Effect of Dicumyl Peroxide on a Poly(lactic acid) (PLA)/Poly(butylene succinate) (PBS)/Functionalized Chitosan-Based Nanobiocomposite for Packaging: A Reactive Extrusion Study

Abstract

Nanobiocomposites with balanced mechanical characteristics are fabricated from poly(lactic acid) (PLA)/poly(butylene succinate) (PBS)blend at a weight ratio of 80/20 in association with varying concentrations of functionalized chitosan (<i>F</i>CH) through reactive extrusion at a temperature of 185 °C. The combined effect of <i>F</i>CH and dicumyl peroxide (DCP) showed insignificant change in tensile strength with a remarkable increase in % elongation at break (∼45%) values. Addition of DCP also caused increase in the molecular weight (<i>M</i> _w ∼ 22%) of the PLA/PBS/1D<i>F</i>CH nanobiocomposite, which is attributed to the cross-linking/branching effect of <i>F</i>CH on the polymers. The interfacial polymer-filler adhesion is also improved, which is observed from the field-emission scanning electron microscopy images of PLA/PBS/1D<i>F</i>CH. For PLA/PBS/1D<i>F</i>CH, the crystallization rate and nucleation density of PLA are increased because of cross-linked/branched structures are developed, which acted as nucleating sites. Therefore, the present work facilitates a simple extrusion processing with a combination of balanced thermal and mechanical properties, improved hydrophobicity (∼27%), and UV-C-blocking efficiency, which draw the possibility for the utilization of the ecofriendly nanobiocomposite in the packing of UV-sensitive materials on a commercial level.