The specialist properties of polysulfide polymers (resistance to fuels and solvents, and to ageing) were immediately recognised on discovery, and technology was soon developed to convert these materials into useful products. In this Rapra Review Report, the author describes the factors controlling the structure of polysulfide polymers and the properties which influence their use and performance in products.

For the purpose of this report, polysulfide polymers are defined as aliphatic polymers with two or more consecutive sulfur atoms in the backbone. Polysulfides are available in three forms: millable solid elastomers, aqueous dispersions of high molecular weight polymer, and liquid polymers, the last of which account for the bulk of production. Aspects of all three types are considered within this review.

The general principles of synthesis of commercial millable and liquid polysulfides are reviewed, with the author also describing cure through oxidation and addition reactions and providing a discussion of the thermal properties and degradation of the materials. The unique properties offered by the cured polysulfides are discussed under the following headings:

Polysulfides have become the basis for a large number of technologies. Millable polysulfide polymers find major use in hoses for the paint industry and in various applications within the printing industry. The liquid polymers are utilised in sealants for many industries: aircraft building and construction and transportation, and also for sealant tapes. Other applications of liquid polysulfides discussed include coatings, epoxy modification, and blends with other rubbers. The author reviews the properties of the polysulfides and the advantages they bring to these applications.

This review is supported by an extensive bibliography compiled from the Polymer Library.