The use of natural fibres in composites is continually growing, but despite the progression, a lot of barriers still exist such as the poor mechanical performance of natural fibres and existing resin systems. Natural fibres tend to absorb moisture and bond best to resins of similar composition. The issue is that resins currently used in composites are optimized for glass and carbon fibres and do not bond well to natural fibres. This issue leads to poor mechanical performance. This project looked at how to improve the bond and therefore the mechanical performance of natural fibres in composites.
To do this, a better understanding of the surface properties of natural fibres is required. This is to identify modifications, treatments and/or additives that optimize the compatibility between biofibres and resins (synthetic and bio-based).
In this project, three fibre-resin systems were investigated: two consisting of biofibre mats with traditional synthetic resins such as epoxy and polyester used in thermoset composites, and one consisting of biofibre mats with a bio-based resin that is currently in development. To examine the adhesion properties at the fibre-resin interface of these composites, various analytical and imaging methods were used to probe the interfacial regions as well as mechanical testing.
Follow up studies are planned to explore other resin-fibre systems of known chemical interactions to better understand their possibilities and limitations. The future work will also include the modification of natural fibres to get composites with improved mechanical properties. Mechanical tests will also be performed using these new composites in order to correlate the findings with the imaging results.