Controlled release polyurea microcapsules can be prepared from a combination of polyisocyanates using emulsion polymerization. Encapsulated catalysts prepared using the polyurea microcapsules can be used to control the cure rate of coatings and sealants.

Disclosed are particles that have an exterior surface coated with a thin polymeric coating, such as a coating that includes a sulfur-containing polymer. Also disclosed are compositions, such as fuel-resistant sealant and coating compositions, which include such particles. Aerospace vehicles having an aperture at least partially sealed with a sealant deposited from such a sealant composition are also disclosed.

Provided are two-component curable compositions and methods thereof. The composition includes a base component comprised of a curable resin and a first compressible filler dispersed therein. The composition further includes a curative component comprised of a curing agent and a second compressible filler dispersed therein. The base and curative components react with each other upon mixing to provide a crosslinked network. When used with automated metering pumps, the compressibility of the base and curing agent components can be matched, allowing for a constant mix ratio despite variability in applied pressure.

Dual cure compositions include a combination of an organoborane complex and a radical oxidizing agent as co-catalysts. The compositions are curable under dark conditions and can be used to catalyze thiol-ene reactions. The compositions are useful as sealants.

Polysulfide compositions having a polyether synergist are disclosed. Polysulfide compositions that contain polyether synergists exhibit a rapid onset of cure and have acceptable final properties. The polysulfide compositions can be used as sealants.

Provided is a sealant sheet formed as a sheet. The sealant sheet comprises an epoxy group-containing polysulfide. The epoxy group-containing polysulfide has a disulfide structure and an epoxy group in its molecule.

Chemically resistant sealant compositions include high equivalent weight sulfur-containing prepolymers. Upon exposure to chemicals the properties of sealants prepared using the prepolymers exhibit excellent fuel and phosphate ester resistance.

Low density particles that have an exterior surface coated with a thin polymeric coating of an aminoplast can be used in aerospace sealants to reduce the specific gravity of a sealant.

The present invention relates to a sealing compound for coating a substrate, which is a mixture of a predominantly uncured base mass and a curing agent containing at least one epoxy composition, wherein the base mass contains a mercapto-terminated base polymer based on polyether, polythioether, polythioethersulfide, polysulfide, copolymers thereof and/or mixtures thereof, wherein the base mass, the curing agent or both contain at least one photoinitiator based on a sterically hindered nitrogen-containing organic base, and, through the effects of high-energy actinic radiation, the at least one photoinitiator dissociates at least one radical per molecule based on a nitrogen-containing organic base, from which a nitrogen-containing organic base having a pKa value of the conjugated acid in the region of 6 to 30 is formed, which acts as an active catalyst for the curing of the base mass. The present invention also relates to a corresponding method for coating a substrate with a sealing compound.

Disclosed are compositions comprising a liquid carrier, a polysulfide rubber curing agent, a metal cation, and an ionic liquid. Also disclosed are methods for curing a surface of an uncured polysulfide rubber. These methods involve applying the disclosed compositions to the surface of the uncured polysulfide rubber.