Abstract:

Adhesion interaction in the fibre-matrix interface is important in all composites used in load-bearing applications. To improve interfacial adhesion, various treatment methods of the fibre surface are applied. In this work the influence of chemical and/or mechanical treatment on the adhesion interaction of polyester (UP) resin or poly(lactic acid) (PLA) polymer composites reinforced by flax or cotton yarns was investigated by means of contact angle measurements and uniaxial tensile testing. It was obtained that the tensile strength of UP or PLA biocomposites increases when cotton and flax fibre undergo mercerisation, twisting or pre-tension, while the effect of bleaching was negligible. The combination of treatment methods is especially effective when mercerised or twisted fibres are pre-tensioned. The investigations proved that fibre treatment creates possibilities to obtain natural fibre reinforced biocomposites with mechanical properties comparable to those of glass fibre reinforced composite.