Study on poly(lactic acid)/natural fibers composites

Abstract Recently, the natural fibers‐reinforced composites have attracted substantial attention as a potential structural material for low cost applications. The composites of poly(lactic acid) (PLA) with three kinds of natural fibers, such as bamboo fibers, wood fibers, and coconut fibers (CTFs), were prepared by solution‐casting technique. The natural fibers were modified by aluminum acid ester coupling agent and stearic acid to improve compatibility. To compare the mechanical and thermal properties of composites, tensile test, dynamic mechanical analysis, differential scan calorimeter, scanning electron microscopy (SEM), and Vicat softening point test were carried. The results showed that the addition of three kinds of natural fibers all could improve the mechanical and thermal properties of composites, and natural fibers after modification could further improve tensile strength of composites. And in comparison, the composite of PLA/CTF had highest tensile strength and best thermal properties. When the content of natural fibers were 2%, the highest tensile strength of PLA/modified CTF composites was highest, and it reached 22.5 Mpa which was 20.4% higher than that of pure PLA, and VST of this composite increased compared with pure PLA. Meanwhile, the results of SEM indicated that the modified CTF had best interfacial compatibility to PLA. These results indicated that PLA/natural fiber composites had higher strength and better heat resistance than pure PLA. This study provided the application of PLA industry with a feasible method. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012