Polysulfide and organosilicon low-molecular-mass rubbers and sealants on their basis

Abstract

The state of the production of low-molecular-mass rubbers and sealants on their basis in Russia is considered. The history of sealant development is described; organizations and scientists that made the largest contribution to the elaboration and industrial production of these materials are reported. Classification of sealants and the mechanism of their vulcanization are considered. The main attention is paid to materials developed at the All-Russia Institute of Aviation Materials. The sealant brands most widely used in the aircraft industry are presented and their properties are described. Prospective problems in the field of sealant development are considered and the ways of their solution are outlined.

Synthesis and Characterization of Disiloxane Cross-Linked Polysulfides

“…7−9 Current applications based on these properties include wear-and corrosion-resistant coatings, adhesives, and sealants. 10,11 Historically, the most widely used method for the synthesis of polysulfides is a condensation reaction between sodium polysulfide (e.g. Na 2 S n ) with a di-or multi-halide.…”

“…Polysulfides are aliphatic polymers with repeating S–S bonds in the backbone . Their properties, such as high resistance to swelling in solvents, oils, and fuels, high stability to UV and ozone, and the ability to avoid structural degradation under stress, are associated with the S–S backbone. − Current applications based on these properties include wear- and corrosion-resistant coatings, adhesives, and sealants. , …”

Strengthening the mechanical properties of polysulfide adhesives by introducing polyurethane

“…1 However, the integral fuel tanks assembled by sealing materials connecting the various corners, gaps, and bonding surfaces of the structural lap joints must be able to withstand high infiltration from aviation kerosene and significant deformation/vibration from flight loads to ensure their good impermeability, thus eliminating potential safety hazards during the practical application. 2,3 Liquid polysulfide polymers (Thiokols LP) have been widely used in the aerospace sealant industry as sealing materials since 1940s, 4 which due to their ideal resistance to chemical solvents, especially fuel oil. 5 Currently, commercial aircraft fuel tank sealants such as PR1750 or CS540 6 are mainly prepared by blending liquid polysulfide with a metal peroxide curing agent, which forms curing cross-linking by converting -SH groups into S-S bonds/linkage.…”

“…The flexible design of integral fuel tanks can effectively increase space utilization and reduce weight, significantly improving the safety and maneuverability of aircraft, which have gradually replaced traditional fuel tanks 1 . However, the integral fuel tanks assembled by sealing materials connecting the various corners, gaps, and bonding surfaces of the structural lap joints must be able to withstand high infiltration from aviation kerosene and significant deformation/vibration from flight loads to ensure their good impermeability, thus eliminating potential safety hazards during the practical application 2,3 …”

Synthesis of a novel polysulfide via the reaction of a thiol compound and oxidant towards polymer self-healing application

“…Polysulfide can be viewed as a type of polymer bearing atoms of sulfur in its molecular chains 1 . Polysulfide possesses a profusion of incomparable merits, such as showing superb properties at low temperatures 2 , being stable in a wide assortment of solvents and water 3,4 and the ability to stick to catholic surfaces 5 , and has been applied in numerous industrial applications ranging from adhesives 6 , sealants 7 and coatings 8,9 . In addition, the disulfide-bond-owning polymer can be used to synthesize self-healing materials out of the occurrence of S−S links in its main chains [10][11][12] .…”