Preparation and characterization of branched energetic polymers

Abstract

The energetic binders are important constituents of energetic material composites such as propellants. The most widely used energetic binders such as GAP are the polyurethane based, produced by curing reaction of the energetic prepolymers with isocyanates. Energetic plasticizers are key ingredients which help to improve the processability and flexibility of the energetic binders.

The effects of plasticizers on energetic binders are required to be investigated to develop the further applications of plasticized binders. This research aims to investigate the efficiency of GAPA and BuNENA plasticizers to lower the viscosity and glass transition temperature and improve the flexibility of GAP based energetic binder systems with different degree of branching. The viscosities, glass transition temperature and storage modulus of binder/plasticizer mixtures were measured as a function of plasticizer loading. The activation energy for flow and plasticizer efficiencies were calculated respectively for the two plasticizers.

The results indicate that the BuNENA plasticizer provides a lower activation energy to flow of the energetic binders as compared to GAPA. The BuNENA plasticizer had a higher plasticizing efficiency in lowering the glass transition temperature of the binders. The BuNENA plasticizer could improve the flexibility and provide the larger elastic region for the cured binders.