Increasing fire retardancy of natural wood fibre board with colloidal silica-based geopolymer

Abstract

Natural fibre contains cellulose, lignin, and hemicellulose, which makes it a highly flammable material. It is easily burned to decomposition and transformed into black charcoal with an average ignition temperature of around 300℃ [1]. However, natural fibre is widely used in architecture by adding it into brittle concrete or polymer matrix due to the durability, sustainability, and increasing strength of fibre material [2]. Therefore, how to increase the fire retardancy of natural fibre-based material has been a challenge for engineers. Contributions such as attaching common fire retardant materials like Mg(OH)2 and fly ash had been researched. Geo-polymer acts like inorganic polymer with non-carbon element, mainly silica-based network structure, which provides excellent mechanical properties, and high compressive strength up to 100 MPa [3]. Meanwhile, the geopolymer shows high fire retardancy compared with polymers. Thus, geopolymer like concretes have dominated the construction material with its expected characteristics. All above, an optimized system consisting of natural fibre and silica geopolymer was developed by adding 40% colloidal silica solution with Potassium hydroxide into natural fibre board as matrix. This system aims on increasing the fire retardancy of the board by attaching the matrix onto the fibre providing a protection layer. By adjusting the silica versus potassium ratio, the effect of fire retardancy changed. Comparing different systems with several fire property tests; the most appropriate concentration was found.Bachelor of Engineering (Materials Engineering