Effects of heating rate on the foaming behavior and pore structure of carbon foams derived from phenol-formaldehyde resin

Study on Correlation of Mechanical and Thermal Properties of Coal-Based Carbon Foam with the Weight Loss Rate after Oxidation

“…This shows that as the degree of oxidation deepens, more amorphous carbon is consumed, and the remaining material is mostly graphitized carbon flakes. A reasonable explanation for the above phenomenon is that amorphous carbon is more prone to oxidation [ 23 , 24 , 25 ], which is due to the disorderly stacking of carbon atoms on its surface, which fails to form large-scale complete graphite crystallites, resulting in more surface defects and more oxygen-containing groups, which are more prone to oxidation reactions, while graphitized carbon is the opposite [ 25 , 26 , 27 , 28 , 29 ].…”

“…The CF production process studied in this paper is as follows: pulverize the finely washed bituminous coal with a free expansion number of 5.5 to more than 100 mesh, put it into a mold, put it into a high temperature and high pressure reaction kettle with the mold, seal it and vacuumize it to below 0.001 MPa, close the vacuum, and pass high-purity nitrogen until the pressure reaches 1.5 MPa, heat up to 500 °C at a heating rate of 1 °C/min, keep the constant temperature for 300 min, naturally cool to room temperature, depressurize to atmospheric pressure, open the reactor, take out the material, and put it in a vacuum sintering furnace. Under vacuum conditions, the temperature was raised to 1650 °C at a heating rate of 1 °C/min, kept at a constant temperature for 300 min, and then cooled to room temperature at a cooling rate of 2 °C/min to obtain the CF required for the test [ 23 , 24 , 25 ]. It is worth noting that bituminous coal contains metallic impurities, which are very persistent and difficult to remove.…”