Strength and durability that last—Mechanical properties of polyurea and polyurethane coated composites

AbstractMaterials scientists are interested in the development of impact‐resistant materials for military and commercial products. Polyurea and polyurethane are utilized for impact absorption in numerous industries, however, hybrid polymers and their features are rarely explored. Due to their distinct chemical structures and cure kinetics, polyurea‐polyurethane hybrid materials are still in their infancy. The versatility of these materials drives the research to address this challenge. Small‐scale composite companies generally use spray guns to apply chemicals, raising costs. The current study focused on the development of coated composites for impact applications. Polyurea, polyurethane, and their hybrid were used as a coating material on the glass/epoxy composites. The flexural, impact (Charpy and Izod), and thermomechanical properties of these coated composites were investigated. It was observed that coating thickness enhanced impact properties of composite materials. The loss and storage modulus decreased with an increase in temperature for polyurea and polyurethane coated composites. The thermo‐mechanical analysis of hybrid coated composite showed the behavior to be dominantly similar to the polyurethane‐coated composite materials. The flexural strength of glass/epoxy composites increases with the coating, while increasing number of coating layers counters this effect.