Composites Research

The Korean Society for Composite Materials (한국복합재료학회)
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Investigation of Thermal Stability of Epoxy Composite Reinforced with Multi-Walled Carbon Nanotubes and Micrometer-Sized Silica Particles

다중벽 탄소나노튜브와 마이크로미터 크기 실리카 입자로 강화된 에폭시 복합재료의 열 안정성에 관한 연구

  • Oh, Ryun (Division of Mechanical Design Engineering, Chonbuk National University) ;
  • You, Byeong Il (Division of Mechanical Design Engineering, Chonbuk National University) ;
  • Ahn, Ji Ho (Division of Mechanical Design Engineering, Chonbuk National University) ;
  • Lee, Gyo Woo (Division of Mechanical Design Engineering, Chonbuk National University)
  • Received : 2016.05.09
  • Accepted : 2016.10.21
  • Published : 2016.10.31
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Abstract

In this study, to improve the thermal stabilities of the epoxy composite specimens in addition to the enhanced mechanical properties, those were reinforced with carbon nanotubes and micrometer-sized silica particles. To disperse the filler in matrix relatively simple physical process, specimens were fabricated using shear mixing and sonication. Tensile strength, coefficients of thermal expansion and thermal conductivity of the specimens were measured with varied contents of the two fillers. The mechanical and thermal properties were also discussed, and the experimental results of thermal expansion related to the thermal stability of the specimens were compared with those from several micromechanics models. The hybrid composites specimens incorporating 0.6 wt％ of carbon nanotubes and 50 wt％ of silica particles showed better mechanical properties than the others with increase in tensile strength up to 11％, with respect to those of the baseline specimens. As the silica contents were increased the thermal expansion was reduced down to 36%, and the thermal stability was improved with the decreased thermal deformation. Thermal conductivity of the epoxy composite specimens incorporating 50 wt％ of silica particles was enhanced, which demonstrate improvement of 72%. The mechanical and thermal properties of the hybrid composites specimens incorporating the two fillers were improved simultaneously.

본 연구에서는 에폭시 복합재료의 기계적 물성을 향상시킴과 동시에 상대적 단점으로 지적될 수 있는 열안정성과 치수 안정성의 문제를 개선하고자 에폭시 복합재료를 다중벽 탄소나노튜브와 마이크로미터 크기의 실리카 입자로 강화하였다. 두 충전제는 별도의 개질 없이 전단혼합과 초음파기기만을 이용하는 물리적 방법으로 에폭시 수지 내에 분산시켰다. 두 충전제 함량에 따른 시편의 특성은 인장강도, 열팽창계수, 열전도도 측정을 통해 평가하였으며, 시편의 열 안정성을 보다 넓은 범위에서 고찰하기 위해 열팽창계수를 측정한 결과와 미시역학 모델을 이용해 계산한 결과를 비교하였다. 탄소나노튜브 함량 0.6 wt%에 실리카 함량 50 wt%로 강화된 하이브리드 복합재료 시편의 인장강도는 에폭시 복합재료 시편 대비 약 11%의 증가를 보여 가장 좋은 기계적 물성을 나타내었다. 열적 물성을 살펴보면 두 충전제의 함량에 따라 그 결과가 달라지는데, 특히 에폭시 수지 내에 실리카 함량이 증가할수록 열팽창계수는 약 36%까지 감소하였고, 이로 인해 시편의 열 변형이 줄어들면서 열 안정성도 개선되었다. 또한 실리카 함량 50 wt%로 강화된 에폭시 복합재료 시편의 열전도도는 약 72% 정도 증가하였다. 두 충전제로 강화된 하이브리드 복합재료 시편에서는 보다 향상된 기계적, 열적 물성을 확보할 수 있었다.

Keywords

References

  1. Matejka, L., Dukh, O., and Kolarik, J., "Reinforcement of Cross-linked Rubbery Epoxies by In-situ Formed Silica," Polymer, Vol. 41, 2000, pp. 1449-1459. https://doi.org/10.1016/S0032-3861(99)00317-1
  2. Cha, J.M., Jin, S.H., Shim, J.H., Park, C.S., Ryu, H.J., and Hong, S.H., "Functionalization of Carbon Nanotubes for Fabrication of CNT/epoxy Nanocomposites," Materials & Design, Vol. 95, 2016, pp. 1-8. https://doi.org/10.1016/j.matdes.2016.01.077
  3. Wang, J.G., Fang, Z.P., Gu, A.J., Xu, L.H., and Liu, F., "Effects of Amino-functionalization of Multi-wall Carbon Nanotubes on Dispersion with Epoxy Resin Matrix," Journal of Applied Polymer Science, Vol. 48, 2010, pp. 592-603.
  4. Kim, S., Kim, J.K., Lee, S.H., Park, S.J., and Kang, K.H., "Thermophysical Properties of Multiwalled Carbon Nanotube-reinforced Polypropylene Composites," International Journal of Thermophysics, Vol. 27, 2006, pp. 152-160. https://doi.org/10.1007/s10765-006-0043-4
  5. Xia, J., Li, J., Zhang, G., Zeng, X., Niu, F., Yang, H., Sun, R., and Wong, C.P., "Highly Mechanical Strength and Thermally Conductive Bismaleimide-triazine Composites Reinforced by $Al_2O_3$@polyimide Hybrid Fiber," Composites: Part A, Vol. 80, 2016, pp. 21-27. https://doi.org/10.1016/j.compositesa.2015.09.009
  6. Zeng, X., Yu, S., Sun, R., and Xu, J.B., "Mechanical Reinforcement While Remaining Electrical Insulation of Glass Fibre/polymer Composites using core-shell CNT@$SiO_2$ Hybrids as Fillers," Composites: Part A, Vol. 73, 2015, pp. 260-268. https://doi.org/10.1016/j.compositesa.2015.03.015
  7. Kerner, E.H., "The Elastic and Thermo-elastic Properties of Composite Media," Proceeding of the Physical Society Section B, Vol. 69, 1956, pp. 808-813. https://doi.org/10.1088/0370-1301/69/8/305
  8. Wakashima, K., and Tsukamoto, H., "Mean-field Micromechanics Model and Its Application to the Analysis of Thermomechanical Behaviour of Composite Materials," Materials Science Engineering: A, Vol. 146, 1991, pp. 291-316. https://doi.org/10.1016/0921-5093(91)90284-T
  9. Eshelby, J.D., "The Determination of the Elastic Field of an Ellipsoidal Inclusion, and Related Problems," Proceeding of the Royal Society A, Vol. 241, Issue 1226, 1957.
  10. Mori, T., and Tanaka, K., "Average Stress in Matrix and Average Elastic Energy of Materials," Acta Metallurgica, Vol. 21, 1973, pp. 571-574. https://doi.org/10.1016/0001-6160(73)90064-3
  11. Lavorgna, M., Romeo, V., Marton, A., Zarrelli, M., Giordano, M., and Buonocore, G.G., "Silanization and Silica Enrichment of Multiwalled Carbon Nanotubes: Synergistic Effects on the Thermal-mechanical Properties of Epoxy Nanocomposites," European Polymer Journal, Vol. 49, 2013, pp. 428-438. https://doi.org/10.1016/j.eurpolymj.2012.10.003
  12. Chung, E.H., Chen, L.M., Wang, W.H., Lai, Y., Yang, P.F., and Lin, H.P., "Effects of Mesoporous Silica Coated Multi-wall Carbon Nanotubes on the Mechanical and Thermal Properties of Epoxy Nanocomposites," Journal of the Taiwan Institute of Chemical Engineers, Vol. 45, 2014, pp. 2813-2819. https://doi.org/10.1016/j.jtice.2014.05.009
  13. Cui, W., Du, F., Zhao, J., Zhang, W., Yang, Y., Xie, X., and Mai, Y.W., "Improving Thermal Conductivity While Retaining High Electrical Resistivity of Epoxy Composites by Incorporating Silica-coated Multi-walled Carbon Nanotubes," Carbon, Vol. 49, 2011, pp. 495-500. https://doi.org/10.1016/j.carbon.2010.09.047
  14. Shenogin, S., Xue, L.P., Ozisik, P., Keblinski, P., and Cahill, D.G., "Role of Thermal Boundary Resistance on the Heat Flow in Carbon-nanotube Composites," Journal of Applied Physics, Vol. 95, 2004, pp. 8136-8144. https://doi.org/10.1063/1.1736328
  15. Yang, S.Y., Ma, C.C.M., Teng, C.C., Huang, Y.W., Liao, S.H., and Huang, Y.L., "Effect of Functionalized Carbon Nanotubes on the Thermal Conductivity of Epoxy Composites," Carbon, Vol. 48, 2010, pp. 592-603. https://doi.org/10.1016/j.carbon.2009.08.047
  16. Gojnya, F., Wichmanna, M., Fiedlera, B., Kinlochb, I., Bauhofere, W., Windleb, A., and Schultea, K., "Evaluation and Identification of Electrical and Thermal Conduction Mechanisms in Carbon Nanotube/epoxy Composites," Polymer, Vol. 47, 2006, pp. 2036-2045. https://doi.org/10.1016/j.polymer.2006.01.029
  17. Xu, Y., Ray, G., and Abdel-Magid, B., "Thermal Behavior of Single-walled Carbon Nanotube Polymer-matrix Composites," Composites Part A: Applied Science and Manufacturing, Vol. 37, 2006, pp. 114-121. https://doi.org/10.1016/j.compositesa.2005.04.009
  18. Xu, Y., Chung, D.D.L., and Mroz, C., "Thermally Conducting Aluminum Nitride Polymer-Matrix Composites," Composites Part A: Applied Science and Manufacturing, Vol. 32, pp. 2001, 1749-1757. https://doi.org/10.1016/S1359-835X(01)00023-9
  19. Seo, M.K., Lee, J.R., and Park, S.J., "Crystallization Kinetics and Interfacial Behaviors of Polypropylene Composites Reinforced with Multi-walled Carbon Nanotubes," Materials Science and Engineering A, Vol. 404, 2005, pp. 79-84. https://doi.org/10.1016/j.msea.2005.05.065
  20. Chung, D.D.L., "Electromagnetic Interference Shielding Effectiveness of Carbon Materials," Carbon, Vol. 39, 2001, pp. 279-285. https://doi.org/10.1016/S0008-6223(00)00184-6

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  1. Advances in Liquid Crystalline Epoxy Resins for High Thermal Conductivity vol.13, pp.8, 2016, https://doi.org/10.3390/polym13081302