基于分子模拟预判Lyocell纤维原液着色体系中溶剂的稳定性

为探索原液着色法制备Lyocell纤维过程中颜料对溶剂N-甲基吗啉-N-氧化物(NMMO)稳定性的影响,针对传统实验分析测试方法的局限性,采用分子模拟计算的方法研究了金属氧化物、碳材料、有机分子晶体三大类代表性颜料表面与NMMO之间的相互作用,根据NMMO分子中N—O键的平衡键长变化以及O—N—C键键角的变化,说明NMMO水溶液在二氧化钛、碳黑、颜料红、靛蒽醌颜料存在下,化学结构基本不变;而在三氧化二铁、酞菁铜颜料存在的情况下,N—O键的平衡键长明显变长,存在化学键断裂的风险,且这一结果与已有的实验结果相吻合,并且说明分子模拟方法可快速预判颜料对NMMO稳定性的潜在影响。

Predicting stability of solvent in dope-dyed Lyocell solution based on molecular simulation

In order to study the influence of pigment on the stability of solvent N-methylmorpholine-N-oxide (NMMO) in the preparation of dope-dyed Lyocell fibers, the interaction between NMMO and three representative pigments including metal oxide, carbon material, and organic molecular crystal was studied by molecular simulation in view of the limitations of traditional experimental testing methods. According to the change of N—O equilibrium bond length and O—N—C bond angle of NMMO molecule, the chemical structure of NMMO aqueous solution remains basically unchanged in the presence of titanium dioxide, carbon black, pigment red and indoanthraquinone. Nevertheless the equilibrium bond length of N—O bond obviously becomes longer in the presence of Fe₂O₃ and copper (II) phthalocyanine, predicting the risk of chemical bond breakage, which is consistent with the existing experimental results. It indicates that molecular simulation method can quickly predict the potential influence of pigments on the stability of NMMO.