Effects of Processing Methods, DOP Amount and Filler Content on the Mechanical Properties of Recycled Polyvinyl Chloride (PVC) Composites

PVC is one of the most commercialized thermoplastic materials with industrial and household applications. Plastic possesses an important percentage in waste stream and its recycling is vital. Plasticizer usage is also essential for the PVC manufacturing and recycling. It is the purpose of this study to determine the effects of processing methods, DOP concentration and wood flour amount on the mechanical properties of recycled PVC composites. 15 and 30 phr (per-hundred-resin) DOP and 0-15-30 phr wood flour was studied. Composite materials were produced using injection and compression molding methods. Tensile, flexural, impact, hardness (shore D) and density of the composites were determined. Based on these results, DOP and filler content and process had a significant effect on mechanical properties. Utilization of DOP in the PVC matrix made material softer and flexible. Resulting materials had higher elongation at break and impact strength and smaller shore D values. In an expense to these good results, it reduced the tensile and flexural strength and modulus values.  Addition of wood filler in the system, increased modulus values while reducing strength values. In the case of processing methods, injection molded samples provided overall better properties than compression molded ones. It should be noted that, in the case of injection molding, samples were better mixed due to the screw in the machine. Recycling of PVC is a vital subject and more study is needed.