Abstract: Thiol-terminated polythioether compositions and sealants exhibit an extended working time and rapidly cure at room temperature at the end of the working time are disclosed. The compositions comprise a combination of pyridine catalysts.

Abstract: Disclosed are methods for making a cured sealant. The methods include depositing an uncured sealant composition on a substrate and exposing the uncured sealant composition to actinic radiation to provide a cured sealant. The uncured sealant composition includes a thiol-terminated polythioether, a polyene comprising a polyvinyl ether and/or a polyallyl compound, and a hydroxy-functional vinyl ether. Related sealant compositions are also disclosed.

Abstract: Compositions that are resistant to hydraulic fluid and aviation fuel contain sulfur-containing prepolymers and solvent-resistant organic fillers. The compositions are useful in aerospace sealant applications.

Abstract: Disclosed are methods for making a cured sealant. The methods include depositing an uncured sealant composition on a substrate and exposing the uncured sealant composition to actinic radiation to provide a cured sealant. The uncured sealant composition includes a thiol-terminated polythioether, a polyene comprising a polyvinyl ether and/or a polyallyl compound, and a hydroxy-functional vinyl ether. Related sealant compositions are also disclosed.

Abstract: Disclosed are methods for making a cured sealant. The methods include depositing an uncured sealant composition on a substrate and exposing the uncured sealant composition to actinic radiation to provide a cured sealant. The uncured sealant composition includes a thiol-terminated polythioether, a polyene comprising a polyvinyl ether and/or a polyallyl compound, and a hydroxy-functional vinyl ether. Related sealant compositions are also disclosed.

Abstract: Thiol-terminated polythioether compositions and sealants exhibit an extended working time and rapidly cure at room temperature at the end of the working time are disclosed. The compositions comprise a combination of pyridine catalysts.

Abstract: Compositions comprising Michael acceptor-terminated sulfur-containing prepolymers, thiol-terminated sulfur-containing prepolymers, and e phosphine catalysts useful in aerospace sealant applications are disclosed. The compositions exhibit extended pot life, cure rapidly following activation, and provide cured sealants having improved properties useful in aerospace sealant applications.

Abstract: Hydroxyl-containing bis(alkenyl) ethers can be incorporated into the backbone of polythioether prepolymers and can be used as curing agents in thiol-terminated polythioether prepolymer compositions. Cured sealants prepared using compositions containing hydroxyl-containing bis(alkenyl) ether-containing polythioether prepolymers and/or hydroxyl-containing bis(alkenyl) ether curing agents exhibit improved physical properties such as rapid curing and compatibility with fillers suitable for use in aerospace sealant applications.

Abstract: Compositions comprising sulfur-containing prepolymers such as polythioether prepolymers, polyepoxides, and a blocked 1,8-diazabicyclo[5.4.0]undec-7-ene bicarbonate catalyst useful as aerospace sealants are disclosed. The compositions exhibit extended working time and the curing rate can be tailored for specific applications.

Abstract: Sealant systems that are pre-applied to a part to be sealed include a layer of an uncured moisture-curable sealant and a frangible barrier coating applied over the uncured moisture-curable sealant. During assembly, the barrier coating breaks to expose the moisture-curable sealant to moisture to initiate the curing reaction. The moisture-curable sealant systems are suitable for aerospace applications and include sulfur-containing prepolymers. Various curing chemistries can be used.

Abstract: Hydroxyl-containing bis(alkenyl) ethers can be incorporated into the backbone of polythioether prepolymers and can be used as curing agents in thiol-terminated polythioether prepolymer compositions. Cured sealants prepared using compositions containing hydroxyl-containing bis(alkenyl) ether-containing polythioether prepolymers and/or hydroxyl-containing bis(alkenyl) ether curing agents exhibit improved physical properties such as rapid curing and compatibility with fillers suitable for use in aerospace sealant applications.

Abstract: Urethane/urea-containing bis(alkenyl) ethers can be incorporated into the backbone of polythioether prepolymers and can be used as curing agents in thiol-terminated polythioether prepolymer compositions. Cured sealants prepared using compositions containing urethane/urea-containing bis(alkenyl) ether-containing polythioether prepolymers and/or urethane/urea-containing bis(alkenyl) ether curing agents exhibit improved physical properties suitable for use in aerospace sealant applications.

Abstract: Hydroxyl-containing bis(alkenyl) ethers can be incorporated into the backbone of polythioether prepolymers and can be used as curing agents in thiol-terminated polythioether prepolymer compositions. Cured sealants prepared using compositions containing hydroxyl-containing bis(alkenyl) ether-containing polythioether prepolymers and/or hydroxyl-containing bis(alkenyl) ether curing agents exhibit improved physical properties such as rapid curing and compatibility with fillers suitable for use in aerospace sealant applications.

Abstract: Reactive antioxidants, antioxidant-containing prepolymers, compositions containing reactive antioxidants and antioxidant-containing prepolymers, methods of synthesizing reactive antioxidants and reactive antioxidant-containing prepolymers and the use of reactive antioxidants and antioxidant-containing prepolymers in aerospace sealant applications are disclosed. Reactive antioxidants and antioxidant-containing prepolymers can be added to a curable composition and react with a curing agent to become incorporated into the cured polymer network. Antioxidant-containing prepolymers have antioxidants incorporated into the backbone of the prepolymer. Cured sealant compositions comprising reactive antioxidants and antioxidant-containing prepolymers exhibit enhanced thermal resistance.

Abstract: Sulfur-containing polyurea compositions comprising a polyisocyanate and a polyamine are disclosed. The polyisocyanate comprises the reaction product of reactants comprising a diisocyanate having isocyanate groups with different reactivities toward thiol groups, and a thiol-terminated sulfur-containing polymer such as a thiol-terminated polythioether polymer and/or a thiol-terminated polyformal polymer. The polyamine can be an aromatic polyamine and/or an aromatic amine-terminated polythioether adduct. The sulfur-containing polyurea compositions are useful as aerospace sealants.

Abstract: Thiol-terminated polythioether compositions and sealants prepared using the thiol-terminated polythioether compositions that exhibit extended working time and that rapidly cures at room temperature at the end of the working time are disclosed.

Abstract: Compositions comprising sulfur-containing prepolymers such as polythioether prepolymers, polyepoxides, and a blocked 1,8-diazabicyclo[5.4.0]undec-7-ene bicarbonate catalyst useful as aerospace sealants are disclosed. The compositions exhibit extended working time and the curing rate can be tailored for specific applications.

Abstract: Curable compositions containing thiol-terminated polythioethers and encapsulated polyepoxy curing agents are disclosed. The compositions exhibit extended pot life.

Abstract: Reactive antioxidants, antioxidant-containing prepolymers, compositions containing reactive antioxidants and antioxidant-containing prepolymers, methods of synthesizing reactive antioxidants and reactive antioxidant-containing prepolymers and the use of reactive antioxidants and antioxidant-containing prepolymers in aerospace sealant applications are disclosed. Reactive antioxidants and antioxidant-containing prepolymers can be added to a curable composition and react with a curing agent to become incorporated into the cured polymer network. Antioxidant-containing prepolymers have antioxidants incorporated into the backbone of the prepolymer. Cured sealant compositions comprising reactive antioxidants and antioxidant-containing prepolymers exhibit enhanced thermal resistance.

Abstract: Sulfur-containing polymer adducts such as polythioethers, polysulfides, and sulfur-containing polyformals having terminal maleimide groups, and in particular, sulfur-containing polymers and sulfur containing adducts having terminal 1,1?-(methylenedi-4,1-phenylene)bismaleimide groups are disclosed. The adducts provide cured sealants having improved tensile strength and elongation and are useful as aerospace sealants.