doi:10.3390/polym13203531engCandal, M.V.Safari, M.Fernández, M.Otaegi, I.Múgica, A.Zubitur, M.Gerrica-Echevarria, G.Sebastián, V.Irusta, S.Loaeza, D.Maspoch, M.L.Santana, O.O.Müller, A.J.Structure and properties of reactively extruded opaque post-consumer recycled PETART-2021-126527The 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.2021http://zaguan.unizar.es/record/15197910.3390/polym13203531http://zaguan.unizar.es/record/151979oai:zaguan.unizar.es:151979info:eu-repo/grantAgreement/EUR/INTERREG POCTEFA-RevalPET'UP-EFA329/19Polymers 13, 20 (2021), 3531 [30 pp.]byhttps://creativecommons.org/licenses/by/4.0/deed.esinfo:eu-repo/semantics/openAccess