Study of adhesive behavior of lignin-containing polyurethane on aluminum: chemical interactions and bondline thickness effects

Abstract

Kraft lignin is a non-edible industrial residue generated worldwide in large quantities (50 million tons per year), and less than 2% of this amount is isolated and commercially available for industrial applications. The most part of produced Kraft lignin is burned providing energy required for pulp mills operation. However, more lignin is produced than required for such current applications. This project intends to elucidate the possible interactions between lignin-containing polyurethane (PU) adhesives and a native aluminum surface (Al), which might corroborate to the development of this polymer applied as adhesives, and consequently, to the reuse (in large scale) of this industrial bio-based and non-edible waste. Adhesive interactions between PU and Al are investigated by combining two infrared spectroscopy methods (ATR and ERAS). The effects of bondline thickness on mechanical behavior are studied under finite deformation and shear loading experiments. (AU)