头-尾双氢键互锁式分散染料的构筑及其耐碱稳定性调控机制

Alkali-resistant disperse dyes could realize one-bath dyeing for polyester-cotton blended fabric, so they are environment-friendly dyes with extremely splendid potential. However, because of the existence of easily hydrolyzed groups, there is generally a problem of poor alkali resistance for this kind of dyes. Aiming at such problem, substituents with large steric hindrance will be introduced to the ortho-position of the easily hydrolyzed groups to hinder the attack of nucleophile. At the same time, hydrogen bonds construction groups will be introduced to both ends of the dye conjugated system to regulate the distance and arrangement of adjacent molecules, forming “head-tail double hydrogen bond interlock” disperse dyes with stable structures. The influence of steric effect of substituents on the stereoscopic configuration, coplanar, arrangement and orientation of the molecule will be systematically studied. The relationship between the electronegativity, position and quantity of hydrogen bonds construction groups and the intermolecular hydrogen bonding strength, the coupling degree of the π-orbit, the π-π stacking method, the order of the molecule arrangement, the accumulation density and association strength will be discussed. The cooperative regulatory mechanism of hydrogen bonds and steric-hindrance effect on the high temperature and alkali resistance of the dyes will be illuminated. The relationship between the coplanar and aggregation state and photochemical stability of dye molecules will be investigated. According to these studies, the effective regulation of high-alkali and high-photochemical stable disperse dyes will be realized. This project will provide theoretical basis for the preparation of disperse dyes with high alkali stability. The core technology can be used by relevant enterprises to improve the additional values of dyes.

耐碱型分散染料可以实现涤/棉混纺织物同浴着色是当今极具发展潜力的环保染料。但是，由于结构中含有易水解基团，该类染料普遍存在耐碱稳定性不高的问题。针对该问题，本课题拟在易水解基团相邻位置引入具有较大空间位阻效应的取代基团以阻碍亲核试剂的进攻，同时在染料共轭体系的两端引入氢键构筑基团调控相邻分子间距离和排布方式，制备“头-尾双氢键互锁式”稳定结构的分散染料；系统研究取代基空间效应对分子立体构型、共平面性、排列和取向等的影响规律，探讨氢键构筑基团的电负性和位置与分子间氢键强度、π轨道耦合程度、分子排布有序度、堆积方式、堆积密度和缔合强度的关系；阐明氢键和空间位阻效应协同调控染料高温耐碱稳定性机制，揭示染料分子共平面性与聚集状态和光化学稳定性的关系，实现耐碱型分散染料结构与性能的有效调控。研究成果可以为制备高性能耐碱型分散染料提供理论依据，核心技术可供相关企业借鉴以提高染料的附加值。

耐碱型分散染料可以实现T/C混纺织物同浴着色，且着色织物具有手感柔软、匀染性好和疵点少等优点，对改善印染行业“三高”现状和提升着色织物品质具有重要的意义。然而，纵观目前产业化的耐碱型分散染料，大多数结构中含有易水解基团，普遍存在耐碱稳定性不高的问题，应用范围受到极大的限制。针对该问题，本项目通过在易水解基团（如氰基和酯基）相邻位置引入空间位阻较大的取代基团和在染料共轭体系两端引入氢键构筑基团调控相邻分子间距离和排布方式制备高耐碱型分散染料。主要研究工作和成果总结如下：. （1）制备了三种结构耐碱性分散染料：选取特征偶合组分中间体，调控水解基团相邻位置取代基团的空间尺寸；优化重氮组分和偶合组分中间体结构，通过重氮化-偶合反应可控制备了一系列苯胺类单偶氮、苯胺类双偶氮和苯并（异）噻唑杂环类耐碱性分散染料。. （2）染料高温碱性水解行为：采用高温高压染色法，分组对比了不同取代结构的分散染料高温碱性水解动力学过程；考察了水解前后染料化学结构的变化；系统研究了取代基空间尺寸和染色时间对不同水解时刻染液中剩余染料含量和最大吸收波长的影响，分析染液中剩余染料含量及水解产物生成量与时间的关系，定量评价了取代基空间位阻效应与染料水解速率之间的关系。. （3）氢键和空间位阻效应协同调控染料高温耐碱稳定性机理：通过组对比取代基空间尺寸与染料分子立体构型、母体结构扭转角、分子间距离和堆积方式的关系，解析了取代基空间位阻效应对阻碍亲核试剂进攻水解基团程度的影响规律。结果表明，在氰基相邻位置引入了空间位阻效应较大的苄基，使得染料在单分子状态下具有较高的化学稳定性。此外，苄基具有较好的平面性，增加了π-π堆积相互作用，这有利于形成紧密的聚集体结构，降低单分子染料释放速率。并且染料共轭体系两端引入的氢键构筑基团间形成分子内和分子间氢键作用有助于形成更加紧密的聚集体结构，进一步阻碍亲核试剂的进攻。