Effects of temperature on Hardness and Stiffness of NR and SBR Vulcanizates

NR과 SBR 가황물의 경도와 강성도 대한 온도의 영향

  • Jin, Hyun-Ho (Department of Advanced Chemicals, Chonnam National University) ;
  • Hong, Chong-Kook (Center for functional Nano Fine Chemicals (BK21)) ;
  • Cho, Dong-Lyun (School of Applied Chemical Engineering, Chonnam National University) ;
  • Kaang, Shin-Young (School of Applied Chemical Engineering, Chonnam National University)
  • 진현호 (전남대학교 신화학소재공학과) ;
  • 홍창국 (기능성 나노 신화학소재 사업단(BK21)) ;
  • 조동련 (전남대학교 응용화학공학부) ;
  • 강신영 (전남대학교 응용화학공학부)
  • Published : 2007.09.29

Abstract

Hardness of rubbery materials, which is important for dimensional stability and product performance, was investigated upon temperature change in this study. A newly developed IRHD (International Rubber Hardness Degree) tester was used to measure the hardness changes of NR and SBR specimens at various temperatures and the hardness values were compared with the Young's modulus. The harness and Young's modulus of NR and SBR showed an abrupt change near the glass transition temperatures. The hardness and Young's modulus were increased by increasing temperature due to the increased random chain conformation of molecules. The effect of temperature on hardness and Young's modulus of NR and SBR specimens filled with carbon black and silica was decreased by increasing filler content.

본 연구에서는 고무제품의 수치 안정성과 성능유지에 직접적으로 영향을 미치는 중요한 특성 중 하나인 온도변화에 따른 고무재료의 경도변화를 고찰하였다. 새롭게 제작된 Inter-national Rubber Hardness Degree(IRHD, Normal type) 경도측정 시험기를 사용하여 미충전된 NR과 SBR 시편의 여러 온도에서 경도변화를 측정하였으며 Young's modulus 값과 비교하였다. NR과 SBR 모두 유리전이온도 근처에서 경도와 Young's modulus의 급격한 변화를 보였다. 온도가 증가함에 따라 경도와 Young's modulus 값이 증가하는 경향을 보였으며 이는 분자의 운동성과 엔트로피 영향으로 해석할 수 있다. 카본블랙과 실리카가 충전된 NR과 SBR의 경우 충전제의 함량이 증가함에 따라 경도에 미치는 온도의 영향이 감소함을 관찰하였다.

Keywords

References

  1. J. A. Shaw, A. S. Jones, and A. S. Wiliam, 'Chemorheological Response of Elastomers at Elevated Temperature: Experiment and Simulations', J. Mech. Phys. Solids, 53, 2758 (2005) https://doi.org/10.1016/j.jmps.2005.07.004
  2. C. K. Hong, S. Park, and S. Kaang, 'A test method for measuring the dimensional stability of elastomeric materials upon heating', Polymer Testing, submitted
  3. 박상민, 홍창국, 조동련, 강신영, '충진된 고무재료의 열변화에 따른 수축력/팽창력 측정', Elastomer, submitted
  4. A. N. Gent, 'Elasticity' in 'Engineering with Rubber: How to Design Rubber Components', ed. by A. N. Gent, Hanser Publishers, New York, 1992
  5. A. K. Sircar, 'Thermal Characterization of Polymeric Materials', ed. by E. A. Turi, 2nd ed., Academic Press, New York, 1997
  6. A. N. Gent, 'On the Relation between Indentation Hardness and Young's modulus', IRI, 34, 46-57 (1958)
  7. D. J. Hitt and M. Gilbert, 'Dimensional Stability of Oriented, Rigid Poly(vinyl chloride)', J. Appl. Polym. Sci., 89, 3859 (2003) https://doi.org/10.1002/app.12576
  8. D. D. Wright, E. P. Lautenschlager, and J. L. Gilbert, 'Constrained Shrinkage of Highly Oriented Poly(methyl methacrylate) Fibers', J. Appl. Polym. Sci., 91, 4047 (2004) https://doi.org/10.1002/app.13621
  9. B. J. Briscoe and K. S. Sebastian, 'An Analysis of the Durometer Indentation', Rubber Chem. Technol., 66, 827 (1993) https://doi.org/10.5254/1.3538347
  10. N. Rattanasom, T. Saowapark, and C. Deeprasertkul, 'Reinforcement of Natural Rubber with Silica/Carbon Black Hybrid Filler', Polymer Testing, 26, 369 (2007) https://doi.org/10.1016/j.polymertesting.2006.12.003
  11. S.-S. Choi, C. Nah, S. G. Lee, and C. W. Joo, 'Effect of Filler-Filler Interaction on Rheological Behavior of Natural Rubber Compounds Filled with Both Carbon Black and Silica', Polym. Int., 52, 23 (2003) https://doi.org/10.1002/pi.975
  12. C. K. Hong, H. Kim, C. Ryu, C. Nah, Y. Huh, and S. Kaang, 'Effects of Particle Size and Structure of Carbon Black on the Abrasion of Filled Elastomer Compounds', J. Materials Sci., (accepted)
  13. Sung-Seen Choi, 'Influence of Polymer-Filler Interactions on Retraction Behaviors of Natural Rubber Vulcanizates Reinforced with Silica and Carbon Black', J. Appl. Polym. Sci., 99, 691 (2006) https://doi.org/10.1002/app.22562
  14. A. Kasner and E. Meinecke, 'Porosity in Rubber, a Review', Rubber Chem. Technol., 69, 424 (1996) https://doi.org/10.5254/1.3538379
  15. I. Franta, 'Elastomers and Rubber Compounding Materials', Elsevier, NY, 1989
  16. D. A. Wasylyshyn and G. P. Johari, 'Mechanical Relaxation Spetroscopy of Three Triepoxide-Based Polymers', J. Polym. Sci.: Part B: Polym. Phys., 37, 3071-3083 (1999) https://doi.org/10.1002/(SICI)1099-0488(19991101)37:21<3071::AID-POLB16>3.0.CO;2-A
  17. Y.-C. Ou, Z.-Z. Yu, A. Vidal, and J. B. Donnet, 'Effect of Alkylation of Silica Filler on Rubber Reinforcement', Rubber Chem. Technol., 67, 834 (1994) https://doi.org/10.5254/1.3538714
  18. N. Suzuki and F. Yatsuyanagi, 'Effect of Rubber/Filler Interactions on Deformation Behavior of Silica Filled SBR Systems.' Polymer, 46, 193-201 (2005) https://doi.org/10.1016/j.polymer.2004.10.066
  19. Sung-Seen Choi, 'Influence of internal strain on change of crosslink density of natural rubber vulcanizates by thermal ageing', Polym. Int., 50, 107-112 (2001) https://doi.org/10.1002/1097-0126(200101)50:1<107::AID-PI593>3.0.CO;2-Z