Methods of makng high-purity dibasic acid compositions
High-purity dibasic acid compositions are generally disclosed. In some embodiments, the dibasic acid compositions are solutions or suspensions. In some other embodiments, the compositions are solid-state compositions. In some such embodiments, the solid-state compositions comprise a dibasic acid as a crystalline solid and further comprise a low quantity of certain impurities, such as monobasic acids, various esters, and the like. Methods and systems for making such high-purity dibasic acid compositions are also disclosed.
1. A method for saponifying a dibasic ester, comprising:
introducing a dibasic ester to a reactor; and
saponifying the dibasic ester in the reactor to form a dicarboxylate compound, wherein the saponifying comprises reacting the dibasic ester with a base in an aqueous medium;
acidifying the dicarboxylate compound to form a dibasic acid, wherein the acidifying is carried out in an aqueous medium, whereby the dibasic acid is formed in an aqueous suspension; and
contacting the aqueous suspension with an organic solvent to form a system having an aqueous phase and an organic phase;
wherein the dibasic ester is a compound of formula (I):
wherein:
Y 1 is −(CH 2 ) 16 −; and
R 1 and R 2 are independently C 1-8 alkyl.
2. The method of claim 1 , wherein R 1 and R 2 are independently methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, tert-pentyl, neopentyl, hexyl, or 2-ethylhexyl.
3. The method of claim 2 , wherein R 1 and R 2 are methyl.
4. The method of claim 1 , wherein the base is selected from the group consisting of: an alkali metal hydroxide, an alkaline earth metal hydroxide, an alkali metal C 1-4 alkoxide, an alkaline earth metal C 1-4 alkoxide, and combinations thereof.
5. The method of claim 4 , wherein the base is sodium hydroxide, potassium hydroxide, or combinations thereof.
6. The method of claim 1 , wherein the dicarboxylate compound is a compound of formula (II):
wherein Y 1 is as defined in claim 1 .
7. The method of claim 1 , wherein the dibasic acid is a compound of formula (III):
wherein Y 1 is as defined in claim 1 .
8. The method of claim 7 , wherein the acidifying comprises reacting the dicarboxylate compound with an acid.
9. The method of claim 1 , wherein the organic solvent comprises toluene, ortho-xylene, meta-xylene, para-xylene, acetone, dimethylformamide, tetrahydrofuran, methylene dichloride, dimethyl sulfoxide, or any mixture thereof.
10. The method of claim 9 , wherein the organic solvent comprises toluene, ortho-xylene, meta-xylene, para-xylene, or any mixture thereof.
11. The method of claim 10 , wherein the organic solvent comprises toluene.