Preparation and property evaluations of PCL/PLA composite films

Composite materials prepared from polylactic acid have been used more and more widely in many fields. However, PLA has high brittleness, which largely restricts its application. Blending PLA with polycaprolactone (PCL) helps improve the disadvantages of pure PLA. In this study, different molecular weights of PCL were used and blended with PLA in different proportions to form a composite film by melt blending. The mechanical properties, thermal properties, and water wettability of Composite films are evaluated to examine the influences of the relative molecular weight of PCL and PCL/PLA ratio. When the relative molecular weight of PCL is 50,000, Composite films have high stress, strain, hydrophilicity, thermal properties, and UV-resisting property, but their thermal properties are not affected. At a specific relative molecular weight of PCL and PCL/PLA ratio of 30/70, the composite films reach their maximum stress and exhibit high strain, good hydrophilicity, and UV transmittance lower than 10%. Moreover, the PCL/PLA ratio has a marginal effect on the thermal properties of the composite films. This research has certain significance for promoting the application of PCL/PLA composite film in many fields.