Titanium complexes, methods of preparation and uses thereof

Abstract

The present invention relates to a titanium complex having an empirical Formula (I): Ti(glycerol)a(X)b Formula (I) where X is a di-, or tri- alkanolamine, or a mixture thereof; and wherein a is a numb

Description

[0001] TITANIUM COMPLEXES, METHODS OF PREPARATION AND USES THEREOF

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to organo-metallic titanium complexes including glycerol as a ligand, in particular titanium complexes with glycerol and at least one di- or trialkanolamine as ligands. The present invention further relates to compositions including the titanium complexes, methods of making such complexes, and uses thereof, in particular uses as catalysts and cross linkers in a variety of industrial applications.

[0004] BACKGROUND OF THE INVENTION

[0005] Organic compounds or complexes of titanium are well known for use as:

[0006] (i) catalysts, e.g., for catalysing esterification and polyurethane reactions;

[0007] (ii) cross-linkers, e.g., for coatings and well fracturing fluids; and

[0008] (iii) adhesion promoting compounds for printing inks.

[0009] The reactivity of titanium complexes makes them suitable for the production of polyesters such as polybutylene terephthalate. However, due to their high reactivity, titanium complexes commonly form polychrome linkages, which can lead to yellow discolouration of the final products.

[0010] Additionally, titanium complexes commonly used as catalysts are not water stable and can lead to polyesters with low thermal stability, and catalyst present within the final product. Attempts have been made in the prior art to overcome the lack of water stability of titanium complexes, for example, by attempting to stabilise the titanium with a hydroxy acid or citrate ligands. However, the resultant titanium complexes have not been truly water stable and have either yellowed overtime to result in a yellowed polymer or have resulted in polymer products with poor thermal stability. Both outcomes are due to water damage. Reversal of the water damage of titanium has also been attempted, but has so far been unsuccessful. It is therefore desirable to provide novel titanium complexes which are stable in water. It is also desirable to provide novel titanium complexes which are stable in water and active as catalysts under appropriate conditions.

[0011] SUMMARY OF THE INVENTION

[0012] At its most general, the present invention provides a titanium complex including at least one glycerol ligand and at least one alkanolamine ligand. Typically, the at least one alkanolamine ligand is selected from a di- or tri- alkanolamine.

[0013] In a first aspect, the present invention provides a titanium complex having an empirical formula (I):

[0014] Ti(glycerol)a(X)b Formula (I) where X is a di-, or tri- alkanolamine, or a mixture thereof; and wherein a is a number > 1 ; and b is a number > 1.

[0015] The present inventors surprisingly found that titanium complexes with ligands of glycerol and at least one alkanolamine may provide certain advantages, such as an improved water stability compared to conventional titanium complexes. The present inventors found that the titanium complex of Formula (I) is particularly useful as a water stable catalyst and cross-linker, as the complexes can be handled as liquids or in solution without degradation of catalytic activity due to water damage. Water being available as a solvent for a chemical reaction provides significant environmental benefits over complexes and catalysts that are unstable in water. Furthermore, if water or alcohol are produced during the chemical reaction, or if trace water or alcohol are present during the chemical reaction, for example from solvent, reactants, or from the atmosphere in which the reaction is carried out, the reaction may proceed without the risk of unwanted hydrolysis of the complex. Recovery of the complex may also be improved due to the water-stable nature, as it may be separated from the reaction mixture and / or product more easily, and then reused, this may be particularly beneficial when the complex is used as a catalyst.

[0016] In a second aspect, the present invention provides a composition comprising the titanium complex of the first aspect and a solvent and / or diluent. In a third aspect, the present invention provides the use of a complex having an empirical Formula (I):

[0017] Ti(glycerol)a(X)b Formula (I) where X is a di-, or tri- alkanolamine, or a mixture thereof; and wherein a is a number > 1 ; and b is a number > 1 , as a catalyst in a chemical reaction.

[0018] In a fourth aspect, the present invention provides a method of catalysing a chemical reaction using a complex having an empirical Formula (I):

[0019] Ti(glycerol)a(X)b Formula (I) where X is a di-, tri- alkanolamine, or a mixture thereof; and wherein a is a number > 1 ; and b is a number > 1.

[0020] In a fifth aspect, the present invention provides a method of synthesising a complex having an empirical Formula (I):

[0021] Ti(glycerol)a(X)b Formula (I) where X is a di-, tri- alkanolamine, or a mixture thereof; and wherein a is a number > 1 ; and b is a number > 1 , the method comprising the steps of: a) mixing together glycerol, X and a titanium starting material to form a reaction mixture; and then b) reacting the reaction mixture to synthesise the complex of Formula (I).

[0022] Certain embodiments of the present invention may provide one or more of the following advantages:

[0023] • desired water stability;

[0024] • desired ease of synthesis;

[0025] • desired biodegradability of ligands;

[0026] • desired non-acidic pH;

[0027] • reduction in yellowing reactions of impurities in commercially used alcohols.

[0028] The details, examples and preferences provided in relation to any particular one or more of the stated aspects of the present invention apply equally to all aspects of the present invention. Any combination of the embodiments, examples and preferences described herein, and all possible variations thereof is encompassed by the present invention unless otherwise indicated herein, or otherwise clearly contradicted by context.

[0029] DETAILED DESCRIPTION

[0030] The present invention is based on the surprising finding that titanium complexes including glycerol and at least one alkanolamine as ligands provide water stable catalysts.

[0031] When ranges are used herein, all combinations and sub-combinations of ranges and specific embodiments therein are intended to be included.

[0032] As used herein, the term "about" when referring to a number or a numerical range means that the number or numerical range referred to is an approximation within experimental variability (or within statistical experimental error), and thus the number or numerical range may vary.

[0033] As used herein, the term "comprising" (and related terms such as "comprise" or "comprises" or "having" or "including") has an open meaning and therefore a composition comprising described features may comprise additional components in addition to the described features.

[0034] Abbreviations used herein have their conventional meaning within the chemical and biological arts, unless otherwise indicated.

[0035] The features described below may be included in any one of the first to fifth aspects of the present invention as appropriate.

[0036] The present invention provides a titanium complex having an empirical formula (I): Ti(glycerol)a(X)b Formula (I) where X is a di-, tri- alkanolamine, or a mixture thereof; and wherein a is a number > 1 ; and b is a number > 1. Titanium

[0037] The titanium included in the titanium complex is typically Ti(IV). In other words, the titanium is in a +4 oxidation state.

[0038] The titanium complex may have a titanium content in the range of about 2.5 wt.% to about 20 wt.% based upon the total weight of the complex. For example, in some embodiments, the titanium complex may have a titanium content in the range of about 5 wt.% to about 18 wt.%, or in the range of about 7 wt.% to about 17 wt.%. based upon the total weight of the complex.

[0039] Glycerol

[0040] In the empirical formula Ti(glycerol)a(X)b, (glycerol) is used to denote the ligand derived from glycerol. The glycerol ligand typically has the formula (CH2OHCH(OH)CH2O)'. a Value a is a number > 1. As the complex is defined by an empirical formula, the number a is not limited to integers. In some embodiments, a is a number between about 1 and 3. In some embodiments, a is about 1 (e.g., in a range of 0.9 to 1.1 , or 0.95 to 1.05, or 1.0). In some embodiments, a is about 2 (e.g., in a range of 1.9 to 2.1 , or 1.95 to 2.05, or 2.0). In some embodiments, a is about 3 (e.g., in a range of 2.9 to 3.1 , or 2.95 to 3.05, or 3.0).

[0041] When > 1 , the resulting titanium complex may be stable in water and can be dehydrated and rehydrated to form a stable aqueous solution. When a <1 , it is believed that the resulting titanium complex may be stable in water under ambient conditions, but if water is removed to dryness, rehydration is unsuccessful, and as such, a titanium complex where a<1 is not considered truly water stable.

[0042] It should be noted that excess glycerol may be present within the titanium complex. In these circumstances, any uncoordinated glycerol may function as diluent.

[0043] Ligand X

[0044] The ligand X is a di-, or tri- alkanolamine, or a mixture thereof. In other words, the titanium complex of formula (I) may include a first di- or tri- alkanolamine (Xi), and Xi is the sole di- or tri- alkanolamine. Alternatively, the titanium complex of formula (I) may contain a first di- or tri- alkanolamine (Xi) and one or more subsequent first di- or tri- alkanolamines. Where the titanium complex includes more than one di- or tri- alkanolamine, the value of b applies to total amount of first di- or tri- alkanolamine.

[0045] In particular embodiments, the ligand X is a di- or tri-Ci-salkanolamine, or a mixture thereof. Non-limiting examples of di-Ci-3alkanolamines include dimethanolamine, diethanolamine and diisopropanolamine. Non-limiting examples of tri-Ci-3alkanolamines include trimethanolamine, triethanolamine (TEA) and triisopropanolamine.

[0046] In some embodiments, X is selected from the group consisting of triethanolamine, diethanolamine, triisopropanolamine and mixtures thereof. b Value b is a number > 1. As the complex is defined by an empirical formula, the number b is not limited to integers. In some embodiments, b is a number between about 1 and about 3. In some embodiments, b is about 1 (e.g., in a range of 0.9 to 1.1 , or 0.95 to 1.05, or 1.0). In some embodiments, b is about 2 (e.g., in a range of 1.9 to 2.1 , or 1.95 to 2.05, or 2.0). In some embodiments, b is about 3 (e.g., in a range of 2.9 to 3.1 , or 2.95 to 3.05, or 3.0).

[0047] When b is a number > 1 the resulting titanium complex is stable in water and can be dehydrated and rehydrated to form a stable aqueous solution. When b <1 but > 0, the resulting complex may be stable in water under ambient conditions, but if water is removed to dryness, the rehydration of the titanium complex may be unsuccessful, and as such, the titanium complex is not truly water stable. When b = 0, an insoluble solid may form.

[0048] It should be noted that excess alkanolamine may be present with the titanium complex. In these circumstances, any uncoordinated alkanolamine may function as diluent. a plus b Value

[0049] In some embodiments, a plus b equals a number between about 2 (e.g., in a range of 1.9 to 2.1 , or 1.95 to 2.05, or 2.0) and about 4 (e.g., in a range of 3.9 to 4.1 , or 3.95 to 4.05, or 4.0). In particular embodiments, a plus b equals about 2 (e.g., in a range of 1 .9 to 2.1 , or 1.95 to 2.05, or 2.0), about 3 (e.g., in a range of 2.9 to 3.1 , or 2.95 to 3.05, or 3.0) or about 4 (e.g., in a range of 3.9 to 4.1 , or 3.95 to 4.05, or 4.0). In particular embodiments, a plus b equals about 2 (e.g., in a range of 1.9 to 2.1 , or 1.95 to 2.05, or 2.0) or about 3 (e.g., in a range of 2.9 to 3.1 , or 2.95 to 3.05, or 3.0).

[0050] In some embodiments, a plus b equals about 2 (e.g., in a range of 1.9 to 2.1 , or 1.95 to 2.05, or 2.0). In some embodiments, a plus b equals about 3 (e.g., in a range of 2.9 to 3.1 , or 2.95 to 3.05, or 3.0). In some embodiments, a plus b equals about 4 (e.g., in a range of 3.9 to 4.1 , or 3.95 to 4.05, or 4.0). In some embodiments, a is greater than b. In some embodiments, a is equal to b. In other embodiments, b is greater than a.

[0051] When a plus b equals a number in the range of about 2 to about 4, the resulting titanium complex is stable in water and can be dehydrated and rehydrated to form a stable aqueous solution. When a plus b equals < 2, either an insoluble solid forms, or the resulting titanium complex may be stable in water under ambient conditions, but if water is removed to dryness, the rehydration of the titanium complex may be unsuccessful, and as such, the titanium complex is not truly water stable.

[0052] X, a and / or b values

[0053] In a particular embodiment, where the alkanolamine is a di- or tri- alkanolamine, b is equal to about 1 (e.g., in a range of 0.9 to 1.1 , or 0.95 to 1.05, or 1.0). In some embodiments, where the alkanolamine is a di- or tri- alkanolamine, a is equal to about 1 (e.g., in a range of 0.9 to 1.1 , or 0.95 to 1.05, or 1.0), and b is equal to about 1 (e.g., in a range of 0.9 to 1.1 , or 0.95 to 1.05, or 1.0). In particular embodiments, where the alkanolamine is diethanolamine, a is equal to about 1 (e.g., in a range of 0.9 to 1.1 , or 0.95 to 1.05, or 1.0), and b is equal to about 1 (e.g., in a range of 0.9 to 1.1 , or 0.95 to 1.05, or 1 .0). In particular embodiments, where the alkanolamine is triethanolamine, a is equal to about 1 (e.g., in a range of 0.9 to 1.1 , or 0.95 to 1.05, or 1.0), and b is equal to about 1 (e.g., in a range of 0.9 to 1.1 , or 0.95 to 1.05, or 1.0).

[0054] In some embodiments, where the alkanolamine is a di- or tri- alkanolamine, a is equal to about 1 (e.g., in a range of 0.9 to 1.1 , or 0.95 to 1.05, or 1.0), and b is equal to about 2 (e.g., in a range of 1.9 to 2.1 , or 1.95 to 2.05, or 2.0). In particular embodiments, where the alkanolamine is triethanolamine, a is equal to about 1 (e.g., in a range of 0.9 to 1.1, or 0.95 to 1.05, or 1.0), and b is equal to about 2 (e.g., in a range of 1.9 to 2.1 , or 1.95 to 2.05, or 2.0).

[0055] In some embodiments, where the alkanolamine is a di- or tri- alkanolamine, a is equal to about 2 (e.g., in a range of 1.9 to 2.1 , or 1.95 to 2.05, or 2.0), and b is equal to about 1 (e.g., in a range of 0.9 to 1.1 , or 0.95 to 1.05, or 1.0). In particular embodiments, where the alkanolamine is triethanolamine, a is equal to 2 (e.g., in a range of 1.9 to 2.1 , or 1.95 to 2.05, or 2.0), and b is equal to about 1 (e.g., in a range of 0.9 to 1.1 , or 0.95 to 1.05, or 1.0).

[0056] In some embodiments, where the alkanolamine is a di- or tri- alkanolamine, a is equal to about 2 (e.g., in a range of 1.9 to 2.1 , or 1.95 to 2.05, or 2.0), and b is equal to about 2 (e.g., in a range of 1.9 to 2.1 , or 1.95 to 2.05, or 2.0). In particular embodiments, where the alkanolamine is triethanolamine, a is equal to about 2 (e.g., in a range of 1.9 to 2.1, or 1.95 to 2.05, or 2.0), and b is equal to 2 (e.g., in a range of 1.9 to 2.1 , or 1.95 to 2.05, or 2.0).

[0057] Water Stability

[0058] The complex is typically water stable. The term “water stable” as defined herein refers to a complex in which 0.5 g of the complex is dissolved in 10 g of deionised water and the solution does not result in haziness or the formation of particulates. The term describes solutions which remain substantially clear after 0.5 g of the complex is dissolved in 10 g of deionised water. Solutions which form white haze or particulates are not considered water stable, as defined herein.

[0059] In some embodiments, the complex is additionally water stable after the dissolved complex described above is dehydrated and re-dissolved or re-hydrated with 10 g of water. In other words, 0.5 g the complex may be added to 10 g of deionised water to form a first solution that does not result in haziness or the formation of particulates, and further the resulting solution is dehydrated (e.g. by heating under reduced pressure) and rehydrated in 10 g of deionised water to form a subsequent solution that also does not result in haziness or the formation of particulates. The first solution may be dehydrated by heating to a temperature in the range of about 100 to about 150 °C to remove water. For example, the first solution may be heated to a temperature of about 110 °C, of about 120 °C, of about 130 °C, or of about 140 °C. pH of the complex

[0060] The pH of the complex may be non-acidic. In other words, the complex may have a pH of at least about 7. Complexes with an acidic pH may cause polymer processing problems.

[0061] In some embodiments, the pH is about 7.0 or greater, about 7.5 or greater, about 8.0 or greater, about 9.0 or greater or about 10.0 or greater. The pH may be in the range of about 6.5 to about 11.0, for example, about 7.0 to about 10, or about 8.0 to about 9.0.

[0062] Biodegradable

[0063] Glycerol is biodegradable. In particular embodiments, X is biodegradable. Where X is more than one alkanolamine, all species of X may be biodegradable. In some embodiments, the complex is biodegradable. The term "biodegradable" pertains to a ligand and / or complex in which the degradation results from the action of naturally occurring microorganisms such as bacteria, fungi, and algae.

[0064] Compositions

[0065] The complex of the present invention may be supplied as a neat (undiluted) or solid substance. This may be particularly common when the complex is a liquid.

[0066] In an aspect, the present invention provides a composition comprising the complex and a solvent and / or diluent. In some embodiments, the solvent and / or diluent may be up to about 90 wt.% of the total composition. In some embodiments, the solvent and / or diluent may be up to about 75 wt.% of the total composition, about 50 wt.% of the total composition, or about 25 wt.% of the total composition.

[0067] The solvent and / or diluent may comprise water, an alcohol, diol or polyol, or another protic solvent.

[0068] In some embodiments, the solvent and / or diluent may comprise excess di- or trialkanolamine, and / or excess glycerol. In some embodiments, the solvent and / or diluent may act as a spectator ligand in the titanium complex.

[0069] The pH of the composition may be non-acidic. In other words, the composition may have a pH of at least about 7. Compositions with an acidic pH may cause polymer processing problems.

[0070] In some embodiments, the pH is about 7.0 or greater, about 7.5 or greater, about 8.0 or greater, about 9.0 or greater or about 10.0 or greater. The pH may be in the range of about 6.5 to about 11.0, for example, about 7.0 to about 10, or about 8.0 to about 9.0.

[0071] In particular embodiments, the pH of the composition is the same as the pH of the complex. In particular embodiments, the solvent and / or diluent within the composition may maintain the pH of the complex.

[0072] Use of complex as a catalyst and method of catalysing chemical reaction with complex The present disclosure includes a use of a titanium complex having an empirical formula (I):

[0073] Ti(glycerol)a(X)b Formula (I) where X is a di- or tri- alkanolamine, or a mixture thereof; and wherein a is a number

[0074] > 1 ; and b is a number > 1 , as a catalyst in a chemical reaction.

[0075] The present disclosure includes a method of catalysing a chemical reaction using a complex having an empirical formula (I):

[0076] Ti(glycerol)a(X)b Formula (I) where X is a di- or tri- alkanolamine, or a mixture thereof; and wherein a is a number

[0077] > 1 ; and b is a number > 1 , as a catalyst in a chemical reaction. In some embodiments, the chemical reaction comprises the formation of one or more single or multiple bonds between carbon and oxygen and / or oxygen and hydrogen and / or carbon and carbon, and / or carbon and nitrogen.

[0078] The chemical reaction may be a polymerisation reaction. In some embodiments, the titanium complex is used to catalyse a chemical reaction resulting in a biodegradable polymer.

[0079] In some embodiments, the chemical reaction is a polyester reaction (e.g., by reacting an acid or anhydride with an alcohol in the presence of the complex). In particular embodiments, the titanium complex is used to catalyse a chemical reaction to produce a polyurethane (Pll) (e.g., by reacting a polyisocyanate with a polyol in the presence of the complex). In more particular embodiments, the titanium complex is used to catalyse a chemical reaction to produce poly(butylene adipate-co-terephthalate) (PBAT) (e.g., by reacting terephthalic acid (TPA), 1 ,4-butanediol, and adipic acid in the presence of the complex).

[0080] The chemical reaction may be an esterification reaction. In some embodiments, the esterification reaction may be a direct esterification reaction, where an ester is formed from the reaction of two reactants, for example, an alcohol and an acid / anhydride. In some embodiments, the esterification reaction may be transesterification, where an ester is reacted with an alcohol to change one ester into another, for example for degrading triglycerides.

[0081] In some embodiments, the complex is added before or during the chemical reaction, i.e., added to the starting materials or during the reaction of the starting materials.

[0082] In some embodiments, the titanium complex is added to the chemical reaction in an amount resulting in a titanium content, based on the weight of ester, in the range of from about 0.5 to about 550 ppm, preferably from about 1 to about 500 ppm, most preferably from about 5 to about 250 ppm.

[0083] In some embodiments, the reaction using the titanium complex has a % conversion in the range of about 80.0% to about 99.9%, for example, from about 85.0% to about 98.5%, from about 90.0% to about 98.0%, from about 92.5% to about 97.5%, or from about 95.0% to about 97.0%.

[0084] In some embodiments, the complex or composition may be used to prepare a catalyst mixture. In some embodiments, the titanium complex or composition disclosed herein may be mixed with 1 ,2-ethylene glycol or 1 ,4, -butanediol to form a catalyst mixture.

[0085] In some embodiments, where the titanium complex or composition disclosed herein is mixed with 1 ,2-ethylene glycol to form a catalyst mixture, the titanium complex is added to the chemical reaction in an amount resulting in a titanium content, based on the weight of ester, in the range of from about 0.5 to about 25 ppm, preferably from about 1 to about 20 ppm.

[0086] In some embodiments, where the titanium complex or composition disclosed herein is mixed with 1 ,4, -butanediol to form a catalyst mixture, the titanium complex is added to the chemical reaction in an amount resulting in a titanium content, based on the weight of ester, in the range of from about 25 to about 550 ppm, preferably from about 50 to about 500 ppm, for example, from about 80 to about 250 ppm.

[0087] Method of Synthesising the Complex

[0088] The present disclosure includes a method of synthesising a titanium complex having an empirical formula (I):

[0089] Ti(glycerol)a(X)b Formula (I) where X is a di- or tri- alkanolamine, or a mixture thereof; and wherein a is a number > 1 ; and b is a number > 1 , as a catalyst in a chemical reaction, the method comprising the steps of: a) mixing together glycerol, X and a titanium starting material to form a reaction mixture; and then b) reacting the reaction mixture to synthesise the complex of Formula (I). In some embodiments, the method comprises: i. mixing glycerol and X together to form a mixture, and adding a titanium starting material to said mixture; or ii. mixing glycerol and X together to form a mixture and adding said mixture to a titanium starting material; or iii. mixing X and a titanium starting material together and then adding glycerol to said mixture.

[0090] The glycerol / X / titanium starting material may be mixed together with stirring.

[0091] The titanium starting material is capable of reacting with at least one of the hydroxyl groups present in glycerol to form a titanium-oxygen bond. In some embodiments, the titanium starting material is selected from the group consisting of titanium halides, titanium alkoxides, titanium halo-alkoxides, titanium carboxylates and combinations thereof.

[0092] In some embodiments, the titanium starting material is a titanium alkoxide having the general formula Ti(OR)4, where R is a substituted or unsubstituted, cyclic or linear, alkyl, alkenyl, aryl or alkyl-aryl group or mixtures thereof. In some embodiments, R contains up to 8 carbon atoms. In preferred embodiments, R contains up to 6 carbon atoms.

[0093] In some embodiments, all of the OR groups are identical. In embodiments, however, alkoxides derived from a mixture of alcohols may be used. In some embodiments, a mixture of alkoxides may be used.

[0094] In particular embodiments, R is an alkyl group, preferably having from 1 to 8 carbon atoms. Each R group may be the same as or different from the other R groups.

[0095] In some embodiments, the titanium starting material is selected from the group consisting of titanium tetrachloride, titanium tetra-isopropoxide, titanium tetra-n-propoxide, titanium tetra-n-butoxide, and titanium tetra-ethoxide (tetraethyl titanate). In some embodiments, the method of synthesising the titanium complex having an empirical formula (I) further may comprise the presence of a suitable solvent, if required. Examples of suitable solvents include, alcohols, glycols. Exemplary glycols include 1 ,2- ethylene glycol and 1 ,4, -butanediol.

[0096] In some embodiments, the reactants (the glycerol, titanium starting material, X and optionally solvent and / or diluent) may be heated or cooled if required. In some embodiments, the temperature of the reaction may be controlled by the rate of addition of the reactants. In some embodiments, the temperature of the reaction may be controlled by cooling the mixture. In some embodiments, the temperature of the reaction may be controlled by heating the mixture.

[0097] In some embodiments, the rate of addition of the ligand, or of the glycerol and X mixture, to the titanium starting material is controlled such that the temperature of the reaction does not exceed about 85 °C , for example, such that the temperature of the reaction does not exceed about 80 °C, such that the temperature of the reaction does not exceed about 75 °C, such that the temperature of the reaction does not exceed about 70 °C, or such that the temperature of the reaction does not exceed about 65 °C.

[0098] In some embodiments, the rate of addition the titanium starting material to X, or to the glycerol and X mixture, is controlled such that the temperature of the reaction does not exceed about 85 °C, for example, such that the temperature of the reaction does not exceed about 80 °C, such that the temperature of the reaction does not exceed about 75 °C, such that the temperature of the reaction does not exceed about 70 °C, or such that the temperature of the reaction does not exceed about 65 °C.

[0099] In some embodiments, wherein the titanium starting material is titanium isopropoxide, the rate of addition of the titanium isopropoxide to X, or to the glycerol and X mixture is controlled such that the temperature of the reaction does not exceed about 70 °C.

[0100] In some embodiments, wherein the titanium starting material is titanium isopropoxide, the rate of addition of X, or of glycerol and X mixture, to the titanium isopropoxide is controlled such that the temperature of the reaction does not exceed about 70 °C. In some embodiments, the method of synthesising the titanium complex having an empirical formula (I) further comprises the step of adding water to the reaction mixture formed by step i). In some embodiments, the water is added with stirring. In some embodiments, the water is added before the removal of any co-product(s).

[0101] In some embodiments, part or all of the co-product(s) resulting from the synthesis may be removed from the reaction mixture by suitable means such as distillation, evaporation, or other separation means depending on the nature of the co-product(s). In some embodiments, the co-product may be an alcohol when a titanium alkoxide is used as the titanium starting material. In some embodiments, the co-product may be a hydrogen halide when a titanium halide is used as the titanium starting material. Alternatively, the co-product may be retained in the final product, if desired.

[0102] In some embodiments, the method of synthesising the titanium complex having an empirical formula (I) further comprises placing the reaction mixture formed by step i) under reduced pressure. In some embodiments, the method of synthesising the titanium complex having an empirical formula (I) further comprises placing the reaction mixture formed by step i) under reduced pressure whilst heating the reaction mixture. For example, the reaction mixture may be heated to about 120 °C, for example, about 110 °C, about 100 °C or about 90 °C.

[0103] In some embodiments, where the titanium starting material is titanium isopropoxide, isopropanol may be removed from the reaction mixture formed by step i) by placing it under reduced pressure and heating the reaction mixture. For example, the reaction may be heated to about 120 °C, for example, about 110 °C, about 100 °C or about 90 °C.

[0104] In some embodiments, ambient pressure distillation may be used to remove solvent and / or excess ligand and / or co-product(s).

[0105] In some embodiments, where water has been added to the reaction mixture formed by step a), b) or c), water is removed from the reaction mixture under ambient pressure distillation. In some embodiments, the distillation head temperature is about 120 °C, for example about 110 °C, about 100 °C, about 90 °C, about 80 °C or about 70 °C. In some embodiments, where the titanium starting material is titanium isopropoxide, and water has been added to the reaction mixture, both water and isopropanol are removed from the reaction mixture. In some embodiments, the removal of water and isopropanol is performed under ambient pressure distillation to a head temperature of about 100 °C.

[0106] Other Properties

[0107] In some embodiments, the titanium complex is free, or substantially free from isopropanol. The term “free, or substantially free from isopropanol” as used herein refers to compositions where isopropanol has been removed from the titanium complex. For example, “free, or substantially free from isopropanol” means that isopropanol is present in the composition in an amount of less than about 3.0 wt.%, or less than about 2.5 wt.%, or less than about 2.0 wt.%, or less than about 1.5 wt.%, or less than about 1.0 wt.%, or less than about 0.5 wt.%, or less than about 0.3 wt.%, or less than about 0.2 wt.%, or less than about 0.1 wt.%, or less than about 0.05 wt.%, or less than about 0.01 wt.%, or less than about 0.005 wt.% based on the total weight of the solid titanium complex.

[0108] EXAMPLES

[0109] The following non-limiting Examples are provided for further illustration of the present invention. Thus, these examples should not be considered to restrict the present disclosure, but are merely in place to teach how to carry out the processes and obtain the products of the present disclosure.

[0110] Materials and Methods

[0111] Commercial reagents were purchased from Alfa Aesar, Thermo Scientific and Merck and were used without further purification unless otherwise specified. All air and moisture sensitive manipulations were carried out using standard vacuum line and Schlenk techniques, or in a drybox containing a purified argon atmosphere. Solvents for air and moisture sensitive manipulations were either purchased from Alfa Aesar, Thermo Scientific and Merck or were distilled and dried over activated molecular sieves.

[0112] Example 1 - According to the invention

[0113] Triethanolamine (1 mole, 149.2 g) was added to glycerol (1 mole, 92.1 g) and stirred until well mixed. Titanium isopropoxide (1 mole, 284.2 g) was added slowly with the rate of addition controlled so that the reaction temperature did not exceed 70 °C. The mixture was stirred for an additional 15 minutes and then isopropanol (4 moles, 240.4 g) was removed under reduced pressure, heating the residual mixture to 120 °C and to constant weight to yield a pale yellow solid (Ti content 16.77% by weight).

[0114] Example 2 - According to the invention

[0115] Triethanolamine (2 mole, 298.4 g) was added to glycerol (1 mole, 92.1 g) and stirred until well mixed. Titanium isopropoxide (1 mole, 284.2 g) was added slowly with the rate of addition controlled so that the reaction temperature did not exceed 70 °C. The mixture was stirred for an additional 15 minutes and then isopropanol (4 moles, 240.4 g) was removed under reduced pressure, heating the residual mixture to 120 °C and to constant weight to yield a highly viscous yellow liquid (Ti content 11.01% by weight).

[0116] Example 3 - According to the invention

[0117] Triethanolamine (2 mole, 298.4 g) was added to glycerol (2 mole, 184.2 g) and stirred until well mixed. Titanium isopropoxide (1 mole, 284.2 g) was added slowly with the rate of addition controlled so that the reaction temperature did not exceed 70 °C. The mixture was stirred for an additional 15 minutes and then isopropanol (4 moles, 240.4 g) was removed under reduced pressure, heating the residual mixture to 120 °C and to constant weight to yield a highly viscous yellow liquid (Ti content 9.09 % by weight).

[0118] Example 4 - According to the invention

[0119] Triethanolamine (1 mole, 149.2 g) was added to glycerol (2 mole, 184.2 g) and stirred until well mixed. Titanium isopropoxide (1 mole, 284.2 g) was added slowly with the rate of addition controlled so that the reaction temperature did not exceed 70 °C. The mixture was stirred for an additional 15 minutes and then isopropanol (4 moles, 240.4 g) was removed under reduced pressure, heating the residual mixture to 120 °C and to constant weight to yield a highly viscous yellow liquid (Ti content 12.68 % by weight).

[0120] Example 5 - According to the invention

[0121] Triethanolamine (1 mole, 149.2 g) was added to glycerol (1 mole, 92.1 g) and stirred until well mixed. This mixture was added slowly to titanium isopropoxide (1 mole, 284.2 g) with the rate of addition controlled so that the reaction temperature did not exceed 70 °C. The mixture was stirred for an additional 15 minutes and then isopropanol (4 moles, 240.4 g) was removed under reduced pressure, heating the residual mixture to 120 °C and to constant weight to yield a pale yellow solid (Ti content 16.77% by weight).

[0122] Example 6 - According to the invention

[0123] Triethanolamine (2 mole, 298.4 g) was added to glycerol (1 mole, 92.1 g) and stirred until well mixed. This mixture was added slowly to titanium isopropoxide (1 mole, 284.2 g) with the rate of addition controlled so that the reaction temperature did not exceed 70 °C. The mixture was stirred for an additional 15 minutes and then isopropanol (4 moles, 240.4 g) was removed under reduced pressure, heating the residual mixture to 120 °C and to constant weight to yield a highly viscous yellow liquid (Ti content 11.01% by weight).

[0124] Example 7 - According to the invention

[0125] Triethanolamine (1 mole, 149.2 g) was added to titanium isopropoxide (1 mole, 284.2 g) with the rate of addition controlled so that the reaction temperature did not exceed 70 °C. Glycerol (1 mole, 92.1 g) was then added, and the mixture stirred for an additional 15 minutes. Isopropanol (4 moles, 240.4 g) was removed under reduced pressure, heating the residual mixture to 120 °C and to constant weight to yield a pale yellow solid (Ti content 16.77% by weight).

[0126] Example 8 - According to the invention

[0127] Triethanolamine (2 mole, 298.4 g) was added to titanium isopropoxide (1 mole, 284.2 g) with the rate of addition controlled so that the reaction temperature did not exceed 70 °C. Glycerol (1 mole, 92.1 g) was then added, and the mixture stirred for an additional 15 minutes. Isopropanol (4 moles, 240.4 g) was removed under reduced pressure, heating the residual mixture to 120 °C and to constant weight to yield a highly viscous yellow liquid (Ti content 11.01% by weight).

[0128] Example 9 - According to the invention

[0129] Titanium isopropoxide (1 mole, 284.2 g) was added to triethanolamine (1 mole, 149.2 g) with the rate of addition controlled so that the reaction temperature did not exceed 70 °C. Glycerol (1 mole, 92.1 g) was then added, and the mixture stirred for an additional 15 minutes. Isopropanol (4 moles, 240.4 g) was removed under reduced pressure, heating the residual mixture to 120 °C and to constant weight to yield a pale yellow solid (Ti content 16.77% by weight).

[0130] Example 10 - According to the invention

[0131] Titanium isopropoxide (1 mole, 284.2 g) was added to triethanolamine (2 mole, 298.4 g) with the rate of addition controlled so that the reaction temperature did not exceed 70 °C. Glycerol (1 mole, 92.1 g) was then added, and the mixture stirred for an additional 15 minutes. Isopropanol (4 moles, 240.4 g) was removed under reduced pressure, heating the residual mixture to 120 °C and to constant weight to yield a highly viscous yellow liquid (Ti content 11.01% by weight).

[0132] Example 11- According to the invention

[0133] Triethanolamine (1 mole, 149.2 g) was added to glycerol (1 mole, 92.1 g) and stirred until well mixed. Titanium isopropoxide (1 mole, 284.2 g) was added slowly with the rate of addition controlled so that the reaction temperature did not exceed 70 °C. Water (26.67 moles, 480 g) was added, and the mixture was stirred for an additional 15 minutes. Isopropanol (4 moles, 240.4 g) and water (7.78 moles, 240 g) was removed under ambient pressure distillation to a head temperature of 100 °C, to yield a pale yellow aqueous solution (Ti content 9.12 % by weight, pH 10).

[0134] Example 12 - According to the invention

[0135] Triethanolamine (2 moles, 298.4 g) was added to glycerol (1 mole, 92.1 g) and stirred until well mixed. Titanium isopropoxide (1 mole, 284.2 g) was added slowly with the rate of addition controlled so that the reaction temperature did not exceed 70 °C. Water (26.67 moles, 480 g) was added, and the mixture was stirred for an additional 15 minutes. Isopropanol (4 moles, 240.4 g) and water (7.78 moles, 240 g) was removed under ambient pressure distillation to a head temperature of 100 °C, to yield a pale yellow aqueous solution (Ti content 7.10 % by weight, pH 9-10).

[0136] Example 13 - According to the invention

[0137] Triisopropanolamine (1 mole, 191.27 g) was added to glycerol (1 mole, 92.1 g) and stirred until well mixed. Titanium isopropoxide (1 mole, 284.2 g) was added slowly with the rate of addition controlled so that the reaction temperature did not exceed 70 °C. The mixture was stirred for an additional 15 minutes to yield a pale yellow liquid (Ti content 8.44 % by weight).

[0138] Example 14 - According to the invention

[0139] Diethanolamine (1 mole, 105.14 g) was added to glycerol (1 mole, 92.1 g) and stirred until well mixed. Titanium isopropoxide (1 mole, 284.2 g) was added slowly with the rate of addition controlled so that the reaction temperature did not exceed 70 °C. The mixture was stirred for an additional 15 minutes to yield a pale yellow liquid (Ti content 9.95 % by weight).

[0140] Comparative Example 15

[0141] Triethanolamine (1 mole, 149.2 g) was added to ethylene glycol (1 mole, 62.1 g) and stirred until well mixed. Titanium isopropoxide (1 mole, 284.2 g) was added slowly with the rate of addition controlled so that the reaction temperature did not exceed 70 °C. The mixture was stirred for an additional 15 minutes to yield a pale yellow liquid (Ti content 9.67 % by weight).

[0142] Comparative Example 16

[0143] Triethanolamine (2 mole, 298.4 g) was added to ethylene glycol (1 mole, 62.1 g) and stirred until well mixed. Titanium isopropoxide (1 mole, 284.2 g) was added slowly with the rate of addition controlled so that the reaction temperature did not exceed 70 °C. The mixture was stirred for an additional 15 minutes to yield a pale yellow liquid (Ti content 7.43 % by weight).

[0144] Comparative Example 17

[0145] Triethanolamine (2 mole, 298.4 g) was added to 1 ,3-propane diol (1 mole, 76.09 g) and stirred until well mixed. Titanium isopropoxide (1 mole, 284.2 g) was added slowly with the rate of addition controlled so that the reaction temperature did not exceed 70 °C. The mixture was stirred for an additional 15 minutes to yield a pale yellow liquid (Ti content 7.27 % by weight).

[0146] Comparative Example 18

[0147] Triethanolamine (2 mole, 298.4 g) was added to 1 ,2-propane diol (1 mole, 76.09 g) and stirred until well mixed. Titanium isopropoxide (1 mole, 284.2 g) was added slowly with the rate of addition controlled so that the reaction temperature did not exceed 70 °C. The mixture was stirred for an additional 15 minutes to yield a pale yellow liquid (Ti content 7.27 % by weight).

[0148] Comparative Example 19

[0149] Triethanolamine (1 mole, 149.2 g) was added to 1 ,2-propane diol (2 mole, 152.18 g) and stirred until well mixed. Titanium isopropoxide (1 mole, 284.2 g) was added slowly with the rate of addition controlled so that the reaction temperature did not exceed 70 °C. The mixture was stirred for an additional 15 minutes to yield a pale yellow liquid (Ti content 8.18 % by weight).

[0150] Comparative Example 20

[0151] Triethanolamine (1 mole, 149.2 g) was added to 1 ,2-propane diol (1 mole, 76.09 g) and stirred until well mixed. Titanium isopropoxide (1 mole, 284.2 g) was added slowly with the rate of addition controlled so that the reaction temperature did not exceed 70 °C. The mixture was stirred for an additional 15 minutes to yield a pale yellow liquid (Ti content 9.40 % by weight).

[0152] Comparative Example 21

[0153] Titanium isopropoxide (1 mole, 284.2 g) was added to triethanolamine (2 moles, 298.4 g) with the rate of addition controlled so that the reaction temperature did not exceed 70 °C. The mixture was stirred for an additional 15 minutes to yield a pale yellow liquid (Ti content 8.22 % by weight).

[0154] Comparative Example 22

[0155] Titanium isopropoxide (1 mole, 284.2 g) was added to triethanolamine (3 moles, 447.6 g) with the rate of addition controlled so that the reaction temperature did not exceed 70 °C. The mixture was stirred for an additional 15 minutes to yield a pale yellow liquid (Ti content 6.55 % by weight).

[0156] Comparative Example 23

[0157] Titanium isopropoxide (1 mole, 284.2 g) was added to triethanolamine (4 moles, 596.8 g) with the rate of addition controlled so that the reaction temperature did not exceed 70 °C. The mixture was stirred for an additional 15 minutes to yield a pale yellow liquid (Ti content 5.44 % by weight).

[0158] Comparative Example 24

[0159] Titanium isopropoxide (1 mole, 284.2 g) was added to glycerol (1 moles, 92.1 g) with the rate of addition controlled so that the reaction temperature did not exceed 70 °C. The reaction mixture formed a pale yellow solid that did not redissolve on heating or in water.

[0160] Comparative Example 25

[0161] Triethanolamine (0.8 mole, 119.36 g) was added to glycerol (1 mole, 92.1 g) and stirred until well mixed. Titanium isopropoxide (1 mole, 284.2 g) was added slowly with the rate of addition controlled so that the reaction temperature did not exceed 70 °C. The mixture was stirred for an additional 15 minutes to yield a pale yellow liquid (Ti content 9.66 % by weight).

[0162] Comparative Example 26

[0163] Triethanolamine (1 mole, 149.2 g) was added to glycerol (0.8 mole, 73.7 g) and stirred until well mixed. Titanium isopropoxide (1 mole, 284.2 g) was added slowly with the rate of addition controlled so that the reaction temperature did not exceed 70 °C. The mixture was stirred for an additional 15 minutes to yield a pale yellow liquid (Ti content 9.45 % by weight).

[0164] Comparative Example 27

[0165] Triethanolamine (0.8 mole, 119.36 g) was added to glycerol (0.8 mole, 73.7 g) and stirred until well mixed. Titanium isopropoxide (1 mole, 284.2 g) was added slowly with the rate of addition controlled so that the reaction temperature did not exceed 70 °C. The mixture was stirred for an additional 15 minutes to yield a pale yellow liquid (Ti content 10.04 % by weight).

[0166] Comparative Example 28

[0167] Triethanolamine (2 mole, 298.4 g) was added to glycerol (0.5 mole, 46.05 g) and stirred until well mixed. Titanium isopropoxide (1 mole, 284.2 g) was added slowly with the rate of addition controlled so that the reaction temperature did not exceed 70 °C. The mixture was stirred for an additional 15 minutes to yield a pale yellow liquid (Ti content 7.62 % by weight).

[0168] Comparative Example 29

[0169] Triethanolamine (0.5 mole, 74.6 g) was added to glycerol (1 mole, 92.1 g) and stirred until well mixed. Titanium isopropoxide (1 mole, 284.2 g) was added slowly with the rate of addition controlled so that the reaction temperature did not exceed 70 °C. The mixture was stirred for an additional 15 minutes to yield a pale yellow liquid (Ti content 10.62 % by weight).

[0170] Water Stability Testing

[0171] A 0.5 g sample of each Example complex was dissolved in 10 g of deionised water and examined for formation of any haze or particulates. Each sample was then heated under reduced pressure to 130 °C to remove any volatile components to constant weight. A further 10 g of deionised water was then added to the residual solid / liquid and the sample again examined for the formation of haze or particulates.

[0172] Samples without true stability to water formed white haze to different degrees and failed the stability test. Only samples that redissolved, did not form any haze and remained completely clear solutions were considered to have passed the water stability test.

[0173] The results for each Example are shown below in Table 1 .

[0174] Table 1 - Empirical formula and water stability of Examples 1 to 14 and

[0175] Comparative Examples 15 to 29

[0176] 1C. denotes a Comparative Example.

[0177] 2TEA denotes triethanolamine

[0178] 3TIPA denotes triisopropanolamine4DEA denotes diethanolamine

[0179] As shown in Table 1, the complexes of Examples 1 to 14, having an empirical formula (I): Ti(glycerol)a(X)b, Formula (I) where X is a di- or tri- alkanolamine; and wherein a is a number > 1; and b is a number > 1, are truly water stable, and do not form haziness or particulates when hydrated and / or rehydrated in water. The results show that a variety of di- or tri- alkanolamine may be successfully used, such as triethanolamine, triisopropanolamine and diethanolamine.

[0180] The results also show that a glycerol derived ligand is needed for water stability. This is illustrated by Comparative Examples 15 and 16 which contain ethylene glycol instead of glycerol. The resultant complexes of Comparative Examples 15 and 16 lacked water stability and formed haziness and / or particulates when rehydrated. The need for a glycerol derived ligand within the titanium complex is further illustrated by Comparative Examples 17 to 23, which did not contain a glycerol derived ligand and also resulted in complexes which were unstable when rehydrated in water.

[0181] The results also show that X being a di- or tri- alkanolamine is needed for water stability. Comparative Example 24, which contained a glycerol derived ligand, but did not have a di- or tri- alkanolamine formed an insoluble solid.

[0182] Furthermore, it can be seen from the results above that in order to form water stable complexes, in the empirical formula (I): Ti(glycerol)a(X)b, where X is a di- or trialkanolamine, a must be a number > 1 ; and b must be a number > 1. This is illustrated by Comparative Examples 25 to 29, where either a is a number < 1 ; and / or b is a number < 1 , and the resulting titanium complexes were stable in water under ambient conditions, but when water was removed to dryness, the titanium complexes were unsuccessfully rehydrated and resulted in the formation of the formation of haziness and / or particulates, and as such, not truly water stable.

[0183] Esterification

[0184] The product of Example 2, Ti(glycerol)(triethanolamine)2, was tested as a catalyst for the preparation of bis(2-ethylhexyl phthalate). Titanium isopropoxide Ti(O'Pr)4 was used as a comparative catalyst.

[0185] The apparatus used was a 0.5 litre, 3 necked round bottom flask. The flask was equipped with a thermometer, a rubber seal with a long metal needle below the surface of the reactants, and a Dean and Stark apparatus. The equipment was operated at atmospheric pressure and connected to a water condenser fitted above the Dean and Stark apparatus. The needle in the flask was connected to a supply of oxygen-free nitrogen to provide a nitrogen bleed to aid the removal of water during the reaction.

[0186] 0.5 mole (74.0 g) of phthalic anhydride was added to 1.21 moles (157.5 g) of 2- ethylhexanol. The mixture was heated to dissolve the phthalic anhydride and the nitrogen flow started.

[0187] When the temperature reached 185 °C, 0.37 g of Ti(glycerol)(triethanolamine)2 was added via the rubber seal, with the syringe remaining below the surface of the reactants. The reaction was maintained at a reflux at 200 °C by suitable adjustment of the heating rate. The water produced was removed as it was formed and collected in the Dean and Stark apparatus.

[0188] The reaction was continued for a total of 160 minutes and the mixture allowed to cool. A known weight of sample was titrated against standard potassium hydroxide solution in ethanol using bromothymol blue as indicator. The results were used to calculate the amount of unreacted half-ester present.

[0189] For the comparative example, the same methodology was used, but 0.24 g of Ti(O'Pr)4 catalyst was added as solution in 5 g of 2-ethylhexanol.

[0190] Table 2 shows the % conversion to bis(2-ethylhexyl phthalate), based upon the amount of unreacted half-ester present.

[0191] Table 2 - Comparing the use of Ti(O'Pr)4 and Ti(glycerol)(triethanolamine)2 as catalysts

[0192] 5Wt. of Ti based on weight of ester in parts per million.

[0193] As is shown in T able 2, Ti(glycerol)(triethanolamine)2 was successfully used as a catalyst for the preparation of bis(2-ethylhexyl phthalate). The results also show that the use of Ti(glycerol)(triethanolamine)2 improved the conversion of phthalic anhydride to bis(2- ethylhexyl phthalate) compared to the conventionally used catalyst Ti(O'Pr)4. Without wishing to be bound by theory, the increased conversion may be due to the water stability of Ti(glycerol)(triethanolamine)2 compared to Ti(O'Pr)4.

[0194] Discolouration Testing

[0195] A solution of the product of Example 2, Ti(glycerol)(triethanolamine)2, (75%) in water (25%) (pH 9, 0.5 g) was added to a colourless sample of 1 ,4-butane diol (10 g) that was greater than six months old. The liquids were mixed together. The colour of the 1 ,4- butane diol did not noticeably increase.

[0196] A solution of titanium citrate (55%) in water (45%) (pH 1 , 0.5 g) was added to a colourless sample of 1 ,4-butane diol (10 g) that was greater than six months old. The liquids were mixed. The colour of the 1 ,4-butane diol substantially increased to orange.

[0197] Each 1 ,4-butane diol (10 g) sample used for the discolouration tests was taken from the same bulk 1 ,4-butane diol supplied by Sigma Aldrich, and the discolouration tests were performed at the same time as one another. In other words, the age of the 1 ,4-butane diol samples used for the above tests was the same.

[0198] The results show that the use of Ti(glycerol)(triethanolamine)2, according to the present invention results in a reduction in yellowing reactions of impurities in commercially used alcohols, when compared to the commercially available titanium citrate.

Claims

CLAIMS1. A titanium complex having an empirical Formula (I):Ti(glycerol)a(X)b Formula (I) where X is a di-, or tri- alkanolamine, or a mixture thereof; and wherein a is a number > 1 ; and b is a number > 1.

2. The titanium complex according to claim 1, wherein X is selected from a di- or tri-alkanolamine.

3. The titanium complex according to claim 1 or 2, wherein at least one ligand is selected from the group consisting of triethanolamine, diethanolamine or triisopropanolamine.

4. The titanium complex according to any one of the preceding claims, wherein a plus b is in the range of about 2 to about 4.

5. The titanium complex according to any one of the preceding claims, wherein the titanium complex is water stable.

6. The titanium complex according to any one of the preceding claims, wherein the titanium complex has a pH of at least 7.

7. The titanium complex according to any one of the preceding claims, wherein the titanium complex is biodegradable.

8. A composition comprising the titanium complex of any of claims 1 to 7, and a solvent and / or diluent.

9. Use of a titanium complex having an empirical Formula (I):Ti(glycerol)a(X)b Formula (I) where X is a di-, or tri- alkanolamine, or a mixture thereof; andwherein a is a number > 1 ; and b is a number > 1 , as a catalyst in a chemical reaction.

10. A method of catalysing a chemical reaction using a titanium complex having an empirical Formula (I):Ti(glycerol)a(X)b Formula (I) where X is a di-, or tri- alkanolamine, or a mixture thereof; and wherein a is a number > 1 ; and b is a number > 1.

11. The use according to claim 9, or the method according to claim 10, wherein the chemical reaction is an esterification reaction.

12. The use according to claims 9 or 11 , or the method according to claims 10 or 11 , wherein the complex is used neat or as a composition as claimed in claim 8.

13. A method of synthesising a titanium complex having an empirical Formula (I):Ti(glycerol)a(X)b Formula (I) where X is selected from a di-, tri- alkanolamine, or a mixture thereof; and wherein a is a number > 1 ; and b is a number > 1 , the method comprising the steps of: a) mixing together glycerol, X and a titanium starting material to form a reaction mixture; and then b) reacting the reaction mixture to synthesise the complex of Formula (I).

14. The method according to claim 13, wherein the method comprises: a) mixing glycerol and X together to form a mixture, and adding a titanium starting material to said mixture; or b) mixing glycerol and X together to form a mixture and adding said mixture to a titanium starting material; orc) mixing X and a titanium starting material together and then adding glycerol to said mixture.

15. The method according to claim 14, wherein the titanium starting material is selected from the group consisting of titanium halides, titanium alkoxides, titanium halo-alkoxides, titanium carboxylates and combinations thereof.

16. The method according to claim 14 or 15, wherein the titanium starting material is a titanium alkoxide having the general formula Ti(OR)4, where R is a substituted or unsubstituted, cyclic or linear, alkyl, alkenyl, aryl or alkyl-aryl group or mixtures thereof.

17. The method according to claim 16, wherein R contains up to 8 carbon atoms and, more preferably, wherein R contains up to 6 carbon atoms.

18. The method according to claim 16 or 17, wherein all of the OR groups are identical.

19. The method according to claims 14 to 18, wherein the titanium starting material is selected from the group consisting of titanium tetrachloride, titanium tetra- isopropoxide, titanium tetra-n-propoxide, titanium tetra-n-butoxide, and titanium tetra-ethoxide.