Effect of pellet size and compatibilization on thermal decomposition kinetic of recycled polyethylene terephthalate/recycled polypropylene blend

Abstract

This study considers the effects of pellet geometry and compatibilization on its moisture absorption and thermal degradation behavior of recycled polyethylene terephthalate (RPET) and recycled polypropylene (RPP) blend with the ultimate goal of optimizing the design of pellets to enhance their processability. The isoconversion of Flynn-Wall-Ozawa (FWO) was used for the kinetic study, which was suitable for thermal degradation of RPET/RPP blend in N 2 while the second order polynomial function was fitted for thermal oxidative degradation in air. Finer geometries, such as powders, were found to have higher moisture absorption rates due to their large surface area although they could also be easily dried. Furthermore, large surface area of fine powder as well as good interaction between RPP disperse particles and RPET matrix eased to decompose in the presence of oxygen thus accelerated chain breaking during thermal oxidative degradation especially at low heating rate. Meanwhile, larger pellets exhibited higher degradation activation energies, which suggest that they are more resistant to thermal degradation than smaller grains.

Role of Crystallinity on Moisture Absorption and Mechanical Performance of Recycled PET Compounds

“…In addition, pellets geometries i.e. size and shape are influenced on moisture absorption of polymers [2,4]. Thumsorn et al [4] showed that finer geometries, such as powders of RPET and recycled polypropylene (RPP) blends, were found to have higher moisture absorption rates due to their large surface area although they could be easily dried.…”

Effectiveness of Talc Filler on Thermal Resistance of Recycled PET Blends

“…Therefore, recycling of PET bottles offers a very practical solution to reduce landfill waste thus preventing environmental problems. Indeed, there are some researches [2][3][4][5][6][7] about recycled PET (RPET) injection moldings from PET bottles.…”

Effect of ammonium polyphosphate and fillers on flame retardant and mechanical properties of recycled PET injection molded

“…It can be noted that degradation temperature at elevated temperature (T d50 ) of the filled RPET composites slightly increased when increasing the fillers contents, which indicated the improvement of thermal stability in the filled RPET composites. The residual from the decomposition corresponded to the additives content and ash from the polymer …”

“…Polymer blends and additives have been developed to RPET in order to improve its thermal stability and mechanical properties . Pattabiraman et al discussed on thermal and mechanical properties of virgin PET, recycled PET, and their blends.…”