Physical Properties of PP/Recycled PET Blends Prepared by Pulverization Technique

摘要

Polymer blends between pristine polypropylene (PP) and post-consumer soft-drink PET bottles (rPET) were prepared using pulverization technique. The polymer mixtures were pulverized, at the amounts of rPET in PP of 0, 10, 15, 20 and 30 phr (parts per hundred of resin) by weight, into powder. In an extruder, the polymer powders were mixed with maleic anhydride-grafted polypropylene (MAPP) and polyethylene wax (PE wax) as a compatibilizer and a processing aid, respectively. The extrudates were prepared into test specimens by injection molding. Physical properties of PP/rPET blends were subsequently investigated. The results pointed out that, for the pulverized blends without compatibilizer, tensile and flexural strength were improved at the lower amount of rPET. The compatibilizing effect of MAPP was exhibited at the higher amount of rPET. The reduction of melt flow index (MFI) may cause difficulties for some processing techniques which required polymers with high MFI. The addition of PE wax successfully brought up the MFI as well as elongation at break while other mechanical properties decreased.