Gkaliou Kyriaki, Benedini Lidia, Sárossy Zsuzsa, Dalsgaard Jensen Claus, Henriksen Ulrik B, Daugaard Anders E
Technical University of Denmark, Department of Chemical and Biochemical Engineering, The Danish Polymer Centre, Kongens Lyngby 2800, Denmark.
Technical University of Denmark, Department of Chemical and Biochemical Engineering, CHEC Research Centre, Kongens Lyngby 2800, Denmark.
Waste Manag. 2023 Jun 1;164:191-199. doi: 10.1016/j.wasman.2023.04.007. Epub 2023 Apr 13.
Recycled PMMA was prepared by directly polymerizing crude pyrolysis oils from lab-scale pyrolysis of collected industrial waste PMMA. The pyrolysis oils consisted mainly of methyl methacrylate (MMA, >85%), while the type and number of by-products from the thermal process were assigned through GC-MS analysis showing a clear correlation to the pyrolysis temperature. By-products can be removed by distillation; however, directly employing the crude oils to prepare PMMA through solution, suspension, emulsion, or casting polymerization was investigated to assess the potential for omitting this costly step. It was found that the crude pyrolysis oils could be polymerized efficiently via solution, emulsion, and casting polymerization to produce a polymer similar to the PMMA prepared from a pristine monomer. The impurities in the PMMAs prepared from the crude mixtures were investigated by extraction analyses followed by screening by GC-MS. In the case of casting polymerization, the GC-MS analysis, as expected, revealed various residual by-products, while solution and emulsion polymerization showed only very few impurities, mainly originating from the polymerization and not the feed material. Additional purification of the crude pyrolysis oils would be required for applications in casting polymerization. In contrast, direct polymerization by emulsion or solution polymerization is considered applicable for producing pristine PMMA from crude waste PMMA pyrolysis oil.
回收聚甲基丙烯酸甲酯（PMMA）是通过将收集的工业废弃PMMA进行实验室规模热解得到的粗热解油直接聚合制备而成。热解油主要由甲基丙烯酸甲酯（MMA，>85%）组成，同时通过气相色谱-质谱联用（GC-MS）分析确定热解过程中副产物的类型和数量，结果表明其与热解温度存在明显的相关性。副产物可通过蒸馏去除；然而，研究了直接使用粗油通过溶液聚合、悬浮聚合、乳液聚合或浇铸聚合来制备PMMA，以评估省略这一成本高昂步骤的可能性。结果发现，粗热解油可通过溶液聚合、乳液聚合和浇铸聚合有效地聚合，从而制备出与由原始单体制备的PMMA相似的聚合物。通过萃取分析，随后用GC-MS进行筛选，研究了由粗混合物制备的PMMA中的杂质。在浇铸聚合的情况下，正如预期的那样，GC-MS分析揭示了各种残留副产物，而溶液聚合和乳液聚合仅显示出极少的杂质，主要源自聚合过程而非进料。对于浇铸聚合应用，需要对粗热解油进行额外的纯化。相比之下，乳液聚合或溶液聚合直接制备被认为适用于从粗废PMMA热解油生产原始PMMA。
