Preparation,structures and properties of mesophase pitch-based carbon foams

Nascent foams with uniform pore size were produced from naphthalene mesophase pitch in a high pressure chamber,they were carbonized and graphitized by heat treating to 700-(1 000 ℃) and(2 300-2 800 ℃) to form carbon and graphite foams.The influence of the basic properties of the pitch,foaming and heat treatment parameters on the microstructures and mechanical properties of the foams were investigated.It was found that an uniform temperature environment is the key to the preparation of carbon foams with uniform pore size and that the foaming pressure is the main factor for the control of pore size.The microstructure,crystal structure and microwave absorbing properties of carbon foams exhibited an anisotropic characteristic in the xz-and xy-plane directions(parallel and perpendicular to the gravitational directions,respectively).