A New Biodegradable Flexible Composite Sheet from Poly(lactic acid)/Poly(ε-caprolactone) Blends and Micro-Talc

The influence of talc loading on phase morphology of PLA/PCL/talc composites and improvement in resulting properties are reported. Talc-based composites of PLA/PCL blends were prepared by melt blending. SEM analysis demonstrates that PLA appears as discrete domain phase, while PCL acts as a bulk phase in the blend. Talc addition decreases PLA domain sizes and voids in the matrix. This results in significant improvement of oxygen and water vapor barrier properties of composite by 33 and 25%, respectively, at 3 wt.-% talc loading. DSC shows that talc acted as nucleating agent for PCL phase in the composite and improves its crystallinity. Various theoretical models based on dispersion and filler geometry are used to predict the tensile modulus and oxygen permeability.