• Michelin, M.
• Silva, L.
• Ma, Cerqueira
• Ja, Teixeira
• Lm, Pastrana
• Jm, Vieira
• Colussi, Francieli
• Jt, Martins

Abstract

Organosolv lignin extracted from vine pruning residues was added to hydroxypropyl methylcellulose (HPMC)-based films using three strategies: i) lignin incorporated into the film (lignin-based film), ii) lignin nanoparticles (LNPs) incorporated into the film (LNPs-based film), and iii) lignin coated on HPMC films' surface (lignin-coated film). The films obtained by solvent casting were evaluated in terms of morphology, water barrier and mechanical properties, and antioxidant capacity. Results showed that LNPs incorporation did not affect the films´ water vapour permeability (WVP). Nonetheless, the lignin-based and lignin-coated films improved the water barrier properties of HPMC-based films, achieving a 31.5 and 36 % reduction of WVP, respectively. The morphological evaluation, performed by scanning electron microscopy, revealed films' morphology changes with the lignin incorporation, which was more evident in the lignin-based films. Fourier transform infrared spectroscopy (FTIR) showed minor changes in the film's structure using the different lignin incorporation methods. The mechanical properties were improved, including a significant increase in the tensile strength in the lignin-based and lignin-coated films. All films showed high radical scavenging activity (RSA) after 24 h, with a gradual increase in the lignin-coated films throughout time. The lignin-coated films showed to be the most promising incorporation strategy to improve the HPMC-based film's properties.

Topics

• nanoparticle
• surface
• scanning electron microscopy
• strength
• lignin
• permeability
• solvent casting
• casting
• tensile strength
• Fourier transform infrared spectroscopy