Rheological behavior and morphology of poly(lactic acid)/low-density polyethylene blends based on virgin and recycled polymers: Compatibilization with natural surfactants

Blends based on poly(lactic acid) and low-density polyethylene were compatibilized exploiting an innovative strategy involving the introduction of different mixtures of two sustainable liquid surfactants characterized by dissimilar hydrophilic-lipophilic ratios. The compatibilization method was first applied on blends made of virgin polymers, aiming at assessing the surfactant mixture inducing a more significant morphology refinement. Besides, to verify the effectiveness of the selected compatibilizers on recycled materials, the same process was carried out on blends based on reprocessed polymers. Interestingly, the compatibilization caused a significant microstructure modification, with a decrease of 54% of the mean size of the dispersed particles, in the case of virgin polymers-based blends, with a consequent increase of 19% of the dynamic elastic modulus. On the other hand, in the case of reprocessed polymers-based blends, a different compatibilizer efficiency was observed, as the noncompatibilized blend showed amore regular microstructure compared to the compatibilized counterpart.

Automated summary

The study involved using mixtures of two sustainable liquid surfactants with different hydrophilic-lipophilic ratios to compatibilize blends of poly(lactic acid) and low-density polyethylene. The compatibilization significantly altered the microstructure, reducing particle size and increasing dynamic elastic modulus in virgin polymer-based blends. However, the efficiency of the selected compatibilizers varied in reprocessed polymer-based blends, showing different effects on microstructure compared to noncompatibilized blends.