Cured Epoxy Resin and Method of Curing an Epoxy Resin Using an Amine Compound

1 . A method of forming a cured epoxy resin, the method comprising

curing an epoxy resin in the presence of an amine compound comprising a diamine, a triamine, or a mixture thereof;

wherein the cured epoxy resin has a shear modulus at failure of 55 MPa or more as determined in accordance with ASTM 5045-14.

2 . The method of claim 1 , wherein the cured epoxy resin has a shear modulus at failure of 55 MPa or more to 500 or less as determined in accordance with ASTM 5045-14.

3 . The method of claim 1 , wherein the cured epoxy resin has a shear modulus at failure of 55 MPa or more to 200 MPa or less as determined in accordance with ASTM 5045-14.

4 . The method of claim 1 , wherein the cured epoxy resin exhibits a shear modulus at failure of 55 MPa or more to 95 MPa or less as determined in accordance with ASTM 5045-14.

5 . The method of claim 1 , wherein the cured epoxy resin exhibits a critical stress intensity factor (K IC ) of 0.25 MPa·m 1/2 or more to 5 MPa·m 1/2 or less as determined in accordance with ASTM 5045-14.

6 . The method of claim 1 , wherein the epoxy resin comprises a diglycidyl ether.

7 . The method of claim 1 , wherein the epoxy resin comprises a diglycidyl ether bisphenol A and/or a diglycidyl ether bisphenol F.

8 . The method of claim 1 , wherein the epoxy resin comprises a diglycidyl ether bisphenol A.

9 . The method of claim 1 , wherein the amine compound has the following structure:

wherein

R 1 and R 2 are independently hydrogen, alkyl or aryl;

R 3 and R 4 are independently hydrogen or alkyl;

R 5 and R 6 are independently a direct bond or a divalent radical;

at least one of R 1 and R 3 is not hydrogen; and

at least one of R 2 and R 4 is not hydrogen.

10 . The method of claim 1 , wherein the amine compound has the following structure:

wherein

R 1 and R 2 are independently hydrogen, alkyl or aryl;

R 5 and R 4 are independently hydrogen or alkyl;

at least one of R 1 and R 3 is not hydrogen; and

at least one of R 2 and R 4 is not hydrogen.

11 . The method of claim 1 , wherein the amine compound comprises a diamine.

12 . The method of claim 11 , wherein the diamine comprises two amine groups and wherein each amine group is a secondary amine.

13 . The method of claim 1 , wherein the amine compound comprises a diamine comprising N,N′-diphenyl-p-phenylenediamine; N,N-bis-(1,4-dimethylpentyl)-p-phenylenediamine; 1,4-benzenediamine, N, N′-mixed phenyl and tolyl derivatives; N-isopropyl-N′-phenyl-1,4-phenylenediamine; bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate; bis(1,2,2,6,6pentamethyl-4-piperidyl) sebacate; N-(1,4-dimethylpentyl)-1,4-benzenediamine; N-1,3-dimethylbutyl-N′-phenyl-p-phenylenediamine; N,N′-di-2-butyl-1,4-phenylenediamine; N-1-(1,4-dimethylpentyl)-1,4-benzenediamine; m-xylylenediamine; or a mixture thereof.

14 . The method of claim 1 , wherein the amine compound comprises N,N-bis-(1,4-dimethylpentyl)-p-phenylenediamine, N,N′-di-2-butyl-1,4-phenylenediamine, m-xylylenediamine, or a mixture thereof.

15 . The method of claim 1 , wherein the amine compound comprises a first amine compound and a second amine compound.

16 . The method of claim 15 , wherein the first amine compound has the following structure:

wherein

R 1 and R 2 are independently hydrogen, alkyl or aryl;

R 3 and R 4 are independently hydrogen or alkyl;

at least one of R 1 and R 3 is not hydrogen; and

at least one of R 2 and R 4 is not hydrogen.

17 . The method of claim 15 , wherein the second amine compound has the following structure:

wherein

R 1 and R 2 are independently hydrogen, alkyl or aryl;

R 5 and R 4 are independently hydrogen or alkyl; and

R 5 and R 6 are a divalent radical.

18 . The method of claim 15 , wherein the first amine compound comprises N,N-bis-(1,4-dimethylpentyl)-p-phenylenediamine, N,N′-di-2-butyl-1,4-phenylenediamine, or a mixture thereof and the second amine compound comprises m-xylylenediamine.

19 . The method of claim 1 , wherein the cured epoxy resin comprises 0.1 wt. % or less of an impact modifier based on the weight of the cured epoxy resin.

20 . A cured epoxy resin formed from the method of claim 1 .