Optimized epoxy foam interface of CFRP/Epoxy Foam/CFRP sandwich composites for improving compressive and impact properties

Composite materials for vehicle parts require lightweight, high strength and good impact properties. In this study, the optimized manufacturing conditions of epoxy foam (EF) were investigated to improving mechanical performance of carbon fiber reinforced plastic (CFRP)/EF/CFRP sandwich composites for vehicle parts such as impact, flexural property. The optimal curing temperature was found to be 60 °C, by measuring the reaction rate, volume increase rate, density, cell size, glass transition temperature, and specific compressive strength of the EF. In addition, foams after 180 °C thermal aging were observed, and the properties of the EF cured at 60 °C were the most stable under the thermal aging. The performance of the sandwich EF composites was investigated using compressive, flexural strength, lap shear strength, and impact tests. The optimized cell condition of the EF was correlated to improving interfacial adhesion of sandwich composite.