橡胶助剂还原和改性氧化石墨烯及其对橡胶结构和性能的影响

Due to its excellent physical and electronic properties, graphene has attracted more and more attention as nanofiller for rubber in the rubber industry. However, unmodified graphene is both hydrophobic and oleophobic with strong Van der Waals force between graphene sheets, leading to the poor dispersion of graphene in rubber matrix and weak graphene-rubber interfacial interaction. Therefore, it is hard to take full advantage of the superior capabilities of graphene in rubber composites. Even worse, hydrazine hydrate, as the most commonly used reducing agent of graphene during the large-scale production, is both toxic and explosive. On the other hand, traditional organic rubber additives with low molecular weight are easy to migrate and volatile, leading to their physical loss and low efficiency. In this project, nontoxic and environmentally friendly rubber additives are used as reducing agents and surface modifiers for graphene oxide to prepare organically modified graphene by a one-step approach, which not only improves the graphene dispersion in rubber matrix and the graphene-rubber interfacial interaction, but also avoids the physical loss of rubber additives and organic pollution caused by the migration and volatilization of rubber additives. The preparation conditions and properties of the rubber additives reduced and modified graphene will be systematically studied and characterized, respectively. Then, the effects of rubber additives reduced and modified graphene on the structure and performance of rubber composites will be explored in depth, which is expected to provide a rigorous theoretical basis and guidance for the preparation of high performance and functional rubber/graphene composites.

由于优异的物理和电子特性，石墨烯作为橡胶纳米填料在橡胶工业中越来越受到重视。然而，未改性的石墨烯既疏水又疏油且片层间范德华力很强，造成与橡胶的界面作用弱，在橡胶中的分散性差，使其独特优势难以发挥，而采用可规模化生产的氧化还原法制备石墨烯往往又需使用剧毒易爆的还原剂水合肼；另一方面，传统的有机小分子橡胶助剂具有易迁移、易挥发、功能单一、效率不高等缺点。本项目采用无毒的小分子橡胶助剂作为氧化石墨烯的还原剂和改性剂制备有机改性石墨烯，使还原和改性一步完成，既能改善石墨烯在橡胶中的分散状态，增强其与橡胶的相容性和界面作用，又能避免因橡胶助剂的迁移和挥发造成的有机污染与物理损失，提高助剂作用效率。探索和优化橡胶助剂还原和改性氧化石墨烯的反应条件，表征其分子结构和理化性质，并系统深入研究其对橡胶结构和性能的影响，探讨其作用机理，得出规律性认识，为石墨烯橡胶复合材料的高性能化提供一定的理论和实验基础。

未改性的石墨烯既疏水又疏油且片层间范德华力很强，造成与橡胶的界面作用弱，在橡胶中的分散性差，使其独特优势难以发挥，而采用可规模化生产的氧化还原法制备石墨烯往往又需使用剧毒易爆的还原剂水合肼；另一方面，传统的有机小分子橡胶助剂具有易迁移、易挥发、功能单一、效率不高等缺点。本项目提出以无毒的小分子橡胶助剂作为氧化石墨烯的还原剂和改性剂制备有机改性石墨烯，使还原和改性一步完成。得到的主要研究成果包括:（1）采用工业生产中常用的促进剂CZ、M和防老剂4020、MB与GO反应，同步实现了GO在低毒、温和条件下的高效还原及有机改性；（2）成功制备了综合性能优良的橡胶助剂还原和改性的石墨烯/橡胶复合材料，并赋予了橡胶助剂在加工和使用过程中的耐迁移和耐挥发性；（3）通过系统研究橡胶助剂改性的石墨烯对橡胶复合材料结构和性能的影响机理，得出了规律性认识，为石墨烯橡胶复合材料的高性能化和功能化提供了一些新的的理论和实验基础。