An open-loop recycling for textile waste: high-value carbon materials from PET-PU industrial scraps

In the past few decades, global fiber consumption has been progressivelyincreasing, leading to a higher amount of post-industrial and post-consumerfiber waste. Thus, an enormous amount of synthetic waste is generated, mostof which is disposed of in landfills. Post-industrial waste is generated in themanufacturing process and, depending on the stage of manufacturingactivities, it can be a single polymer or a complex multi-material system. Sincea single polymer is easier to be recycled, a blend recycling process should bedesigned and projected. For companies, industrial blended scrapsmanagement is a very high challenge.The most used textile fiber is polyester (PET), with an estimated production of26 million tons per year. The PET is often blended with other polymers, mainlywith polyurethane (PU), to improve the elastic characteristics of the finalproducts. The PET-PU separation is not an easily manageable process,especially for industrial scraps. For this reason, in this work, the obtainment ofa high-value carbon material from PET-PU industrial waste was investigated.The PET-PU scraps were subjected to a pyrolysis treatment at 800°C leading toan 18% of carbon yield. The carbon was thoroughly characterized with severaltechniques (FTIR spectroscopy, surface area analysis, SEM) and a comparisonwith PET and PU carbons was also performed. Moreover, the adsorbingproperties were evaluated in simulated-wastewater treatment by measuringtheir adsorption performances in removing two dyes: Orange II and MethyleneBlue. These tests showed that the PET-PU-derived carbon is able to removemore than 60% of the two selected dyes. Thus, these preliminary resultsunderline that the PET-PU blend can be easily recycled in an open-loop systemin which the synthetic scraps are efficiently transformed into a new high-added value product.