Investigation of SMC Flame Retardants for Application in Battery electric Vehicles

The growing importance of electric mobility has led to an increased demand for safety technologies in the automotive sector such as flame protection of battery cases for electric vehicles. Sheet molding compound (SMC) has gained increasing popularity as a structural material for battery cases in recent years. The excellent co-molding capabilities of unsaturated polyester polyurethane hybrid (UPPH) resin-based SMC with prepreg materials enable an economical process and excellent mechanical properties. In this study, the flame resistance of UPPH SMC in combination with the flame retardants (FR) aluminum trihydrate (ATH) and expandable graphite (EG) have been investigated. SMC formulations were developed and material with ATH and EG was produced. All materials were characterized using viscosity measurements, thermogravimetric analysis and the UL94 flammability test as well as tensile tests and bending tests.