桉木抽出物的主要化学组成及结构类型的初步研究

A PRELIMINARY STUDY ON CHEMICAL COMPONENT AND STRUCTURAL TYPE OF EXTRACTIVES IN EUCALYPT WOOD

采用化学分析和光谱分析相结合的方法，对不同树种和树龄桉木抽出物的主要化学组成及结构类型进行初步研究，结果表明：桉木抽出物主要集中于心材；树龄越大，抽出物越多；幼龄材的抽出物较少，适宜于制浆造纸，桉木的颜色主要是由多酚类化合物所引起的。存放过久的桉木中的抽出物大部分变成黄粉，既不溶于水，也不溶于丙酮，只溶于稀碱或亚硫酸钠。在制浆前采用稀碱或亚硫酸钠预处理桉木是必要的。桉木多酚类化合物以水解单宁为主，属鞣花酸类，其次是缩合单宁。

This paper studied the chemical component and structural type of extractives in the different eucalypt wood,by the chemical and spectrophometric analysis. The results showed that the extractives mainly centralized in the heart wood of Eucalyptus; the older the tree was the more the content of extractives had, the darken color of eucalypt wood was due to the polyphenol compounds. The polyphenol compounds would give yellow sediment (regard as “bloom” or “yellow powder”) when the extractives of eucalypt wood stored for a long time. The bloom did not dissolve in water or acetone, but it dissolved only in the alkali or Na 2SO 3. So it is necessary to pretreat with NaOH or Na 2SO 3 before pulping from Eucalypt wood. The polyphenol compounds in Eucalyptus included the hydrolysable tannis with the ellagic acid structural type and the condensed tannis with the flavanol structural type.