Applied Chemistry for Engineering (공업화학)

The Korean Society of Industrial and Engineering Chemistry (한국공업화학회)
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Mar Behavior of Polyurethane Acrylate Coating due to Thermal Degradation

열 산화에 따른 폴리우레탄 아크릴레이트 코팅소재의 긁힘 거동

  • Sun Hae Huh (Department of Safety Engineering, Dongguk University) ;
  • Jong-Il Weon (Department of Safety Engineering, Dongguk University) ;
  • Young-Cheol Shin (Department of Safety Engineering, Dongguk University)
  • 허선혜 (동국대학교 안전공학과) ;
  • 원종일 (동국대학교 안전공학과) ;
  • 신영철 (동국대학교 안전공학과)
  • Received : 2025.07.12
  • Accepted : 2025.07.24
  • Published : 2025.08.10
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Abstract

This study investigated the effects of thermal aging on the mar resistance of a polyurethane acrylate coating over a 16-week period. Mar tests were conducted using an area-contact scratch tip capable of applying a constant load under relatively low stress conditions. Normalized changes in gloss and quantified mar damage were proposed as reliable and effective methods for evaluating subtle surface deterioration. During the initial stages of thermal oxidation, increasing aging time led to improved mar resistance and overall performance. However, depending on the aging temperature, mar resistance tended to decrease with prolonged exposure beyond a certain threshold. Surface morphology and mar-induced damage were examined using a flatbed scanner and optical microscopy. The concentration of oxygen-containing polar functional groups on the coating surface increased with aging time, whereas hydrocarbon groups decreased. The results of scratch coefficient of friction measurements exhibited strong correlation with the normalized gloss loss and mar damage metrics.

폴리우레탄 아크릴레이트(polyurethane acrylate, PUA) 코팅소재의 긁힘 저항성에 대한 열 산화 노출 시간의 효과를 16주에 걸쳐 조사하였다. 긁힘 시험은 비교적 낮은 응력 수준에서 일정하중을 가할 수 있는 면적 접촉 스크래치 팁을 사용하여 수행되었다. 무차원된 광택도와 긁힘 손상도는 코팅 표면의 미세한 손상을 정량적으로 평가하기 위한 신뢰 할 수 있고 유효한 측정 방법임을 확인하였다. 열 산화의 초기 단계에서는 열화 시간이 증가함에 따라 긁힘 저항성이 증가하였다. 열화 온도에 의존적이지만, 특정 열화 시간 이후 열화 환경이 지속되면 긁힘 저항성이 감소하는 경향을 보였다. 평판 스캐너와 광학 현미경을 이용하여 PUA 코팅소재의 긁힘 손상에 관한 표면 특성과 모폴리지를 관찰하였다. PUA 표면의 산소 함유 극성 관능기는 열화 시간이 증가할수록 증가하는 반면, 탄화수소기는 감소하였다. 스크래치 마찰 계수의 측정 결과는 무차원화된 광택도 및 긁힘 손상도의 결과와 잘 일치하였다.

Keywords

Acknowledgement

이 논문은 2024년도 동국대학교 연구년 지원에 의하여 이루어졌음.

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