Effects of Sizing Treatment of Carbon Fibers on Mechanical Interfacial Properties of Nylon 6 Matrix Composites

탄소섬유의 사이징처리가 탄소섬유/나일론6 복합재료의 기계적 계면 특성에 미치는 영향

  • Received : 2010.01.06
  • Accepted : 2010.01.15
  • Published : 2010.03.30

Abstract

The sizing treatments of PAN-based carbon fiber surfaces were carried out in order to improve the interfacial adhesion in the carbon fibers/nylon6 composite system. The parameter to characterize the wetting performance and surface free energy of the sized fibers were determined by a contact angle method. The mechanical interfacial properties of the composites were investigated using critical stress intensity factor ($K_{IC}$). The cross-section morphologies of sized CFs/nylon6composites were observed by SEM. As the experimental results, it was observed that silane-based sizing treated carbon fibers showed higher surface free energies than other sizing treatments. In particular, the KIC of the sizing-treated carbon fibers reinforced composites showed higher values than those of untreated carbon fibers-reinforced composites. This result indicated that the increase in the surface free energy of the fibers leads to the improvement of the mechanical interfacial properties of carbon fibers/nylon6 composites.

탄소섬유/나일론 수지 복합재료의 계면결합력의 향상을 위해 폴리아크릴로니트릴(PAN)계 탄소섬유의 표면에 실란계, 설파이드계, 이미드계 계면결합제를 이용해서 사이징 처리를 수행하였으며, 사이징 처리된 탄소섬유의 젖음성과 표면자유에너지는 접촉각을 통해 확인하였다. 사이징 처리되어 제조된 복합재료의 기계적 계면물성은 임계응력세기인자를 통하여 확인하였으며, 파단실험 후 파단면은 주사전자현미경을 통해 관찰하였다. 실험결과 실란계로 사이징 처리된 탄소섬유가 다른 사이징 처리에 비해 표면자유에너지가 큰 것을 접촉각 측정을 통해 관찰하였다. 한편 사이징 처리된 탄소섬유 강화 나일론 복합재의 경우 미처리 탄소섬유를 이용한 복합재에 비해 높은 기계적 계면강도를 보였다. 이러한 결과는 섬유의 표면자유에너지가 탄소섬유와 나일론6 기지 사이의 계면결합력의 증대를 유도하여 복합재료의 기계적 계면강도가 증가된 것으로 판단된다.

Keywords

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