{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,4]],"date-time":"2026-05-04T15:14:24Z","timestamp":1777907664138,"version":"3.51.4"},"reference-count":46,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2025,6,3]],"date-time":"2025-06-03T00:00:00Z","timestamp":1748908800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"project UID 00481 Centre for Mechanical Technology and Automation (TEMA)"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Polymers"],"abstract":"<jats:p>The increasing demand for sustainable materials has renewed interest in recycling polyolefins, particularly polypropylene (PP), due to its widespread use and environmental persistence. Post-consumer recycled polypropylene (PPr), however, often exhibits compromised properties from prior exposure to thermal, oxidative, and mechanical degradation. This study investigates the potential of using post-consumer PPr in melt-blended extrusion formulations with virgin PP (PPv), focusing on how different PPr contents affect processability, thermal stability, oxidative resistance, and mechanical performance. Blends containing 25%, 50%, and 75% PPr, as well as 100% PPr and virgin PP, were evaluated using melt flow index (MFI), differential scanning calorimetry (DSC), oxidation induction time (OIT), thermogravimetric analysis (TGA), and tensile testing. Results show that increasing PPr content improves polymer fluidity and thermal stability under inert conditions but significantly reduces oxidation resistance and ductility. However, the 25% PPr blend demonstrated a favourable balance between performance and recyclability, presenting 96% of the elastic modulus and 101% of the yield strength of PPv. Homogenization by extrusion improved the oxidative stability of recycled PP by 22% compared to its non-extruded form. These findings support the use of low-to-moderate levels of PPr in virgin PP for applications requiring predictable and tunable performance. contributing to circular economy goals.<\/jats:p>","DOI":"10.3390\/polym17111556","type":"journal-article","created":{"date-parts":[[2025,6,3]],"date-time":"2025-06-03T06:21:51Z","timestamp":1748931711000},"page":"1556","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":11,"title":["Sustainable Polypropylene Blends: Balancing Recycled Content with Processability and Performance"],"prefix":"10.3390","volume":"17","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2150-6241","authenticated-orcid":false,"given":"Tatiana","family":"Zhiltsova","sequence":"first","affiliation":[{"name":"TEMA\u2014Centre for Mechanical Technology and Automation, Department of Mechanical Engineering, University of Aveiro, 3810-193 Aveiro, Portugal"},{"name":"LASI\u2014Intelligent Systems Associate Laboratory, 4800-058 Guimar\u00e3es, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6190-1238","authenticated-orcid":false,"given":"M\u00f3nica S. A.","family":"Oliveira","sequence":"additional","affiliation":[{"name":"TEMA\u2014Centre for Mechanical Technology and Automation, Department of Mechanical Engineering, University of Aveiro, 3810-193 Aveiro, Portugal"},{"name":"LASI\u2014Intelligent Systems Associate Laboratory, 4800-058 Guimar\u00e3es, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2025,6,3]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"257","DOI":"10.1038\/s43247-025-02169-5","article-title":"Complexities of the global plastics supply chain revealed in a trade-linked material flow analysis","volume":"6","author":"Houssini","year":"2025","journal-title":"Commun. Earth Environ."},{"key":"ref_2","unstructured":"Circularise (2025, May 04). Global Plastic Consumption, Production, and Sustainability Efforts. 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