A Review of Bio-Based Adhesives from Primary and Secondary Biomass for Wood Composite Applications

Today there is a great demand in the market of wood-based panels like medium density fibreboard (MDF), plywood and oriented strand board (OSB). These boards provide functionality in various industrial fields from building to furniture production. All are produced from timber and some type of binding resin, the most often used in Europe are phenol formaldehyde (FF), isocyanate (MDI) and melamine urea formaldehyde (MUF). These resins guarantee sturdiness of the material but are toxic to humans and makes recycling of the wood-based panels very difficult. There are attempts of wood-based panels industry to transition away from fossil-based adhesives. Various resins have been developed using lignin and tannin or protein. Soy based adhesive SOYAD™ has already reached the market, other soy protein-based adhesives are integrated into ultra-low formaldehyde emission particle boards like Nu green 2 and Transform™. This paper gives an overview on bio-based adhesives that are used or have the potential to be used for wood-based panel production.