Biobased composites of poly(lactic acid) melt-compounded with bacterial and vegetal nanocelluloses incorporated through different strategies

BOVI, JIMENA; DELGADO, JUAN FRANCISCO; DE LA OSA, ORLANDO; PELTZER, MERCEDES; BERNAL, CELINA; FORESTI, MARÍA LAURA

Polymers

Polymers

Lugar: Basel; Año: 2024

2073-4360

In the current contribution, bacterial nanocellulose obtained from a by-product of Kombucha tea production and vegetal nanocellulose isolated from milled rice husks, were employed as fillers of PLA-based composites prepared by intensive mixing followed by compression molding. Three different nanofibrils incorporation strategies were studied: i.e. direct mixing of dried milled nanocelluloses and PLA; masterbatching by solvent casting of native nanocelluloses followed by melt compounding; and masterbatching by solvent casting of acetylated nanocelluloses followed by melt compounding. Composites with varying filler content (from 0.5 wt.% to 7 wt.%) were characterized in terms of morphology, optical properties, and mechanical performance. Results revealed the relative suitability of each strategy employed to promote nanocelluloses dispersion within the PLA matrix. PLA/nanocelluloses masterbatches prepared by solvent-casting proved to be particularly useful to feed the nanocelluloses into the processing equipment in a dry state with limited hornification. Acetylation also contributed to a better dispersion of both nanocelluloses within the PLA matrix, although no clear positive impact on the mechanical properties of the films was observed. Finally, filler loading played an important role on the films properties by increasing their stiffness while reducing their translucency.