PET recycling and chain extension during reactive processing in the presence of pyromellitic dianhydride (PMDA)Author(s): Tasnim Kossentini-Kallel, Nizar Mnif, Fatma Fourti, Boubaker Elleuch
In this study, poly(ethylene terephthalate)(PET) industrial scraps with lowintrinsic viscosity [ïÂ¨], coming froma PET bottle processing plantwas chain extended with pyromellitic dianhydride(PMDA). The reaction was performed in a single step through reactive extrusion. 13C NMR spectroscopy, Differential ScanningCalorimetry(DSC), IntrinsicViscosity andMelting FlowIndex(MFI) measurements were carried out to study the chemical structure, the thermal properties(glass transition, melting point and crystallinity) and the molecular characteristics of different PET samples. Properties of recycled poly(ethylene terephthalate) (PET-R) were compared with those of the virgin polymer(PET-V). The effect of the chain extension process on the properties of PET-Rwas then evaluated.Modified PET(PET-M) samples were tested based on two different PMDA concentrations(0,3 and 1%wt). The PMDA concentrationwas varied with the intention of reaching a higher recycled PET intrinsic viscosity and to investigate the effect of PMDA content on the chemical structure and properties of recycled PET.