Single‐stage chemical recycling of plastic waste to yield durable composites via a tandem transesterification‐thiocracking process
Single‐stage chemical recycling of plastic waste to yield durable composites via a tandem transesterification‐thiocracking process
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DOI：
10.1002/pol.20220686
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发表时间：
2023-02
影响因子：
3.4
通讯作者：
Charini Maladeniya;Andrew G. Tennyson;Rhett C. Smith
中科院分区：
文献类型：
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作者：
Charini Maladeniya;Andrew G. Tennyson;Rhett C. Smith
塑料垃圾对环境的污染对环境和人类健康的威胁日益严重。不幸的是，大多数消费后塑料仍然被丢弃在垃圾填埋场，即使是可以通过简单的化学过程轻松回收的塑料。技术和实施之间的脱节部分是由于将塑料废物转化为商品的多步骤过程造成的经济障碍。迫切需要绿色方法，通过简单的工艺将塑料废物直接转化为可销售的商品。在此，我们报告了一种简单的单阶段工艺，用于化学回收聚对苯二甲酸乙二醇酯（PET），以产生具有与商业结构材料（如波特兰水泥）竞争的热和机械性能的复合材料。在该方案中，将PET和香叶醇的混合物与元素硫一起加热。在该过程中，香叶醇和PET之间的酯交换反应伴随着PET主链的硫裂解，导致形成高度交联的硫-PET-香叶醇（SPG）网络复合物。该复合材料的抗压强度（23.1 MPa）大于建筑地基中使用的波特兰水泥所需的抗压强度。因此，这种新的单阶段化学回收策略采用生物烯烃和废硫将PET废物转化为耐用的复合材料，可以作为传统水泥的可持续替代品。
Environmental contamination by plastic waste is a growing threat to the environment and human health. Unfortunately, most post‐consumer plastics are still disposed of in landfills, even plastics that could be easily recycled via simple chemical processes. This disconnect between technology and implementation is partly due to the economic barrier posed by multi‐step processes that convert plastic waste into commodity goods. There is an urgent need for green methods to convert plastic waste directly into marketable commodities via simple processes. Herein we report a simple, single‐stage process to chemically recycle poly(ethylene terephthalate) (PET) to yield composites having thermal and mechanical properties that are competitive with commercial structural materials like Portland cement. In this protocol, a mixture of PET and geraniol are heated with elemental sulfur. In this process, transesterification between geraniol and PET with concomitant thiocracking of the PET backbone leads to the formation of a highly‐crosslinked sulfur–PET–geraniol (SPG) network composite. The composite exhibited compressive strength (23.1 MPa) greater than that required for Portland cement to be used in building foundations. This new, single‐stage chemical recycling strategy thus employs a bio‐olefin and waste sulfur to convert PET waste into a durable composite that could serve as a sustainable alternative to traditional cements.