Impact and tensile properties of PLA/Cordenka and PLA/flax composites

The interest for biodegradable polymers and natural fibre-reinforced polymers has recently grown because of increasing environmental concerns. But the impact properties of bast fibres reinforced polymers cannot reach the levels of traditional fibre-reinforced polymers. PLA (polylactic acid) was reinforced with Cordenka rayon fibres and flax fibres, respectively. The mechanical properties of these composites which are examples for completely biodegradable composites were tested and compared. The samples were produced using injection moulding. The highest impact strength (72 kJ/m2) and tensile strength (58 MPa) were found for Cordenka reinforced PLA at a fibre-mass proportion of 30%. The highest Young’s modulus (6.31 GPa) was found for the composite made of PLA and flax. A poor adhesion between the matrix and the fibres was shown for both composites using SEM. The promising impact properties of the presented PLA/Cordenka composites show their potential as an alternative to traditional composites.