PBAT/kraft lignin blend in flexible laminated food packaging: Peeling resistance and thermal degradability

This work evaluates the peeling resistance of PBAT-kraft lignin (KL) blend films as a laminated food packaging layer. PBAT-KL blend films were obtained by extrusion with 0, 1, 3, 5, and 10 wt% KL. The blend homogeneity and miscibility were investigated by atomic force microscopy (AFM) and dynamic mechanical analysis (DMA), respectively. Contact angle measurements were carried out to quantify changes in surface energy. Multilayer composites were obtained by lamination, in which PBAT-KL blend films were bonded to a polyethylene layer using polyurethane adhesive. Peeling specimens were subjected to aging at 60 °C to evaluate the effects of KL addition on the practical adhesion and PBAT degradation. The DMA results indicated polymer miscibility, and the contact angles increased upon KL incorporation. PBAT-KL could be a synergetic solution for food packaging that can integrate the reuse of industrial waste, mechanical properties, flexibility, peeling resistance, and the well-known biodegradability of PBAT. •Combined application of industrial residue and biodegradable polymer in food packages.•Polyurethane adhesion to blends was confirmed by cohesive failure of adhesive layer.•High peeling strength even for blends with high lignin content.•Slight PBAT degradation after aging with no significant practical adhesion loss.•Higher peeling resistance than current food packaging.