Wood‐fiber‐reinforced poly(lactic acid) composites: Evaluation of the physicomechanical and morphological properties

TLDR

The study investigates the processing and physicomechanical properties of environmentally friendly wood‑fiber‑reinforced poly(lactic acid) composites. Using a microcompounding molding system, the authors fabricated PLA composites, compared them with wood‑fiber‑reinforced polypropylene composites, measured mechanical, thermomechanical, and morphological properties, and examined interfacial bonding via scanning electron microscopy. The PLA composites exhibited mechanical properties comparable to conventional polypropylene composites, significantly higher than virgin resin, with a flexural modulus of 8.9 GPa versus 3.4 GPa for PP, increased storage modulus, and further improvement from a maleated polypropylene coupling agent, suggesting suitability for automotive and packaging applications. © 2006 Wiley Periodicals, Inc., J Appl Polym Sci 102: 4856–4869.

Abstract

Abstract This article presents the results of a study of the processing and physicomechanical properties of environmentally friendly wood‐fiber‐reinforced poly(lactic acid) composites that were produced with a microcompounding molding system. Wood‐fiber‐reinforced polypropylene composites were also processed under similar conditions and were compared to wood‐fiber‐reinforced poly(lactic acid) composites. The mechanical, thermomechanical, and morphological properties of these composites were studied. In terms of the mechanical properties, the wood‐fiber‐reinforced poly(lactic acid) composites were comparable to conventional polypropylene‐based thermoplastic composites. The mechanical properties of the wood‐fiber‐reinforced poly(lactic acid) composites were significantly higher than those of the virgin resin. The flexural modulus (8.9 GPa) of the wood‐fiber‐reinforced poly(lactic acid) composite (30 wt % fiber) was comparable to that of traditional (i.e., wood‐fiber‐reinforced polypropylene) composites (3.4 GPa). The incorporation of the wood fibers into poly(lactic acid) resulted in a considerable increase in the storage modulus (stiffness) of the resin. The addition of the maleated polypropylene coupling agent improved the mechanical properties of the composites. Microstructure studies using scanning electron microscopy indicated significant interfacial bonding between the matrix and the wood fibers. The specific performance evidenced by the wood‐fiber‐reinforced poly(lactic acid) composites may hint at potential applications in, for example, the automotive and packaging industries. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4856–4869, 2006