Energy efficient out-of-oven manufacturing of natural fibre composites with integrated sensing capabilities and improved water barrier properties

Bio-based and eco-friendly materials have gained a great amount of attention, thanks to the increased awareness of sustainable development and global environments. The use of natural fibres in composites can reduce greenhouse gas emissions and the carbon footprint compared to many synthetic fibres. However, some challenges and concerns remain in natural fibre-reinforced plastics, such as the high moisture absorption and high energy consumption during their manufacturing stage. To tackle these challenges, this study developed an energy-efficient out-of-oven manufacturing method based on a conductive biopolymer nanocomposite film to fabricate natural fibre-reinforced composites with integrated multifunctionalities throughout their life cycle. The smart nanocomposite layer works as an autonomous self-regulating heating element to cure the laminates at the desired temperature without the risk of overheating. Extremely high energy efficiency has been achieved with a significantly reduced energy consumption (a 95% reduction compared with traditional oven curing), which has been attained through the direct heat conduction from the surface layer to the laminates. The embedded nanocomposite surface film on the cured laminate subsequently becomes an integrated multifunctional layer, providing integrated real-time deformation and damage sensing capabilities with enhanced water barrier properties to prolong the service life of natural fibre composites.