Evaluation of whey protein for modifying urea-formaldehyde in medium-density fiberboard (MDF) production

Abstract

During the cheese-making process, a protein-rich solution becomes a by-product. When released into nature, it damages the ecosystem and harms the environment. This waste material, named “whey,” is a renewable resource. This study aimed to use the whey protein to modify urea-formaldehyde (UF) adhesive for medium-density fiberboard (MDF) production. Concentrated (CWP) and isolated (IWP) whey proteins were selected, along with different combinations of lignocellulosic fibers: mostly hardwood (HBF), mostly softwood (SBF), and pure hardwood (PHw). Some physical and mechanical properties and formaldehyde emission values of produced panelswere determined. The best result for the 24-hour water absorption test was determined with a value of 35% with 10% IWP and PHw. The highest tensile strength (0.8 N/mm2), bending strength, and modulus of elasticity were obtained from boards produced with 10% IWP. It was determined that the free formaldehyde emission value obtained from the panel groups produced with WP and IWP was higher than that produced with standard UF. As a result, whey protein should be evaluated for modifying the UF adhesives and should get some satisfactory MDF properties. More research should be done to improve the formaldehyde emission values of the MDF panels produced with CWP/IWP-modified UF resin.