摘要：依据标准色度学系统和表面粉末抽提实验,研究了在不同的成形温度下杨木粉压坯表面的化学成分和颜色的变化规律。实验结果表明:在成形温度升高过程中,多糖类物质和半纤维素在高温下发生降解,压坯表面生成了导致颜色加深的有色抽提物;随着成形温度的升高,压坯表面的颜色随之加深;成形温度在160～180℃区间时,总体色差值增加,明度值下降趋势显著,该成形温度区间对压坯表面颜色影响较大;压坯样件粉末的含水量随成形温度升高而降低;在同等温度条件下,不同的抽提方法导致抽提物的含量发生较大变化,1%氢氧化钠法的抽提物含量最高,热水法的抽提物含量较冷水法略多,苯醇法的抽提物含量最低。

关键词：杨木粉；温压成形；有色抽提物；化学成分；颜色

Abstract: According to the standard colorimetric system and surface powder extraction experiments，the variation of chemical composition and color of the surface of poplar powder compacts at different forming temperatures were studied．The experimental results show that: in the process of increasing the forming temperature，polysaccharides and hemicellulose are degraded at high temperatures and colored extracts are formed on the compaction surface to cause the color to darken．As the forming temperature increases，the color of the compaction surface becomes darker．When the forming temperature is in the range of 160～180 ℃，the overall color difference value increases and the brightness value decreases significantly．This range of forming temperature has a great impact on the color of compaction surface．The water content of powder of the compaction surface decreases with the increase of the forming temperature．Different extraction methods lead to large changes in the content of extracts．Under the same temperature conditions，the content of extracts obtained by 1% NaOH method is the highest，the content of the extracts obtained by hot water method is slightly more than that obtained by cold water method，and the content of the extracts obtained by benzyl alcohol method is the lowest． 

Keywords: poplar powder; warm compaction; colored extract; chemical composition; color