Composites Research

The Korean Society for Composite Materials (한국복합재료학회)
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Thermal Decomposition Activation Energy of Liquid Crystalline Epoxy using Cationic Initiator

양이온 개시제를 이용한 열경화성 액정 에폭시의 열분해 활성화에너지

  • Jung, Ye Ji (Department of Organic Materials and Fiber Engineering, Soong-sil University) ;
  • Hyun, Ha Nuel (Department of Organic Materials and Fiber Engineering, Soong-sil University) ;
  • Cho, Seung Hyun (Department of Organic Materials and Fiber Engineering, Soong-sil University)
  • Received : 2021.02.18
  • Accepted : 2021.05.10
  • Published : 2021.07.01
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Abstract

Due to the formation of random three dimensional network structure, which cause a lot of scattering of phonons, the thermal conductivity is low when the liquid crystalline epoxy is cured with amine-based curing agent. This problem is solved by using a cationic initiator that can make mesogen groups to be stacked structure. In this experiment, the thermal stability is compared by investigating the activation energy of isothermal decomposition through TGA of an epoxy using an amine-based curing agent and a cationic initiator. As a result, the energy of the activation of the epoxy using a cationic initiator is high. Compared with the previous experiments, the thermal stability is similar to the thermal conductivity.

기존 아민계 경화제를 사용해 액정 에폭시를 경화할 경우, 랜덤 한 3차원 네트워크 구조의 생성으로 인해 phonon의 산란이 많이 발생하기 때문에 열전도도가 낮게 나타났다. 이러한 문제를 mesogen그룹을 적층된 구조로 형성하는 양이온 개시제를 이용하여 해결하기 위해 본 연구에서는 아민계 경화제와 양이온 개시제를 사용한 에폭시의 TGA분석(Thermogravimetric Analysis)을 통해 등온 열분해 활성화에너지를 조사하여 열적안정성을 비교하였다. 양이온 개시제를 이용한 에폭시의 경우 활성화가 에너지가 높았으며 기존 실험과 비교했을 때, 열적안정성은 열전도도와 비슷한 양상을 보인다.

Keywords

Acknowledgement

본 연구는 한국연구재단의 기초과학연구 프로그램 지원으로 수행되었습니다(NRF-2018R1A2B60004512).

References

  1. Chen, S.C., Wan, C.C., and Wang, Y.Y., "Thermal Analysis of Lithium-ion Batteries", Journal of Power Soureces, Vol. 140, No. 1, 2005, pp. 111-124. https://doi.org/10.1016/j.jpowsour.2004.05.064
  2. Kizilel, R., Sabbah, R., Selman, J.R., and Al-Hallaj, S., "An Alternative Cooling System to Enhance the Safety of Li-ion Battery Packs", Journal of Power Soureces, Vol. 194, No. 2, 2009, pp. 1105-1112. https://doi.org/10.1016/j.jpowsour.2009.06.074
  3. Choi, J.R., and Park, S.J., "A Study on Thermal Conductivity and Fracture of Alumina Nanofibers and Powders-filled Epoxy Matrix Coposites", Polymer, Vol. 37, No. 1, 2013, pp. 47-51.
  4. Harada, M., Hamaura, N., Ochi, M., and Agari, Y., "Thermal Conductivity of Liquid Crystalline Epoxy/BN Filler Composites Having Ordered Network Structure", Composites Part B: Engineering, Vol. 55, 2013, pp. 306-313. https://doi.org/10.1016/j.compositesb.2013.06.031
  5. You, J., Dou, L., Hong, Z., Li, G., and Yang, Y., "Recent Trends in Polymer Tandem Solar Cells Research", Progress in Polymer Science, Vol. 38, No. 12, 2013, pp. 1909-1928. https://doi.org/10.1016/j.progpolymsci.2013.04.005
  6. Yeo, H., Islam, A.M., You, N.H., Ahn, S., Goh, M., Hahn, J.R., and Jang, S.G., "Characteristic Correlation between Liquid Crystalline Epoxy and Alumina Filler on Thermal Conducting Properties", Composites Science and Technology, Vol. 141, 2017, pp. 99-105. https://doi.org/10.1016/j.compscitech.2017.01.016
  7. Yi, J.W., "Trend of Chemical Recycling Technoiogies for Fiber-reinforced Thermoset Composites", Polymer Science and Technology, Vol. 30, 2019, pp. 503-504.
  8. Seo, D.K., Ha, N.R., Lee, J.H., Park, H.G., and Bae, J.S., "Property Evaluation of Epoxy Resin based Aramid and Carbon Fiber Composite Material", Textile Coloration and Finishing, Vol. 27, No. 1, 2015, pp. 11-17. https://doi.org/10.5764/TCF.2015.27.1.11
  9. Kwon, W., Lee, M.K., Han, M.W., and Jeong, E.G., "Effect of Polytriazolesulfone Addition on Fracture Toughness of DGEBA Epoxy Resin", Textile Coloration and Finishing, Vol. 31, No. 2, 2019, pp. 118-126. https://doi.org/10.5764/TCF.2019.31.2.118
  10. Kim, Y., Jung, J., Yeo, H., You, N.H., Jang, S. G., Ahn, S., Lee, S. H., and Goh, M., "Development of Highly Thermal Conductive Liquid Crystalline Epoxy Resins for High Thermal Dissipation Composites", Composites Research, Vol. 30, No. 1, 2017, pp. 1-6. https://doi.org/10.7234/composres.2017.30.1.001
  11. Park, J.H., and Cho, S.H., "Thermal Decomposition Behavior of Liquid Crystalline Epoxy-Based Composites", Textile Science and Engineeringy, Vol, 55, No. 5, 2018, pp. 324-329.
  12. Kim, Y., Jung, J., Yeo, H., You, N.-H., Jang, S.G., Ahn, S., Lee, S. H., and Goh, M., "Development of Highly Thermal Conductive Liquid Crystalline Epoxy Resins for High Thermal Dissipation Composites", Composites Research, Vol. 30, No. 1, 2017, pp. 1-6. https://doi.org/10.7234/composres.2017.30.1.001
  13. Ha, S.M., Lee, H.L., Lee, S.G., Kim, B.G., Kim, Y.S., Won, J.C., Choi, W.J., Lee, D.C., and Yoo, Y., "Thermal Conductivity of Graphite Filled Liquid Crystal Polymer Composites and Theoretical Predictions," Composites Science and Technology, Vol. 88, 2013, pp. 113-119. https://doi.org/10.1016/j.compscitech.2013.08.022
  14. Zhang, Z.Y., Zhang, Q.K., Shen, Z., Yu, J.P., Wu, Y.X., and Fan, X.H., "Synthesis and Characterization of New Liquid Crystalline Thermoplastic Elastomers Containing Mesogen-Jacketed Liquid Crystalline Polymers", Macromolecules, Vol. 49, No. 2, 2016, pp. 475-482. https://doi.org/10.1021/acs.macromol.5b02630
  15. Hirn, B., Carfagna, C., and Lanzetta, R., "Linear Precursors of Liquid Crystalline Thermosets", Journal of Materials Chemistry, Vol. 6, No. 9, 1996, pp. 1473-1478. https://doi.org/10.1039/JM9960601473
  16. Choi, J.H., Song, H.J., Jung, J., Yu, J.W., You, N.H., and Goh, M., "Effect of Crosslink Density on Thermal Conductivity of Epoxy/Carbon Nanotube Nanocomposites", Journal of Applied Polymer Science, Vol. 134, No. 4, 2017, Paper ID. 44253.
  17. Yu, J.W., Jung, J., Choi, Y.M., Choi, J.H., Yu, J., Lee, J.K., You, N. H., and Goh, M., "Enhancement of the Crosslink Density, Glass Transition Tempertature, and Strength of Epoxy Resin by Using Functionalized Graphene Oxide Co-curing Agents", Polymerer Chemistry, Vol. 7, No. 1, 2016, pp. 36-43. https://doi.org/10.1039/C5PY01483B
  18. Park, S.J., Seo, M.K., and Lee, J.R., "Isothermal Cure Kinetics of Epoxy/Phenol-Novolac Resin Blend System Initiated by Cationic Latent Thermal Catalyst", Journal of Polymer Science Part A: Polymer Chemistry, Vol. 38, No. 16, 2000, pp. 2945-2956. https://doi.org/10.1002/1099-0518(20000815)38:16<2945::AID-POLA120>3.0.CO;2-6
  19. Kim, Y.C., Park, S.J., and Lee, J.R., "Effects of N-Benzylpyrazinium Hexafluoroantimonate Concentration on Rheological Properties in Cationic Epoxy Cure System", Polymer Journal, Vol. 29, No. 9, 1997, pp. 759-765. https://doi.org/10.1295/polymj.29.759
  20. Islam, A.M., Lim, H., You, N.H., Ahn, S., Goh, M., Hahn, J.R., Yeo, H.M., and Jang, S.G., "Enhanced Thermal Conductivity of Liquid Crystalline Epoxy Resin using Controlled Linear Polymerization", ACS Macro Letters, Vol. 7, No. 10, 2018, pp. 1180-1185. https://doi.org/10.1021/acsmacrolett.8b00456
  21. Zhang, T., Wu, X., and Luo, T., "Polymer Nanofibers with Outstanding Thermal Conductivity and Thermal Stability: Fundamental Linkage between Molecular Characteristics and Macroscopic Thermal Properties", The Journal of Physical Chemistry C, Vol. 118, No. 36, 2014, pp. 21148-21159. https://doi.org/10.1021/jp5051639