponifiable matters contents of resin acids precipitates were 71 %,183 mg/g and 2 %,respectively.Without special equipment and complex procedure,the solvent precipitation separation method could be used in all kind of oleoresin containing less amount of turpentine and beneficial to utilized the oleoresin resources reasonably because it did not change the chemical compositions of resin acids from oleoresin raw materials.