Particle refinement and graphene doping effects on thermal properties of potassium picrate

The ultrafine potassium picrate (KPA) was prepared under the action of crystalline controlling agent and modified by graphene. KPA, ultrafine FKPA, and graphene-doped GKPA were studied by the particle size analysis, DPTA, DSC, and thermal sensitivity tests. The particle size arranged in an increasing order is FKPA < GKPA < KPA. The kinetic and thermodynamic parameters of thermal decomposition are ranked as FKPA < GKPA < KPA. The results indicate that the particle refinement increases the thermal sensitivity, because the ultrafine particles have large surface area and high surface bonding energy which endow them with high reaction activity. The doped-graphene nanoparticles with larger surface area partly hinder the effective collisions of KPA particles and accelerate the heat dispersion. Thus, the graphene doping improves the thermal stability, while still preserving the ultrafine size. GKPA has better thermal stability than FKPA and higher thermal sensitivity than KPA.