Polyisocyanate-based water-soluble polyurethane/CaCO3 composites for gunpowder storage

Abstract

The need for improved gunpowder storage to recycle used gunpowder is increasing due to global warming and the economic losses incurred by withdrawing the gunpowder and by its storage. Herein, we fabricated an aliphatic water-soluble polyurethane (WPU) to be used for gunpowder storage, which allows for easy separation of the matrix (WPU) from the gunpowder by solubilizing the WPU with water. We used an aliphatic polyisocyanate as the main hard segment and polyethylene glycol as the soft segment. The usage of an aliphatic polyisocyanate is assumed to enhance the thermal stability and mechanical properties of the composites. We applied the solution polymerization process to fabricate the WPU. CaCO3 was used as a fake gunpowder. The tensile strength of the 40% diisocyanate-treated CaCO3 WPU composites was increased by 3.5 times as compared to the neat WPU and the elongation at break point was also significantly improved. The thermal stability of the composites was greatly improved by the utilization of the treated CaCO3 particles in the WPU matrix. The hydrophilic nature, identified by contact angle measurements, of the composite is interesting, less than 65°, which proves a good hydrophilic composite has been fabricated. The structure of the polymer was confirmed via FTIR analysis and proton NMR investigation.