Lithium catalyst concentration influence on bio-polyols structure and polyurethane adhesives properties

Abstract

Polyol structure can be affected by the catalyst used for its synthesis and may affect the curing kinetics and mechanical strength of the final polyurethane (PU). This work aimed to study the influence of catalyst concentration on the structure of bio-based polyols and on the final properties of the polyurethane adhesive obtained from these polyols. Polyols were investigated by Fourier transform infrared (FTIR), gel permeation chromatography (GPC) and hydroxyl index analysis, with the purpose of investigating the polyols chemical state after the synthesis. Results suggest that higher catalyst concentration led to polyols with higher hydroxyl index and other differences in the polyols structure. The influence of the catalysts concentration on the cure kinetics of the polyurethanes was verified using the Fourier transform infrared (FTIR). In addition, peel strength of PU adhesives was obtained by increasing catalyst concentration on polyol synthesis.