Reducing VOCs from Surfactants in Coatings

摘要

Traditionally, nonionic surfactants have been the standard surfactant type for coatings applications with uses ranging from stabilizing the pigment to improving the wetting characteristics. These surfactants have been based primarily on the ethoxylation of various alcohols using a caustic catalyst, which results in a product that contains a broad range of ethoxymers centered on the desired level of ethoxylation. Additionally, a percentage of the alcohol remains unreacted, and it is this portion that leads to increased volatile organic compounds (VOCs). With increasing environmental regulations throughout the world focused on reducing the amount of VOCs present in coatings, all raw materials including surfactants, are under pressure to have less VOC content. By employing narrow range ethoxylation technology instead of the standard caustic catalyst, the amount of residual alcohol is reduced with increasing degree of ethoxylation. This leads to lower VOCs for most narrow range ethoxylates when compared to ethoxylates made from traditional caustic catalysis. The following paper examines the VOCs from various nonionic surfactants catalyzed using EPA Method 24 and ASTM D6886 with traditional and narrow-range technology.