Synthesis of Poly (Lactic Acid) ( PLA )/Graphene Oxide ( GO ) Composite Films With Improved Mechanical and Gas Barrier Properties

Biodegradable polylactic acid (PLA) is promising in food packaging and biomedical engineering fields due to its biodegradability, renewability, and biocompatibility. PLA/graphene oxide (GO) composite films were manufactured by melt blending PLA and solution cast PLA/GO masterbatch. The morphologies, microstructures, thermal behaviors, mechanical properties, and oxygen barrier property of PLA and PLA/GO composite films were holistically investigated. It has been found that GO decreases the cold crystallization onset temperature ( T c ) of PLA and thus promotes the nucleation of PLA matrices. PLA matrices within PLA/GO composites possess double melting peaks in thermograms based on differential scanning calorimetry (DSC). The tensile strength of PLA/GO composite films with 0.5% GO is enhanced by 9.1%, without much loss of ductility as compared with neat PLA film. The oxygen permeability of such composite films is reduced by 62.4% with 0.5 wt% GO inclusion, which is attributed to uniformly dispersed thin‐sheet GO within PLA matrices and enhanced crystallinity of PLA. The results obtained from X‐ray diffraction and Raman spectra analyses indicate that no evident chemical interaction takes place between GO and PLA matrices. GO is regarded as a promising filler to reinforce PLA biopolymer films, which shows great potential as the source materials of packaging and tissue engineering.