In this work, the silane coupling agents, such as γ-glycidoxy propyl trimethoxy silane (403), γ-methacryloxy propyl trimethoxy silane(503), and γ-amino propyl triethoxy silane (903) were used for the surface treatment of glass fibers. To understand the role of interfacial adhesion of glass fiber/unsaturated polyster composites, contact angles of the silane-treated glass were measured by the wicking method based on Washburn equation using deionized water and diiodomethane as testing liquids. According to the contact angle measurements, the silane-treated glass fibers do lead to an increase in surface free energy, mainly due to the increase of polarity of component. For the mechanical interfacial properties of glass fiber/unsaturated polyester composites, the interlaminar shear strength (ILSS) and the critical stress intensity factor (KIC) were performed. As a result, the mechanical interfacial properties were improved in the case of silane-treated composites compared with untreated one. It reveals that the hydrogen bonding, which is one of the specific component of the surface free energy, between the glass fibers and the coupling agents plays an important role in improving the degree of adhesion in composite system.

본 연구에서는 유리섬유의 표면 처리를 위해 실란 커플링제, γ-glycidoxy propyl trimethoxy silane (403), γ-methacryloxy propyl trimethoxy silane(503), 그리고 γ-amino propyl triethoxy silane (903)이 사용되었다. 유리섬유 강화 복합재료의 계면 결합력을 알아보기 위해, 실란 처리된 유리섬유의 접촉각은 Washbum 식에 기초한 wicking method를 사용하였고, 젖음액으로는 증류수와 diiodomethane이 사용되었다. 접촉각 측정 결과, 실란 처리된 유리섬유는 극성 요소에 의한 표면 자유에너지의 증가를 확인할 수 있었다. 유리섬유 복합재료의 기계적 계면 결합력을 알아보기 위해 층간 전단강도(ILSS)와 암계 응력세기 인자(KIC)가 행해졌다. 그 결과로, 기계적 물성은 실란 처리되지 않은 것에 비하여 증가됨을 알 수 있었고, 이는 유리섬유와 실란 커플링제 사이의 수소 결합에 의한 극성 요소가 그들 간의 계면을 증가시키는데 크게 작용하였음을 알 수 있다