【作者】 李连峰；

【导师】 樊永明；

【作者基本信息】 北京林业大学 ， 林产化学加工工程， 2007， 硕士

【摘要】 本论文以杨木为原料，对甲酸法制备粘胶纤维浆生产过程中过甲酸的稳定性、杨木甲酸预浸渍的影响因素、制浆过程中过氧化氢和硫酸用量对浆料性能的影响以及杨木甲酸法制备粘胶纤维浆的工艺流程进行了探索，并对甲酸段浆料进行了红外光谱分析，为杨木甲酸法制备粘胶纤维浆的进一步研究做了铺垫。研究结果表明，在过甲酸制备过程中，随反应时间的延长，过甲酸浓度首先升高，然后逐渐降低；过甲酸在高温下易于分解；随甲酸浓度增加，过氧化氢转化为过甲酸的比例增加；随过氧化氢用量的增加，所生成的过甲酸比例增加；硫酸的加入有利于活性氧的生成，但加入盐酸时会有部分过甲酸分解。甲酸(F)预浸渍杨木时，初期木片吸收甲酸的速度较快，随后逐渐变慢，温度是影响吸收甲酸速率的最主要因素。相同预浸渍时间内，温度每升高10℃木片吸收甲酸的量约增加10％；过氧化氢(P)或硫酸(S)的加入，对木片吸收甲酸有一定的促进作用。F、FP、FS以及FPS法蒸煮过程中，木素脱除和碳水化合物的降解都可以分为初期快速脱除(降解)阶段，中期缓和脱除(降解)阶段以及后期缓慢脱除(降解)阶段。杨木甲酸制浆时加入过氧化氢可提高脱木素的选择性，浆中α-纤维素含量也有所提高，但纤维素聚合度降低；硫酸用量增加时会促进碳水化合物的降解，使浆的得率降低，但脱木素速度加快，且聚合度稍有降低。甲酸浓度为85％，过氧化氢用量为8％，硫酸用量为3％，95℃的条件下蒸煮240min后经过碱处理和过氧化氢漂白，浆中α-纤维素含量可达到97.6％，可达到粘胶纤维棉浆的二级国家标准。更多还原

【Abstract】 The technology in the preparation of dissolving pulp was studied in the paper, the effect of hydrogen peroxide and sulfuric acid on pulp properties, pretreatment of raw material and the stability of performic acid.It was showed in the results that the amount of active oxygen increased and then decreased in the process of preparation of performic acid; meanwhile the speed of decomposition of active oxygen of performic acid could be increased with the as the rising of temperature; the amount of active oxygen in the form of performic acid increased with the concentration of formic acid. It could be found that the sulfuric acid could accelerate the speed of preparation of active oxygen of performic acid.At the first pretreatment stage, the cooking liquor could be readily absorbed by poplar material. The main factors which might influence the inpregnation included: temperature, hydrogen peroxide and sulfuric acid.The cooking process could be devided into three stages: high speed stage, slow speed stage and finishing stage. The selectvity of delignification could be obviously improved by the addition of hydrogen peroxide to the formic acid, and α-cell concentration in pulp could be increased with a little decrease of DP. The pulp yield will be decreased with the addition of sulfuric acid, but delignification and α-cell contents could be improved.At the condition of formic acid 85%, hydrogen peroxide 8% and sulfuric acid 3%, the α-cell concentration could be as high as 97.6%, which is above the second grade of the GB standard.更多还原