Investigation of stress-relaxation behaviors of wood plastic composites

Abstract

In this study, it was aimed to determine the stress and relaxation behavior of wood plastic composites produced by using magnesiumoxysulphate and lignocellulosic filler. For this purpose, test specimens were produced by using 10% and 20% magnesiumoxysulfate, lignocellulosic filler (Pinus brutia Ten.), 3% wax and maleic anhydride grafted polypropylene (MAPP) into the polymer matrix. Extrusion and injection molding methods were used in the manufacturing of test specimens. In order to determine the stress relaxation behavior of wood plastic composites in tensile, a total of 15 test samples, 3 for each variable parameter of each production code, were prepared in depend on the ASTM D 638 (2004) standard. The stress-relaxation behaviors of test samples were determined at 600 Newton force, tensile speed of 5mm/min and tensile for 2 hours. The experiments were carried out in room conditions and the temperature of the room where the experiment was conducted was adjusted with air conditioning. According to the test results; It has been determined that the ratio and type of filler materials have a significant effect on the stress relaxation values. It has been determined that the Synthetic and lignocellulosic filler participation rates are effective on the stress relaxation values of the test samples and the stress relaxation values decrease significantly as the participation rate increases. It has been determined that the filler ratio reduces the mobility of the polymer chains between them, this delays the relaxation and as the amount of filler increases, the relaxation decreases. In applications where stress relaxation behaviour it is important, specific care should be paid on the selection of filler amount.

Keywords

• wood plastic composite
• stress-relaxation
• red pine
• magnesiumoxysulphate
• odun plastik kompozit
• gerilme-gevşeme
• kızılçam
• magnezyumoksisulfat