- Author
- Nguyen, T. | Byrd, W. E. | Alsheh, D. | McDonough, W. | Seiler, J. F., Jr.
- Title
- Interfacial Water and Adhesion Loss of Polymer Coatings on a Siliceous Substrate.
- Coporate
- National Institute of Standards and Technology, Gaithersburg, MD
- Book or Conf
- Materials Research Society Symposium Proceedings. Volume 385. 1995, 57-63 p., 1995
- Keywords
- substrates | water | adhesion | coatings | FT-IR
- Identifiers
- materials and specimen preparations; measurement of water at the polymer coating/siliceous substrate interface; measurement of adhesion loss
- Abstract
- Water is often the main cause of adhesion loss of a polymer coating/substrate system. The buildup of the interfacial water layer and the loss of adhesion of polymer-coated siliceous substrates exposed to liquid water has been investigated. The thickness of the interfacial water layer was measured on epoxy-coated SiO₂-Si prisms using FTIR-multiple internal reflection (FTIR-MIR) spectroscopy. Adhesion loss on flat siliceous substrates was determined by a wet peel test on epoxy-coated SiO₂-Si wafers and adhesion loss of composites was obtained by measuring the interlaminar shear strengths of epoxy/E-glass fiber composites. Both untreated and 0.1% silane-treated substrates were used. Little water was observed at the interface of the silane-treated samples but about 10 monolayers of water have accumulated at the interface of the untreated samples after 100 h of exposure to 24 ºC water. Untreated, flat substrates lost most of their bonding strengths within 75 h of exposure but silane-treated specimens retained 80% of their adhesion after 600 h of exposure to 24 ºC water. Adhesion loss of untreated composites immersed in 60 ºC water was greater than that of treated samples; however, the rate of loss of both silane-treated and untreated composites was much lower than that of flat substrates. Adhesion loss was found to follow the same trend as interfacial water buildup.