Furan matrix and flax fibre as a sustainable renewable composite: Mechanical and fire-resistant properties in comparison to phenol, epoxy and polyester

Abstract

Due to environmental and fossil fuel supply concerns, polyfurfuryl alcohol or ‘furan’ resin has recently gained attention as a renewable alternative thermoset resin with reduced CO2 emissions in comparison to the existing petrochemical-based systems. When combined with natural flax fibres, it offers the potential to produce a fully bio-derived sustainable composite with structural mechanical capabilities and fire-resistant properties. In this study, the mechanical properties of furan flax and E-glass fibre laminates are characterised and directly compared to polyester, epoxy and phenolic laminates produced using identical reinforcing fibres and methods. In addition, the acidity and fire-resistant properties are also compared. Furan resin E-glass laminates were found to have mechanical properties comparable to existing resin systems with excellent fire-resistant properties, which are equal to that of phenolic and exceeding polyester and epoxy performance. However, both phenolic and furan flax laminates were found to give reduced mechanical performance in comparison to polyester and epoxy. This reduction in strength was attributed mostly to micro voids surrounding elementary flax fibres believed to be the result of post-cured fibre shrinkage due to moisture uptake.