纤维形态分析在二醋酸纤维素生产过程中的应用

Applications of Fiber Morphology Analysis in Production of Cellulose Diacetate

关键词:  纤维形态分析  醋化反应  二醋酸纤维素片  颗粒数

Key Words:fiber morphology analysis  cellulose acetylation reaction  cellulose diacetate flake  particle count

摘要:本研究通过对浆粕研磨后的纤维形态进行分析，研究了切断纤维比例、细小纤维含量对醋化反应速率、二醋酸纤维素片（醋片）颗粒数的影响，分析了醋片丙酮溶液中不溶物的组成及高乙酰化值不溶物的变化趋势。结果表明，提高切断纤维比例可加快醋化反应速率，但随着反应程度增加，高乙酰化值不溶物增多；调节研磨后切断纤维比例可优化醋片5~10 μm颗粒数，本研究通过数据拟合得出切断纤维比例为56.0%时，5~10 μm颗粒数达最小值4013个，对应的细小纤维含量为9.75%，反应速率为0.425 ℃/min，即研磨机动静磨盘间隙为4 mm，能最大限度减少5~10 μm颗粒数，从而改善醋片的可纺性。

Abstract:In this study， by analyzing the fiber morphology of pulp after grinding， the effects of cut-off fiber ratio and small fiber content on the reaction rate of vinegarization and the particle number of cellulose diacetate flakes （vinegar flakes） were investigated， and the composition of insoluble substances in acetone solution of vinegar flakes and the trend of insoluble substances with high acetylation value were analyzed. The results showed that increasing the ratio of cut-off fiber could accelerate the reaction rate of vinegarization. However， with the increase of reaction intensity， the insoluble substances with high acetylation value increased. Adjusting the cut-off fiber ratio could optimize the result of 5 μm particle count of vinegar flakes. By data fitting， at the cut-off fiber ratio of 56.0%， the minimum value of 5 μm particle counts was 4013， and the small fiber content was 9.75% and the reaction rate was 0.425 ℃/min.The clearance between the dynamic and static grinding discs was 4 mm，which could minimize 5~10 μm particle counts， and improving the spinnability of clellalose diacetate.