甘蔗渣原料磨木素和磺化甘蔗渣磨木素的研究

STUDIES ON BAGASSE MWL AND SULPHONATED BAGASSE MWL

在甘蔗渣碱性亚硫酸钠化学机械法制浆研究的基础上,采用化学分析方法和仪器测试技术,研究了甘蔗渣原料磨木素和磺化处理后甘蔗渣磨木素的化学结构及其变化情况。在化学预处理过程中,甘蔗渣木素中的酯键和烷基芳基醚键等连接形式在一定程度上断裂,愈创木基结构单元发生较多的磺化和溶出,对羟苯基结构单元也有一定数量的溶出,因而使得留存于浆料木素中的紫丁香基结构单元相对增加。经过磺化处理后,甘蔗渣木素的平均分子量和多分散性减小,基于化学机械浆的预处理条件,木素大分子的碎解和溶出是有限度的。除了溶出的一部分磺化木素之外,残留于甘蔗渣的木素中仍有相当含量的磺酸基(达到0.15HSO_3/C_9),甲氧基含量明显增加(从1.00OCH_(?)/C_9增至1.22OCH_3/C_9),酚羟基含量有所增加(从0.29Ph-OH/C_9增至0.33Ph—OH/C_9),而醇羟基含量减少(从1.50Alc-OH/C_9减至0.79AlC-OH/C_9)。

On the basis of bagasse alkali sulphite chemimechanical pulping, by means of chemical and instrumental analysis methods, chemical compositions and changes of bagasse MWL and sulphonated bagasse MWL have been studied.In chemical pretreatment, ester bond alkylaryl ether linkage in bagasse lignin broke to a certain extent, more sulphonation and dissolution took place for guaiacyl, p—hydroxyphenyl also dissolved somewhat therefore, syringyl remained in lignin increased relatively. After sulphonation treatment, average molecular weight dispersion of bagasse lignin decreased.It was due to conditions of chemimechanical pulping that there is a limitation to breakage and dissolutioii of lignin structure. Except for part of dissolved lignin sulphonate, quite amount of sulphonic groups stiil existed in residual lignin, meanwhile, methoxyl group content increased evidently.phenolic hydroxyl content increased somewhat and alcoholic hydroxyl content decreased.