Sustainable Treatments of Pineapple Leaf Fibers for Polylactic Acid Based Biocomposites

Sustainable composite materials based on biopolymers and natural fibers have attracted remarkable consideration globally due to their tremendous potential for a variety of applications. However, the poor compatibility among the natural fibers and biopolymers causes the reduced mechanical properties of the biocomposites, limiting their application spectrum and acting as one of the major barriers to commercialization. Therefore, surface modification of fibers using chemicals has been explored by several authors. However, most of the chemicals used are hazardous to the environment when used commercially. In the current investigation, sustainable chemicals (sodium bicarbonate and borax) were used to modify the surface of the pineapple leaf fibers (PALFs). Untreated and treated PALF/polylactic acid biocomposites were manufactured using the commercial-scale injection molding machine. The selected chemical treatment strategies were found to be efficient for improving the strength, crystallinity, and thermal properties of pineapple leaf fiber (PALF). An improved adhesion among the fibers and matrix, enhanced strength (tensile, flexural, and impact), and modulus (tensile and flexural) of the biocomposites were also recorded after the treatment. A robust structure-property linkage for PALF and their biocomposites has also been developed.

Automated summary

Sustainable composite materials based on biopolymers and natural fibers have shown great potential for various applications, but the poor compatibility between natural fibers and biopolymers limits their commercialization. In this study, sustainable chemicals were used to modify the surface of pineapple leaf fibers, resulting in improved strength, crystallinity, and thermal properties. The treatment also enhanced the adhesion between fibers and matrix, and improved the strength and modulus of the biocomposites.