We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Citric-acid-crosslinked starch/polyvinyl alcohol composite films reinforced with sodium lignosulfonate for sustainable packaging applications
Summary
Researchers developed starch/PVA composite films crosslinked with citric acid and reinforced with sodium lignosulfonate, finding that the aromatic lignin component simultaneously enhanced mechanical stiffness, cut water vapor transmission, blocked nearly all UV light, and raised antioxidant activity to 90% — combining multiple packaging functions in a single biodegradable film.
Plastic pollution remains a critical global environmental challenge. Although biodegradable polymers offer a sustainable alternative to petroleum-based plastics, their industrial uptake is limited by high moisture sensitivity and insufficient mechanical and functional performance. This study develops multifunctional starch/poly(vinyl alcohol) (PVA) films reinforced with sodium lignosulfonate (LS) and crosslinked with citric acid to address these limitations. A systematic variation of LS content was employed to clarify its role in tailoring interfacial interactions and film performance. Spectroscopic and morphological analyses revealed strong hydrogen bonding and aromatic-polar interactions between LS and the hydroxyl-rich polymer network, modifying surface chemistry and microstructure without disrupting the polysaccharide backbone. These synergistic interactions yielded films with tunable mechanical behavior (modulus 60-218 MPa; elongation up to 0.76), improved barrier performance, such as WVTR reduced to 174 g·m -2 ·day -1 , markedly enhanced antioxidant activity up to 90% DPPH scavenging, and nearly complete UV blocking (∼99.99%). The findings elucidate the molecular mechanisms underlying LS’s simultaneous enhancement of reinforcement, moisture resistance, UV shielding, and antioxidant capacity. Overall, LS-reinforced starch/PVA-citric-acid films demonstrate strong potential as sustainable, high-performance materials for food packaging applications, particularly for protecting photosensitive and oxidation-sensitive products. • Citric-acid-crosslinked starch/PVA films were reinforced with sodium lignosulfonate • Lignosulfonate formed strong interactions within the starch/PVA polymer network • Films showed reduced WVTR and nearly complete UV blocking (∼99.99%) • Antioxidant activity increased up to 90% due to lignosulfonate incorporation • Multifunctional films are promising for sustainable active food packaging