A natural-fiber-reinforced bio-based polymer matrix can be considered a sustainable and environmentally harmless source. Natural fibers such as flax, sisal, jute, harakeke, and hemp are bio-based, which makes them fully biodegradable, simply recyclable for detoxification of materials, and appropriate for carbon dioxide footprint purposes. Synthetic fibers have left their place to natural fibers due to natural fiber has decreased greenhouse gas (GHG) emissions, oil dependence, and total cost. In the current study, short flax fiber-reinforced PLA matrix bio-composite was manufactured using extrusion and injection methods. To enhance the interfacial adhesion between the flax fiber and the PLA matrix, alkali treatment was applied to the flax fiber before the extrusion process. The effect of coupling agent and internal lubricant on the composite materials was investigated concerning the mechanical, and thermomechanical properties of the injected composites. The flexural and tensile moduli of the composites were significantly enhanced compared with those of pure PLA samples. The results show that the compatibilizer has a significant effect on the thermal, thermo-mechanical, and mechanical properties of the composite. Dynamic mechanical thermal analysis and thermogravimetric analysis (TGA) results show that the storage modulus of PLA/flax fiber composites is improved compared with those of both pure PLA and composites with the coupling agent. Compared with PLA, the impact strength of composite increased by more than 2 times; while, the elongation at the break did not suffer an obvious reduction.
Anahtar Kelimeler: PLA, Bio-composite, Mechanical properties