Investigation of modified polyurea against thermal, shock wave and high-speed fragment threats

The accidents caused by explosions often result in a variety of destructive threats. Protection techniques designed for a single destructive factor are difficult to resist the multiple threats that may exist in the explosion, so it is urgent to have a multi-effective protection function of the protection technology. Within the scope of this research, a new modified polyurea with the addition of halloysite nanoparticle fillers was designed and produced. The influence of different ratios of halloysite on the thermal properties, mechanochemical properties, shock wave attenuation properties, and penetration resistance of the material was investigated. The experimental results show that the addition of halloysite to polyurea materials can significantly improve their thermal stability, thermal insulation and flame retardancy, and also enhance their mechanical properties under quasi-static and dynamic loading. In addition, the halloysite particles can enhance the shock wave attenuation of polyurea materials, and the attenuation effect can be about 20% when the content of halloysite is 3%. Moreover, the addition of halloysite improves the penetration resistance of the polyurea material, increasing the ballistic limiting velocity of halloysite-modified polyurea to 1.24 times that of the pure polyurea material. Highlights: The halloysite-modified polyurea material was designed. The effect of halloysite particles on polyurea materials was investigated. The materials were evaluated for thermal, mechanical, and protective properties.