Interfacial Water and Adhesion Loss of Polymer Coatings on a Siliceous Substrate.
Interfacial Water and Adhesion Loss of Polymer Coatings
on a Siliceous Substrate.
(369 K)
Nguyen, T.; Byrd, W. E.; Alsheh, D.; McDonough, W.;
Seiler, J. F., Jr.
Materials Research Society Symposium Proceedings.
Volume 385. 1995, 57-63 pp, 1995.
Keywords:
substrates; water; adhesion; coatings; FT-IR
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 DGC 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 DGC water. Adhesion loss of untreated
composites immersed in 60 DGC 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.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899