Improved Structural Adhesives from Natural Products for High-Moisture Environments

At present, four classes of structural adhesives (epoxy resins, phenolic resins, acrylic adhesives and urethanes) are commonly employed in applications where the adhesive joint is either totally immersed in salt or fresh water or subject to high levels of moisture while simultaneously experiencing large shear loads. Each of these synthetic polymer formulations suffers from individual disadvantages such as toxicity, the requirement for extreme conditions of heat and/or pressure to effect a reliable cure, or the necessity of meticulous preparation of the adherend surfaces before reliable bonding can occur. The greatest drawback of these materials as a group, however, resides in the inherent conflict between these synthetic adhesives with their common mode of adhesion and water itself. With this conflict in mind, it is the object of this research to utilize the natural marine adhesives produced by mussels and barnacles, covalently crosslinked by a proprietary catalyzed chemical reaction to produce an alternative structural adhesive naturally designed for use in high moisture environments. The resulting adhesive will have high shear strength, cure at ambient temperatures and pressures, be environmentally safe and require minimal pretreatment of the adherend surfaces prior to bonding. Multiple dual use opportunities exist for a water resistant adhesive in a multi-billion dollar marketplace. Anticipated Benefits: An adhesive that binds readily to wet and/or minimally prepared surfaces, which can bond a wide range of dissimilar materials, and which retains its binding capacity and strength for long periods in high moisture environments would be a distinct improvement over existing adhesives. Such an environmentlaly safe adhesive would have numerous dual use applications in marine and high humidity environments, e.g., military ships, pleasure craft, ATV's, automotive, oil pipelines and drilling platforms, etc.