Analysis of the Influence of Active Compounds Contained in Waste Bio-Fillers on the Biological Degradation Processes of Polylactide Compositions

Fruit pomace, used as bio-fillers for polymeric materials, possesses compounds including polyphenols, showing antimicrobial and antioxidant properties. The aim of this study was to analyze the influence of active substances contained in bio-fillers (apple and chokeberry pomace) on biological degradation of polylactide (PLA) under laboratory composting and in a home composter. The scope of work included chromatographic analysis of the bio-fillers and investigation of changes in the physicochemical properties (color, FTIR spectroscopy, surface energy, mechanical properties) of PLA materials after composting. The chokeberry pomace extract had a more diverse polyphenol profile, including phenolic acids, flavonoids and tocopherols. The presence of polyphenols in chokeberry pomace was found to inhibit PLA biodegradation more effectively than the addition of apple pomace, as evidenced by reduced sample weight loss (maximum 6.9% for PLA/apple and 0.9% for PLA/chokeberry). Despite an initial delay in the initiation of the biodegradation processes of the samples, the pomace did not have a negative impact on PLA composting processes and the materials remained highly susceptible to this type of degradation. The research has provided new data on the effect of mixtures of bio-active compounds from bio-additives on the composting and can be helpful in optimizing the composition of compostable packaging bio-composites.