Poly(lactic acid) composites reinforced with leaf fibers from ornamental variety of hybrid pineapple (Potyra)

Abstract

While there have been many studies of fibers extracted from pineapple leaves as reinforcement in polymer composites, to date, only commercial varieties have been examined. This work aims to investigate the fibers from the leaves of a hybrid pineapple called Potyra as a mechanical reinforcement in a poly(lactic acid) (PLA) matrix. The fibers were pre‐treated in a NaOH solution (1 wt%) and were incorporated into the PLA by a torque rheometer mixer followed by twin‐screw extrusion. Samples of each composition were injected. The molded composites showed increases of tensile strength from 58.8 to 69.6 MPa, of Young's modulus from 1.9 to 3.5 GPa, and of impact resistance from 28 to 44 J/m, and showed an increase of 5°C in the heat deflection temperature (Abstract Figure). The measured tensile strength and Young's modulus values are lower than the theoretical values obtained by micromechanics theory due to the pull‐out of the matrix fiber and due to the orientation of the fibers in the composites. It was concluded that the pineapple hybrid fibers have potential for use as mechanical reinforcement in green composites.