Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE Waste polyethylene terephthalate (PET) is converted into recycled polyester polyols through an alcoholysis–esterification process and subsequently used to prepare thermoplastic polyurethane elastomers and polyurethane foams. The resulting materials exhibit balanced mechanical performance and recyclability, demonstrating the feasibility of producing polyurethane materials from recycled PET for practical applications.

ABSTRACT
The recycling of waste polyester (PET) has emerged as a vital strategy for mitigating white pollution and reducing carbon emissions. In this paper, postconsumer PET was subjected to a chemical conversion process involving alcoholysis and esterification, resulting in the production of recycled polyester polyols (rPOLs). These rPOLs were subsequently employed as soft-segment precursors for the synthesis of thermoplastic polyurethane elastomers (rTPUs) and polyurethane foams (rPUFs). The obtained rTPUs exhibit commendable mechanical properties and low-carbon economy, with a tensile strength of 12.93 MPa, which can significantly reduce the carbon footprint by approximately 44.5%. Furthermore, it has the capacity to substitute 57% of the fossil-derived polyester polyol in polyurethane satin. In the context of foam preparation, the rPOLs facilitated the production of rPUFs characterized by high porosity and resilience, with porosity levels exceeding 90%. Furthermore, even after the chemical recycling of rTPUs to produce recycled polyester polyols in a secondary cycle, the resulting recycled TPU (rrTPUs) exhibited 81.2% of the initial rTPUs fracture strength. These findings confirm the technical feasibility of implementing multiple closed-loop recycling processes for TPUs based on waste polyester-derived polyols, thus providing experimental support for the valorization of polyester waste in high-value elastomeric and porous materials.