The effect of plastic additives onto isotactic polypropylene wood composite structure and properties

In recent years, wood plastic composites has gain significant interests in the material science. The use of different wastes obtained from wood dust with thermoplastics lead to new application areas. Especially the sheet and profile forms of wood plastic composites can be used in many applications such as siding, chair, bench, table, on the side of the pool, garden furniture and walking paths, stairs, picture frames and so on. However, some applications are required more durable, quick and easy producible wood plastic composites. In the combination of two different materials, woods and plastics, there are some problems with the production of wood plastic composites. Especially polypropylene (PP) based wood composites has a serious problem during the process. The combustion of wood spread severe gas and weakened the physical properties of resulting composites. The amount of moisture in the dried wood material, volume shrinkage, high temperature and pressure during the extrusion step decompose the composite material and causes a decrease in their qualities. In this case, the color of the product is darkened and the internal structure of composite has a porosity (gas product). In this study; PP based wood composites with dry wood shavings are investigated with various additives to overcome practical problems and to improve physical and mechanical properties of the composites. For this purpose, various additives such as anti-oxidants, heat stabilizers, and compatibilizer with internal and external lubricants are used in the preparation of the composite. Firstly, wood shavings and PP were mixed in the mixer and then they processed in the extruder to form of granules. The test samples were also prepared to evaluate their physical and mechanical properties. Tensile-elongation test, scanning electron microscopy and differential scanning calorimeter were used to determine their mechanical, surface characteristics, phase compatibility and thermal transitions.