同步辐射X射线成像技术研究炭黑填料网络的结构调控和补强机理

用纳米粒子补强高分子材料是实现材料轻质、高强的重要途径。由于缺少对纳米粒子与高分子基体相互作用界面性质及其对粒子空间分布影响进行有效表征的手段，对纳米粒子和高分子基体的微观作用机制，还缺乏统一认识。本项目以经典的炭黑填料补强天然橡胶的微观补强机理为内容，利用同步辐射扫描透射X射线谱学成像具有高空间分辨、灵敏的元素和化学价态分辨、X射线Nano-CT具有对微区结构进行高空间分辨的三维成像优势，研制与成像技术联用的微型拉伸装置。通过改变炭黑表面活性来调控橡胶与炭黑相互作用关系，建立将几种X射线成像技术组合的、用于橡胶-炭黑相互作用界面性质和填料网络微区三维结构研究的方法学。在此基础上，原位研究从炭黑表面活性到结合胶特性、到填料网络结构、再到复合材料力学性能之间的对应关系，探索构建填料网络结构调控和材料力学增强的微观模型，为针对性设计、制作高性能高分子纳米复合材料提供理论和实验依据。

Polymers filled with nanoparticles for reinforcement can enhance the strengths of nano-composites and decrease the weights of automobiles and aeroplanes, etc, which can save energy consumption. However, because of the lack of proper detecting techniques to study the interfacial interactions between nano-particles and polymer matrices, the structural evolutions of filler network and their roles to the mechanical properties of polymer nano-composites are not fully understood.. As one of typical polymer nano-composites, natural rubber filled with carbon black can dramatically enhance the toughness and strength of filled rubber. However, the reinforcing mechanism is still under debated. Aiming to understand the reinforcing mechanism of carbon black, we will firstly design and fabricate a micro tensile device which can be installed on the sample stages of scanning transmission X-ray microscopy (STXM), soft X-ray nano-CT and hard X-ray nano-CT, and then develop relative data processing and analyzing software. With the modification of the surface chemical activities of carbon black, the interactions between carbon black and natural rubber will be manipulated, and the methodologies of how to study the structural evolutions of carbon black and their roles to mechanical properties of filled rubber in situ will be established. On this basis, the correlations of the surface activities of carbon black to the properties of bound rubber, bound rubber to filler network structures and their roles to the mechanical properties of filled rubber will be systematically studied, and the micro reinforcing model will be set up exploratively, which can provide the experimental and theoretical evidences for designing and producing polymer nano-composites with special properties.