Effect of Coating of Ammonium Perchlorate with Fluorocarbon on Ballistic and Sensitivity Properties of AP/Al/HTPB Propellant

Fluorocarbon polymers are used to enhance thermal stability and electrostatic protection of composite propellant compositions. A precipitation technique has been developed to coat ammonium perchlorate (AP) using a copolymer of hexafluoropropylene and vinylidene fluoride (HFP‐VF) with the help of solvent‐counter solvent method. The coated AP has been used to prepare propellant compositions in different ratio based on hydroxyl terminated polybutadiene (HTPB), aluminium powder along with uncoated AP and studied for viscosity build‐up and visco‐elastic behaviour as well as mechanical, ballistic, thermal and sensitivity properties keeping 86% solid loading. The data on viscosity build‐up indicate that as the percentage of viton coated AP increases end of mix viscosity and viscosity build‐up increase accordingly. The mechanical properties data reveal that tensile strength and percentage elongation are found in increasing order. The burn rate of the composition also increases on higher percentage of HFP‐VF coated AP. The thermal stability of composition increases as the percentage of HFP‐VF coated AP increases. The data on sensitivity indicate that impact sensitivity decreases on increasing the percentage of HFP‐VF coated AP while no change is observed in friction sensitivity value.