Polymer(Korea) (폴리머)

The Polymer Society of Korea (한국고분자학회)
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Study on the Isomerization and Dehydrobromination Mechanism of Brominated Butyl Rubber

브롬화된 부틸고무의 탈브롬화 밑 이성질체화 메커니즘에 대한 연구

  • Wu, Yibo (Department of Material Science and Engineering, Beijing Institute of Petrochemical Technology) ;
  • Guo, Wenli (Department of Material Science and Engineering, Beijing Institute of Petrochemical Technology) ;
  • Li, Shuxin (Department of Material Science and Engineering, Beijing Institute of Petrochemical Technology) ;
  • Gong, Liangfa (Department of Material Science and Engineering, Beijing Institute of Petrochemical Technology) ;
  • Shang, Yuwei (Department of Material Science and Engineering, Beijing Institute of Petrochemical Technology)
  • Published : 2010.01.25
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Abstract

Effects of reaction time and temperature on the isomerization and dehydrobromination reactions of brominated butyl rubber were investigated. The structural composition of brominated butyl rubber was determined by Fourier transform infrared spectroscopy (FT-IR) and proton nuclear magnetic resonance spectroscopy($^1H$-NMR), Density functional theory (DFT) was used to study on the isomerization and dehydrobromination mechanisms of model compounds. The geometries for model compounds of 3-bromo-5,5,7,7-tetramethyl-2(2',2',4',4'-tetramethyl)pentyl-1-octylene (3BrOE), 1-bromo-5,5,7,7-tetramethyl-2(2',2',4',4'-tetramethyl)pentyl-2-octylene (1Br2OE) and 5,5,7,7-tetramethyl-2(2',2', 4',4'-tetramethyl)pentyl-1,3-octadiene (CD) had been optimized by using density functional theory at B3LYP/3-21G and B3LYP/6-31G levels. The predicted energy of 3BrOE lies higher than that of 1Br2OE which suggests that 1Br2OE configuration is more stable than the 3BrOE configuration. Compared with the energy barrier, the pathway of dehydrobromination is less competitive than that of isomerization. This is qualitatively consistent with the experimental results.

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References

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