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<p>In this study, organic halides, such as 2-bromobutane (C<sub>4</sub>H<sub>9</sub>Br), ethyl α-bromophenylacetate (BPA), ethyl 2-bromoisobutyrate (EBiB), and ethyl 2-bromopropionate (EBP) are utilized in conjunction with copper nanopowder (Nano-Cu) to initiate the polymerization of methyl methacrylate (MMA). Among these, BPA combined with nano-Cu exhibits the highest reactivity, resulting in the production of poly(methyl methacrylate) (PMMA) with a number-average molecular weight (<i>M</i><sub>n</sub>) of 1.91 × 10<sup>6</sup> Da, a weight-average molecular weight (<i>M</i><sub>w</sub>) of 3.46 × 10<sup>6</sup> Da, and a polydispersity index (PDI) of 1.81. A kinetic analysis of the polymerization reveals that the reaction orders for MMA, BPA, and nano-Cu concentration are 0.76, 0.49, and 0.77, respectively. The activation energy of the polymerization of MMA initiated by BPA is calculated to be 59.6&#xa0;kJ/mol. The molecular weight of PMMA product is determined using gel permeation chromatography (GPC), while the structure of the synthesized PMMA is characterized through proton nuclear magnetic resonance (<sup>1</sup>H NMR). Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) is employed to analyze the precise structure and molecular weight of PMMA. Additionally, the nano-Cu recovered after the polymerization is examined using X-ray photoelectron spectroscopy (XPS). An electron paramagnetic resonance (EPR) spectrometer is employed to detect the reaction intermediate formed during the polymerization. Results from MALDI-TOF, XPS and EPR reveal that the polymerization of MMA proceeds via a radical mechanism, with the combination of nano-Cu and BPA leading to the formation of BPA residual radicals that initiate the polymerization of MMA.</p>

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Synthesis of ultra-high molecular weight poly(methyl methacrylate) initiated by the combination of copper nanopowder with organic halides

  • 期刊论文

  • 出版模式：

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  • 发表日期：

    2025年7月26日

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  • Ming Yuan,
  • Xiaofang Han,
  • Zekai Zhang,
  • Ruijia Wang,
  • Shengrong Guo

摘要

In this study, organic halides, such as 2-bromobutane (C4H9Br), ethyl α-bromophenylacetate (BPA), ethyl 2-bromoisobutyrate (EBiB), and ethyl 2-bromopropionate (EBP) are utilized in conjunction with copper nanopowder (Nano-Cu) to initiate the polymerization of methyl methacrylate (MMA). Among these, BPA combined with nano-Cu exhibits the highest reactivity, resulting in the production of poly(methyl methacrylate) (PMMA) with a number-average molecular weight (Mn) of 1.91 × 106 Da, a weight-average molecular weight (Mw) of 3.46 × 106 Da, and a polydispersity index (PDI) of 1.81. A kinetic analysis of the polymerization reveals that the reaction orders for MMA, BPA, and nano-Cu concentration are 0.76, 0.49, and 0.77, respectively. The activation energy of the polymerization of MMA initiated by BPA is calculated to be 59.6 kJ/mol. The molecular weight of PMMA product is determined using gel permeation chromatography (GPC), while the structure of the synthesized PMMA is characterized through proton nuclear magnetic resonance (1H NMR). Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) is employed to analyze the precise structure and molecular weight of PMMA. Additionally, the nano-Cu recovered after the polymerization is examined using X-ray photoelectron spectroscopy (XPS). An electron paramagnetic resonance (EPR) spectrometer is employed to detect the reaction intermediate formed during the polymerization. Results from MALDI-TOF, XPS and EPR reveal that the polymerization of MMA proceeds via a radical mechanism, with the combination of nano-Cu and BPA leading to the formation of BPA residual radicals that initiate the polymerization of MMA.