The Research On The Preparation Of Carbon Foams And Their Composites

Carbon foams, which exhibit an interconnected structure and a large porosity made up of macrospores, are important in many areas of modern science and technology, including aerospace, heat exchanger, catalyst support and electrode material due to their remarkable properties, such as low density, high open-cell ratio, low coefficient of thermal expansion, resistance to corrosion, easy machining and other superior performances. Moreover, Composites with specific properties can be obtained via combination of carbon foam with other materials.In the present thesis, carbon foams were prepared using polyurethane foam as template and furfuryl alcohol (FA), polyimide acid (PAA) as well as asphaltene (AS) extracted from CLR as carbon precursors. The synthesis process involves the impregnation of the carbon resources, solidification and carbonization. The products were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The basic parameters, electric conductivity and antioxidant ability were also investigated. The results indicate that the as-prepared products which have low density and high porosity are made up of interconnected ligament composed by turbostraic carbon structure.The products are semiconducting materials and show good antioxidant ability. The structure and impregnation ability of the template is improved via the pretreatment by alkali solution, consequently the carbon foam with higher open porosity; carbonization yield as well as bulk density can be obtained. In order to expand the application of carbon foams, composites were also synthesized by adding Ni (NO₃)₂ and CNT into polyamide acid. This thesis not only enriches the category of materials for the preparation of carbon foams, but also makes valuable contributions to the research and application of carbon foams.