Title The use of rheological behavior to monitor the processing and service life properties of recycled polypropylene
Date 01.03.2019
Number 56463
Abstract The influence of multiple reprocessing cycles on the rheological, thermal and mechanical properties of pre-consumer polypropylene (PP) waste (or manufacturing scrap) was investigated. An increase in the melt flow rate (MFR) and a decrease in the viscosity and the mass average molecular weight were found as well as a narrowing of the molecular weight distribution. As a typical industry practice, manufacturing scrap is often mixed with virgin material. Thus, production material with 70% regrind was also examined. The measured properties followed the same trends as for reprocessing without refreshing. A separate investigation of thermal and thermal oxidative degradation showed a constant MFR at processing temperatures for thermally degraded material and a significant increase for thermal oxidative tests. The results provide a better understanding of the degradation mechanisms of PP and show that the rheological behaviors, MFR and melt viscosity, are well suited to assess these effects.
Publisher Food Packaging and Shelflife
Citation Food Packaging and Shelflife 19 (2019) 174-183
Authors Spicker, C. ; Rudolph, N. ; Kühnert, I. ; Aumnate, C.

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