Poly(arylene ether) copolymer

1. A poly(arylene ether) copolymer,

wherein the poly(arylene ether) copolymer is the product of oxidative copolymerization of monomers comprising a monohydric phenol comprising 2,6-dimethylphenol and a dihydric phenol comprising 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane,

wherein the poly(arylene ether) copolymer comprises less than or equal to 0.1 weight percent of incorporated amine groups and

wherein the poly(arylene ether) copolymer comprises less than 150 parts per million by weight of residual 2,6-dimethylphenol and less than 1 weight percent of residual 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane, each as measured by gas chromatograph.

2. The poly(arylene ether) copolymer of claim 1 , wherein the monomers further comprise 2 methylphenol, 2,5-dimethylphenol, 2,3,6-trimethyl phenol, or a combination thereof.

3. The poly(arylene ether) copolymer of claim 1 , wherein the poly(arylene ether) copolymer has a number average molecular weight of 500 to 2,500 grams per mole and a weight average molecular weight of 1,000 to 6,000 grams per mole, wherein number average molecular weight and weight average molecular weight are as determined by gel permeation chromatography.

4. The poly(arylene ether) copolymer of claim 1 , wherein the oxidative copolymerization is in the presence of a catalyst composition comprising di-n-butylamine; and wherein the poly(arylene ether) copolymer comprises less than or equal to 0.1 weight percent of incorporated dibutylamine groups.

5. The poly(arylene ether) copolymer of claim 1 , wherein the oxidative copolymerization is in the presence of a catalyst composition excluding di-n-butylamine; and

wherein the poly(arylene ether) copolymer is devoid of incorporated dibutylamine groups.

6. The poly(arylene ether) copolymer of claim 1 , wherein the poly(arylene ether) copolymer has an intrinsic viscosity is 0.04 to 0.15 deciliter per gram measured at 25° C. in chloroform.

7. The poly(arylene ether) copolymer of claim 1 , wherein the poly(arylene ether) copolymer has an average of 1.8 to 2 hydroxyl groups per molecule.

8. A method of making a poly(arylene ether) copolymer, the method comprising:

oxidatively copolymerizing a monohydric phenol comprising 2,6-dimethyl phenol and a dihydric phenol comprising 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane in a solvent in the presence of a catalyst composition comprising

a metal source;

0.18 to 0.40 weight percent of a secondary alkylene diamine ligand;

0 to 0.2 weight percent of a secondary monoamine; and

a tertiary monoamine;

wherein weight percent of each component of the catalyst composition is based on the total weight of the monohydric phenol and the dihydric phenol;

to form the poly(arylene ether) copolymer,

wherein the poly(arylene ether) copolymer comprises less than 150 parts per million by weight of residual 2,6-dimethylphenol and less than 1 weight percent of residual 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane, each as measured by gas chromatograph.

9. The method of claim 8 , wherein the catalyst composition comprises 0.05 to 0.15 weight percent di-n-butylamine; and wherein the poly(arylene ether) copolymer comprises 0.01 to 0.1 weight percent of incorporated dibutylamine groups.

10. The method of claim 8 , wherein the catalyst composition excludes a secondary monoamine and the poly(arylene ether) copolymer is devoid of incorporated amine groups.

11. The poly(arylene ether) copolymer made by the method of claim 8 , wherein the poly(arylene ether) copolymer has

a number average molecular weight of 500 to 2,500 grams per mole and a weight average molecular weight of 1,000 to 6,000 grams per mole, wherein number average molecular weight and weight average molecular weight are as determined by gel permeation chromatography;

an intrinsic viscosity is 0.04 to 0.15 deciliter per gram measured at 25° C. in chloroform;

less than or equal to 0.1 weight percent of incorporated dibutylamine groups.

12. A curable composition comprising

the poly(arylene ether) copolymer of claim 1 ;

an auxiliary curable resin, a curable unsaturated monomer composition, or both; and

optionally, a curing promoter.

13. The curable composition of claim 12 , comprising

the poly(arylene ether) copolymer of claim 1 ,

an epoxy resin, a cyanate ester resin, or a combination thereof; and

optionally a curing promoter.

14. A thermoset composition comprising a cured product of the composition of claim 12 .

15. An article comprising the thermoset composition of claim 14 .

16. The poly(arylene ether) copolymer of claim 1 , wherein the poly(arylene ether) copolymer comprises residual 2,6-dimethylphenol in an amount of 50 ppm or less as measured by gas chromatography.

17. The method of claim 8 , wherein up to 3 weight percent of the tertiary monoamine is present.

18. The article of claim 15 , wherein the article is in the form of a composite, a foam, a fiber, a layer, a coating, an encapsulant, an adhesive, a sealant, a molded component, a prepreg, a casing, or a combination comprising at least one of the foregoing.

19. The poly(arylene ether) copolymer of claim 1 , wherein monomers further comprise a dihydric phenol different from 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane, wherein the dihydric phenol has the formula

wherein R 3 and R 4 and R 5 and R 6 are independently at each occurrence hydrogen, halogen, unsubstituted or substituted C 1-12 primary or secondary hydrocarbyl, C 1-12 hydrocarbylthio, C 1-12 hydrocarbyloxy, or C 2-12 halohydrocarbyloxy wherein at least two carbon atoms separate the halogen and oxygen atoms; and Y has a structure

wherein each occurrence of R 7 is independently hydrogen or C 1-12 hydrocarbyl, and each occurrence of R 8 and R 9 is hydrogen, C 1 -12 hydrocarbyl, or C 1-6 hydrocarbylene wherein R 8 and R 9 collectively form a C 4-12 cycloalkylene group.