采用单因素实验法,考察了水/乙醇反应溶剂体积比,反应温度和氢氧化钠加入方式对碱木质素的羧甲基化反应转化率及产物羧基含量的影响。结果表明,碱木质素的羧甲基化反应转化率及产物羧基含量随着水/乙醇体积比的增大而急剧减小,随着反应温度的升高而先增大后缓慢降低,二次加碱方式有利于反应的转化率及产物的羧基含量的提高。在70℃,水/乙醇体积比为20∶80的介质中,采用二次加碱方式,制备羧甲基碱木质素的反应转化率可达94.798%,产物的羧基含量可达2.764 mmol/g。红外光谱（FT-IR）和核磁共振（13C-NMR）表征结果表明,羧甲基化反应在碱木质素的酚羟基和α-醇羟基上成功接入了大量的羧甲基。
The effects of the volume ratio of water to ethanol,the reaction temperature and the way of NaOH addition on the conversion ratio of carboxymethylation of wheat straw alkali lignin(WAL) and the carboxyl group content of the obtained carboxymethylated alkali lignin(CML) were examined by single factor experiments.The results show that the conversion ratio of WAL is up to 94.798% of and CML with the carboxyl group content of 2.764 mmol/g can be obtained with the following conditions: reaction temperature of 70 ℃,the volume ration of water to ethanol of 20∶80 as the reaction medium and adding NaOH twice.The FT-IR and 13C-NMR spectroscopy show that the carboxymethyl groups are successfully engrafted into the WAL molecule structure,and the carboxymethylation substitutions simultaneously occur in the phenolic hydroxyl group and the α-position aliphatic hydroxyl group of the WAL molecule.
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