Process to prepare a cyclic oligomer and a cyclic oligomer obtainable thereby

1. A process to prepare a cyclic polyester oligomer composition comprising a cyclic polyester oligomer having furanic units, wherein the process comprises:

a step of either:

(I) reacting a monomer component C 1 or D 1 in the presence of an optional catalyst and/or optional organic base in a ring closing oligomerization step under conditions of a reaction temperature and reaction time sufficient to yield a cyclic polyester oligomer having furanic units and of structure Y 1 , wherein the monomer component C 1 comprises the structure

and wherein each of the groups A is an optionally-substituted linear, branched or cyclic alkyl, phenyl, aryl, or alkylaryl, and wherein l is an integer from 1 to 100,

and wherein

R 1 =OH, OR, halogen, or O-A-OH,

R=optionally substituted linear, branched or cyclic alkyl, phenyl, aryl or alkylaryl,

R 2 =H or

wherein the monomer component D 1 comprises the structure

and wherein A is an optionally-substituted linear, branched or cyclic alkyl, phenyl, aryl, or alkylaryl, and wherein each of the groups X is an OH, a halogen, or an optionally-substituted alkyloxy, phenoxy, or aryloxy, and wherein the groups X are not OH when A is n-butyl, and wherein the structure Y 1 of the cyclic polyester oligomer having furanic units is

wherein m is an integer from 1 to 20,

OR

(II) reacting a monomer component C 2 or D 2 in the presence of an optional catalyst and/or optional organic base in a ring closing oligomerization step under conditions of a reaction temperature and reaction time sufficient to yield a cyclic polyester oligomer having furanic units and of structure Y 2 , wherein the monomer component C 2 comprises the structure

and wherein each of the groups B is an optionally-substituted linear, branched or cyclic alkyl, phenyl, aryl, or alkylaryl, wherein l is an integer as defined above, and wherein n′ is an integer from 1 to 20, and wherein

R 3 =OH, OR, halogen, or O—(B—O) n —H,

R=optionally substituted linear, branched or cyclic alkyl, phenyl, aryl or alkylaryl,

R 4 =H or

the monomer component D 2 comprises the structures

and wherein each of the groups X is an OH, a halogen, or an optionally-substituted alkyloxy, phenoxy, or aryloxy, each of the groups B is an optionally-substituted linear, branched or cyclic alkyl, phenyl, aryl, or alkylaryl, and n′ is an integer as defined above,

and wherein the structure Y 2 of the cyclic polyester oligomer having furanic units is

wherein each of the groups B is an optionally-substituted linear, branched or cyclic alkyl, phenyl, aryl, or alkylaryl, n′ is an integer as defined above, and m is an integer from 1 to 20, AND

a subsequent step (III) in which linear oligomeric polyester species having furanic units are separated and removed from the cyclic oligomeric composition.

2. The process of claim 1 , wherein either:

(I)—the monomer component is C 1 and A is an optionally-substituted linear, branched or cyclic alkyl, l is an integer from 3 to 25,

OR

the monomer component is D 1 and A is an optionally-substituted linear, branched or cyclic alkyl, X is a halogen, or optionally-substituted alkyloxy or phenoxy, and m is as defined previously in this claim, and wherein the structure of the cyclic polyester oligomer having furanic units is one of Y 1 ,

OR

(II)—the monomer component is C 2 and wherein B is an optionally-substituted linear, branched or cyclic alkyl, l and m are integers as defined above, and n′ is an integer from 2 to 10,

OR

the monomer component is D 2 , and wherein X is an OH, a halogen, or optionally-substituted alkyloxy, phenoxy, or aryloxy, B is an optionally-substituted linear, branched or cyclic alkyl, or phenyl, and n′ and m are integers as defined previously in this claim, and wherein the structure of the cyclic polyester oligomer having furanic units is one of Y 2 .

3. The process of claim 1 , wherein either

the monomer component is C 1 and A is an optionally-substituted linear, branched or cyclic C 1 to C 6 alkyl, and l is an integer from 3 to 25, and m is an integer from 3 to 10,

the monomer component is D 1 and A is an optionally-substituted linear, branched or cyclic C 1 to C 6 alkyl, X is a halogen, or optionally-substituted alkyloxy or phenoxy, and m is an integer as defined above,

the monomer component is C 2 and wherein B is an optionally-substituted linear, branched or cyclic C 1 to C 6 alkyl, l and m are integers as defined above and n′ is an integer from 2 to 10,

OR

the monomer component is D 2 , X is a halogen, or an optionally-substituted alkyloxy, phenoxy, or aryloxy, B is an optionally-substituted linear, branched or cyclic C 1 to C 6 alkyl, or phenyl, and n′ and m are integers as defined in claim 2 .

4. The process of claim 1 , wherein the monomer component is C 1 or C 2 and the reaction temperature is from 100 to 350° C., and wherein the reaction time is from 30 to 600 minutes,

OR

wherein the monomer component is D 1 or D 2 and the reaction temperature is from −10 to 150° C., and wherein the reaction time is from 5 to 240 minutes.

5. The process of claim 1 , wherein either the monomer component C 1 comprises the specific structure

or the monomer component D 1 comprises the specific structure

and the structure Y 1 of the cyclic polyester oligomer having furanic units is the specific structure

wherein

R 5 =OH, OR, halogen, or O—CH 2 CH 2 —OH,

R=optionally substituted linear, branched or cyclic alkyl, phenyl, aryl or alkylaryl,

R 6 =H or

and X, l, and m are defined as indicated in the previous claim on which this claim depends.

6. The process of claim 1 , wherein either the monomer component C 1 comprises the specific structure C 1″

or the monomer component D 1 comprises the specific structure D 1″

and the structure Y 1 of the cyclic polyester oligomer having furanic units is the specific structure Y 1″

R 7 =OH, OR, halogen, or O—CH 2 CH 2 CH 2 CH 2 —OH,

R=optionally substituted linear, branched or cyclic alkyl, phenyl, aryl or alkylaryl,

R 8 =H or

and X, l, and m are defined as indicated in the previous claim on which this claim depends.

7. The process of claim 1 , wherein the optional organic base E is present and it is a monoamine compound or a compound having the structure

wherein each of the groups R 9 to R 12 are hydrogen, optionally-substituted alkyl, phenyl, aryl, or alkaryl, and wherein each of the groups R 9 to R 12 may optionally be bonded together by a single or double bond group as part of a cyclic substituent in a cyclic optional organic base E.

8. The process of claim 1 , wherein the optional organic base E is present and it is either:

(i) DABCO, having the structure:

OR

(ii) DBU, having the structure:

and wherein DABCO or DBU are optionally used together with an alkyl amine.

9. The process of claim 1 , wherein the optional catalyst is either absent or it is present and it is a metal alkoxide or metal carboxylate.

10. The process of claim 1 , wherein the optional organic base E is present in a stoichiometric ratio of from 0.5 to 6 mol relative to 1 mol of all monomer component species used as a reactant in the process.

11. The process of claim 1 , wherein the step (III) in which linear oligomeric polyester species having furanic units are separated and removed from the cyclic oligomeric composition comprises one or more separation sub-steps of passing a mobile phase of the cyclic oligomeric composition through a stationary phase, selective precipitation, distillation, extraction, crystallization or their combinations.

12. A cyclic polyester oligomer composition made by the process according to claim 1 , wherein the composition contains less than 5 weight % of linear oligomeric polyester species having furanic units relative to the total weight of the composition.

13. The cyclic polyester oligomer composition of claim 12 , wherein the composition contains a halogenated impurity.

14. The cyclic polyester oligomer composition of claim 12 , wherein the composition comprises the specific cyclic polyester oligomer having furanic units of structure Y 1′

wherein m is an integer from 1 to 20.

15. The cyclic polyester oligomer composition of claim 12 , wherein the composition comprises the specific cyclic polyester oligomer having furanic units of structure Y 1″

wherein m is an integer from 1 to 20.

16. A process for preparing a polyester polymer, the process comprising the steps of:

obtaining the cyclic polyester oligomer composition of claim 12 and using it in the production of a polyester polymer.

17. The process of claim 16 , wherein the polyester polymer is:

(i) a PEF polymer comprising the structure

OR

(ii) a PBF polymer comprising the structure

wherein n is an integer from 10 to 100,000.