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麦草碱木素在碱催化下经脱甲基改性可提高其反应活性．本文采用元素分析、扫描电镜、凝胶色谱、１ＨＮＭＲ和１３ＣＮＭＲ波谱较系统地研究脱甲基改性麦草碱木素化学组成、微观表面形态和化学结构的变化．研究结果表明，脱甲基活化改性后，麦草碱木素的甲氧基含量由１０．３％降至６．０９％，而酚羟基和羧基含量分别由２．９８％和４．５８％增至５．５１％和７．１０％．脱甲基改性后氧元素含量下降，改性麦草碱木素的微观形态呈致密的球形，在尺寸上比未改性的麦草碱木素小．改性后麦草碱木素的平均相对分子质量（Ｍｗ）由６２１７降至５１４８，相对分子质量分布情况发生变化．脱甲基改性使苯环上的烷基芳基醚键断开，形成酚羟基，同时，在一定程度上也伴随木素结构单元间化学联接的断裂，体现在其核磁共振波谱和平均相对分子质量的变化．
Wheat straw alkali lignin catalyzed by base demethylation can improve its reactivity. In this paper, elemental analysis, scanning electron microscopy, gel chromatography, 1H NMR and 13C NMR spectroscopy to systematically study the chemical composition, microscopic surface morphology and chemical structure of demethylase modified wheat straw alkaloids changes. The results showed that after demethylation, the methoxyl content of wheat straw alkali alkali lignin decreased from 10.3% to 6.09%, while the content of phenolic hydroxyl group and carboxyl group decreased from 2.98% to 4.58% To 5.51% and 7.10%. After demethylation, the oxygen content decreased, the microscopic morphology of the modified wheat straw alkali lignin showed a dense spherical shape, smaller in size than the unmodified wheat straw alkali lignin. The average relative molecular weight (Mw) of the modified wheat straw alkaloids decreased from 6217 to 5148, and the relative molecular mass distribution changed. Demethylation of the benzene ring on the alkyl aryl ether bond breaking to form a phenolic hydroxyl group, at the same time, to some extent also associated with lignin chemical fragmentation between structural units, reflected in its nuclear magnetic resonance spectrum and the average relative Changes in molecular mass.