High-strength, recyclable and healable polyurea/aramid fiber elastomeric composites

The demanding and rigorous modern work environments present significant challenges to the protective capabilities of engineering materials. Polyurea elastomers often face limitations in terms of inadequate strength and a lack of weather resistance, however, polyurea composites holds great promise in addressing these issues. This study prepared modified ultrafine aramid short fibers using a mechanochemical method. Subsequently, in-situ polymerization was utilized to combine the modified ultrafine aramid short fibers (M-AF) with polyurea, resulting in the synthesis of a composite material characterized by recyclability, robust weather resistance, and favorable mechanical properties. Subsequently, intensive researches were conducted on the mechanical properties, recyclability, self-healing performance, weather resistance, and chemical medium resistance of the composites. The composite at 0.1 wt% of M-AF exhibited improvements in tensile strength (27.2 +/- 0.8 MPa) as well as obviously enhanced impact performance (428.8 +/- 6 kJ/m2), and recovered most of its mechanical properties after recycling and self-healing. Moreover, the composite exhibits excellent weather resistance and chemical resistance, enabling it to uphold its exceptional protective performance even in the face of challenging environments.Highlights Ultrafine aramid fibers were prepared using a simple mechanochemical method. Mechanochemical methods were employed to surface modify aramid fibers. The composites have good strength, recyclability, weather resistance. Modified ultrafine aramid fibers were prepared using mechanochemical methods, and polyurea/aramid fiber composites were prepared. Mechanical and impact tests were conducted on composites. According to the principles of green environmental protection, the recyclability and self-healing performance of composites were studied. In addition, the resistance of composites to chemicals and weather conditions was also tested. image