Advanced Coatings of Polyureas for Building Blast Protection: Physical, Chemical, Thermal and Mechanical Characterization

Due to the increase in the global terrorist threat, there has been a growing demand for materials that can more efficiently protect civil, industrial, and military structures against explosions. In this sense, two new commercial polyureas (A and B), that present high potential to be used as a protective coating on building facades against explosions, were compared in this work, through several tests. Chemical characterization with the Scanning Electron Microscope (SEM) of the surface of the polyureas revealed that the commercial polyurea A has a heterogeneous surface while the other polyurea has a more uniform and homogeneous surface, resulting in a more compact structure. The shock-wave attenuation ability of polyurea is believed to be controlled primarily by the hard domains. The TGA tests revealed that polyurea B has more hard segments than polyurea A in its composition. The mechanical tests performed showed that polyurea B has significantly better tensile properties-almost 3000% of maximum deformation capacity compared with approximately 115% of polyurea A. Thus, it was concluded that polyurea B has more potential to be used as a coating in building blast protection due to its exceptional elongation characteristics, a critical parameter to absorb the high frequency and intensity of blasts.