Preparation and characterization of a bio-based polymeric wood adhesive derived from linseed oil

Abstract

Increasing concerns over environmental health and safety, as well as diminishing fossil fuel reserves, motivate investigation into bio-based alternatives to petrochemically-derived adhesives. Adhesives derived from plant oils show promise as sustainable alternatives due to their abundance and low cost. Such adhesives are especially important in the growing domain of engineered lumber in which the material properties of low-value timber are enhanced using glued layers and joints. Linseed oil, which is derived from flax seeds, is a relatively unexplored feedstock for the preparation of eco-friendly wood adhesives. Herein, we report the preparation of a linseed oil-based adhesive and assess its strength on Liriodendron tulipifera (yellow poplar), Fraxinus americana (white ash) and Pseudotsuga menziesii (Douglas-fir). The results of a systematic study evaluating the influence of crosslinker choice, open-time, press time and adhesive spread rate on the shear strength of the adhesive-wood assembly are reported, as are results from water-soaking-and-drying tests that indicate excellent resistance of the linseed oil adhesive to water. Ultimately, these results show promise for use of the adhesive in timber applications.