Surface grafting of flax fibres with hydrous zirconia nanoparticles and the effects on the tensile and bonding properties

In the present study, a flax fibre yarn was modified through grafting of hydrous zirconia nanoparticles by hydrolysis of zirconium oxychloride solution, and the effects on the fibre and fiber-bonding properties were investigated. The grafting of the nanoparticles was confirmed by microscopy and spectroscopy analysis. The tensile and bonding strength to an epoxy resin (diglycidyl ether of bisphenol - F) of the modified flax fibres were tested with a single fibre tensile test and microbond pull-out test, respectively. Grafting of the nanoparticles onto the flax fibres brings in an obvious increase in the tensile strength and the interfacial shear strength of the flax fibre to the epoxy resin. An unidirectional flax fibre reinforced epoxy model composite was prepared by hand and characterized in terms of the thermo-mechanical and antimicrobial properties. Surface grafting of the flax fibre leads to an increase in the glass transition temperature and storage modulus, which is attributed to the enhanced bonding strength between the grafted fibre and the epoxy resin. In addition, the treated flax fibre-based composites expressed an antimicrobial performance. The study demonstrates that the fibre surface treatment with grafting of hydrous zirconia nanoparticles is a potential method to enhance the tensile and bonding properties of flax fibres.