Enhancement of Natural Flax Fibers’ Mechanical Properties via Supercritical Fluid Treatment

Abstract

The interest and investment in lightweight, carbon-negative material solutions have soared in recent years, as many industries seek to reduce their carbon footprint. Natural fibers and their composites represent a promising solution due to their carbon negativity, low density and high specific strength. Unfortunately, their low modulus and high variability in properties and performance have made them uncompetitive with glass fiber in structural polymer composite applications. This study examines the effects of a treatment in supercritical CO2 on the morphology and properties of flax technical fibers. The treatment resulted in a 50% reduction of fiber porosity, a 33% increase in modulus and 40% increase in strength. Overall, this study develops a treatment with the potential to significantly improve the mechanical properties of natural fibers, making them prospects for use in lightweight, semi-structural composite applications.