Study of disintegrability in compost and enzymatic degradation of PLA and PLA nanocomposites reinforced with cellulose nanocrystals extracted from Posidonia Oceanica

Nanocomposite films based on poly(lactic acid) (PLA) reinforced with cellulose nanocrystals extracted from Posidonia Oceanica plant were prepared by solvent casting method containing 1 or 3%wt of cellulose nanocrystals unmodified (CNC) and modified using a commercial surfactant (s-CNC). The modification improves the dispersion of CNC into the matrix. Enzymatic degradation using efficient enzyme proteinase K and disintegrability in composting conditions were considered to gain insights into the post-use degradation processes of the produced formulations. Results of visual, morphological and thermal analysis of enzymatic degradation studies confirmed that the selected enzyme preferentially degraded amorphous regions with respect of crystalline ones, while the crystallinity degree of the nanocomposite films increased during enzymatic degradation, as a consequence of enzyme action. The disintegration in compositing conditions of different formulations was also investigated by means of visual and morphological analysis. The disintegrability in compost conditions showed that the formulations disintegrated in less than 14 days, in addition it has been proved that CNC modified with surfactant were able to promote the disintegration behaviour. The production of PLA based nanocomposites incorporating cellulose extract from marine wastes suggested the potential application of the proposed material for short-term food packaging with low environmental impact.