Lignin Characterization of Waste Liquor by Modified Pulping Process

개량(改良)펄프화법(化法)으로 제조(製造)된 폐액(廢液)중의 리그닌의 특성(特性)

This study was carried out to investigate the characterization of lignins from waste liquors in SP, KP, ASAM, and AS from Pinus densiflora, Quercus mongolica, and Betula ermanii. Spectroscopic study was applied to examine the lignins separated from different pulping process. Lignin contents in waste liqours increased in order of AS, ASAM, KP, and SP. UV spectra of three types of lignin except AS lignin showed similar pattern. IR spectra of AS lignin showed strong C=O absorptions in the range from 1730 to 1750$cm^{-1}$, where as those of KP, SP, and ASAM showed weak stretch in this region. NMR spectra of AS lignin showed strong characteristic chemical shifts of acetoxyl groups of acetylated aliphatic and aromatic hydroxyl groups at 2.0~2.5 ppm. Molecular weight of ASAM lignin from Pinus densiflora determined and found number average molecular weight 1,199, weight average molecular weight 5,458. z average molecular weight 17,242, and viscosity average molecular weight 5,457. It is considered from the results based on spectroscopic study of lignin that waste liquors (in SP, KP, ASAM and AS) from Pinus densiflora, Quercus mongolica, and Betula ermanii can be used for lignin utilization.