Ligine production and assessment in polystrene composite production

In this study, lignin obtained in the laboratory and purchased from the market was used as a filler in polystyrene polymer. How lignin affects the mechanical, physical and morphological properties of polystyrene material was investigated. The aim of the study is to make polystyrene, one of the most used thermoplastic materials in the world, more environmentally friendly by using lignin, a natural polymer, and to increase the mechanical resistance properties of polystyrene. Polystyrene can remain intact in nature for hundreds of years. For this purpose, waste polystyrene was used in the study. Thus, it also aimed to recycle polystyrene. As a method in the study, the polystyrene acetone lignin mixture was melted in the solvent and the rubber-like mixture was molded and kept in the oven until the solvent was removed. When the solvent acetone moved away from the composite, the composite hardened. Composites taken from the furnace were sized and analysis samples were prepared. In the mechanical characterization of lignin-filled polystyrene composite, bending, modulus of elasticity in bending, tensile and shock analyzes were carried out. In physical characterization, water uptake, swelling and density analyzes were performed. In morphological analysis methods, the surface and matrix inner surface of the composites were examined using a stereo electron microscope. According to the results obtained, an improvement in the bending strength of lignin-filled polystyrene composites was detected. Despite the improvement in bending strengths, the addition of lignin reduced the tensile strengths of the composite. While elongation rates at break decreased in commercial lignin, they increased in the use of lignin obtained by the DES (Deep Eutectic Solvents) method. As the physical properties of the composites increase, the swelling and water absorption amounts increase, while the densities decrease. When the results obtained are evaluated in general, positive results were obtained from the reinforcement of polystyrene polymers with a natural polymer such as lignin.