Preparation and properties of agglomerated cork panels bound with chitosan binder
In this paper, acidified chitosan was used as an adhesive to prepare aldehyde-free, environmentally-friendly agglomerated cork panels by hot-pressing. After preparation, the physical, mechanical, and the finishing properties of the chitosan-glued agglomerated cork panels were investigated. The optimal mass ratio of acetic acid solution (1 wt.%) to chitosan was determined to be 30:1. The resulting hot-pressed agglomerated cork panels, which featured a density of 0.55 g.cm-3 and a thickness of 4 mm, exhibited a tensile strength of 1.70 MPa and a thermal conductivity of 0.11 W.m-1•K-1. The agglomerated cork panels coated with the oil-based polyurethane and water-based, acrylic-modified polyurethane paints exhibited significantly lower lightness and higher glossiness. The total color differences (ΔE*) of both agglomerated cork panels increased before and after finishing. The oil-based polyurethane paint coating exhibited high adhesion of paint film, reaching a level-0 adhesion, while the water-based, acrylic-modified polyurethane paint coating achieved a level-1 adhesion. The abrasion resistance results showed that the substrates of cork agglomerates coated two types of paint did not expose after undergoing abrasion for 100 revolutions at the turntable speed of 60 rpm.