Effects of halloysite nanotube on the performance of natural fiber filled poly(lactic acid) composites

Abstract

Poly(lactic acid) (PLA) derived from renewable resources is an alternative to petroleum-based polymers. In this work, natural fiber filled PLA-halloysite nanotube (HNT) composites were prepared using melt blending followed by compression molding. Maleic anhydride grafted onto PLA (MA-g-PLA) was used to improve the interfacial bonding quality between hydrophobic and hydrophilic phases in the natural fiber filled PLA-HNT composites. The performance properties of the natural fiber filled PLA-HNT composites were characterized by tensile, flexural and impact tests, thermogravimetric analysis, differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). DSC results showed that the loading of HNT could promote cold crystallization, and the improvement of crystallinity of the PLA-HNT composites was by 16% with the addition of MA-g-PLA. The flexural and impact strengths of PLA-HNT composites were not affected adversely up to 10 phr of HNT loading, but tensile strength of PLA-HNT composites decreased gradually. In addition, numerous agglomerates of the nanotubes for PLA-HNT composites with 15 phr loading of HNT were detected with SEM micrographs. However, moduli of elasticity of PLA-HNT composites enhanced by 40% with increment of HNT loading in polymer matrix. Based on the findings, HNT could be used as nanofiller up to 10 phr in PLA matrix.