中国塑料 ›› 2024, Vol. 38 ›› Issue (8): 100-105.DOI: 10.19491/j.issn.1001-9278.2024.08.016

• 塑料与环境 • 上一篇    

填埋场废弃聚苯乙烯老化机制研究

朱晨曦1, 陈辰慧1, 胡国明1, 张蕾2, 江伟1()   

  1. 1.南京大学环境学院,污染控制与资源化研究国家重点实验室,国家有机毒物污染控制与资源化工程技术研究中心,南京 210023
    2.云南师范大学化学化工学院,昆明 650500
  • 收稿日期:2023-11-27 出版日期:2024-08-26 发布日期:2024-08-19
  • 通讯作者: 江伟(1983—),男,博士,教授级高级工程师,从事塑料污染控制与资源化研究,jiangwei@nju.edu.cn
    E-mail:jiangwei@nju.edu.cn

Study on aging mechanism of waste polystyrene in landfill

ZHU Chenxi1, CHEN Chenhui1, HU Guoming1, ZHANG Lei2, JIANG Wei1()   

  1. 1.State Key Laboratory of Pollution Control and Resources Reuse,National Engineering Research Center for Organic Pollution Control and Resource Reuse,School of the Environment,Nanjing University,Nanjing 210023,China
    2.Faculty of Chemistry and Chemical Engineering,Yunnan Normal University,Kunming 650500,China
  • Received:2023-11-27 Online:2024-08-26 Published:2024-08-19
  • Contact: JIANG Wei E-mail:jiangwei@nju.edu.cn

摘要:

模拟了废弃聚苯乙烯(PS)在垃圾填埋场环境下的光热老化,首先对老化样品前后的分子结构进行了表征;并通过X射线衍射、差示扫描量热仪测试以及纳拉扬斯瓦米⁃莫伊尼汉(TNM)模型和全原子分子动力学计算(MD)对PS老化过程中的焓松弛过程进行研究。结果表明,PS在光老化后会断链,分子量从112 200下降至13 000左右,并产生聚苯乙烯低聚物、苯甲酸酐、苯乙酮和苯甲酸甲酯等物质;此外,老化会导致PS结晶度和玻璃化转变温度的降低,其焓松弛的变化在老化初期较为迅速,随着老化的进行趋于平缓,平衡时对应的焓值为4.2 J/g。

关键词: 填埋场, 废弃聚苯乙烯, 老化行为, 性能变化, 理论计算

Abstract:

This study simulated the photo⁃thermal aging of discarded polystyrene (PS) in a landfill environment. Firstly, the molecular structure of the aged samples was characterized. The aging process of PS was then studied through X⁃ray diffraction, differential scanning calorimeter tests, and the tool⁃narayanaswamy⁃moynihan (TNM) model, along with molecular dynamics calculations of enthalpy relaxation processes.The results indicated that PS undergoes chain scission after photoaging, with the molecular weight decreasing from 112 200 to around 13 000. This process generates PS oligomers, benzoic anhydride, acetophenone, and methyl benzoate. Furthermore, aging leads to a reduction in PS crystallinity and the glass transition temperature. The enthalpy relaxation changes rapidly in the early stages of aging, gradually slowing down as aging progresses, with a corresponding enthalpy value of 4.2 J/g at equilibrium.

Key words: landfill, waste polystyrene, aging behavior, performance change, theoretical calculation

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