Patel Arpan D, Schyns Zoé O G, Franklin Thomas W, Shaver Michael P
Department of Materials, School of Natural Sciences, University of Manchester, Manchester, United Kingdom.
Sustainable Materials Innovation Hub, Henry Royce Institute, University of Manchester, Manchester, United Kingdom.
Nat Commun. 2024 Oct 9;15(1):8733. doi: 10.1038/s41467-024-52856-8.
Polyolefins have a multitude of uses across packaging, automotive and construction sectors. Their resistance to degradation during reprocessing enables recyclability, but variability in recycled polymer feedstocks renders it difficult to assure their manufacturing suitability. The lack of quality control methods has disabled circular economy pathways; product failure is costly, wasteful and time-intensive. Using rheology-simulated and extrusion-based recycling experiments, we explore the degradation pathways of high-density polyethylene (HDPE). Chain scission dominates during the initial degradation of HDPE, and increasing exposure to O shifts the dominant mechanism to long-chain branching. Importantly, extending this method to post-consumer recyclate (PCR), the results show potential as a methodology to assess recyclate quality to enable a circular plastics economy. In this study, we establish the validity of this rheology simulation to define a characteristic degradation parameter, relating it to the structural evolution under different environments defined for virgin HDPE and post-consumer recyclate (PCR).
聚烯烃在包装、汽车和建筑领域有多种用途。它们在再加工过程中抗降解的特性使其具有可回收性，但回收聚合物原料的变异性使得难以确保其制造适用性。缺乏质量控制方法阻碍了循环经济路径；产品故障成本高昂、浪费资源且耗时。通过流变学模拟和基于挤出的回收实验，我们探索了高密度聚乙烯（HDPE）的降解途径。在HDPE的初始降解过程中，断链占主导，而增加与氧气的接触会使主导机制转变为长链支化。重要的是，将此方法扩展到消费后回收物（PCR），结果显示出作为评估回收物质量以实现塑料循环经济的一种方法的潜力。在本研究中，我们确立了这种流变学模拟的有效性，以定义一个特征降解参数，并将其与为原始HDPE和消费后回收物（PCR）定义的不同环境下的结构演变相关联。
