Influence of cure conditions on the properties of a one-component moisture-cured polyurethane adhesive in the context of green gluing of wood

A commercial one‐component moisture‐cured polyurethane‐urea wood adhesive was investigated under different curing environments to simulate parameters during green gluing, that is, gluing of freshly sawn and undried timber. This process is an eco‐efficient and waste eliminating process in which only the finished wood product properties have been tested; however, not the adhesive itself. Therefore, the effect of moisture and postcuring heat treatment on the adhesive properties such as cure, chemical, and physical characteristics, and adhesion to wood were studied. It was determined by rheometry that the water content was proportional to the time to gel point, with moisture content of 2.6–5.6 wt % water, resulting in a higher initial storage modulus of the adhesive. Additionally, it was found that the strength of the wet glued bonds was significantly higher after the heat treatment, corresponding to the increase in ordered bidentate groups (Fourier transform infrared spectroscopy), higher storage modulus (rheometry), and higher Tg (dynamic mechanical thermal analysis). © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012