Polysulfide polymers, first marketed in 1929, are mature products that are used in specialty adhesive and sealant applications. These important materials seem to not receive much attention today due to their restricted use, especially as adhesives, and to their competitive market displacement as sealants by silicones and urethanes. However, polysulfide polymers provide unique curing and performance properties that are attractive in many applications.
The original polysulfide polymers were solid rubbery materials containing 37-82 percent bound sulfur. However, today the predominant product is the mercaptan-terminated liquid polymer (LP) that contains approximately 37 percent bound sulfur (see Figure 1). It is the high concentration of sulfur linkages that provide these products with their unique chemical properties.
The liquid polysulfide polymer can be transformed in-situ from a liquid state into a solid elastomer, even at low temperatures.Polysulfide adhesives and sealants have been successful in applications requiring good moisture, solvent.