The current methods for determining the suitability of sealants for use in water environments are discussed. In particular the paper outlines the factors governing the durability of polysulfide sealants to long-term water immersion in building and civil engineering applications. Particular reference is made to the sealant formulation and the guidelines that should be followed to ensure longevity of adhesion in water-retaining structures and bioresistance in sewage plants. Parameters such as polymer content, curative type, and the nature and level of other compounding ingredients as they relate to long-term performance in water are examined. The role of primers is considered.
The nature of the biodeterioration of sealants is discussed, and an accelerated test for determining the performance of polysulfide sealants in bacteria-rich environments and how it correlates to field tests is described. The results of a ten-year trial at a sewage treatment plant are given.
International regulations for the use of nonmetallic materials in potable water and their significance to the sealant industry are reviewed.