Flexible acrylic-polyurethane based graft-interpenetrating polymer networks for high impact structural applications

[Display omitted] •Improvement of the properties due to the chemical bonds between polymers.PU brings.•PU brings impact resistance while copilymer leads thermo-mechanical properties.•Wide range of properties from elastomeric to more ductile.•Excellent transparency and impact resistance. Flexible graft-interpenetrating polymer networks (IPNs) were synthesized out of polyurethane (PU) and acrylic-based copolymers using two co-monomers, styrene and methyl methacrylate (MMA). Chemical bonds between the two polymers participating in the interpenetration network were utilized to decrease the system's phase separation. The effect of changing the composition of the two co-monomers on the properties of the IPN system was studied. Dynamic mechanical analysis (DMA), tensile, and shear tests were used to characterize the thermomechanical and mechanical properties of IPNs sheets/plates and IPNs as an adhesive. A scanning electron microscope (SEM) was utilized to characterize the failure mechanism of the tensile dog bone samples. Moreover, impact tests were performed on a sandwich structure with synthesized IPN as an inter-layer adhesive to characterize the toughness and stiffness of the IPN samples. Overall, excellent transparency and impact resistance in visible light range with a wide range of thermo-mechanical properties (from extreme elastomeric to more ductile) was observed in IPN samples, which shows their tremendous potential in various transparent, high-performance applications.