Methods of manufacture of salts of hydroxy-substituted aromatic compounds and polyetherimides
A method for the manufacture of a metal salt of a hydroxy-substituted aromatic compound comprises: contacting a hydroxy-substituted aromatic compound with a base comprising a metal cation in molten diphenyl sulfone or sulfolane to provide a mixture comprising water, diphenyl sulfone or sulfolane, and a metal salt of the hydroxy-substituted aromatic compound; and removing water from the mixture in the absence of an azeotrope solvent to provide the metal salt of the hydroxy-substituted aromatic compound that contains less than 3,000 ppm of water.
1. A method for the manufacture of a polyetherimide composition, the method comprising:
contacting a hydroxy-substituted aromatic compound with a base comprising a metal cation in molten diphenyl sulfone or sulfolane to provide a mixture comprising water, diphenyl sulfone, or sulfolane, and a metal salt of the hydroxy-substituted aromatic compound;
removing water from the mixture in the absence of an azeotrope solvent to form the metal salt of the hydroxy-substituted aromatic compound, wherein the metal salt of the hydroxy-substituted aromatic compound comprises less than 3,000 ppm of water; determining the stoichiometry of the hydroxy-substituted compound relative to the metal salts thereof, wherein determining the stoichiometry of the hydroxy-substituted compound relative to the base comprises contacting the mixture comprising water, diphenyl sulfone, and a metal salt of the hydroxy-substituted aromatic compound with a methylating agent selective for methylation of aromatic hydroxyl salts to provide a methylation product mixture; and determining the molar ratio of the hydroxy-substituted aromatic compound to one or of methylated hydroxy-substituted aromatic compounds in the methylation product mixture; optionally adjusting the stoichiometry of the hydroxy-substituted compound relative to the base; and
polymerizing a substituted bis(phthalimide) and the metal salt of the dihydroxy aromatic compound in the presence of diphenyl sulfone, sulfolane, or a combination comprising at least one of the foregoing solvent to form a polyetherimide composition.
2. The method of claim 1 , wherein the hydroxyl-substituted aromatic compound is at least one dihydroxy-substituted aromatic compound having formula
wherein R a and R b are each independently a halogen atom or a monovalent hydrocarbon group; p and q are each independently integers of 0 to 4; c is 0 to 4; and X a is a single bond, —O—, —S—, —S(O)—, —S(O) 2 —, —C(O)—, or a C 1-18 organic bridging group.
3. The method of claim 1 , wherein the hydroxyl-substituted aromatic compound is 2,2-bis(4-hydroxyphenyl)propane or 4,4′-dihydroxybiphenyl.
4. The method of claim 1 , wherein the base is an alkali hydroxide, an alkali carbonate, an alkali bicarbonate, or a combination comprising at least one of the foregoing.
5. The method of claim 1 , wherein the base is sodium hydroxide or potassium hydroxide.
6. The method of claim 1 , wherein the base and the hydroxy-substituted aromatic compound are present in amounts corresponding to a molar ratio of the base to the hydroxy-substituted aromatic compound which deviates from ideal stoichiometry by no more than 5 mole %.
7. The method of claim 1 , wherein
weight
of
hydroxy
-
substituted
aromatic
compound
weight
of
hydroxy
-
substituted
aromatic
compound
+
weight
of
diphenyl
sulphone
or
sulfolane
(
100
)
is 1 to 30%.
8. The method of claim 1 , wherein the contacting is carried out at a temperature in a range from 140° C. to 250° C.
9. The method of claim 1 , wherein the contacting is carried out under an inert atmosphere.
10. The method of claim 1 , wherein the contacting comprises adding the base in a solid form to molten diphenyl sulfone to provide a solution;
and adding the hydroxy-substituted compound to the solution.
11. The method of claim 1 , wherein water is removed from the mixture by distillation.
12. The method of claim 1 , wherein the metal salt of the dihydroxy aromatic compound is not isolated from the diphenyl sulfone prior to polymerization.
13. The method of claim 1 , wherein the polymerization is carried out without a phase transfer catalyst.
14. The method of claim 1 , wherein the polymerization is carried out in the presence of a phase transfer catalyst.
15. The method of claim 1 , wherein the methylation agent is methyl methane sulfonate.