The effect of surface treatment on the performance of flax/biodegradable composites

In the present study, three series of natural fiber-polymeric composite materials have been prepared and experimentally studied, in terms of Scanning Electron Microscopy, Differential Scanning Calorimetry, Tensile-Flexural testing, Dynamic mechanical analysis and Creep. The materials are unidirectional flax fiber composites, prepared with the “film stacking method”, based on three types of biodegradable polymeric matrices. The addition of flax fibers with this method leads to a significant toughening of the polymers under investigation. In order to further improve the composites thermomechanical performance, three different surface treatments of flax fibers, namely silanization, plasticization and treatment with maleic anhydride, were employed. The effect of the fibers treatment on the mechanical properties of the composites has been comparatively studied and discussed. The surface treatment with maleic anhydride resulted to the highest Young's modulus increment, whereas silanization and plasticization improved both tensile and flexural properties. Similar effect was obtained for storage modulus increment, as well creep resistance of the composites with modified flax fibers.