Padhi Ganeshdev, Khopade Kishor V, Moyilla Nageswararao, Rangappa Raghavendrakumar, Chikkali Samir H, Barsu Nagaraju
Organic Chemistry Division, CSIR-National Chemical Laboratory Ganeshdev Padhi, Nageswararao Moyilla, and Dr. Nagaraju Barsu, Dr. Homi Bhabha Road, Pune, 411008, India.
Academy of Scientific and Innovative Research (AcSIR), Sector 19, Kamla Nehru Nagar, Ghaziabad, 201002, Uttar Pradesh, India.
Angew Chem Int Ed Engl. 2025 Apr 1;64(14):e202422609. doi: 10.1002/anie.202422609. Epub 2025 Feb 10.
Synthesis of value-added products from post-consumer waste polyolefins is fascinating as well as challenging. Here we report ruthenium-catalyzed up-cycling of the polyethylene to long-chain alkene derivatives. The developed methodology mainly involves two steps i.e., dehydrogenation of polyethylene through hydrogen atom transfer and its metathesis using the HG-II catalyst. The dehydrogenation of polyethylene using ruthenium catalysis derived up to 3.38 %, of double bonds; with 90 % of the recovered polyolefin material. The obtained unsaturated polyethylene was subjected to cross-metathesis with ethylene using HG-II catalytic system. This resulted in the synthesis of predominantly dodecene (C12) derivatives, with 58 % selectivity, along with other derivatives of varying chain lengths. The overall reaction produced terminal and internal olefins in the ratio 1:0.8 respectively. The dehydrogenation of polyethylene and its deconstruction was confirmed by NMR spectroscopy, Gel Permeation Chromatography (GPC) and Differential Scanning Calorimetry (DSC). The origin of C12 selectivity has been demonstrated by control experiments. The scope of the methodology was extended to post-consumer waste polyethylene which gave high conversion to value-added dodecene derivatives as a major product.
从消费后废弃聚烯烃合成增值产品既具有吸引力又具有挑战性。在此，我们报道了钌催化将聚乙烯向上循环转化为长链烯烃衍生物。所开发的方法主要涉及两个步骤，即通过氢原子转移使聚乙烯脱氢，以及使用HG-II催化剂对其进行复分解反应。使用钌催化使聚乙烯脱氢可得到高达3.38%的双键；回收的聚烯烃材料占90%。将所得的不饱和聚乙烯使用HG-II催化体系与乙烯进行交叉复分解反应。这主要生成了选择性为58%的十二碳烯（C12）衍生物，以及其他不同链长的衍生物。整个反应生成的端烯烃和内烯烃比例分别为1:0.8。通过核磁共振光谱、凝胶渗透色谱（GPC）和差示扫描量热法（DSC）证实了聚乙烯的脱氢及其解构过程。通过对照实验证明了C12选择性的来源。该方法的适用范围扩展到了消费后废弃聚乙烯，其能高效转化为作为主要产物的增值十二碳烯衍生物。
