To improve the interfacial adhesion between a glass fiber and a matrix, silane coupling agent was used. The γ-methacryloxypropyltrimethoxy silane (90 wt%, MPS) containing γ-aminopropyltriethoxy siland (10 wt%, APS) was used for the surface treatment of glass fibers with different concentrations. To understand the role of the interfacial adhesion of glass fiber/unsaturated polyester composites, the contact angles of the silane-treated glass fibers were measured by the wicking method based on the Washburn equation using both deionized water and diiodomethane as testing liquids. The Owens-Wendt and Wu's harmonic models were used to analyze the surface free energy of the composites. According to the contact angle measurements, the silane-treated glass fibers yield and increase in the surface free energy, mainly due to the increase of its specific(or polar) component. For the evaluation of mechanical interfacial properties of the glass fiber/unsaturated polyester composites, the interlaminar shear strength(ILSS) was measured. The mechanical interfacial properties were improved in the case of silane-treated composites compared to composites prepared with untreated glass fibers, and yield the maximum value at a concentration of 0.2 wt% of the silane coupling agent. It was revealed that the hydrogen bonding, which was one of the specific components of surface free energy between glass fibers and the coupling agents, played an important role in improving the degree of adhesion at the interfaces of composite.

강화재인 유리섬유와 매트릭스와의 계면 결합력을 향상시키기 위해 실란 커플링제가 사용되었으며, γ-aminopropyltriethoxy silane (10 wt%, APS)를 함유한 γ-methacryloxypropyltrimethoxy silane (90 wt%, MPS)은 각 농도에 따라 유리섬유에 처리하였다. 유리섬유강화 복합재료의 계면 결합력을 알아보기 위해, 실란 처리된 유리섬유의 접촉각은 Washburn 식에 기초한 wicking method를 사용하였고, 젖음액으로는 증류수와 diiodomethane이 사용되었다. 본 연구에서, Owens-Wendt와 Wu의 Harmonic model이 복합재료의 표면 자유에너지를 측정하는데 사용되었다. 접촉각 측정 결과, 실란 처리된 유리섬유는 극성 요소에 의한 표면 자유에너지의 증가를 확인할 수 있었다. 또한 유리섬유강화 복합재료의 기계적 계별 결합력을 알아보기 위해 층간 전단강도 (interlaminar shear strength, ILSS) 측정이 행해졌다. 그 결과로, 기계적 물성은 실란 처리되지 않은 것에 비하여 증가됨을 알 수 있었고, 특히 MPS/APS 0.2 wt%에서 가장 높은 값을 나타내었다. 이는 유리 섬유와 실란 커플링제 사이의 수소 결합에 의한 극성 요소가 그들 간의 계면 결합력을 증가시키는데 크게 작용하였음을 알 수 있었다.