The Biodegradation and the Rheological Properties of Polypropylene/Hyperbranched Polyester Blends for Industrial Applications

Abstract

Abstract. In this research, four novel types of hyperbranched polyester polymers (HBPs) were used and blended with polypropylene polymer PP, virgin VPP and recycled rPP, using a twin-screw extrusion machine. Hyperbranched polyester was added in different weight ratios (5%, 10%, and 20%). The Fourier transform spectroscopy FTIR, the water contact angle CA, the biodegradation in soil, and the rheological properties (melt flow rate MFR) of the prepared blends were investigated. The results showed that the contact angle of VPP and rPP blends has improved with the addition of HBPs, and in addition, the biodegradation results in soil showed that weight loss increased as the amount of HBPs increased in VPP and rPP blends. The rheological properties, melt flow rate MFR, showed that the addition of HBPs increased the MFR for both PP blends, VPP and rPP. In addition, it was found that the blends' viscosity was decreased and their shear rate was increased. This is an indication that the HBPs work as a processing aid additive by increasing the shear thinning behavior.