BR112020004941B1 - PROCESS FOR THE TRANSFORMATION OF A POLYESTER INTO A TEREPHTHALATE - Google Patents

Abstract

The present disclosure relates to the formation of terephthalate esters of Formula (I) which are formed by the depolymerization of polyethylene terephthalate (PET) or poly(ethylene glycol-co-1,4-cyclohexanedimethanol terephthalate). The depolymerization process comprises contacting the poly(ethylene glycol-co-1,4-cyclohexanedimethanol terephthalate) with a solvent for swelling the polyester, an alcoholic solvent and a substoichiometric amount of an alkoxide. In Formula (I) R1 and R2 are independently selected from the group consisting of hydrogen, C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 hydroxyalkyl, C3 -C8 cycloalkyl, optionally substituted (C1-C6 alkyl)(C3 - C8 cycloalkyl ), optionally substituted aryl and optionally substituted (C1-C6 alkyl)(aryl); provided one of R1 or R2 is not hydrogen. (I)

Description

CROSS REFERENCE

[0001] This patent application claims the benefit of Application No. US 15/706,484, filed on September 15, 2017, which is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

[0002] The present disclosure relates to the formation of ester derivatives from polyesters and, more specifically, to the formation of terephthalic acid esters from polyethylene terephthalate (PET) or poly(ethylene glycol-co-1 terephthalate, 4-cyclohexanedimethanol) (PETG). The present disclosure also relates to the formation of dimethyl terephthalate (DMT). The present disclosure also relates to the formation of monoethylene glycol (MEG).

BACKGROUND OF THE INVENTION

[0003] The market for polyethylene terephthalate (PET) bottle resins has grown strongly as PET resins replace glass in carbonated soft drinks, bottled water and food containers.

[0004] Dimethyl terephthalate (DMT) is mainly used in the manufacture of polyethylene terephthalate (PET) for applications in fibers, films, packaging plastics and specialty plastics.

[0005] The largest sector for polyester is the fiber market, where it is used to make clothing, home textiles such as sheets and curtains, carpets and rugs, and industrial products such as tire cords, seat belts, hoses and ropes . PET film is used in electrical applications such as foil dielectric capacitors and in food packaging.

[0006] Polyester growth has not been converted into DMT demand. For most types of polyester used in textiles and food and beverage packaging, it is more economical to use purified terephthalic acid instead of DMT.

SUMMARY OF THE INVENTION

[0007] A process is disclosed here for transforming a polyester selected from the group consisting of polyethylene terephthalate and poly(ethylene glycol-co-1,4-cyclohexanedimethanol terephthalate) into a terephthalate of Formula (I): independently selected consists of hydrogen, C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 hydroxyalkyl, optionally substituted C3-C8 cycloalkyl, optionally substituted (C1-C6 alkyl)(C3-C8 cycloalkyl), optionally substituted aryl, and (optionally substituted optionally substituted C1-C6)(aryl); provided that one of R1 or R2 is not hydrogen; the process comprising mixing the polyester with a mixture comprising: (a) a solvent to swell the polyester; (b) an alcoholic solvent; and (c) a substoichiometric amount of an alkoxide.

[0008] In some embodiment of the process, R1 or R2 is methyl.

[0009] In some embodiments of the process, the alcoholic solvent is selected from the group consisting of methanol, ethanol, n-propanol, isopropanol, t-butanol, ethylene glycol, glycerol, cyclohexane-1,4-diyldimethanol, phenol , benzyl alcohol and any combinations thereof.

[00010] In some embodiments of the process, the alcoholic solvent is methanol.

[00011] In some embodiments of the process, the solvent for swelling the polyester is selected from the group consisting of a non-polar solvent, a polar aprotic solvent, a polar protic solvent and any combination thereof.

[00012] In some embodiments of the process, the solvent for swelling the polyester is selected from the group consisting of DMSO, DMF, acetone, a halogenated solvent, n-hexane, nitrobenzene, methanol, benzyl alcohol, benzaldehyde and any combination thereof.

[00013] In some embodiments of the process, the solvent for swelling the polyester is a halogenated solvent.

[00014] In some embodiments of the process, the solvent to swell the polyester is methanol.

[00015] In some embodiments of the process, the proportion of solvent to swell the polyester in relation to the alcoholic solvent is between about 0.1:1 and about 2:1 (w:w).

[00016] In some embodiments of the process, the proportion of solvent to swell the polyester in relation to the alcoholic solvent is between about 0.5:1 and about 1:1 (w:w).

[00017] In some embodiments of the process, the alkoxide is selected from the group consisting of an alkali metal alkoxide, an alkaline earth metal alkoxide, a metal alkoxide, an ammonium alkoxide, and any combinations thereof.

[00018] In some embodiments of the process, the alkoxide is selected from the group consisting of sodium methoxide, potassium ethoxide, aluminum tri-n-propoxide and tetrabutylammonium methoxide.

[00019] In some embodiments of the process, the alkoxide is sodium methoxide.

[00020] In some embodiments of the process, the alkoxide is generated in situ by adding an alkali metal, an alkaline earth metal or a metal to the alcoholic solvent.

[00021] In some embodiments of the process, the ratio of polyester to alkoxide is between about 15:1 and about 125:1 (w:w).

[00022] In some embodiments of the process, the ratio of polyester to alkoxide is between about 20:1 and about 25:1 (w:w).

[00023] In some embodiments of the process, the ratio of polyester to alkoxide is between about 15:1 and about 60:1 (w:w).

[00024] In some embodiments of the process, the ratio of polyester to alkoxide is between about 20:1 and about 50:1 (w:w).

[00025] In some embodiments of the process, the process is carried out until a yield of about 80% of the terephthalate of formula (I) is reached.

[00026] In some embodiments of the process, the process is carried out without external heat.

[00027] In some embodiments of the process, the process is carried out at a temperature between about 25 °C and about 85 °C.

[00028] In some embodiments of the process, the process is carried out at a temperature between about 25 °C and about 80 °C.

[00029] In some embodiments of the process, the process is carried out at atmospheric pressure.

[00030] In some embodiments of the process, the polyester is polyethylene terephthalate.

[00031] In some embodiments of the process, the process further comprises recovering monoethylene glycol (MEG).

[00032] In some process modalities, the polyester is in the form of polymer flakes and is part of a raw material.

[00033] In some embodiments of the process, the average particle size of the polymer flakes is between 1 mm and 20 mm.

[00034] In some embodiments of the process, the average particle size of the polymer flakes is between 1 mm and 5 mm.

[00035] Also disclosed herein is a process for transforming polyethylene terephthalate into dimethyl terephthalate, comprising mixing the polyethylene terephthalate with a mixture comprising: (d) a solvent for swelling the polyethylene terephthalate; (e) methanol; and (f) a substoichiometric amount of an alkoxide.

[00036] In some embodiments of the process, the solvent for swelling polyethylene terephthalate is selected from the group consisting of a halogenated solvent, DMSO, benzyl alcohol, methanol and any combination thereof.

[00037] In some embodiments of the process, the solvent for swelling the polyethylene terephthalate is a halogenated solvent.

[00038] In some embodiments of the process, the solvent to swell the polyethylene terephthalate is methanol.

[00039] In some embodiments of the process, the ratio of polyethylene terephthalate to alkoxide is between about 20:1 and about 25:1 (w:w).

[00040] In some embodiments of the process, the ratio of polyester to alkoxide is between about 15:1 and about 60:1 (w:w).

[00041] In some embodiments of the process, the ratio of polyester to alkoxide is between about 20:1 and about 50:1 (w:w).

[00042] In some embodiments of the process, the alkoxide is selected from the group consisting of sodium methoxide, potassium ethoxide, aluminum tri-n-propoxide and tetrabutylammonium methoxide.

[00043] In some embodiments of the process, the alkoxide is sodium methoxide.

[00044] In some embodiments of the process, the ratio of solvent to swell polyethylene terephthalate to methanol is between about 0.5:1 and about 1:1 (w:w).

[00045] In some embodiments of the process, the process is carried out until a yield of about 80% of dimethyl terephthalate is achieved.

[00046] In some embodiments of the process, the process is carried out without external heat.

[00047] In some embodiments of the process, the process is carried out at a temperature between about 25 °C and about 85 °C.

[00048] In some embodiments of the process, the process is carried out at a temperature between about 25 °C and about 80 °C.

[00049] In some embodiments of the process, the process is carried out at atmospheric pressure.

[00050] In some embodiments of the process, the process further comprises recovering monoethylene glycol (MEG).

[00051] In some embodiments of the process, polyethylene terephthalate is in the form of polymer flakes and is part of a raw material.

[00052] In some embodiments of the process, the average particle size of the polymer flakes is between 1 mm and 20 mm.

[00053] In some embodiments of the process, the average particle size of the polymer flakes is between 1 mm and 5 mm.

[00054] Also provided herein is dimethyl terephthalate (DMT) prepared using a process described herein.

[00055] Also provided herein is monoethylene glycol (MEG) prepared using a process described herein.

[00056] Also provided herein is a reaction mixture comprising: (g) a polyester selected from polyethylene terephthalate and poly(ethylene glycol-co-1,4-cyclohexanedimethanol terephthalate); (h) a solvent to swell the polyester; (i) an alcoholic solvent; and (j) a substoichiometric amount of an alkoxide.

[00057] In some embodiments of a reaction mixture, the alcoholic solvent is selected from the group consisting of methanol, ethanol, n-propanol, isopropanol, t-butanol, ethylene glycol, glycerol, cyclohexane-1,4-di- yldimethanol, phenol, benzyl alcohol and any combination thereof.

[00058] In some embodiments of a reaction mixture, the solvent for swelling the polyester is selected from the group consisting of a non-polar solvent, a polar aprotic solvent, a polar protic solvent and any combinations thereof.

[00059] In some embodiments of a reaction mixture, the solvent for swelling the polyester is a halogenated solvent.

[00060] In some embodiments of a reaction mixture, the solvent for swelling the polyester is methanol.

[00061] In some embodiments of a reaction mixture, the alcoholic solvent is methanol.

[00062] In some embodiments of a reaction mixture, the ratio of solvent to swell polyester to alcoholic solvent is between about 0.5:1 and about 1:1 (w:w).

[00063] In some embodiments of a reaction mixture, the ratio of polyester to alkoxide is between about 15:1 and about 30:1 (w:w).

[00064] In some embodiments of a reaction mixture, the ratio of polyethylene terephthalate to alkoxide is between about 20:1 and about 25:1 (w:w).

[00065] In some embodiments of a reaction mixture, the ratio of polyester to alkoxide is between about 15:1 and about 60:1 (w:w).

[00066] In some embodiments of a reaction mixture, the ratio of polyester to alkoxide is between about 20:1 and about 50:1 (w:w).

[00067] In some embodiments of a reaction mixture, the alkoxide is selected from the group consisting of sodium methoxide, potassium ethoxide, aluminum tri-n-propoxide, and tetrabutylammonium methoxide.

[00068] In some embodiments of a reaction mixture, the alkoxide is sodium methoxide.

[00069] In some embodiments of a reaction mixture, the polyester is polyethylene terephthalate.

DETAILED DESCRIPTION OF THE INVENTION

[00070] Dimethyl terephthalate (DMT) is used in the production of polyesters, including polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT) and polybutylene terephthalate (PBT). As DMT is volatile, it is an intermediate in some schemes for recycling PET, for example from plastic bottles. The hydrogenation of DMT produces the diol 1,4-cyclohexanedimethanol, which is a useful monomer in the formation of polyester resins.

[00071] DMT was produced in several ways. Conventionally and still of commercial value is the direct esterification of terephthalic acid. Alternatively, it is prepared by alternating oxidation and esterification steps of methyl from para-xylene through methyl para-toluate. The method for producing DMT from para-xylene and methanol consists of four main steps: oxidation, esterification, distillation and crystallization. A mixture of para-xylene and pare-toluic ester is oxidized with air in the presence of a transition metal (Co/Mn) catalyst. The acid mixture resulting from the oxidation is esterified with methanol to produce a mixture of esters. The crude ester mixture is distilled to remove all heavy boiler and waste produced; the lighter esters are recycled to the oxidation section. Crude DMT is then crystallized to remove DMT isomers, residual acids and aromatic aldehydes.

[00072] An improvement in the production of DMT from PET recycling: due to the increasing use of PET and PETG in the packaging and fiber industries (carpets and other textiles), an efficient, low energy consumption, high yield and low cost of forming DMT from PET or PETG.

POLYESTERS

[00073] A process for transforming a polyester into an ester derivative is described here; the process comprising mixing the polyester with a mixture comprising: (a) a solvent to swell the polyester; (b) an alcoholic solvent; and (c) a substoichiometric amount of an alkoxide.

[00074] In some embodiments, the polyester is selected from polyethylene terephthalate (PET), poly(ethylene glycol-co-1,4-cyclohexanedimethanol terephthalate) (PETG), polyglycolide or polyglycolic acid (PGA), polylactic acid ( PLA), polycaprolactone (PCL), polyhydroxybutyrate (PHB), polyethylene adipate (PEA), polybutylene succinate (PBS), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), polybutylene terephthalate (PBT) ), polytrimethylene terephthalate (PTT), polyethylene naphthalate (PEN), Vectran®, cutin and any combination thereof.

[00075] In some embodiments, the polyester is polyethylene terephthalate (PET):

[00076] In some embodiments, the polyester is a terephthalic acid/ethylene glycol oligomer.

[00077] In some embodiments, the polyester is poly(ethylene glycol-co-1,4-cyclohexanedimethanol terephthalate) (PETG):

[00078] In some embodiments, the polyester is polyglycolide or polyglycolic acid (PGA),

[00079] In some embodiments, the polyester is polylactic acid (PLA):

[00080] In some embodiments, the polyester is polycaprolactone (PCL):

[00081] In some embodiments, the polyester is polyhydroxybutyrate (PHB):

[00082] In some embodiments, polyethylene adipate (PEA):

[00083] In some embodiments, polybutylene succinate (PBS):

[00084] In some embodiments, the polyester is poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV):

[00085] In some embodiments, the polyester is polybutylene terephthalate (PBT):

[00086] In some embodiments, the polyester is polytrimethylene terephthalate (PTT):

[00087] In some embodiments, the polyester is polyethylene naphthalate (PEN):

[00088] In some embodiments, the polyester is Vectran®:

[00089] In some embodiments, the polyester is cutin. Cutina is one of two waxy polymers that are the main components of the plant cuticle, which covers all aerial surfaces of plants. Cutin consists of omega fatty acids and derivatives thereof, which are interconnected by ester linkages, forming a polyester polymer. There are two main families of cutin monomers, the C16 and C18 families. The C16 family consists mainly of 16-hydroxy palmitic acid and 9,16- or 10,16-dihydroxypalmitic acid. The C18 family consists mainly of 18-hydroxyoleic acid, 9,10-epoxy-18-hydroxystearic acid and 9,10,18-trihydroxystearate. Tomato cutin consists of 16-hydroxy-palmitic acid and 10,16-dihydroxypalmitic acid, where the 10-isomer is largely dominant. Tomato cutin is an interesterified polyester biopolymer. The significant proportion of secondary esters (esterification at the C-10 secondary hydroxyl) shows that the polyester structure is significantly branched.

[00090] In some embodiments, the polyester is in a raw material that comprises contaminants, such as additional polymers (for example, polyethylene, polypropylene, polyvinyl chloride (PVC), paper, dyes, dirt, ethylene vinyl alcohol (EvOH), polycarbonate (PC), polyvinylidene chloride (PVDC), ethylene vinyl acetate (EVA), glue, polyamide or any combination thereof. In some embodiments, the raw material comprises between about 5% and about 20% contaminants .

[00091] Mishra et al. (Kinetic and thermodynamic study of methanolysis of poly(ethylene terephthalate) waste powder Polym. Int Int. 52:337-342 (2003)) showed that increasing the particle size of PET flakes causes a decrease in depolymerization. Mishra et al. registered 127.5 μm as the ideal particle size. A depolymerization process is needed that allows the use of larger polymer flakes. In some embodiments, the feedstock comprises polymer flakes. In some embodiments, the average particle size of the polymer flakes is between 1 mm and 20 mm. In some embodiments, the average particle size of the polymer flakes is between 1 mm and 15 mm. In some embodiments, the average particle size of the flakes is between 1 mm and 10 mm. In some embodiments, the average particle size of the polymer flakes is between 1 mm and 5 mm.

ESTER DERIVATIVES

[00092] A process for transforming a polyester into an ester derivative is described herein; the process comprising mixing the polyester with a mixture comprising: (a) a solvent to swell the polyester; (b) an alcoholic solvent; and (c) a substoichiometric amount of an alkoxide.

[00093] In some embodiments, the polyester is polyglycolide or polyglycolic acid (PGA) and the ester derivative is a 2-hydroxyacetate derivative. In some embodiments, the ester derivative is methyl 2-hydroxyacetate.

[00094] In some embodiments, the polyester is polylactic acid (PLA) and the ester derivative is a 2-hydroxypropanoate derivative. In some embodiments, the ester derivative is methyl 2-hydroxypropanoate.

[00095] In some embodiments, the polyester is polycaprolactone (PCL) and the ester derivative is a 6-hydroxyhexanoate derivative. In some embodiments, the ester derivative is a methyl 6-hydroxyhexanoate.

[00096] In some embodiments, the polyester is polyhydroxybutyrate (PHB) and the ester derivative is a hydroxybutyrate derivative. In some embodiments, the ester derivative is methyl hydroxybutyrate.

[00097] In some embodiments, the polyester is polyethylene adipate (PEA) and the ester derivative is an adipate derivative. In some embodiments, the ester derivative is dimethyl adipate.

[00098] In some embodiments, the polyester is polybutylene succinate (PBS) and the ester derivative is a succinate derivative. In some embodiments, the ester derivative is dimethyl succinate.

[00099] In some embodiments, the polyester is poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and the ester derivative is a hydroxybutyrate derivative, a hydroxyvalerate derivative, or a combination thereof. In some embodiments, the ester derivative is methyl hydroxybutyrate, methyl hydroxyvalerate, or a combination thereof.

[000100] In some embodiments, the polyester is polyethylene naphthalate (PEN) and the ester derivative is a naphthalate derivative. In some embodiments, the ester derivative is dimethyl naphthalate.

[000101] In some embodiments, the polyester is vectran and the ester derivative is a naphthoate derivative, a benzoate derivative, or a combination thereof. In some embodiments, the ester derivative is methyl hydroxynaphthate or methyl hydroxybenzoate.

[000102] In some embodiments, the polyester is cutin and the ester derivative is a hydroxypalmitate or dihydroxypalmitate derivative. In some embodiments, the ester derivative is methyl hydroxypalmitate or methyl dihydroxypalmitate.

[000103] In some embodiments, the polyester is polyethylene terephthalate (PET), poly(ethylene glycol-co-1,4-cyclohexanedimethanol terephthalate) polytrimethylene terephthalate (PTT) or polybutylene terephthalate (PBT) and ester derivative is a terephthalate derivative. In some embodiments, the terephthalate derivative is a compound of formula (I): wherein R1 and R2 are independently selected from hydrogen, C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 hydroxyalkyl, optionally substituted C3-C8 cycloalkyl, (optionally substituted C1-C6 alkyl)(C3-C8 cycloalkyl), optionally substituted aryl and optionally substituted (C1-C6 alkyl)(aryl); provided one of R1 or R2 is not hydrogen.

[000104] In some embodiments of a compound of Formula (I), R1 and R2 are independently C1-C6 alkyl or C1-C6 hydroxyalkyl.

[000105] In some embodiments of a compound of Formula (I), R1 and R2 are independently C1-C6 alkyl. In some embodiments of a compound of Formula (I), R1 and R2 are independently methyl, ethyl, propyl, isopropyl or butyl. In some embodiments of a compound of Formula (I), R1 and R2 are independently methyl or ethyl. In some embodiments of a compound of Formula (I), R1 and R2 are methyl. In some embodiments of a compound of Formula (I), R1 and R2 are ethyl. In some embodiments of a compound of Formula (I), R1 and R2 are not hydrogen.

[000106] In some embodiments of a compound of Formula (I), R1 and R2 are independently hydroxy C1-C6 alkyl. In some embodiments of a compound of Formula (I), R1 and R2 are independently hydroxyethyl or propanediol. In some embodiments of a compound of Formula (I), R1 and R2 are hydroxyethyl. In some embodiments of a compound of Formula (I), R1 and R2 are 2-hydroxyethyl. In some embodiments of a compound of Formula (I), R1 and R2 are dihydroxypropyl. In some embodiments of a compound of Formula (I), R1 and R2 are 2,3-dihydroxypropyl.

[000107] In some embodiments of a compound of Formula (I), R1 and R2 are independently optionally substituted (C1-C6 alkyl)(C3-C8 cycloalkyl). In some embodiments of a compound of Formula (I), R1 and R2 are independently optionally substituted (C1-C6 alkyl)(C3-C8 cycloalkyl). In some embodiments of a compound of Formula (I), R1 and R2 are 4-(hydroxymethyl)cyclohexyl)methyl.

[000108] In some embodiments of a compound of Formula (I), R1 and R2 are independently optionally substituted aryl. In some embodiments of a compound of Formula (I), R1 and R2 are phenyl.

[000109] In some embodiments of a compound of Formula (I), R1 and R2 are independently (C1-C6 alkyl)(aryl) optionally substituted. In some embodiments of a compound of Formula (I), R1 and R2 are benzyl.

[000110] In some embodiments, the ester derivative contains less than about 10% impurity (w/w). In some embodiments, the ester derivative contains less than about 9% impurity (w/w). In some embodiments, the ester derivative contains less than about 8% impurity (w/w). In some embodiments, the ester derivative contains less than about 7% impurity (w/w). In some embodiments, the ester derivative contains less than about 6% impurity (w/w). In some embodiments, the ester derivative contains less than about 5% impurity (w/w). In some embodiments, the ester derivative contains less than about 4% impurity (w/w). In some embodiments, the ester derivative contains less than about 3% impurity (w/w). In some embodiments, the ester derivative contains less than about 2% impurity (w/w). In some embodiments, the ester derivative contains less than about 1% impurity (w/w). In some embodiments, the ester derivative contains less than about 0.5% impurity (w/w). In some embodiments, the ester derivative contains less than about 0.4% impurity (w/w). In some embodiments, the ester derivative contains less than about 0.3% impurity (w/w). In some embodiments, the ester derivative contains less than about 0.2% impurity (w/w). In some embodiments, the ester derivative contains less than about 0.1% impurity (w/w).

[000111] In some embodiments, the ester derivative contains less than about 250 ppm of any metal, less than about 240 ppm of any metal, less than about 230 ppm of any metal, less than about 220 ppm of any less than about 210 ppm of any metal, less than about 200 ppm of any metal, less than about 190 ppm of any metal, less than about 180 ppm of any metal, less than about 170 ppm of any less than about 160 ppm of any metal, less than about 150 ppm of any metal, less than about 140 ppm of any metal, less than about 130 ppm of any metal, less than about 120 ppm of any less than about 110 ppm of any metal, less than about 100 ppm of any metal, less than about 90 ppm of any metal, less than about 80 ppm of any metal, less than about 70 ppm of any less than about 60 ppm of any metal, less than about 50 ppm of any metal, less than about 40 ppm of any metal, less than about 30 ppm of any metal, less than about 20 ppm of any less than about 10 ppm of any metal, less than about 5 ppm of any metal, less than about 4 ppm of any metal, less than about 3 ppm of any metal, less than about 2 ppm of any metal, less than about 1 ppm of any metal, less than about 0.9 ppm of any metal, less than about 0.8 ppm of any metal, less than about 0.7 ppm of any metal, less than less than about 0.6 ppm of any metal, less than about 0.5 ppm of any metal, less than about 0.4 ppm of any metal, less than about 0.3 ppm of any metal, less than about 0.2 ppm of any metal, less than about 0.1 ppm of any metal, less than about 0.09 ppm of any metal, less than about 0.08 ppm of any metal, less than about 0, 07 ppm of any metal, less than about 0.06 ppm of any metal, less than about 0.05 ppm of any metal, less than about 0.04 ppm of any metal, less than about 0.03 ppm of any metal, less than about 0.02 ppm of any metal or less than about 0.01 ppm of any metal.

GLYCOL

[000112] A process for transforming a polyester into an ester derivative is described here; the process comprising mixing the polyester with a mixture comprising: (a) a solvent to swell the polyester; (b) an alcoholic solvent; and (c) a substoichiometric amount of an alkoxide.

[000113] In some embodiments, the process further comprises forming a glycol. In some embodiments, the glycol is monoethylene glycol (MEG) (or ethylene glycol). In some embodiments, the glycol is propylene glycol. In some embodiments, the glycol is butylene glycol.

[000114] In some embodiments, the glycol is obtained in between about 80 and about 99 mol% yield. In some embodiments, the glycol is obtained in between about 85 and about 99 mol% yield. In some embodiments, the glycol is obtained in between about 90 and about 99 mol% yield. In some embodiments, the glycol is obtained in at least about 80 mol% yield. In some embodiments, the glycol is obtained in at least about 85 mol% yield.

[000115] In some embodiments, the glycol contains less than about 10% impurity (w/w). In some embodiments, the glycol contains less than about 9% impurity (w/w). In some embodiments, the glycol contains less than about 8% impurity (w/w). In some embodiments, the glycol contains less than about 7% impurity (w/w). In some embodiments, the glycol contains less than about 6% impurity (w/w). In some embodiments, the glycol contains less than about 5% impurity (w/w). In some embodiments, the glycol contains less than about 4% impurity (w/w). In some embodiments, the glycol contains less than about 3% impurity (w/w). In some embodiments, the glycol contains less than about 2% impurity (w/w). In some embodiments, the glycol contains less than about 1% impurity (w/w). In some embodiments, the glycol contains less than about 0.5% impurity (w/w). In some embodiments, the glycol contains less than about 0.4% impurity (w/w). In some embodiments, the glycol contains less than about 0.3% impurity (w/w). In some embodiments, the glycol contains less than about 0.2% impurity (w/w). In some embodiments, the glycol contains less than about 0.1% impurity (w/w).

[000116] In some embodiments, the glycol contains less than about 250 ppm of any metal, less than about 240 ppm of any metal, less than about 230 ppm of any metal, less than about 220 ppm of any metal, less than about 210 ppm of any metal, less than about 200 ppm of any metal, less than about 190 ppm of any metal, less than about 180 ppm of any metal, less than about 170 ppm of any metal, less than about 160 ppm of any metal, less than about 150 ppm of any metal, less than about 140 ppm of any metal, less than about 130 ppm of any metal, less than about 120 ppm of any metal, less than about 110 ppm of any metal, less than about 100 ppm of any metal, less than about 90 ppm of any metal, less than about 80 ppm of any metal, less than about 70 ppm of any metal, less than about 60 ppm of any metal, less than about 50 ppm of any metal, less than about 40 ppm of any metal, less than about 30 ppm of any metal, less than about 20 ppm of any metal, less than about 10 ppm of any metal, less than about 5 ppm of any metal, less than about 4 ppm of any metal, less than about 3 ppm of any metal, less than about 2 ppm of any metal, less than about 1 ppm of any metal, less than about 0.9 ppm of any metal, less than about 0.8 ppm of any metal, less than about 0.7 ppm of any metal, less than about 0.6 ppm of any metal, less than about 0.5 ppm of any metal, less than about 0.4 ppm of any metal, less than about 0.3 ppm of any metal, less than about 0, 2 ppm of any metal, less than about 0.1 ppm of any metal, less than about 0.09 ppm of any metal, less than about 0.08 ppm of any metal, less than about 0.07 ppm of any metal, less than about 0.06 ppm of any metal, less than about 0.05 ppm of any metal, less than about 0.04 ppm of any metal, less than about 0.03 ppm of any metal metal, less than about 0.02 ppm of any metal, or less than about 0.01 ppm of any metal.

ALCOHOLIC SOLVENT

[000117] A process for transforming a polyester into an ester derivative is described here; the process comprising mixing the polyester with a mixture comprising: (a) a solvent to swell the polyester; (b) an alcoholic solvent; and (c) a substoichiometric amount of an alkoxide.

[000118] In some embodiments, the process described herein comprises an alcoholic solvent. In some embodiments, the alcoholic solvent is a linear alcohol, branched alcohol, cyclic alcohol, or any combination thereof. In some embodiments, the alcoholic solvent is selected from methanol, ethanol, n-propanol, isopropanol, t-butanol, ethylene glycol, glycerol, cyclohexane-1,4-diyldimethanol, phenol, benzyl alcohol, and any combinations thereof. same.

[000119] In some embodiments, the alcoholic solvent is a linear C1-C4 alcohol. In some embodiments, the alcoholic solvent is methanol, ethanol, propanol, butanol or a combination thereof. In some embodiments, the alcoholic solvent is methanol, ethanol, propanol or a combination thereof. In some embodiments, the alcoholic solvent is methanol. In some embodiments, the alcohol is ethanol. In some embodiments, the alcoholic solvent is a C3-C4 branched alcohol. In some embodiments, the alcoholic solvent is t-butanol, s-butanol, i-butanol, i-propanol, or any combination thereof. In some embodiments, the alcoholic solvent is a C3 -C8 cyclic alcohol. In some embodiments, the alcoholic solvent is cyclopropanol, cyclobutanol, cyclopentanol, cyclohexanol, cycloheptanol, cyclohexane-1,4-diyldimethanol, or any combination thereof. In some embodiments, the alcoholic solvent is cyclohexane-1,4-diyldimethanol.

[000120] In some embodiments, the alcoholic solvent is a polyol. In some embodiments, the alcoholic solvent is selected from ethylene glycol, glycerol and any combinations thereof.

[000121] In some embodiments, the alcoholic solvent is selected from phenol, benzyl alcohol and any combination thereof.

SOLVENT FOR SWELLING POLYESTER

[000122] A process for transforming a polyester into an ester derivative is described here; the process comprising mixing the polyester with a mixture comprising: (a) a solvent to swell the polyester; (b) an alcoholic solvent; and (c) a substoichiometric amount of an alkoxide.

[000123] In some embodiments, the process described herein comprises pre-treating the polyester with a solvent to swell the polyester before adding the alcoholic solvent and alkoxide. In some embodiments, pretreatment with the solvent to swell the polyester is carried out for about 5 minutes and about 60 minutes before adding the alcoholic solvent and alkoxide. In some embodiments, pretreatment with the solvent to swell the polyester is done for about 5 minutes and about 40 minutes before adding the alcoholic solvent and alkoxide. In some embodiments, pretreatment with the solvent to swell the polyester is done for about 5 minutes and about 20 minutes before adding the alcoholic solvent and alkoxide. In some embodiments, pretreatment with the solvent to swell the polyester is done for about 5 minutes and about 10 minutes before adding the alcoholic solvent and alkoxide. In some embodiments, pretreatment with the solvent to swell the polyester is done for about 5 minutes. In some embodiments, pretreatment with the solvent to swell the polyester is done for about 10 minutes. In some embodiments, pretreatment with the solvent to swell the polyester is done for about 15 minutes. In some embodiments, pretreatment with the solvent to swell the polyester is done for about 20 minutes. In some embodiments, pretreatment with the solvent to swell the polyester is done for about 25 minutes. In some embodiments, pretreatment with the solvent to swell the polyester is done for about 30 minutes. In some embodiments, pretreatment with the solvent to swell the polyester is done for about 35 minutes. In some embodiments, pretreatment with the solvent to swell the polyester is done for about 40 minutes. In some embodiments, pretreatment with the solvent to swell the polyester is done for about 45 minutes. In some embodiments, pretreatment with the solvent to swell the polyester is done for about 50 minutes. In some embodiments, pretreatment with the solvent to swell the polyester is for about 55 minutes. In some embodiments, pretreatment with the solvent to swell the polyester is done for about 60 minutes.

[000124] In some embodiments, the process described herein comprises treating the polyester with a solvent to swell the polyester at the same time as adding the alcoholic solvent and alkoxide.

[000125] In some embodiments, the solvent for swelling the polyester is selected from a non-polar solvent, a polar aprotic solvent, a polar protic solvent and any combination thereof.

[000126] In some embodiments, the solvent for swelling the polyester is selected from dimethylsulfoxide (DMSO), N,N-dimethylformamide (DMF), acetone, a halogenated solvent, n-hexane, nitrobenzene, methanol, benzyl alcohol, benzaldehyde and any combinations thereof. In some embodiments, the solvent for swelling the polyester is selected from DMSO, a halogenated solvent and any combinations thereof. In some embodiments, the solvent for swelling the polyester is DMSO. In some embodiments, the solvent for swelling the polyester is a halogenated solvent. In some embodiments, the solvent for swelling the polyester is a chlorinated solvent. In some embodiments, the solvent for swelling the polyester is dichloromethane, dichloroethane, tetrachloroethane, chloroform, tetrachloromethane, trichloroethane or any combination thereof. In some embodiments, the solvent for swelling the polyester is dichloromethane. In some embodiments, the solvent for swelling the polyester is methanol.

[000127] In some embodiments, the proportion of solvent to swell the polyester relative to the alcoholic solvent is between about 0.1:1 and about 2:1 (w:w). In some embodiments, the ratio of solvent to swell polyester to alcoholic solvent is between about 1:1 and about 2:1 (w:w). In some embodiments, the ratio of polyester-swelling solvent to alcoholic solvent is between about 0.1:1 and about 2:1 (w:w), or between about 0.2:1 and about 2:1 (w:p), or between about 0.3:1 and about 2:1 (w:p) or between about 0.4:1 and about 2:1 (p:p), or between about 0.5:1 and about 2:1 (w:w), or between about 0.6:1 and about 2:1 (w:w), or between about 0.7: 1 and about 2:1 (w:p) or between about 0.8:1 and about 2:1 (w:p), or between about 0.9:1 and about 2:1 (p :p), or between about 1:1 and about 2:1 (p:p) or between about 1:2 and about 2:1 (p:p), or between about 1:3 and about of 2:1 (p:p), or between about 1:4 and about 2:1 (p:p), or between about 1:4 and about 2:1 (p:p), or between about 1:6 and about 2:1 (p:p), or between about 1:7 and about 2:1 (p:p), or between about 1:8 and about 2:1 ( p:p), or between about 1:9 and about 2:1 (p:p), or between about 0.5:1 and about 1.5:1 (p:p), or between about from about 0.8:1 to about 1.2:1 (w:p) or from about 0.5:1 to about 1:1 (w:p), or from about 1:1 to about 1.5:1 (w:w). In some embodiments, the ratio of polyester-swelling solvent to alcoholic solvent is between about 0.5:1 and about 1:1 (w:w).

Alkoxides

[000128] A process for transforming a polyester into an ester derivative is described here; the process comprising mixing the polyester with a mixture comprising: (a) a solvent to swell the polyester; (b) an alcoholic solvent; and (c) a substoichiometric amount of an alkoxide.

[000129] In some embodiments, the process described in this document comprises the addition of a substoichiometric amount of an alkoxide. In some embodiments, the process described herein comprises adding a catalytic amount of an alkoxide.

[000130] "Substoichiometric amount", as used herein, is used to indicate that the amount of material used is less than a stoichiometric amount. The term is used interchangeably herein with "catalytic amount". In some embodiments, a substoichiometric amount is less than or equal to about 95% of a stoichiometric amount. In some embodiments, a substoichiometric amount is less than or equal to about 90% of a stoichiometric amount. In some embodiments, a substoichiometric amount is less than or equal to about 85% of a stoichiometric amount. In some embodiments, a substoichiometric amount is less than or equal to about 80% of a stoichiometric amount. In some embodiments, a substoichiometric amount is less than or equal to about 75% of a stoichiometric amount. In some embodiments, a substoichiometric amount is less than or equal to about 70% of a stoichiometric amount. In some embodiments, a substoichiometric amount is less than or equal to about 65% of a stoichiometric amount. In some embodiments, a substoichiometric amount is less than or equal to about 60% of a stoichiometric amount. In some embodiments, a substoichiometric amount is less than or equal to about 55% of a stoichiometric amount. In some embodiments, a substoichiometric amount is less than or equal to about 50% of a stoichiometric amount. In some embodiments, a substoichiometric amount is less than or equal to about 45% of a stoichiometric amount. In some embodiments, a substoichiometric amount is less than or equal to about 40% of a stoichiometric amount. In some embodiments, a substoichiometric amount is less than or equal to about 35% of a stoichiometric amount. In some embodiments, a substoichiometric amount is less than or equal to about 30% of a stoichiometric amount. In some embodiments, a substoichiometric amount is less than or equal to about 25% of a stoichiometric amount. In some embodiments, a substoichiometric amount is less than or equal to about 20% of a stoichiometric amount. In some embodiments, a substoichiometric amount is less than or equal to about 15% of a stoichiometric amount. In some embodiments, a substoichiometric amount is less than or equal to about 10% of a stoichiometric amount.

[000131] "Stoichiometric amount", as used herein, is used to indicate that the amount of material used is equivalent to the number of ester bonds present in the polyester.

[000132] In some embodiments, the alkoxide, which comprises an alkoxide anion and a cation, is selected from an alkali metal alkoxide, an alkaline earth metal alkoxide, a metal alkoxide, an ammonium alkoxide and any combinations of the same. In some embodiments, the alkoxide anion is a C1-C4 alkoxide anion. In some embodiments, the alkoxide anion is selected from methoxide, ethoxide, n-propoxide, n-butoxide, t-butoxide, sec-butoxide, isobutoxide, isopropoxide, and a combination thereof. In some embodiments, the alkoxide anion is methoxide, ethoxide, or any combination thereof. In some embodiments, the alkoxide anion is methoxide. In some embodiments, the cation is lithium, sodium, potassium, magnesium, calcium, strontium, barium, zinc, aluminum or ammonium. In some embodiments, the alkoxide is sodium methoxide, potassium ethoxide, or aluminum tri-n-propoxide. In some embodiments, the ammonium alkoxide is a tetraalkylammonium alkoxide. In some embodiments, the ammonium alkoxide is a tetrabutylammonium alkoxide. In some embodiments, the alkoxide is sodium methoxide, potassium ethoxide, aluminum tri-n-propoxide or tetrabutylammonium methoxide.

[000133] In some embodiments, the alkoxide is generated in situ by adding an alkali metal, an alkaline earth metal or a metal to the alcoholic solvent.

[000134] In some embodiments, the ratio of polyester to alkoxide is between about 15:1 and about 125:1 (w:w), or between about 15:1 and about 100:1 (w:w) , or between about 15:1 and about 80:1 (w:p), or between about 15:1 and about 60:1 (w:p), or between about 15:1 and about 40 :1 (p:p), or between about 15:1 and about 25:1 (p:p), or between about 15:1 and about 20:1 (p:p), or between about 20:1 and about 25:1 (p:p), or between about 20:1 and about 50:1 (p:p) or between about 30:1 and about 60:1 (p:p) ) or between about 40:1 and about 70:1 (w:p), or between about 50:1 and about 80:1 (w:p), or between about 60:1 and about 90 :1 (p:p), or between about 20:1 and about 125:1 (p:p), or between about 40:1 and about 125:1 (p:p), or between about 60 :1 and about 125:1 (w:w) or between about 80:1 and about 125:1 (w:w) or between about 100:1 and about 125:1 (w:w). In some embodiments, the polyester to alkoxide ratio is between about 20:1 and about 25:1 (w:w).

REACTION TIME

[000135] A process for transforming a polyester into an ester derivative is described here; the process comprising mixing the polyester with a mixture comprising: (a) a solvent to swell the polyester; (b) an alcoholic solvent; and (c) a substoichiometric amount of an alkoxide.

[000136] In some embodiments, the mixture of the polyester with the solvent to swell the polyester, the alkoxide and the alcoholic solvent is carried out for a sufficient time. In some embodiments, mixing the polyester with the solvent to swell the polyester, the alkoxide and the alcoholic solvent is carried out until a yield of about 70% of the desired ester is achieved. In some embodiments, mixing the polyester with the solvent to swell the polyester, the alkoxide and the alcoholic solvent is carried out until a yield of about 75% of the desired ester is achieved. In some embodiments, mixing the polyester with the solvent to swell the polyester, the alkoxide and the alcoholic solvent is carried out until a yield of about 80% of the desired ester is achieved. In some embodiments, mixing the polyester with the solvent to swell the polyester, the alkoxide and the alcoholic solvent is carried out until a yield of about 85% of the desired ester is achieved. In some embodiments, mixing the polyester with the solvent to swell the polyester, the alkoxide and the alcoholic solvent is carried out until a yield of about 90% of the desired ester is achieved. In some embodiments, mixing the polyester with the solvent to swell the polyester, the alkoxide and the alcoholic solvent is carried out until a yield of about 95% of the desired ester is achieved.

[000137] In some embodiments, the mixture of the polyester with the solvent to swell the polyester, the alkoxide and the alcoholic solvent is carried out for about 10 minutes and 5 hours, or between about 10 minutes and 4 hours, or between about 10 minutes to 3 hours, or between about 10 minutes and 2 hours, or between about 20 minutes and 2 hours, or between about 30 minutes and 2 hours, or between about 40 minutes and 2 hours, or between about 30 minutes to 1 hour, or between about 30 minutes and 1.5 hours. In some embodiments, mixing the polyester with the solvent to swell the polyester, the alkoxide and the alcoholic solvent is carried out for about 10 minutes or about 15 minutes or about 20 minutes or about 25 minutes or about 30 minutes or about 35 minutes or about 40 minutes or about 45 minutes or about 50 minutes or about 60 minutes or about 70 minutes or about 80 minutes or about 90 minutes or about 100 minutes or about 110 minutes or about 120 minutes or about 130 minutes or about 140 minutes or about 150 minutes or about 160 minutes or about 170 minutes or about 180 minutes. In some embodiments, mixing the polyester with the solvent to swell the polyester, the alkoxide, and the alcoholic solvent is carried out for about 1 hour, or about 2 hours, or about 3 hours, about 4 hours, or about 5 hours. hours.

TEMPERATURE

[000138] A process for transforming a polyester into an ester derivative is described here; the process comprising mixing the polyester with a mixture comprising: (a) a solvent to swell the polyester; (b) an alcoholic solvent; and (c) a substoichiometric amount of an alkoxide.

[000139] In some embodiments, the process disclosed in this document is conducted at room temperature. In some embodiments, the ambient temperature is 25 ± 5 °C.

[000140] In some embodiments, the process disclosed in this document is conducted without external heat. In some embodiments, the process is exothermic and the temperature of the reaction mixture rises to at least 30°C, at least 35°C, at least 40°C, at least 45°C, at least 50°C, at least 55°C °C or at least 60 °C. In some embodiments, no external heat source is used to increase the temperature of the reaction mixture.

[000141] In some embodiments, the process disclosed in this document is conducted with external heat. In some embodiments, the process disclosed herein is conducted with external heat between about 25°C and about 100°C, or between about 25°C and about 85°C, or between about 25°C and about 80°C, or between about 25°C and about 60°C, or between about 40°C and about 60°C, or between about 40°C and about 50°C, or between about 30 °C and about 50 °C. In some embodiments, the process disclosed herein is conducted at about 26°C, about 27°C, about 28°C, about 29°C, about 30°C, about 31°C, about 32°C °C, around 33°C, around 34°C, around 35°C, around 36°C, around 37°C, around 38°C, around 39°C, around 40°C , about 41 °C, about 42 °C, about 43 °C, about 44 °C, about 45 °C, about 46 °C, about 47 °C, about 48 °C, about about 49 °C, about 50 °C, about 51 °C, about 52 °C, about 53 °C, about 54 °C, about 55 °C, about 56 °C, about 57 °C, around 58°C, around 59°C, around 60°C, around 61°C, around 62°C, around 63°C, around 64°C, around 65°C , about 66 °C, about 67 °C, about 68 °C, about 69 °C, about 70 °C, about 71 °C, about 72 °C, about 73 °C, about about 74°C, about 75°C, about 76°C, about 77°C, about 78°C, about 79°C, about 80°C, about 81°C, about 82 °C, around 83°C, around 84°C, around 85°C, around 86°C, around 87°C, around 88°C, around 89°C, around 90°C , about 91 °C, about 92 °C, about 93 °C, about 94 °C, about 95 °C, about 96 °C, about 97 °C, about 98 °C, about 99 °C, or about 100 °C.

PRESSURE

[000142] In some embodiments, the process disclosed in this document is conducted at atmospheric pressure. In some embodiments, the process disclosed herein is conducted at elevated pressures. In some embodiments, the process disclosed herein is conducted at a pressure between about atmospheric pressure and about 220 psi, or between about atmospheric pressure and about 200 psi, or between about atmospheric pressure and about 150 psi. , or between about atmospheric pressure and about 100 psi, or between about atmospheric pressure and about 50 psi, or between about 20 and about 150 psi, or between about 50 and about 100 psi. In some embodiments, the process disclosed herein is conducted at about 14 psi, about 15 psi, about 16 psi, about 17 psi, about 18 psi, about 19 psi, about 20 psi, about 30 psi , about 40 psi, about 50 psi, about 60 psi, about 70 psi, about 80 psi, about 90 psi, about 100 psi, about 110 psi, about 120 psi, about 130 psi , about 140 psi, about 150 psi, about 160 psi, about 170 psi, about 180 psi, about 190 psi, about 200 psi, about 210 psi, or about 220 psi.

AGITATION

[000143] A process for transforming a polyester into an ester derivative is described here; the process comprising mixing the polyester with a mixture comprising: (a) a solvent to swell the polyester; (b) an alcoholic solvent; and (c) a substoichiometric amount of an alkoxide.

[000144] In some embodiments, the process disclosed in this document is conducted without agitation. In some embodiments, the process disclosed herein is conducted with increased agitation. In some embodiments, a stirred batch reactor is used to provide agitation. In some embodiments, a continuous reactor is used to provide agitation.

CERTAIN TERMINOLOGIES

[000145] Section titles used herein are for organizational purposes only and should not be construed as limiting the subject matter described.

[000146] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as is commonly understood to which the claimed object belongs. In the event that there are a plurality of definitions for the terms contained herein, those in this section shall prevail.

[000147] It should be understood that the general description and the detailed description are exemplary and explanatory only and are not restrictive to any claimed matter. In this order, the use of the singular includes the plural unless otherwise noted. It should be noted that, as used in the specification and accompanying claims, the singular forms "an", "an" and "the" include plural referents, unless the context clearly indicates otherwise. In this order, the use of "or" means "and/or" unless otherwise noted. Furthermore, the use of the term "including" as well as other forms such as "include", "includes" and "included" is not limiting.

[000148] Unless the context otherwise requires, throughout the specification and claims that follow, the word "comprises" and its variations, such as "comprises" and "comprising", are to be interpreted in an open and inclusive sense , i.e. as "including but not limited to". Furthermore, titles provided herein are for convenience only and do not interpret the scope or meaning of the claimed invention.

[000149] As used in this specification and the accompanying claims, the singular forms "a", "a" and "and/or" include plural referents, unless the content clearly indicates otherwise. It should also be noted that the term “or” is generally used in its meaning, including “and/or”, unless the content clearly indicates otherwise.

[000150] As used herein, the term "about" or "approximately" means within 10%, preferably within 10%, and most preferably within 5% of a given value or range.

[000151] As used here, ambient temperature is a colloquial expression for the typical or preferred indoor temperature (climate) to which people are generally accustomed. It represents the small range of temperatures at which the air feels neither hot nor cold, around 21°C. In some embodiments, the ambient temperature is 25 ± 5 ºC. In some embodiments, the ambient temperature is 18 °C. In some embodiments, the ambient temperature is 19 °C. In some embodiments, the ambient temperature is 20 °C. In some embodiments, the ambient temperature is 21 °C. In some embodiments, the ambient temperature is 22°C. In some embodiments, the ambient temperature is 23°C. In some embodiments, the ambient temperature is 24 °C. In some embodiments, the ambient temperature is 25 °C. In some embodiments, the ambient temperature is 26 °C. In some embodiments, the ambient temperature is 27 °C. In some embodiments, the ambient temperature is 28 °C. In some embodiments, the ambient temperature is 29 °C. In some embodiments, the ambient temperature is 30 °C.

[000152] As used in this specification and the accompanying claims, depolymerization refers to a way of breaking down a polymer into its starting material. It is essentially the opposite of polymerization. In some embodiments, depolymerization is achieved by glycolysis, methanolysis, or hydrolysis, categorized by the depolymerization reagent used, such as glycol, methanol, or water, respectively.

[000153] The definition of standard chemical terms can be found in reference works including, but not limited to, Carey and Sundberg "Advanced Organic Chemistry 4th Ed." vols. A (2000) and B (2001), Plenum Press, New York.

[000154] The terms below, as used herein, have the following meanings, unless otherwise indicated.

[000155] "Alkyl" refers to a straight or branched hydrocarbon chain radical that is attached to the remainder of the molecule by a single bond. A linear alkyl comprising up to 4 carbon atoms is referred to as linear C1-C4 alkyl, likewise, for example, a linear alkyl comprising up to 3 carbon atoms is a linear C1-C3 alkyl. Linear alkyl groups include C1-C4 linear alkyl, C1-C3 linear alkyl, C1-C2 linear alkyl, C2-C3 linear alkyl, and C2-C4 linear alkyl. Representative alkyl groups include methyl, ethyl, propyl and butyl. A branched alkyl comprising between 3 and 4 carbon atoms is referred to as a branched C3-C4 alkyl. Representative branched alkyl groups include, but are not limited to, t-butyl, sec-butyl, isobutyl, and isopropyl. Unless otherwise specified in the specification, an alkyl is optionally substituted by oxo, halogen, -CN, -CF3, OH, -OMe, NH2 or -NO2. In some embodiments, an alkyl is optionally substituted by oxo, halogen, -CN, -CF3, OH, or -OMe. In some embodiments, the alkyl is optionally replaced with halogen.

[000156] "Halo" or "halogen" refers to bromine, chlorine, fluorine or iodine. In some embodiments, halogen is fluorine or chlorine. In some embodiments, halogen is fluorine.

[000157] "Haloalkyl" refers to an alkyl radical, as defined above, which is substituted by one or more halo atoms, as defined above, for example, trifluoromethyl, difluoromethyl, fluoromethyl, trichloromethyl, 2,2,2-trifluoroethyl , 1,2-difluoroethyl, 3-bromo-2-fluoropropyl, 1,2-dibromoethyl and the like.

[000158] "Hydroxyalkyl" refers to an alkyl radical, as defined above, which is substituted by one or more -OH groups, for example, hydroxymethyl, hydroxyethyl, hydroxypropyl, propanediol and the like.

[000159] "Cycloalkyl" refers to a stable, partially or fully saturated monocyclic or polycyclic carbocyclic ring, which may include fused or bridged ring systems. Representative cycloalkyls include, but are not limited to, cycloalkyls having three to fifteen carbon atoms (C3-C15 cycloalkyl), three to ten carbon atoms (C3-C10 cycloalkyl), three to eight carbon atoms (C3-C10 cycloalkyl C8), three to six carbon atoms (C3-C6 cycloalkyl), three to five carbon atoms (C3-C5 cycloalkyl) or three to four carbon atoms (C3-C4 cycloalkyl). In some embodiments, the cycloalkyl is a 3- to 6-membered cycloalkyl. In some embodiments, the cycloalkyl is a 5- to 6-membered cycloalkyl. Monocyclic cycloalkyls include, for example, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl and cyclooctyl. Cycloalkyls or polycyclic carbocycles include, for example, adamantyl, norbornyl, decalinyl, bicyclo[3.3.0]octane, bicyclo[4.3.0]nonane, cis-decalin, trans-decalin, bicyclo[2.1.1]hexane, bicyclo[2.2 .1] heptane, bicyclo[2.2.2]octane, bicyclo[3.2.2]nonane and bicyclo[3.3.2]decane and 7,7-dimethylbicyclo[2.2.1]heptanyl. Partially saturated cycloalkyls include, for example, cyclopentenyl, cyclohexenyl, cycloheptenyl and cyclooctenyl. Unless otherwise specifically stated in the specification, a cycloalkyl is optionally substituted by oxo, halogen, methyl, ethyl, -CN, -CF3, OH, -OMe, NH2 or -NO2. In some embodiments, a cycloalkyl is optionally substituted with oxo, halogen, methyl, ethyl, -CN, -CF3, OH, or -OMe. In some embodiments, the cycloalkyl is optionally substituted with halogen.

[000160] "Aryl" refers to a radical derived from a hydrocarbon ring system comprising hydrogen, 6 to 30 carbon atoms and at least one aromatic ring. The aryl radical may be a monocyclic, bicyclic, tricyclic or tetracyclic ring system, which may include fused or bridged ring systems. In some embodiments, the aryl is a 6- to 10-membered aryl. In some embodiments, the aryl is a 6-membered aryl. Aryl radicals include, but are not limited to, aryl radicals derived from the anthrylene, naphthylene, phenanthrylene, anthracene, azulene, benzene, chrysene, fluoranthene, fluorene, as-indacene, s-indacene, indane, indene hydrocarbon ring systems , naphthalene, phenalene, phenanthrene, pleiadene, pyrene and triphenylene. In some embodiments, the aryl is phenyl. Unless otherwise specifically stated in the specification, an aryl may optionally be substituted, for example, by halogen, amino, nitrile, nitro, hydroxyl, alkyl, alkenyl, alkynyl, haloalkyl, alkoxy, aryl, cycloalkyl, heterocycloalkyl, heteroaryl and the like. In some embodiments, an aryl is optionally substituted with halogen, methyl, ethyl, -CN, -CF3, OH, -OMe, NH2, or -NO2. In some embodiments, an aryl is optionally replaced by halogen, methyl, ethyl, -CN, -CF3, OH, or -OMe. In some embodiments, the aryl is optionally replaced with halogen.

[000161] As used herein, the term "mol" when referring to PET is the molar amount and is calculated using the molecular weight of the "PET" unit which is 192.17 g/mol.

EXAMPLES

[000162] The following examples are intended to illustrate, but not limit, the disclosed embodiments.

Example 1:

[000163] Polyethylene terephthalate (1000 g) was introduced into a reactor. Dichloromethane (500g) was added and the mixture was stirred at room temperature and atmospheric pressure for about 40 minutes. Sodium methoxide and methanol were then added to the reaction mixture, the mixture was stirred and heated for 120 minutes (see table below for amounts, time and temperature details).

[000164] The reaction mixture was then filtered and the filter cake was washed with methanol. The filter cake was then melted and filtered at 140°C to remove any unreacted materials. The filtered dimethyl terephthalate was then vacuum distilled at 200°C. The liquid recovered from the filtration was distilled to recover solvents and monoethylene glycol.

Example 2:

[000165] Polyethylene terephthalate (1000 g) was introduced into a reactor. DMSO (500 g) was added and the mixture was stirred at room temperature and atmospheric pressure for about 40 minutes. Sodium methoxide (45g) and methanol (550g) were then added to the reaction mixture, stirred and heated at 55 °C for 120 minutes.

[000166] The reaction mixture was then filtered and the filter cake was washed with methanol. The filter cake was then melted and filtered at 140°C to remove any unreacted materials. The filtered dimethyl terephthalate was then vacuum distilled at 200°C. The liquid recovered from the filtration was distilled to recover solvents and monoethylene glycol.

[000167] Dimethyl terephthalate was obtained with a yield of 89%.

Example 3:

[000168] The PET (10000 g) was treated with methanol (6000 g) at 60 °C for one hour. The methanol was then drained off. After draining, the reactor was heated from 60°C to 70°C and sodium methoxide (25% methanol by weight) was added. Thirty minutes after adding sodium methoxide, the balance of methanol was added. The reaction was stopped 3 hours after adding sodium methoxide. The reaction mixture was cooled to room temperature and then filtered to separate MEG, sodium methoxide and residual methanol from DMT and unreacted material. Filtration worked in tests 3 to 5, while tests 1 and 2 were not filtered, even with the use of different methods of separation of liquids and solids (centrifugation, filter press, vacuum filter or pressure filter). Since filtration was not possible, distillation of methanol was attempted, followed by distillation of MEG and then distillation of DMT from the reaction mixture on a rotary evaporator. After methanol recovery, the reaction mixture turned into a paste from which MEG and DMT distillation was not possible due to side reactions with contaminants.

[000169] For tests 3 to 5, after solid-liquid separation. Residual methanol and MEG were recovered from the liquid phase in two different fractions using a rotary evaporator. DMT was successfully recovered from the solid phase using a thin film evaporator.

[000170] The table below shows the recovery of DMT and MEG with varying amounts of sodium methoxide. 1 dimethyl terephthalate 2 monoethylene glycol 3 The slurry was heated to try to evaporate the DMT and MEG, but it was not possible due to the generation of mixed products with all the contaminants. 4 Pure DMT was recovered from the cake free of MEG and catalyst. Pure MEG was recovered from mother liquor and washes containing less than 1% DMT.

Claims (10)

1. Process for transforming a polyester selected from polyethylene terephthalate and poly (ethylene glycol-co-1,4-cyclohexanedimethanol terephthalate) into dimethyl terephthalate, the process characterized in that it comprises mixing the polyester with a mixture that comprises: (a) methanol; and (b) a substoichiometric amount of an alkoxide; wherein the process is carried out at a temperature between 25°C and 80°C; wherein the polyester to alkoxide ratio is between 20:1 and 50:1 (w/w); and wherein the process achieves at least 70% yield of dimethyl terephthalate. 2. Process according to claim 1, characterized in that the alkoxide is selected from the group consisting of an alkali metal alkoxide, an alkaline earth metal alkoxide, a metal alkoxide and an ammonium alkoxide, or any combination thereof. 3. Process according to claim 1, characterized in that the alkoxide is selected from the group consisting of sodium methoxide, potassium ethoxide, aluminum tri-n-propoxide and tetrabutylammonium methoxide. 4. Process according to claim 1, characterized in that the alkoxide is sodium methoxide. 5. Process according to claim 1, characterized in that the alkoxide is generated in situ by adding an alkali metal, an alkaline earth metal or a metal to methanol. 6. Process, according to claim 1, characterized by the fact that the ratio of polyester to alkoxide is between 20:1 and 25:1 (w/w). 7. Process according to claim 1, characterized in that the process reaches at least 80% yield of dimethyl terephthalate. 8. Process according to claim 1, characterized in that the process reaches at least 90% yield of dimethyl terephthalate. 9. Process according to claim 1, characterized in that the process reaches at least 95% yield of dimethyl terephthalate. 10. Process according to claim 1, characterized in that the process is carried out at atmospheric pressure.