Preparation of solid carbon spheres by pyrolysis of allyl COPNA-BMI resin

The copolymer of allyl condensed polynuclear aromatic (COPNA) resin and 4,4′-bismaleimidodiphenyl methane (BMI) was used to prepare resin microspheres using silicone oil as dispersant by means of suspension polymerization, and solid carbon spheres were prepared by direct pyrolysis of the resin microspheres in this paper. Thermal behavior of the resin microspheres was studied by TG–DTG, FTIR and element analyze instrument. The resultant carbon spheres were characterized by SEM, XRD and nitrogen adsorption–desorption measurement. Results show that the resin microspheres, which have a mean particle diameter of 14.6 μm, possess fine degree of sphericity and smoothness. The resin microspheres possess excellent thermal properties, indicated by that initial decomposition temperature is 420 °C and carbonization yield reaches 49.1% in nitrogen. Furthermore, pyrolysis products of the resin microspheres are made up of solid carbon spheres with a nongraphitized carbonaceous structure. When pyrolysis temperature is 1000 °C, the BET surface area and total pore volume of the carbon spheres arrive at 595 m2 g−1 and 0.29 cm3 g−1, respectively.