Korean Chemical Engineering Research

The Korean Institute of Chemical Engineers (한국화학공학회)
권호 표지

Decrosslinking of Cross-linked Polyethylene using Supercritical Methanol

초임계 메탄올을 이용한 가교 폴리에틸렌의 탈가교화

  • Hong, Soon Man (Polymer Hybrids Research Center, Korea Institute of Science and Technology) ;
  • Cho, Hang-kyu (Polymer Hybrids Research Center, Korea Institute of Science and Technology) ;
  • Koo, Chong Min (Polymer Hybrids Research Center, Korea Institute of Science and Technology) ;
  • Lee, Jang Hoon (Youngbo Chemical Co. Ltd.) ;
  • Park, Wan Yong (Youngbo Chemical Co. Ltd.) ;
  • Lee, Hong-Shik (School of Chemical and Biological Engineering & Institute of Chemical Processes, Seoul National University) ;
  • Lee, Youn-Woo (School of Chemical and Biological Engineering & Institute of Chemical Processes, Seoul National University)
  • Received : 2007.11.18
  • Accepted : 2007.12.26
  • Published : 2008.02.28
Download PDF
⟨ Previous Next ⟩

Abstract

We investigated the recycling method to re-plasticize cross-linked polyethylene by using supercritical methanol. The cross-linked polyethylene is successfully fragmented to thermoplasticized polyethylene with little degradation reactions in supercritical fluids. The thermo-plasticization reaction was accelerated with increase in temperature in the range from $360^{\circ}C$ to $400^{\circ}C$, resulting in decrease in crosslinking density, molecular weight and mechanical properties. However, the thermoplasticized polyethylene at $360^{\circ}C$ showed comparable tensile strength and impact strength with a raw resin of crosslinked polyethylene. Chemical structure of main chain of polyethylene was not affected by reaction condition.

초임계 유체 공정을 이용하여 가교 폴리에틸렌 수지를 탈가교화하여 재활용하는 방법을 조사하였다. 가교 폴리에틸렌 수지는 메탄올을 이용한 초임계 반응 시 탈가교화가 이루어져 재활용 될 수 있다. 초임계를 이용한 탈가교화 반응은 반응온도에 의해 크게 영향을 받으며 $360^{\circ}C$부터 $400^{\circ}C$ 구간에서 온도의 증가에 따라 탈가교화가 급격히 촉진되었다. 반응온도의 증가에 따라 생성물인 탈가교 폴리에틸렌의 가교도, 분자량, 기계적 물성은 감소했지만, $360^{\circ}C$에서 탈가교된 폴리에틸렌은 가교전의 원료로 사용된 폴리에틸렌과 비교할만한 연신강도와 내충격강도를 보였다. 본 연구의 모든 반응조건에서 폴리에틸렌의 주쇄의 화학구조는 반응조건에 거의 영향을 받지 않았다.

Keywords

Acknowledgement

Supported by : 과학기술부, 환경부

References

  1. "Act on the Peomotion of Saving and Recycling of Resources," Law Nr. 8611, Korea.
  2. Arai, Y., Sako, T. and Takebayashi, Y.(Eds.), Supercritical Fluids- Molecular Interactions, Physical Properties, and New Applications, Springer, Heidelberg(2002).
  3. Nagase, Y., Yamagata, M. and Fukuzato, R., "Chemical Recycling Process for Waste Plastics Using Supercritical Water," R&D Kobe Steel Engine. Reports, 47(3), 43-46(1997).
  4. Genta, M., Iwaya, T., Sasaki, M., Goto, M. and Hirose, T., "Depolymerization Mechanism of Poly(ethylene terephthalate) in Supercritical Methanol," Ind. Eng. Chem. Res., 44, 3894-3900 (2005). https://doi.org/10.1021/ie0488187
  5. Tagaya, H., Shibasaki, Y., Kato, C., Kadokawa, J. and Hatano, B., "Decomposition Reactions of Epoxy Resin and Polyetheretherketone Resin in Sub- and Supercritical Water," J. Mater. Cycles Waste Manag., 6, 1-5(2004). https://doi.org/10.1007/s10163-003-0098-2
  6. Goto, M., Sasaki, M. and Hirose, T., "Reactions of Polymers in Supercritical Fluids for Chemical Recycling of Waste Plastics," J. Mater. Sci., 41, 1509-1515(2006). https://doi.org/10.1007/s10853-006-4615-2
  7. Goto, T. and Yamazaki, T., "Recycling of Silane Cross-linked Polyethylene for Insulation of Cables using Supercritical Alcohols," Hitachi Cable Review, 23, 24-27(2004).
  8. Watanabe, S., Komura, K., Nagaya, S., Morita, H., Nakamoto, T., Hirai, S. and Aida, F., "Development of Cross-linked Polymer Material Recycling Technology by Supercritical Water," Properties and Applications of Dielectric Materials, 2, 595-598 (2003).
  9. Kamimura, A., Yamada, K., Kuratani, T., Taguchi, Y. and Tomonaga, F., "Effective Depolymerization Waste FRPs by Treatment with DMAP and Supercritical Alcohol," Chemistry Letters, 35(6), 586-587(2006). https://doi.org/10.1246/cl.2006.586
  10. Lee, J. R., Lee, D. G., Hong, S. M. and Kang, H. J., "Enhancement of Physical Properties in Partially Crosslinked Waste High Density Polyethylene," Polymer (Korea), 31(1), 25-30(2007).
  11. Jeon, B. H., Yoon, H., Hwang, S. S., Kim, J. and Hong, S. M., "Enhancement of Compatibility and Toughening of Commingled Packing Film Wates," Polymer (Korea), 29, 1-8(2005).
  12. Hong, S. M. and Economy, J., "Effect of Annealing on the Physical Properties of Biaxially Oriented Liquid Crystalline Copolyester Films," Macromolecules, 28, 6481(1995). https://doi.org/10.1021/ma00123a014