The effect of different atmosphere on the particle size and morphology of the B₄C was studied by using organic precursor method of low temperature pyrolysis with glycerol borate condensate as raw material. The same mole of boric acid and glycerol were directly mixed, and the condensed product was prepared by dehydration condensation. The precursor powder was pyrolyzed in still air(a), air flow(b), nitrogen flow(c) and argon flow(d) respectively to get rid of excess carbon. The precursors all have a three-dimensional continuous B₂O₃/carbon network structure, in which the pore size of the carbon network in the static air flow is about 1um, and the pore size of the carbon network in the air flow is about 0.1 um. The influence of the other two gases on the pore size structure of the carbon network is between the static air and the air flow. The morphology and size of B₄C powders produced by different synthetic routes (a, b, c, d) were polygonal with 5.7 um, smooth granular with 1.5 um, flake and rod-shaped particles with 14.0 um, and hexagonal with 23.3 um, respectively. This paper is the first time to study the effect of pyrolysis atmosphere on the morphology control of boron carbide from the molecular leve

Keywords: Boron carbide, Different pyrolysis atmosphere, Network structure, Morphology, Glycerol