Post Modification of Poly Glycidyl Azide with lonic-Liquid-Based Reactive Plasticizer through Catalyst-Free Click Reaction

摘要

Glycidyl azide polymer (GAP), due to its energy, has found widespread applications in propellants. However, one of the most critical challenges in the propellants is preventing the migration of the plasticizer material from the polymeric matrix. To counter this, a covalent bond was established between GAP and propargyl imidazolium as the reactive plasticizer via click chemistry reaction. Fourier-transform infrared spectroscopy (FTIR) and ~1HNMR analyses were implemented to confirm that the connection has been made properly to minimize the plasticizer migration. Optimization of the amount of the reactive ionic liquid plasticizer in GAP was another issue investigated in this study. Examinations by Differential scanning calorimetry (DSC) analyses, viscometer, and heat of combustion showed that increasing the reactive plasticizer content leads to the lower glass transition temperature, the higher viscosity, and the lower GAP energy. In order to compensate for the lost energy, due to the formation of the covalent bond, a dicyanamide based ionic liquid plasticizer was synthesized as a replacement for the bromide one. It was found that in addition to the reduction of the glass transition temperature (from -50 ℃ to-59 ℃), it was possible to achieve lower viscosity (from 7 Pa.s to 2 Pa.s) and greater propulsion energy (from 19.24 kJ/g to 21.31 kJ/g).