Thermal Curing of Cold-Mixing Polyurea: Mechanical Performance Enhancement

Polyurea elastomers are widely used in industry thanks to their exceptional mechanical properties. However, cold-pour systems typically require extended ambient curing times to achieve optimal performance. This study investigates whether accelerated thermal curing can replicate or exceed the mechanical properties obtained through the standard ambient cure protocol. Specimens were prepared by hand-mixing and then cured at temperatures of 50 °C and 70 °C for 1 h, 3 h and 6 h. Selected specimens were then aged at room temperature for up to 7 d. Uniaxial tensile tests were conducted, with strain measured via a video-tracking technique. Porosity analysis was performed using cross-section micrographs. The results show that a 6 h cure at 50 °C yields mechanical properties comparable to those obtained through the standard ambient cure, while a 6 h cure at 70 °C significantly surpasses them. Post-cure aging was found to be particularly effective for specimens with a thickness of 1.5 mm, achieving a tensile strength of 4.7 MPa after 7 d, exceeding that declared by the manufacturer.