EFFECT OF RECYCLING OF THERMOPLASTICS: EVALUATION OF THE PROPERTIES OF MIXTURE OF VIRGIN AND RECYCLED HIGH-DENSITY POLYETHYLENE

Abstract

Plastic recycling was carried out on the virgin HDPE, mixture of both collected recycled HDPE material and virgin HDPE. Processing aids in terms of certain percentage of anti-oxidants and slipping agents were added to virgin and 50/50 mixture of HDPE recycled material. The specific emphasis was placed on the effect of thermal stabilizer concentration in the base material during processing cycle. Thermo-oxidative degradation was observed in polymeric material during injection molding cycle. The performances of resulting reprocessed plastics were monitored using Fourier transformation infra-red (FTIR), Differential scanning calorimeter (DSC), and Mechanical properties. The results clearly reveal the rapid thermo-oxidative degradation of the 50/50 mixture of fresh and recycled HDPE material after three re-processing cycles, which can be attributed to the antagonistic mixing effect of two materials and the early loss of added anti-oxidant and processing stabilizers. The better processing stability can be achieved by incorporating appropriate percentages of processing stabilizers in polymer resin up-to limited number of processing cycles.