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

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