Development of the Fire-Retardant Truss Core Sandwich Structures Using Carbon Fiber Reinforced Epoxy Composites

摘要

Abstract The requirement of lightweight structures fabricated from polymer composite-based sandwich panels is ever rising in various industrial sectors. Still, the usage of polymer composites as fire-proofing structures is limited due to their low operating temperatures. In the current study, flame retardancy and mechanical properties of novel ultra-lightweight truss core-based structures with varying ammonium polyphosphate (APP) content, as a flame retardant additive, in the composites are explored. Sandwich composites are fabricated by using epoxy resin with 0%. 2.5%, 5%. 7.5% and 10% APP content. The influence of APP on flame retardancy of the fabricated sandwich composites is investigated through limiting oxygen index (LOI) and UL-94 vertical burning tests. The results reveal that formulation containing 10% APP achieved UL-94?V-1 rating and corresponding limiting oxygen index (LOI) value of 29%. The thermogravimetric analysis demonstrates the thermal stability for the modified epoxy compositions. Mechanical properties of flame retardant truss core sandwich composites are investigated through shear, flexural, and compression testing. A maximum of 872.5, 3814.0, and 152.3?MPa shear, flexural and compression moduli are observed for the fabricated sandwich composites, respectively, with 10% APP content in epoxy. These fabricated sandwich composites could potentially be used in civil infrastructures and marine industries with optimized flame-retardant and mechanical properties.