Hydrolysis, Biodegradation and Ion Sorption in Binary Biocomposites of Chitosan with Polyesters: Polylactide and Poly(3-Hydroxybutyrate)

The film binary composites polylactide (PLA)-chitosan and poly(3-hydroxybutyrate) (PHB)-chitosan have been fabricated and their functional characteristics, such as hydrolysis resistance, biodegradation in soil, and ion sorption behavior have been explored. It was established that hydrolysis temperature and acidity of solutions are differently affected by the weight loss of these two systems. Thus, in the HCl aqueous solutions, the stability of the PHB-chitosan composites is higher than the stability of the PLA-chitosan one, while the opposite situation was observed for biodegradation in soil. The sorption capacity of both composites to Fe3+ ions was investigated and it was shown that, for PHB-chitosan composites, the sorption is higher than for PLA-chitosan. It was established that kinetics of sorption obeys the pseudo-first-order equation and limiting values of sorption correspond to Henry's Law formalism. By scanning electron microscopy (SEM), the comparative investigation of initial films and films containing sorbed ions was made and the change of films surface after Fe3+ sorption is demonstrated. The findings presented could open a new horizon in the implementation of novel functional biodegradable composites.

Automated summary

In this study, binary composites of polylactide (PLA)-chitosan and poly(3-hydroxybutyrate) (PHB)-chitosan were fabricated and their functional characteristics, such as hydrolysis resistance, biodegradation, and ion sorption behavior were investigated. The stability of PHB-chitosan composites was higher in HCl aqueous solutions, while PLA-chitosan composites showed higher biodegradation in soil. The sorption capacity of PHB-chitosan composites for Fe3+ ions was higher than that of PLA-chitosan composites. The findings suggest potential applications of these biodegradable composites with improved functional properties.