In this work, the blend films of poly(lactic acid) (PLA) and poly(ε-caprolactone) (PCL) were prepared by the solvent casting method. The influence of PCL content and compatibilizer on the structure, tensile and barrier properties was studied. The results indicated that PCL showed good dispersion in PLA matrix as tributyl citrate (TBC) was added as a compatibilizer. PCL showed a promotion effect on the crystallinity of PLA/PCL films. The compatibility of PLA and PCL was improved by TBC. The tensile modulus and the elongation at break of PLA/PCL films increased to various extents due to the input of PCL and TBC compared to pure PLA film. The improvement of oxygen and water vapor barrier properties of the blend films were provided and depended on the content of PCL and the appearance of TBC. The transparency of the blend films decreased with the increase of the PCL content.

Keywords: poly(lactic acid); poly(ε-caprolactone); structure; mechanical properties; barrier properties