Effect of blending sequence and epoxy functionalized compatibilizer on barrier and mechanical properties of PBS and PBS/PLA nanocomposite blown films

This study focuses on developing compostable nanocomposite blown films, aiming to enhance oxygen barrier properties while maintaining good mechanical performance. Polybutylene succinate (PBS) and its blend with polylactic acid (PLA) were selected as matrices for the films. Organo-montmorillonite Delite®43B (D43B) clay was incorporated to improve oxygen barrier, and random ethylene-methyl acrylate-glycidyl methacrylate terpolymer served as a plasticizer and reactive compatibilizer. Different blending sequences were examined to determine the optimal one that led to significant enhancements in both the barrier and mechanical properties of the final nanocomposite blown film. Various techniques, including SEM, TEM, XRD, DSC, oxygen permeability, and tensile testing were employed to characterize the morphology of the compounds and blown films. The results reveal greater oxygen barrier properties depending on the blending sequence. Indeed, a reduction in oxygen permeability exceeding 50% was observed following the addition of 3 wt% of D43B to the PBS/PLA film, selectively localized in the PLA phase. This enhancement further intensified after the addition of 5 wt% of the epoxy functionalized compatibilizer.

Highlights

• Enhancing PLA-PBS compatibility with the epoxy functionalized compatibilizer led to a reduction in the final film's oxygen permeability.
• Achieving ideal ductility and barrier balance in films requires a synergistic blend of components: D43B, PLA, PBS, and compatibilizer.
• Optimizing balanced synergistic effects among compounds depends on the blending sequence method.