The carbon fiber/epoxy composites toughened by fire-resistant glass fiber veils: Flammability and mechanical performance

The fire-retardant properties of high-performance fiber-reinforced composites are the crucial benchmark for composite structure stability. However, in the current flame-retardant solution for composites it is difficult to reach the balance between fire resistance and structural performance due to the deteriorating composite interface. In this work, the carbon fiber-reinforced composite was covered with functional glass fiber layers, in which the glass fiber veil had been treated with flame-retardant agents and silicone-modified waterborne polyurethane, in order to be endowed with flame-retardant capability and structure toughness. As such, a significant improvement in the flame retardancy and mechanical structure of the composites could be observed. When compared with the control, the total heat release and total smoke release for composites with 8% silicone-modified waterborne polyurethane treatment could be decreased by 18.5% and 18.1%, while the tensile and flexural strength were significantly increased by 47.3% and 62.2%, respectively. This well-balanced performance is attributable to the structure design with a toughened glass fiber veil to protect the composite surfaces from fire combustion and structure failure. Therefore, this flame-retardant structure design provides a new strategy to achieve high-performance composites with prospective applications for aircraft and aerospace.

Automated summary

This study presents a flame-retardant structure design for high-performance fiber-reinforced composites, which involves the coating of functional glass fiber layers treated with flame-retardant agents and silicone-modified waterborne polyurethane. This design successfully achieves a balance between fire resistance and structural performance. The composites treated with 8% silicone-modified waterborne polyurethane exhibited a significant decrease in total heat release and total smoke release, while their tensile and flexural strength were significantly increased. This new strategy provides potential applications in aircraft and aerospace.