International Journal of Mechanical Engineering and Technology (IJMET) Volume 9, Issue 7, July 2018, pp. 1485–1493, Article ID: IJMET_09_07_158 Available online at http://iaeme.com/Home/issue/IJMET?Volume=9&Issue=7 ISSN Print: 0976-6340 and ISSN Online: 0976-6359 © IAEME Publication Scopus Indexed POTENTIAL OF NATURAL OIL-BASED POLYURETHANE AS AN ADHESIVE FOR PARTICLEBOARD PRODUCTION: A REVIEW Norazwani Muhammad Zain and Farizah Adliza Ghazali Fabrication & Joining Section, Universiti Kuala Lumpur Malaysia France Institute, Jalan Teras Jernang, 43650 Bandar Baru Bangi, Selangor, MALAYSIA Eida Nadirah Roslin Automotive Engineering Section, Universiti Kuala Lumpur Malaysia France Institute, Jalan Teras Jernang, 43650 Bandar Baru Bangi, Selangor, MALAYSIA ABSTRACT Particleboard is one of the composite panels fabricated from wood particles blended and bonded together with a synthetic or natural resin under hot pressure. These panels are widely used in the production of furniture and house building such as cabinets, stair treads, table tops, sliding doors, and other applications. Many factors contribute to the quality and properties of the panels. The adhesive is one of the considerations that should be measured in the production process of panels which is directly interrelated to the conditions of product, costs, and use. The demands of formaldehyde-free particleboard are continuously rising nowadays due to its low environmental impact and it is not harmful to human health. The natural oil based polyurethane resin is one of the alternatives to formaldehyde-based resins. Keyword: Polyurethane, particleboard, natural oil, composite panel, and natural fiber Cite this Article: Norazwani Muhammad Zain, Farizah Adliza Ghazali and Eida Nadirah Roslin, Potential of Natural Oil-Based Polyurethane as an Adhesive for Particleboard Production: A Review, International Journal of Mechanical Engineering and Technology, 9(7), 2018, pp. 1485–1493. http://iaeme.com/Home/issue/IJMET?Volume=9&Issue=7 1. PARTICLEBOARD AND ITS HISTORY The wood-based industry has become one of the major economic sectors within the last two decades. The particleboard has popularly grown over the years and widely used in furniture manufacturing, flooring, shelves, partition and rooftop development. Generally, particleboards is often used for interior applications because standard particleboard is not appropriate for areas that are susceptible to high humidity or wetting and it is very prone to discoloration and expansion due to moisture. Consequently, it is infrequently utilized outdoors or in places where there are high levels of moisture. Particleboard originated in Germany was invented by a fighter pilot, German Luftwaffe, and an inventor named Max Himmelheber. The first commercial production of particleboard was at a factory in Bremen, Germany which is dated back to 1887, during the World War II. The first particleboard was made up of sawdust, wood scraps, and shavings; all glued together using a specific resin. In early 1903, the particle boards were manufactured traditionally by hot pressing a blend of sawdust and http://iaeme.com/Home/journal/IJMET 1485 [email protected] Potential of Natural Oil-Based Polyurethane as an Adhesive for Particleboard Production: A Review blood albumen. The technology of particleboard production has evolved reasonably with the modernization of thermal press and adhesive technology. Later, the classification of particleboard is based on its density level which is low, medium and high. The significant improvement in particleboard production throughout the years indicates that the particleboard demand is considered rapidly growing. Nowadays particleboards are manufactured by using temperature and compression with various types of resin, particle, and filler. 2. RAW MATERIALS The main components in the particleboards can be divided into three categories i.e. adhesive (resin), fiber (particle) and additives or filler. The types of particleboards differ significantly in terms of the amount and types of resins used, the size and geometry of the particles, as well as the density of particleboard. Hence, the properties of the raw material have a significant effect on both the manufacture and the physical properties of the final product. For instance, the quality of wood furnish in particleboard is controlled by the wood properties such as acidity, extractive content, density, and machinability. Besides, the impacts of particleboard on the environment are also the matter to be considered. The selection of resin is of important to make sure the particleboard produced has a low impact to the environment. In addition, the additives are used to tailor-made the desired additional properties of particleboard. 2.1. Fibers/ Particles In the particleboard industry, a great range of wood and plants species are used as raw materials. The selected of the wood used is normally determined by the availability and price of the raw material. Particle size acts a significant role in affecting the properties of particleboard. There are wide range of particle sizes and shapes of used in particleboard production. However, the declining of forest reserves has attracted researchers to find other lignocellulosic fibers or particles as an alternative raw material for production of these particleboards [1, 2]. Agricultural residues, such as stems, stalks, leaves, and seed pods are the most suitable candidates as an alternative particle or fiber in particleboard. These crop residues are produced in large quantities throughout the world [3]. There are more than 30 agricultural residues were used as raw materials in particleboard production such as sisal, bamboo, jute, sunflower stalks, hazelnut husk, coconut fiber, walnut shell, almond shell, kenaf, rice husk, coffee husk, sugar cane bagasse, pineapple leaf and peanut shell. All types of fiber used have their own characteristics and performances. The physical and mechanical properties of particleboard from various agricultural residue fibers as raw materials are shown in Table 1. Table 1 Physical and mechanical properties of particleboard based on various wood and agricultural fibers. The resin used mostly from urea formaldehyde and melamine formaldehyde Thickness Water Modulus of Modulus of Density, Fibers Swelling 24 Absorption Rupture, Elasticity, Sources kgm-3 h (%) (%) MOR (MPa) MOE (MPa) Oil Palm 22 58 37 2700 1041 [4] Bamboo 14 – 16.5 45.2 – 47.9 15.7 – 19.2 1936.9 – 2636.6 801 – 873 [5] Banana Stem 15 38.4 50.91 3939.25 780 [6] Coconut 35.28 131.89 17.05 2092.44 580 [2] 1253.22 – Kenaf 32 – 49 86 – 130 12.31 – 15.16 700 [7] 1558.96 Woody Biomass and 40 – 60 125 – 130 2.6 – 4.2 800 – 820 620 – 680 [8] Pineapple leaf Wheat straw 27.3 – 27.7 34.2 – 47.5 18.1 – 26.5 2281 – 3052 – [9] Sago 17 – 24 75 – 90 4 – 7.5 800 – 2500 600 [10] Peanut shell 27.54 - 10.98 1200 800 [3] Corn corb 11.5 121.06 0.8 80 413 [11] Sugarcane bagasse 14 – 18 150 – 240 3.8 – 12 – 300 – 500 [12] Rubberwood 35 94 15.56 2001.63 700 [7] 14.36 – 503.67 – Pinus – 4.03 – 13.87 – [13] 26.98 1827.49 http://iaeme.com/Home/journal/IJMET 1486 [email protected] Norazwani Muhammad Zain, Farizah Adliza Ghazali and Eida Nadirah Roslin 2.2. Adhesives/ Resin Adhesive or resin plays an important role in particleboard production as it works as a binder for the particles to bond together. In particleboard manufacture, factors pertaining to the application/pressing process parameter contribute as much as 50% to the final performance, the rest being due to how good the adhesive itself. A quantity of various categories of resins is used in the particleboard industry, and each has its advantages and disadvantages. Although the effect of resin on production costs is the main concern in the particleboard production the manufacturer also need to consider about the environmental impacts the resin probably cause especially when it encompasses to human health. In wood-based industry, adhesive is characterized as a thermoset resin that being utilized as the medium that attracts the wood particles together to assemble a wood-based panel. Many types of adhesives have been employed in the conventional production of particleboard. Generally, adhesives can be classified into two categories, i.e. synthetic and natural adhesives. Synthetic adhesives are the petroleum-based adhesive. Formaldehyde-based adhesive is the most common synthetic adhesive used in particleboard industry including urea formaldehyde, melamine formaldehyde, and phenol formaldehyde. These synthetic adhesives have rapidly grown commercially due to their excellent performance in improving mechanical properties of the composite panels. Although they could provide panels with superior properties but the consumption of formaldehyde-based adhesives generates an undesired problem as its emission is considered hazardous to human health. They can cause irritation of the eyes, risks of cancer, skin irritation and bronchial health impacts. Some of these adhesives are very sensitive to hydrolysis, and stress scission [14], consequently the formaldehyde-based particleboard are susceptible to have a low water resistance. These compounds also cause serious environmental damage and contribute to the global supply shortage of petrochemical products [15]. Therefore, natural adhesives have been explored by the researchers to replace the formaldehyde resin. Natural adhesives are generally extracted from natural resources that commonly obtained from different sort of plants such as tannin, lignin, and starch. Starch and protein-based