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Synthesis of Resole-type Phenolic Beads via Suspension Polymerization Technique

현탁중합을 이용한 레졸형 구형 페놀입자의 합성

  • Hahn, Dongseok (Department of Polymer Science and Engineering, Korea National University of Transportation) ;
  • Kim, Daejung (PureSphere co.) ;
  • Kim, Hongkyeong (Department of Polymer Science and Engineering, Korea National University of Transportation)
  • 한동석 (한국교통대학교 나노고분자공학과) ;
  • 김대정 ((주)퓨어스피어) ;
  • 김홍경 (한국교통대학교 나노고분자공학과)
  • Received : 2012.03.28
  • Accepted : 2013.01.24
  • Published : 2013.04.01

Abstract

The phenolic beads in macrosize range were obtained by suspension polymerization at $98^{\circ}C$ from phenol and formaldehyde in the presence of basic catalyst with a phenol to formaldehyde (P/F) range of 1:1~1:4, and they were carbonized to spherical carbon beads under nitrogen at $700^{\circ}C$. Thermal analysis on spherical phenolic beads obtained by suspension polymerization showed that the postcuring process is essential. In order to optimize the suspension polymerization, the effects of the P/F molar ratio, the pH of catalyst, and the molecular weight of stabilizer on the size distribution and yield of spherical phenol beads were examined separatively. The particle size was increased whereas the yield was decreased with P/F molar ratio. The increasing basicity of catalyst made the particle size to increase, while the molecular weight of stabilizer had more effect on the yield rather than on the particle size distribution. The thermal stability of the spherical phenolic beads obtained through postcure was also examined by TGA. The phenol beads of high P/F ratio still showed the weight loss at $220^{\circ}C$ even after postcure due to the high possibility of dibenzyl ether, while those of low P/F ratio showed the steady decrease in weight during $220^{\circ}C$ to $400^{\circ}C$, which showed that the optimal P/F ratio was 1:2.

암모니아수 또는 트리에틸아민(TEA)을 촉매로 사용하여 페놀과 포름알데히드로부터 구형 페놀수지를 페놀:포름알데히드=1:1~1:4의 몰 비로 $98^{\circ}C$에서 현탁중합을 통해 합성하였고, 이를 $700^{\circ}C$의 질소 환경에서 탄화시켜 구형 탄소입자를 형성하였다. 현탁중합으로 형성된 구형 페놀수지의 열적 특성으로부터 후경화가 필요함을 확인하였다. 현탁중합의 최적조건을 결정하기 위하여 페놀/포름알데히드(P/F)의 몰 비, 촉매의 pH, 안정제의 분자량이 구형 페놀입자의 크기와 수율에 미치는 영향을 나머지 변수를 고정시킨 상태에서 조사하였다. P/F 몰 비에 따라 형성되는 입자 크기는 증가하는 반면 수득율은 감소하는 것을 확인하였고, 촉매의 pH가 클수록 큰 입자가 형성되며, 또한 안정제의 분자량은 입도분포보다는 수득율에 더 큰 영향을 미치는 것을 확인하였다. 또한 후경화를 거쳐 얻어진 구형 페놀수지의 열안정성을 TGA를 통하여 조사하였으며, P/F 몰 비가 높은 경우는 dibenzyl ether의 존재로 인하여 후경화 이후에도 $220^{\circ}C$의 중량감소가 여전히 존재하며, 반면에 P/F 몰 비가 낮은 경우는 $220^{\circ}C$ 이후 $400^{\circ}C$에 걸쳐 꾸준한 중량감소가 일어나는 것으로부터 P/F 몰 비가 1:2인 경우가 열안정성이 가장 우수함을 확인하였다.

Keywords

References

  1. Knop, A. and Pilato, L. A., Phenolic Resins, Springer-Verlag, Berlin (1986).
  2. Weyl, H., Ed. Handbuch der Organischen Chemie, Makromolekulare Stoffie. 4th de., vols. 14/1 and 14/2 Thieme: Stuttgart (1961).
  3. Nylen, P. and Sunderland, E., Modern Surface Coatings, Wiley London (1965).
  4. Bechmann, A. and Miiler, K., Phenoplaste VEB, Verlag, Leipzig (1973).
  5. Hultzsch, K., Chemie der Phenolrarze, Springer, Berlin (1950).
  6. Carswell, T. S., High Polymer, Vol. 3: Phenoplasts, Their Structure, Properties and Chemical Technology, Inter Science, New York (1947).
  7. Martin, R. W., The Chemistry of Phenolic Resins: the Formation, Structure and Reactions of Phenolic Resins Related Products, Wiley, Mew York (1956).
  8. Hesse, W., In Ullmann's Encyclopedia of Industrial Chemistry, Vol. A19, VCH: Weinheim, p371 (1991).
  9. Othmer, K., ed., Encyclopedia of Chemical Technology, 3rd ed., Vol. 17: Phenolic Resins, Wiley, New York (1983).
  10. Geimer, R. L. and Christiansen, A. W., "Critical Variables in the Rapid Cure and Bonding of Phenolic Resins," Forest Prod. J., 46, 67 (1996).
  11. Strong, A. B., Plastics: Materials and Processing, 3rd Ed., Chapter 9, Prentice Hall, New Jersey (2006).
  12. Mark, H., Bikales, N., Overberger, C., and Menges, G., "Encyclopedia of Polymer Science and Engineering," Vol. 11, p. 45, John Wiley Sons, New York (1988).
  13. Mark, H., Othmer, D., Overberger, C., and Seaborg, G., "Encyclopedia of Chenmical Technology," 3rd ed., Vol. 17, p. 384, John Wiley & Sons, New York (1982).
  14. Knop, A. and Scheib, W., Chemistry and Application of Phenolic Resin, Springer-Verlag, New York (1979).
  15. Brode, G. L., Phenolic Resins, in Encyclopedia of Chemical Technology, Kirk-Othmer Ed., Vol. 17, John Wiley, New York (1982).
  16. Kopf, P. W., Phenolic Resin, in Encyclopedia of Polymer Science and Engineering, ed. by Mark, Bikales, Overberger, and Menges, vol. 11, John Wiley, New York (1988).
  17. Anderson, G. J., Ingram, W. H., and Hampden, I. I., "Phenolic Resin Emulsions Comprising a Resol Resin and a Soluble Protein," U.S. Patent No 3, 862, 060(1975).
  18. Udvardy, Otto, G., Titus, Patricia, E., Navratil, and Martin, "Powdered Phenol-formaldehyde Resin," U.S. Patent No 4, 424, 300(1983).
  19. McCarthy, Jr. and Justin N., "Aqueous Phenolic Resole Dispersion Containing Certain Hydroxyalkylated Gums as Interfacial Agents," U.S. Patent No 4, 039, 525(1977).
  20. Kim, S., Woo, S. and Han, I., "Novel Phenol Resin Carbonizing Method for Carbon Interlayer Coating between Reinforcing Fiber and Matrix in Fiber Reinforced Ceramic Composite," Journal of the Korean Ceramic Society, 46, 301-305(2009). https://doi.org/10.4191/KCERS.2009.46.3.301
  21. Wan, P., Barker, B., Diao, L., Fischer, M., Shi, Y., and Yang, C., "1995 Merck Frosst Award Lecture Quinone Methides: Relevant Intermediates in Organic Chemistry," J. Chem. 24, 465-475 (1996).
  22. Chiang, Y., Kresge, A. J., and Zhu, Y., "Flash Photolytic Generation and Study of 5-methoxy-o-quinone a-phenylethide in Aqueous Solution: Comparison of Cis and Trans Isomer Reactivity," Photochem. Photobiol. Sci., 1, 67-70(2002). https://doi.org/10.1039/b107860g
  23. Edward, S., Industrial Polymers Handbook, vol 2. p1139, Wileyvch (2001).

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