Application of Glycidyl Azide Polymer to Hybrid Rocket Motor

*A study on the application of glycidyl azide polymer (GAP) to hybrid rocket motors is presented. Efforts were made to spread the burning rate spectrum of GAP, especially to lower side, and the dilution with an inert polymer was selected. Polyethyleneglycol (PEG) was chosen as the diluent from its functional groups, excellent solubility with GAP and relatively high density and low cost. Dilution of GAP with PEG effectively reduces the linear burning rate without the change of pressure exponent and suppresses the self-combustibility beyond a certain critical concentration of PEG. Two types of hybrid motor, gas hybrid type and conventional type, are considered, and mixtures keep the self-combustibility are used as solid fuel for gas hybrid rocket and mixtures lose that are for conventional hybrid rocket. The firing tests have been conducted with small test motors whose inner diameters are 80mm, and the results are presented and discussed.