Compositions of mono-alkyl ethers of monoanhydro-hexitols, production methods thereof and use of same
A composition of monoanhydro-hexitol monoalkyl ether isomers bearing an alkyl ether radical (OR) at C-3, C-5 or C-6 of the monoanhydro-hexitol, in which the alkyl group (R) is a linear or branched, cyclic or noncyclic hydrocarbon-based group comprising between 4 to 18 carbon atoms, the process for obtaining such a composition and the use thereof as a nonionic surfactant, emulsifier, lubricant, antimicrobial agent or dispersant.
1. A composition of monoanhydro-hexitol monoalkyl ether isomers bearing an alkyl ether radical (OR) in position C-3, C-5 or C-6 of the monoanhydro-hexitol, in which the alkyl group (R) is a linear or branched hydrocarbon-based group comprising between 4 to 18 carbon atoms.
2. The composition as claimed in claim 1 , wherein the monoanhydro hexitol is chosen from monoanhydro sorbitol, monoanhydro mannitol, monoanhydro iditol and monoanhydro galactitol and mixtures thereof.
3. The composition as claimed in claim 1 , comprising at least 1% (w/w) of any one monoanhydro-hexitol monoalkyl ether isomers.
4. The composition as claimed in claim 1 , comprising at least 90% (w/w) of monoanhydro-hexitol monoalkyl ether isomers.
5. The composition as claimed in claim 1 , wherein a ratio of [(3-alkyl monoanhydro-hexitol+5-alkyl monoanhydro-hexitol) to 6-alkyl monoanhydro-hexitol] is between 0.02 and 2.
6. The composition as claimed in claim 1 , wherein the alkyl group (R) comprises between 8 and 12 carbon atoms.
7. A process for obtaining a composition of monoanhydro-hexitol monoalkyl ether isomers bearing an alkyl ether radical (OR) in position C-3, C-5 or C-6 of the monoanhydro-hexitol, in which the alkyl group (R) comprises between 4 to 18 carbon atoms, comprising the following steps:
a) dehydration of a hexitol to obtain a monoanhydro-hexitol substrate;
b) production of a hexitan alkyl acetal by acetalization or trans-acetalization of the monoanhydro-hexitol substrate obtained, with
i. an aliphatic aldehyde reagent comprising from 4 to 18 carbon atoms, by acetalization, or
ii. a derivative of an aliphatic aldehyde reagent comprising from 4 to 18 carbon atoms, by trans-acetalization,
c) catalytic hydrogenolysis of the hexitan alkyl acetal without acid catalyst, and
d) recovery of a composition of monoanhydro-hexitol monoalkyl ether isomers bearing an alkyl ether radical (OR) in position C-3, C-5 or C-6 of the monoanhydro-hexitol, in which the alkyl group (R) comprises 4 to 18 carbon atoms according to claim 1 .
8. The process as claimed in claim 7 , wherein the acetalization or trans-acetalization step b) is performed in the presence of an acid catalyst.
9. The process as claimed in claim 7 , wherein the hydrogenolysis is performed in a solvent or without solvent, in the presence of a catalyst.
10. The process as claimed in claim 9 , wherein the solvent is a polar solvent.
11. The process as claimed in claim 9 , wherein the hydrogenolysis is performed at a temperature of between 80 and 140° C. and/or a pressure of between 15 and 40 bar.
12. The process as claimed in claim 9 , wherein the hydrogenolysis is performed in the presence of a catalyst based on precious metals.
13. The process as claimed in claim 7 , further comprising at least one filtration and/or purification step after any one of steps a), b) and/or d).
14. The process as claimed in claim 13 , wherein the purification step is performed by chromatography or crystallization.
15. The process as claimed in claim 7 , wherein the hexitol is chosen from sorbitol and mannitol.
16. The process as claimed in claim 7 , wherein the aliphatic aldehyde reagent comprising from 4 to 18 carbon atoms is acetalized in a substrate/reagent ratio of between 5/1 and 1/1.
17. The process as claimed in claim 7 , wherein the derivative of an aliphatic aldehyde reagent comprising from 4 to 18 carbon atoms is trans-acetalized in a substrate/reagent ratio of between 1/1 and 1/3.
18. A product obtained by performing the process as claimed in claim 7 .