基于荧光增白剂的高得率浆多功能返黄抑制剂构效关系及其作用机理研究

This project is proposed by using XPS, free radicals catalytic wave, EPR spectrometer and other modern analysis techniques to track free radical generation, migration and dying in the process of yellowing of the high-yield pulp(HYP) and the structural changes of active groups in the fiber surface. At the same time, according to the research of fluorescent whitening agents and novel carbon dots which include fluorescent whitening and stable effect, which we found a few month ago, to improve the optical stability studies, macro-molecularization and amphoteric ionization. In accordance with functional molecular design principles and synthetic technologies, raw materials of divinyl benzene, coumarin, pyrene and naphthalene are used respectively, and UV absorber and free radical capture agents are introduced into the fluorescent brightening agents’ structure. A series of the high-yield pulp(HYP) multifunctional yellowing inhibitors will have been prepared, then those will be made to be water-solubility and macromolecular. The ultraviolet absorption of aim moleculars in different groups and optical brightening agent of absorption in district dislocation and complementary are introduced respectively. The synergistic effect of them can enhance the efficiency of yellowing inhibition above. The different wavelength UV accelerated aging experiments are applied and the relationships of their structure and performance are established. With the modern analysis technologies the adsorption and diffusion of yellowing inhibitors on the wood fiber surface of high percentage lignin are investigated. The studies also have important theoretical guiding significance and industrial applications for yellowing inhibition of waterborne coating, wood, textile fiber, plastics and other polymeric material.

本项目拟利用XPS、自由基催化波、电子顺磁共振波谱仪(EPR)等现代分析技术跟踪返黄过程中自由基的产生、迁移、消亡以及纤维表面活性基团结构的变化。同时根据课题组进行的荧光增白剂高分子水性化以提高光学稳定性研究以及近期发现的纳米碳量子点有荧光增白和稳定作用为基础；首先以萘酰亚胺、香豆素荧光增白剂为起始，利用桥连基将紫外光吸收、自由基捕获基团引入同一分子，并对其离子活性化使之适用于造纸体系；再将其用于碳量子点荧光增白剂的表面修饰，以制备系列具有增白作用的新型高得率浆返黄抑制剂，基于碳量子点、单体功能基团合成中通过取代基来调整紫外吸收基的吸收区与增白剂的紫外吸收区错位与互补，实现紫外区全覆盖、高效抑黄；通过光加速老化试验，并探索返黄抑制剂在高木素纤维表面的吸附、扩散、结合机理；该项目的研究对高得率浆的推广、水性涂料、织物、塑料等材料的光老化、返黄抑制及研发具有重要的理论与工业价值。

本项目利用紫外光谱、红外光谱、XPS等现代分析技术探讨了杨木APMP浆的模拟光致返黄过程中的各化学基团的变化，从而揭示了高得率浆返黄程度与木素纤维表面化学基团结构的关系。在此基础上，依据高得率浆纤维表面物化特性、功能分子设计原理，以萘酰亚胺型、香豆素型、二苯乙烯型荧光增白剂为起始原料，利用亲和取代反应、自由基共聚合反应、偶联反应等，三聚氯氰桥连基团将高效紫外光吸收、自由基捕获基团依次引入并结合在返黄抑制剂分子合成中，并进行离子化、活性化或高分子化使之适用于造纸水性体系，同时将其用于新型碳量子点、二氧化硅等纳米粒子复合荧光增白剂制备出3大类型24种具有增白、返黄抑制、表面施胶增强作用的新型多功能高得率浆返黄抑制剂，并通过取代基引入来调整紫外吸收官能团的最大紫外光吸收区与荧光增白剂紫外吸收区错位与互补且合理分布，实现对紫外光波全范围吸收，从而实现了对高得率浆紫外光致返黄的高效抑制，然后通过不同波长紫外光加速老化的返黄试验，建立其构效关系，并探索了设计合成的新型返黄抑制剂在高得率浆APMP纤维表面的吸附结合机理；该项目的研究成果还可对抑制水性涂料、织物、塑料、橡胶等材料的光老化、返黄、紫外光吸收等具有重要的理论意义和工业应用价值。