The Influence of Lyocell and Kenaf Fibres on the Mechanical Characteristics of Poly(lactic acid) (PLA) Composites

The study investigates tensile, flexural and impact characteristics of compression moulded lyocell and kenaf fibre reinforced PLA composites. For the improvement of the impact strength of brittle kenaf/PLA composites lyocell fibres were used as admixture with different fibre loads. Additional to this, biomimetic fibre composites were produced by layering kenaf/PLA and lyocell/PLA. Results of tensile and flexural tests have shown significant reinforcement effects in comparison to the neat PLA matrix for all composites produced. Considering the impact strength, the highest value (85.3 kJ/m(2)) was achieved by using lyocell as reinforcement in comparison to the pure PLA (17.3 kJ/m(2)). With a raising lyocell content an increasing impact strength up to 36.5 kJ/m(2) was observed for the admixture of 50 mass-% lyocell. The value of kenaf/PLA was measured with 14.2 kJ/m(2). An additional significant improvement was measured for the layered kenaf/lyocell reinforced PLA (Iyocell fibre load also 50%) with a value of 50.1 kJ/m(2).