Polyethylene Terephthalate/Carbon Fabric/Polyurethane Foam Sandwich Composites: Flame Retardance and Mechanical Properties

Polyethylene terephthalate (PET) nonwoven fabrics, carbon fabrics (CF), and flexible polyurethane (PU) foams are made into novel sandwich composites using one-step molding. The flame retradance and mechanical properties of the sandwich composites are evaluated, examining the influences of the content of flame retardant agent (20, 30, 40, and 50 wt%) and areal density of PET panels (200, 300, and 400 g/m2). The test results show that the PET/CF/PU sandwich composites are rated flame retardant as V0 and do not generate melts. The failure mode of PET/CF/PU sandwich composites converts from overall fracture to layered fracture as a result of increasing the flame retardant agent. The tensile strength at break of PET/CF/PU sandwich composites with corresponding PET panels is 650 N for 200 g/m, 928 N for 300 g/m, and 1744 N for 400 g/m2, which are 42.63 %, 60.48 %, and 77.85 % greater than those of the PET/PU sandwich composites. Moreover, the bursting strength of PET/CF/PU sandwich composites with corresponding PET panels is 3322 N for 200 g/m2, 3869 N for 300 g/m2, and 4978 N for 400 g/m2, which are 195%, 180%, and 143% greater than those of the PET/PU sandwich composites.