Abstract

The authors have developed a new class of patent-pending multifunctional smart additives that deliver performance features like corrosion resistance, water repellency and surface self-cleaning for water-based, solvent-based or powder coatings. Upon exposure to changes in pH caused by metal corrosion, the additives release encapsulated corrosion inhibitors preventing further metal deterioration. Simultaneously, they impart hydrophobicity to coatings, preventing water intrusion and resulting in surface self-cleaning effects. This multifunctionality delivers long-lasting corrosion protection without the use of heavy metals or other hazardous materials. The patent-pending platform technology allows for use of numerous types of corrosion inhibitors, thereby complying with current environmental regulation and allowing for compliance with future regulation, as well the opportunity to specifically target different metal alloys. Presented ASTM B117 salt spray testing demonstrates that these smart additives improve the corrosion protection performance of powder based, waterborne and solventborne coatings on carbon steel panels, presenting a step forward in corrosion protection for the coatings industry.

Introduction

Left unprotected, metals corrode quickly which over time contributes to the loss of structural integrity and the failure of buildings, bridges, oil & gas platforms, airplanes, cars and many other metal assets, all of which pose a risk to human safety and the surrounding environment. In 2016, the National Association for Corrosion Engineers (NACE) – now known as AMPP – published a landmark study, well-known to those attending this conference, that estimated the direct cost of corrosion to the world economy as $2.5T per year, equivalent to 3.4% of the Gross World Product (1). In the United States, the annual cost of corrosion is estimated at 3.1% of gross domestic product (2), equivalent to $635B (2018). When including indirect costs, such as asset downtime, ship dry-docking and the impact of bridge collapses, the cost of corrosion is estimated at twice that amount.

Due to its global nature, all societies deal with corrosion which is especially problematic in coastal areas where metals are exposed to humid salty air. High value assets in marine environments, e.g. ships, offshore oil and gas platforms and wind turbine farms, are composed almost entirely of metal and constantly exposed to seawater, rain, waves, wind, sun, industrial chemicals, and abrasion from heavy work. This highly corrosive environment, coupled with their remote location or requirement for dry-docking, makes them difficult and expensive to build and maintain. Asset owners have developed comprehensive and costly maintenance schedules to stay ahead of metal corrosion in this demanding environment and prevent government fines and shutdowns.

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