ONLINE ISSN 2069-7430 ISSN-L 1841-4737 PRO LIGNO Vol. 13 N° 4 2017 www.proligno.ro pp. 276-282 276 DETERMINATION OF SELECTED PROPERTIES OF PP BASED COMPOSITES FILLED EGGPLANT (Solanum melongena) STALKS İbrahim Halil BASBOGA Kahramanmaras Sutcu Imam University Faculty of Forestry, Department of Forest Industry Engineering Address: KSU Avsar Yerleskesi. 46100 Kahramanmaras. Turkey E-mail: ihbasboga@ksu.edu.tr İlkay ATAR Kahramanmaras Sutcu Imam University Faculty of Forestry, Department of Forest Industry Engineering Address: KSU Avsar Yerleskesi. 46100 Kahramanmaras. Turkey E-mail: iatar@ksu.edu.tr Kadir KARAKUS Kahramanmaras Sutcu Imam University Faculty of Forestry, Department of Forest Industry Engineering Address: KSU Avsar Yerleskesi. 46100 Kahramanmaras. Turkey E-mail: karakus@ksu.edu.tr Fatih MENGELOGLU Kahramanmaras Sutcu Imam University 1 Graduate School of Natural and Applied Science, Materials Science and Engineering 2 Faculty of Forestry, Department of Forest Industry Engineering Address: KSU Avsar Yerleskesi. 46100 Kahramanmaras. Turkey E-mail: fmengelo@ksu.edu.tr Abstract: Composite materials are produced by combining two or more different components to form an individual product with better properties. Manufactured new composite materials may provide better performance than one component can provide by itself. Wood-plastic composites are manufactured by using thermoplastics and annual plant waste. In this study, utilization of eggplant (solanum melongena) stalks as a filler in manufacturing of injection molded PP based composites was investigated. For this purpose, neat polypropylene test samples (control group) and eggplant stalks flour-filled thermoplastic composites with different rates (7.5% 15% and 30%) were produced by using single-screw extruder and injection molding machine. Maleic anhydride polypropylene (MAPP) was utilized as coupling agents. Paraffin wax was used as a lubricant. Mechanical properties (tensile strength, flexural strength and impact strength) of produced composites were determined according to ASTM D 638, ASTM D 790 and ASTM D 256 standards. According to the statistical analysis, eggplant stalk flours had significant effect on tensile strength, tensile modulus, flexural strength, flexural modulus, elongation at break properties and density values. However, it had no significant effect on the impact strength properties. All produced composites provided standards requirements. Key words: injection molded; eggplant (solanum melongena) stalks; wood-plastic composite. INTRODUCTION The usage of lignocellulosic fibers as fillers in the manufacturing of thermoplastic-based composites is increasing day by day. Moreover, the production of thermoplastic composites is a rapidly growing sector in the wood-plastic composite industry. A large variety of lignocellulosic wastes (wood flour, agricultural wastes etc.) and thermoplastic polymers such as polylactic acid (PLA), polyethylene (PE), and polypropylene (PP) can be used in the manufacture of composites. The reasons for preference of lignocellulosic fibers in thermoplastic composite are low cost, low density, no excessive wear during production, high specific strength, abundant and easy degradation in the environment. These advantages make it attractive for the usage of lignocellulosic materials in the production of thermoplastic composites (Bodirlu et al. 2009; Taj et al. 2007; Antich et al. 2006; Khalid et al. 2006, Georgopoulos et al. 2005; Renneckar 2004; Nair et al. 2001). In the previous studies, it has reported that various lignocellulosic fibers such as maple and spruce wood fibers, jute, hemp, kenaf, sisal fibers, rice husks, wheat straw have been used in the production of thermoplastic composites (Poletto et al. 2011; Mengeloglu and Karakus 2008b; Mengeloğlu and Kabakcı 2008; Taj et al. 2007; Antich et al. 2006; Bengtsson and Oksman 2006; Digabel et al. 2004; Li and Matuana 2003). It has