Elastomers and Composites

The Rubber Society of Korea (한국고무학회)
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A Study on the Life Time Prediction and Acid-Heat aging Property of NBR Rubber for Fuel Cell Gasket

연료전지 카스켓용 NBR 고무의 산-열 노화 특성과 수명예측에 관한 연구

  • Kim, Mi-Suk (School of Polymer Science & Engineering, Gyeongsang national University) ;
  • Kim, Jin-Hak (School of Polymer Science & Engineering, Gyeongsang national University) ;
  • Kim, Seok-Jin (R&D center, Dong-A Hwa Sung Co., Ltd.) ;
  • Kim, Jin-Kuk (School of Polymer Science & Engineering, Gyeongsang national University)
  • 김미숙 (국립경상대학교 고분자공학과) ;
  • 김진학 (국립경상대학교 고분자공학과) ;
  • 김석진 (동아화성(주)) ;
  • 김진국 (국립경상대학교 고분자공학과)
  • Published : 2007.03.31
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Abstract

Material characteristics and lifetime evaluation are very important in design procedure to assure the safety and reliability of the rubber components. In this paper, the NBR compound was prepared by sulfur-cure system, and was used in predicting the lifetime of rubber gasket made by the compound. The accelerated material aging was investigated at different temperatures at 120, 140 and $160^{\circ}C$ and aging time from 3 hours to 600 hours at 5, 6, 7 vol %. of $H_2SO_4$ concentrations The rubber strips were placed in acid solution using pyrex g1ass tube. Both ends of pyrex g1ass tube were sealed to avoid evaporation of solution during heating at given time. The material test and accelerated acid-heat aging test were carried out to predict the useful life of NBR rubber gasket for a fuel cell stack. In order to investigate the effects of acid-heat aging on the properties of the NBR, tensile strength, elongation at break, hardness and crosslink-density were measured. The tensile strength decreases as the $H_2SO_4$ concentrations and temperature increase. Results were evaluated using Arrhenius equation.

고무의 안정성과 신뢰성 확보를 위해 재료 특성과 수명 평가는 매우 중요하다. 본 연구에서는 연료전지용 고무 가스켓으로 사용되는 황으로 가황한 NBR compound의 수명을 예측하였다. 5, 6, 7 vol% 황산농도에서 120, 140, $160^{\circ}C$ 온도로 각각 3시간에서 600시간까지 가속 노화시험을 하였다. 고무를 황산용액 안에 침지시키기 위해 pyrex glass tube를 사용하였다. 그리고 가열 시간 동안 용액의 증발을 막기 위하여 pyrex glass tube 양쪽 끝을 막았다. 연료전지용 가스켓인 NBR 고무의 수명을 예측하기 위하여 가속 산-열 노화시험 후 물성 실험을 하였으며 산-열 노화시험에서 물리적 특성의 영향을 연구하기 위하여 인장강도, 신장율, 경도, 가교밀도를 측정하였다. 인장강도는 황산농도와 온도가 증가함에 따라서 감소되었는데 이 결과로 Arrhenius 식을 유도하여 수명을 평가하였다.

Keywords

References

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