COMPARISON BETWEEN TYPE AND CYCLES FOR THE REPROCESSING OF HDPE BAG WASTE WITHOUT AND WITH PRO-DEGRADANT IN SURFACE PHYSICOCHEMICAL CHARACTERISTICS

Abstract

The recycling of materials is an alternative that becomes more interesting as it becomes more expensive to obtain raw materials from non-renewable sources, such as oil to produce polymers. There are several processes for recycling polymers, the extrusion and injection process being the most used in Brazil for product forming. Unfortunately, the collection and proper destination of polymers is not yet a consolidated reality. Pro-degrading additives are being developed and incorporated in plastic bags to make the polymers oxy and biodegradable under environmental conditions, to minimize the impact of inappropriate destination. The present study compared the effects on the reprocessing cycles by extrusion and injection of residues from High Density Polyethylene (HDPE) plastic bags, considering the presence of pro-degrading additives, on the physical-chemical characteristics of surfaces. The bag residues were reprocessed separately, totaling four reprocessing by extrusion and three reprocessing by injection. Through the FTIR analyzes, it was noticed the appearance of functional groups with the advance of the reprocessing cycles, and the injection proved to be more aggressive to the polymeric matrix. The presence of a pro-degrading additive makes the polymer's functionalization more evident. The contact angle analyzes corroborate the results of the FTIR, with a decrease in the contact angle of the water drop with the sample surface, as the reprocessing cycles advance, being more evident in the injection cycles.