RHEOLOGICAL AND MECHANICAL PROPERTIES OF RECYCLED POLYPROPYLENE / VIRGIN POLYPROPYLENE BLENDS

Resumo

This paper analyzes the influence of the amount of recycled polypropylene added to virgin polypropylene on the mechanical and rheological properties of the resulting blends. The benefits of knowing these properties include the possibility of using recycled materials in applications which previously were not used because due to the need for superior mechanical properties that recycled material does not have and also to promote reuse of waste material. Results of MFI measurements indicated that increasing the amount of recycled PP in the blend improved the flow property. Results of rheometry tests showed that PPr does not produce a dramatic change in the behavior of PPr/PPv blends during the extrusion process. However, as the content of PP increased in the blend, the viscosity values decreased for a given shear rate. Also, when the temperature increased, a small reduction in viscosity values occurred. These results indicate that by increasing the amount of recycled material in the blend there is a tendency to increase the power index and decrease pseudoplasticity. By increasing the recycled PP content in the blend, i) the elastic modulus values no changed; and ii) yield strength decreased