Structure and Properties of Reactively Extruded Opaque Post-Consumer Recycled PET

Abstract

The recyclability of opaque PET, which contains TiO2 nanoparticles, has not been as well-studied as that of transparent PET. The objective of this work is to recycle post-consumer opaque PET through reactive extrusion with Joncryl. The effect of the reactive extrusion process on the molecular structure and on the thermal/mechanical/rheological properties of recycling post-consumer opaque PET (r-PET) has been analyzed. A 1% w/w Joncryl addition caused a moderate increase in the molecular weight. A moderate increase in chain length could not explain a decrease in the overall crystallization rate. This result is probably due to the presence of branches interrupting the crystallizable sequences in reactive extruded r-PET (REX-r-PET). A rheological investigation performed by SAOS/LAOS/elongational studies detected important structural modifications in REX-r-PET with respect to linear r-PET or a reference virgin PET. REX-r-PET is characterized by a slow relaxation process with enlarged elastic behaviors that are characteristic of a long-chain branched material. The mechanical properties of REX-r-PET increased because of the addition of the chain extender without a significant loss of elongation at the break. The reactive extrusion process is a suitable way to recycle opaque PET into a material with enhanced rheological properties (thanks to the production of a chain extension and long-chain branches) with mechanical properties that are comparable to those of a typical virgin PET sample.

Polystyrene-Free Chain Extenders for Recycled Poly(ethylene terephthalate)

“…Figure S2 shows the intrinsic viscosity (IV) and viscosity average molecular weight ( M n ) of neat rPET and rPET with the chain extender. Neat rPET exhibits an IV of 0.736 dL/g, which is slightly lower than neat PET (0.80 dL/g) as mentioned in the literature . The rPET did not show significant enhancement in IV and M n by the inclusion of ADR or our chain extenders.…”

“…Neat rPET exhibits an IV of 0.736 dL/g, which is slightly lower than neat PET (0.80 dL/g) as mentioned in the literature. 31 The rPET did not show significant enhancement in IV and M n by the inclusion of ADR or our chain extenders.…”

A Review on the Formulation and Rupture Properties of Polyethylene Terephthalate in a Mechanical Recycling Context

“…Thermogravimetric (TGA) analysis can complete the understanding, by observing the various decomposition products at different temperatures. Coupling this technique with NMR, gas-chromatography mass-spectroscopy GC-MS, or SEC measurements allows an even better understanding of the product’s structure. − …”

Manufacture and rheological behavior of all recycled PET/PP microfibrillar blends

“…However, it is not the only one. [5] The blending of polymers is considered as an economical and practical method to obtain new material with improved properties. [6] Nevertheless, usually, the polymers are immiscible in the melt state [7,8] on account of phase separation and low adhesion between two phases.…”