Efficiency of castor oil-based polyurethane in the production of plywood panels

Plywood panels are produced with polymeric adhesives derived from petroleum that can be hazardous to health and the environment, since they are made from non-renewable sources and contain organic solvents in their composition, which can cause diseases such as cancer.Polyurethane adhesives derived from castor oil-based are an alternative to those materials, because it is biodegradable and non-hazardous.The aim of this work was to evaluate the mechanical properties of plywood panels made with polyurethane adhesive derived from castor oil-based.Panels were produced with five sheets of Pinus caribaea bahamensis wood and three different adhesives: urea-formaldehyde, phenol formaldehyde, and polyurethane with a glue spread line of 180 g/m 2 for phenolic adhesives, and 120, 140, 160, 180 g/m 2 for polyurethane.The panels were evaluated in terms of specific mass, shear strength before and after immersion on boiling and cold water, in cycle and without immersion, and bending strength parallel and perpendicular to the fibers orientation.Results were statistically analyzed.The plywood panels produced with polyurethane adhesive derived from castor oil have superior shear strength and bending strength similar than those produced with the others tested adhesives, and the weight of 120 g/m 2 is the most suitable for bonding.