Partial discharge (PD) characteristics of chemically modified polyethylenes were investigated. The chemical modification of polyethylene was made by grafting acrylic acid (AA) or n-butyl acrylate (nBA) onto polyethylene chains. It was found that the partial discharging activities in AA or nBA grafted polyethylenes were considerably suppressed, which was attributed that the change of molecular structure in polyethylene changes the environment in voids formed by the micro-breakdown in the vicinity of needle tip. It was also found that AA was more effective than nBA in preventing partial discharge of polyethylene.

세라믹 압전소자로 만들어진 초음파 센서를 이용하여 아크릴산과 노말부틸아크릴레이트로 그라프트된 저밀도 폴리에틸렌의 부분방전 특성을 알아보았다. 아크릴산과 노말부틸아크릴레이트로 그라프트된 폴리에틸렌의 부분방전 특성이 저밀도 폴리에틸렌에 비하여 크게 억제됨을 확인하였는데, 이는 폴리에틸렌의 분자구조적인 변화가 바늘 끝 부위의 미세절연파괴시 발생한 미세기공내의 환경을 변화시켰기 때문으로 추측된다. 또한 노말부틸아크릴레이트보다 아크릴산이 부분방전 억제효과가 큰 것으로 밝혀졌다.

Keywords: acrylic acid grafted polyethylenes; normal butyl acrylate grafted polyethylenes; partial discharge