The effect of carbon nanotubes-grafted lactide on the mechanical and thermal properties of poly (lactic acid) biocomposites

Abstract

Poly(lactic acid) (PLA) derived from renewable crops is a promising substitute for petroleum-based products. Although PLA exhibits positive features, it also possesses drawbacks, such as brittleness, which hinder its extension in specific applications. In this study, lactide (LA) was used to graft carbon nanotubes (CNTs) to reinforce PLA. Under catalysis, LA was polymerized into PLA through ring-opening polymerization and simultaneously was grafted onto CNTs to obtain CNTs modified by LA (LA/CNTs). And the modified CNTs were used to prepare PLA composite films (LA/CNTs/PLA). Analysis of the Fourier transform infrared spectra (FT-IR) of the modified CNTs indicated that LA was grafted with the nanotubes. The scanning electron microscopy images showed that the modified CNTs were compatible and homogeneously dispersed in the PLA matrix. The excellent dispersibility and compatibility of the CNTs led to good interfacial adhesion, which directly enhanced the mechanical properties of PLA. The addition of CNTs also improved the thermal properties of PLA. This research aims to ameliorate the mechanical and thermal properties of PLA and provides basis for flexible fabrication of bio-based PLA materials for a wide range of applications.