Chae Eunji, Choi Sung-Seen
Department of Chemistry, Sejong University, 209 Neungdong-ro, Gwangjin-gu, Seoul 05006, Republic of Korea.
Polymers (Basel). 2025 Feb 21;17(5):576. doi: 10.3390/polym17050576.
The pyrolysis technique is a useful recycling method for waste polyethylene (PE). Various PEs with different molecular weights have been produced and are widely used. The major pyrolysis products of PE include alkadienes (CH), alkenes (CH), and alkanes (CH). In this study, the differences in pyrolysis behavior of PE based on its molecular weight and the pyrolysis temperature (423-764 °C) were investigated using four types of PEs, with M = 2.0 × 10, 16.0 × 10, 28.3 × 10, and 56.8 × 10 g/mol. More specifically, the pyrolysis products were compared in terms of their type (alkanes, alkenes, and alkadienes) and size (the number of carbon atoms). The order of production was alkenes > alkanes > alkadienes. The alkadiene/alkene ratios tended to increase with the PE molecular weight and size of the pyrolysis products. The alkadiene/alkene ratio increased until the pyrolysis temperature reached 670 °C. The alkane/alkene ratios tended to decrease as the PE molecular weight increased; however, they increased with the increasing size of the pyrolysis products. The alkane/alkene ratio decreased as the pyrolysis temperature increased, until it reached 670 °C. The formation of alkenes was more favorable than that of alkadienes and alkanes.
热解技术是一种用于废旧聚乙烯（PE）的有效回收方法。已生产出各种不同分子量的聚乙烯并被广泛使用。聚乙烯的主要热解产物包括链二烯烃（CH）、烯烃（CH）和烷烃（CH）。在本研究中，使用四种分子量分别为M = 2.0×10、16.0×10、28.3×10和56.8×10 g/mol的聚乙烯，研究了基于其分子量和热解温度（423 - 764°C）的聚乙烯热解行为差异。更具体地说，从热解产物的类型（烷烃、烯烃和链二烯烃）和大小（碳原子数）方面对热解产物进行了比较。产物生成顺序为烯烃>烷烃>链二烯烃。链二烯烃/烯烃比率倾向于随着聚乙烯分子量和热解产物大小的增加而增加。链二烯烃/烯烃比率在热解温度达到670°C之前一直增加。烷烃/烯烃比率倾向于随着聚乙烯分子量的增加而降低；然而，它们随着热解产物大小的增加而增加。烷烃/烯烃比率随着热解温度的升高而降低，直到达到670°C。烯烃的生成比链二烯烃和烷烃更有利。
