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Publication Citation: The Origin of Critical Relative Humidity in Adhesion

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Author(s): Christopher C. White; Kar Tean Tan; Bryan D. Vogt; Donald L. Hunston;
Title: The Origin of Critical Relative Humidity in Adhesion
Published: May 11, 2009
Abstract: Water is ubiquitous in the atmosphere. Unfortunately, adhesive bonding is susceptible to the environmental attack of water leading to significant depreciation in joint strength and subsequently to premature failures [1-6]. This susceptibility of bonding to moisture attack has been a subject of concern for many years. However, there are still unanswered questions concerning the durability of adhesive joints in hostile environments, which has been a stumbling block for wider application of adhesive in load-bearing structures. Understanding the mechanics and mechanisms of degradation of adhesive joints, thus, is a key factor for more extensive use in future engineering applications. The aim of the present study is to develop a more complete understanding of mechanisms of moisture attack. Model adhesive joints consisting of homologous series of poly(n-alkyl methacrylate)s (PAMA) supported on SiOx substrates were studied. This polymer series enables subtle chemistry effects on moisture-induced adhesion loss to be examined. A fracture mechanics approach based on a shaft-loaded blister test was adapted to measure adhesive fracture energy of the joints over humidity extremes. Infrared spectroscopy and contact angle measurement were used to elucidate mechanisms of adhesion loss.
Proceedings: 2009 week of learning Pressure Sensitive Tape Council
Pages: pp. 135 - 144
Location: Orlando, FL
Dates: May 11-15, 2009
Keywords: Adhesion;relative humidity;surface chemistry;neutron reflectivity;
Research Areas: Service Life Prediction, Coatings/Sealants, Building and Fire Research