水热预水解强度对相思木组分及溶剂吸收性能的影响

Effect of Hydrothermal Pre-hydrolysis Strength on Chemical Composition and Solvent Absorption Properties of Acacia Wood Chips

采用不同的预水解强度(P因子)对阔叶材相思木进行水热预水解处理,通过对预水解木片得率、组成成分、1%NaOH抽出物、苯醇抽出物、元素分析、吸水量、耗碱量及表面形貌的分析,探讨了预水解强度对抽出物组分含量及溶剂吸收性能的影响。研究结果显示:随着P因子的增大,预水解后木片得率、综纤维素、聚戊糖、木质素含量都呈下降趋势,而1%NaOH抽出物和苯醇抽出物的含量呈现先上升后下降的趋势。当P因子为0~800时,1%NaOH抽出物和苯醇抽出物分别从12.04%和1.74%增加到25.98%和12.11%;当P因子从800增加到1000时,两者分别从25.98%和12.11%下降到23.19%和11.08%。1%NaOH抽出物中木质素由7.15%(P=0)逐渐增加到48.37%(P=1000);而苯醇抽出物中木质素由16.42%(P=0)增加到47.68%(P=800)。根据水浸渍和碱浸渍实验显示:在预水解前期(P因子为0~310)时,预水解木片的吸水量和耗碱量均呈现上升的趋势,预水解木片的吸收性能有所改善,当P因子为310时,吸水量和耗碱量较高,分别为1.5423 g/g和80.71 mg/g。表面形貌分析显示:随着P因子的增大,预水解后木片的表面越来越疏松,孔隙越来越多。

The hydrothermal pre-hydrolysis of broadleaf acacia woods was carried out by different pre-hydrolysis strength(P factor),and through the analysis of the yield,composition,1%NaOH extractive,benzene-alcohol extractive,elemental analysis,water absorption,alkali consumption and surface morphology of pre-hydrolyzed wood chips,the influence of pre-hydrolysis strength on the content of the extract components and solvent absorption properties were discussed.The results showed that with the increase of the P factor,the yield of wood chips and the content of holocellulose,pentosan and lignin after pre-hydrolysis all showed a decreasing trend.However,the content of sodium hydroxide extractive and benzene-alcohol extractive first increased and then decreased.When P factor was 0-800,the content of 1%NaOH extractive and benzene-alcohol extractive increased from 12.04%and 1.74%to 25.98%and 12.11%,respectively;when P factor was increased from 800 to 1000,the content decreased from 25.98%and 12.11%to 23.19%and 11.08%,respectively.The lignin content of 1%NaOH extractive increased from 7.15%(when P factor was 0)to 48.37%(when P factor was 1000),while the lignin content of benzene-alcohol extractive increased from 16.42%(when P factor was 0)to 47.68%(when P factor was 800).According to the results of water immersion and alkali immersion experiments,as the P factor increased,at the early stage of pre-hydrolysis(P factor was 0-310),the water absorption and alkali consumption of pre-hydrolyzed wood chips both showed a increasing trend,and the absorption properties of pre-hydrolyzed wood chips improved,and then decreased.When P factor was 310,the water absorption and alkali consumption were higher,which were 1.5423 g/g and 80.71 mg/g respectively.The surface morphology analysis results showed that with the increase of P factor,the surface of the wood chips after pre-hydrolysis became looser and more porous.