No abstract

Membranes were prepared from alkaline lignin and poly(vinyl alcohol) (PVA) by a film casting method, and their properties were evaluated. These blend membranes can aptly be termed as green by nature as they are totally non-toxic and eco-friendly. The optimal mass ratio was determined based on the mechanical properties of membranes. The microstructure, mechanical properties, oxygen and carbon dioxide transmission, light transmittance, and thermal stability of the membranes were investigated. The blend membrane exhibited better thermal stability and barrier performance to oxygen and carbon dioxide than a PVA membrane due to the incorporation of alkaline lignin. Both tensile strength and elongation at break were increased with increasing mass fraction of alkaline lignin up to 15%, at which point the maximum of tensile strength and elongation at break were 43.65 MPa and 211.6%, respectively. The blockage of visible light at 600 nm was 62.36%, which was an improvement of 314.90% compared with the PVA membrane (13.36%). Based on this result, we suggest that the mechanical properties of blend membrane containing 15% alkaline lignin are excellent and better than PVA membrane (40.26 MPa, 179.37%). Thus, an alkaline lignin/PVA blend membrane was judged to be potentially suitable as an eco-friendly packing material.