Urea terminated butadiene polymers and butadiene acrylonitrile copolymers
AssigneeHuntsman Advanced Materials Americas LLC
InventorJeremy Pasatta
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Abstract
Urea-terminated polybutadiene polymers and polybutadiene acrylonitrile copolymers useful as both accelerators and tougheners are disclosed for use in epoxy formulations cured with dicyandiamide. The inventive urea-terminated polymers achieve comparable toughness in cured epoxy formulations when compared to that achieved with traditional polymeric or rubber tougheners with little to no change in glass transition temperature. Viscosity improvement and stability over time are also an advantage. A method of preparation emphasizing aspects of reaction stoichiometry is also disclosed.
Claims7
A method for preparing a urea-terminated polybutadiene polymer or a urea-terminated polybutadiene acrylonitrile copolymer, comprising:
- a. providing a polybutadiene polymer or polybutadiene acrylonitrile copolymer having at least one of carboxyl or amine functional groups on a terminal end of the polymer;
- b. reacting the carboxyl or amine terminated polybutadiene polymer or polybutadiene acrylonitrile copolymer with 2,4-toluene diisocyanate as an initial step to form a reaction mixture;
- c. adding dimethylamine to the reaction mixture to react with isocyanate groups to form a urea-terminated polybutadiene polymer or polybutadiene acrylonitrile copolymer;
- and
- d. isolating and collecting the final urea-terminated polybutadiene polymer or polybutadiene acrylonitrile copolymer.
An epoxy formulation comprising:
- a. an epoxy resin;
- b. a curing agent;
- and
- c. a compound that functions as both an accelerator and toughener comprising a urea-terminated polybutadiene polymer or urea-terminated polybutadiene acrylonitrile copolymer, wherein the compound is prepared by a method, comprising:
- providing a polybutadiene polymer or polybutadiene acrylonitrile copolymer having at least one of carboxyl or amine functional groups on a terminal end of the polymer;
- reacting the carboxyl or amine terminated polybutadiene polymer or polybutadiene acrylonitrile copolymer with an isocyanate as an initial step to form a reaction mixture;
- adding an amine terminating agent to the reaction mixture to react with isocyanate groups to form a urea-terminated polybutadiene polymer or polybutadiene acrylonitrile copolymer;
- and
- isolating and collecting the final urea-terminated polybutadiene polymer or polybutadiene acrylonitrile copolymer.
A method of toughening epoxy products, comprising, prior to curing, adding an epoxy formulation to a urea-terminated polybutadiene polymer or urea-terminated polybutadiene acrylonitrile copolymer, wherein the copolymer is prepared by a method comprising,
- providing a polybutadiene polymer or polybutadiene acrylonitrile copolymer having at least one of carboxyl or amine functional groups on a terminal end of the polymer;
- reacting the carboxyl or amine terminated polybutadiene polymer or polybutadiene acrylonitrile copolymer with an isocyanate as an initial step to form a reaction mixture;
- adding an amine terminating agent to the reaction mixture to react with isocyanate groups to form a urea-terminated polybutadiene polymer or polybutadiene acrylonitrile copolymer;
- and
- isolating and collecting the final urea-terminated polybutadiene polymer or polybutadiene acrylonitrile copolymer.
Dependencies are inferred from the claim text.