Preparation and characterization of poly(lactic acid) plasticized with vegetable oils and reinforced with sisal fibers

The aim of this work is to prepare a poly(lactic acid) (PLA) based formulation which shows better toughness than neat PLA and maintains similar tensile strength and modulus values. For this purpose, PLA was plasticized with epoxidized and non-epoxidized linseed and soybean oils and the effect of different plasticizers contents as well as the presence of epoxy groups on the mechanical and thermal properties of plasticized PLA systems were evaluated. On the other hand, PLA systems plasticized with 10 wt% of vegetable oil were reinforced with 30 wt% NaOH treated sisal fibers, and the effects of combination of plasticizers and fibers on the degree of crystallinity, thermal and mechanical properties were studied. It must be highlighted that by the combination of epoxidized vegetable oils and fibers, the elongation at break and tensile modulus values can be improved around 70% and 30%, respectively, respect to neat PLA maintaining similar tensile and impact strength values.