Effect of High Processing Temperature on the Rheological and Morphological Properties of Recycled Polypropylene

This study investigates the effect of high processing temperatures used in the medical syringe factory in Iraq on some rheological and morphological properties of polypropylene. Ten samples consisting of 50% virgin (pure) PP and 50% recycled PP were processed. The mold temperature was varied in the range of 190℃ to 210℃, while maintaining the pressure and secondary time at 78 bar and 0.5 seconds, respectively. The results showed that the density decreased by 45% as the injection temperature increased. In contrast, the Melt Flow Index (MFI) increased by 60% with rising injection temperatures. The results also indicated a severe effect of high processing temperatures on the samples, which was evident in the FTIR test, where the intensity of the peaks changed significantly compared to virgin PP. The DSC test revealed that the Tg value increased to 15.1℃ for recycled PP, compared to 9.8℃ for the virgin sample.