松香基硅橡胶分子构型对其性能的影响机制研究

With petroleum resources gradually exhausted and the demand for environmental protection, the development and utilization of renewable resources as one of the frontiers in polymer science has attracted more and more attention. In this project, rosin-based reactive monomers will be prepared with rosin of distinctive forestry resource by addition, reduction, esterification, amination and other chemical reactions. Furthermore, rosin-based silane functional monomers will be synthesized by sodium condensation reaction, catalyzed addition reaction, amination reaction and so on. Polysiloxane with side chain containing rosin structure will be prepared by chemical grafting. Meanwhile, polysiloxane with both main chain and side chain containing rosin structure will be also prepared from rosin-based silane functional monomers and other silane monomers by catalyzed condensation reaction. Novel silicone rubber modified by rosin will be synthesized from polysiloxane containing rosin structure. The performances of novel silicone rubber, including curing behavior, microstructure, thermal property and mechanical property will be investigated by means of Differential Scanning Calorimetry (DSC), Thermal Gravimetric Analysis (TG), Dynamic Mechanical Analysis (DMA), Scanning Electron Microscope (SEM), Atomic Force Microscopy (AFM), X-ray Photoelectron Spectroscopy (XPS) and other analysis instruments. Effects of polymer chains configuration containing rosin structure on the properties of silicone rubber will be studied. This project can provide theoretical guidance for the development and innovation of biomass-based silicone rubber, as well as open up a new way for the high value utilization of rosin.

随着化石资源的日趋枯竭及环保需求，以天然可再生资源合成或改性高分子材料越来越受到重视。本项目以我国特色林产资源松香为原料，利用加成、还原、酯化、胺化等化学反应，合成松香树脂酸衍生物活性单体，进一步通过钠缩合反应、催化加成反应、胺化反应等合成方法制备松香基有机硅烷功能性单体。采用化学接枝法，制备侧链含有松香基结构单元的聚硅氧烷；以松香基有机硅烷功能性单体与硅烷单体通过催化缩合反应制备主链及侧链含有松香基结构单元的聚硅氧烷。以含有松香基结构单元的聚硅氧烷设计合成硅橡胶，利用差示扫描量热（DSC）、热重分析（TG）、动态热机械分析（DMA）、扫描电镜（SEM）、原子力显微镜（AFM）、X射线光电子能谱（XPS） 等对其硫化行为、微观结构、热学性能及机械性能等进行研究，探索松香基硅橡胶分子构型对其性能的影响机制。为创新生物质基有机硅橡胶的开发提供理论指导，同时也为松香的高值化利用开辟新的途径。

松香是我国重要的特色林业资源，松香树脂酸具有与石油基芳香族和脂环族化合物相类似的刚性和化学稳定性，广泛应用于提高聚氨酯、环氧树脂等高分子材料的力学性能和热稳定性。室温硫化硅橡胶在电子、医疗等领域获得了广泛应用，但因力学性能较差，限制了其应用范围的拓展。针对室温硫化硅橡胶材料力学性能低这一问题，如何将松香氢化菲环结构引入到室温硫化硅橡胶结构中，以提高硅橡胶的力学性能、热稳定性等性能是本项目的主要研究内容和目标。本项目以松香及其衍生物为原料，完成了多种松香改性有机硅烷、松香改性聚硅氧烷的制备，对松香改性有机硅烷和聚硅氧烷的物理和化学性质进行了研究。分别以松香改性有机硅烷为交联剂和扩链剂制备了多种室温硫化硅橡胶，并对硅橡胶的性能进行了研究，明确了松香分子特有刚性结构及其反应活性对硅橡胶性能的影响规律；实现了以松香改性聚硅氧烷作为基础硅油应用于室温硫化硅橡胶的制备，明确了松香刚性结构位于聚硅氧烷侧链对硅橡胶性能的影响规律；以松香季铵盐提高硅橡胶材料的抗菌性能，对大肠杆菌、金黄葡萄球菌等展现出优异的抗菌性能，对人体主动脉平滑肌细胞展现出较好的生物相容性。通过上述工作的开展，实现了多种结构松香基室温硫化硅橡胶材料的设计与合成，与未改性室温硫化硅橡胶相比，松香改性硅橡胶拉伸强度提升大于300%，断裂伸长率提升大于200%，最大热分解速率提升大于100°C，邵氏硬度提升至28A。松香改性硅橡胶对于金黄色葡萄球菌的杀菌性能最佳，对金黄色葡萄球菌和大肠杆菌的菌落指数分别降低了1.77和1.90。本项目的开展明确了松香基硅橡胶分子构型对硅橡胶硫化行为和材料性能的影响规律，拓展了松香的高值化应用。