Description Natural fibres are cheap sustainable materials and have high CO2 adsorption, hence they can be the optimum choice for manufacturing sustainable composites. However, they have lower mechanical properties compared to glass and carbon fibres. They also have high tendency for moisture adsorption and poor fire retardancy. These challenges limited the use of natural fibres heavily in industry. Interestingly, cellulose nanofibers were estimated to have Young modulus of  ca. 140 GPa and tensile strength of 2–3 GPa (doi.org/10.1007/s11223-020-00233-3). Therefore, there is a huge potential to significantly improve the performance of the natural fibres in this project via the use of a novel combination of chemical, thermal surface treatments. Key Objectives To understand the microstructure of natural fibresTo understand the limitations of the natural fibresTo explore the effects of chemical, thermal and surface treatments on the properties of the natural fibres