三倍体毛白杨KP法蒸煮中木素结构的变化

The Change of Lignin Structure of the Triploid of Polulus Tomentosa during Kraft Pulping

以三倍体毛白杨为研究对象,进行了常规硫酸盐法蒸煮。采用酶-弱酸解两段法分别从原料和KP纸浆中分离出原料木素和纸浆残余木素。采用酸析法从KP蒸煮黑液中分离出溶出木素样品,经过弱酸水解得到纯木素试样。通过凝胶渗透色谱分析(GPC),对所有试样分别进行了分子质量的检测,得出各种木素样品的分子质量及其分布,分析了木素溶出过程中的分子质量的变化。通过磷谱核磁共振31P-NMR技术得出木素结构谱图,对原料木素、纸浆残余木素和黑液溶出木素结构中各官能团进行了定量分析对比,研究了木素结构在KP蒸煮过程中的变化规律。

The Chinese northern fast-growing hardwool-Triploid of Polulus Tomentosa was used as the raw material in this study. Conventional kraft pulping was carried out. The two-stage method was tsed to prepare the lignin from raw material and the lignin from the pulp. The acid-precipitating method was used to separate the dissolved lignin from the black liquor and the crude lignin was further purified by mild-acidic hydrolysis. The lignin samples were studied with GPC, and the changes of molecular weight during KP were investigated and compared. The lignin 31P-NMR spectra of different lignin samples were obtained and the functional groups of the lignin were quantitatively analyzed and compared in order to discover the change of lignin structures during kraft pulping.