Design and characterization of ramie fiber-reinforced composites with flame retardant surface layer including iron oxide and expandable graphite

Abstract

Abstract The ramie plain-woven fabric-reinforced epoxy composites with iron oxide (IO) powders and expandable graphite (EG) particles were fabricated by the hand lay-up and vacuum bagging pressing. The flame retardant layers with IO powders and EG particles have been designed on the surface of the composite structure, to improve the composites flame retardancy. The flame retardancy property of the composites was discussed from the limited oxide index (LOI), vertical burning test, and cone calorimeter test, while the flexural property and interlaminar shear strength of the composites were also investigated through the three-point flexural tests, respectively. It was found that the flame retardancy property of the composites, which contains both IO powders and EG particles, can be greatly improved. However, IO powders and EG particles have a negative effect on flexural properties and interlaminar shear strength of the composites. Also, prepreg with IO powders or EG particles which laminated on the surface layer of the composite with different orders would result in different performances.