MXPA97004972A - Direct process for the production of decelul esters - Google Patents

Abstract

The present invention relates to a process for cellulose esters having a total DS / AGU of 0.1 to 3.0, the process comprising contacting the following: (i) a cellulose material, (ii) a solubilizing amount of a solvent comprising a carboxamide diluent or a urea-based diluent, (iii) an acylation reagent, and (iv) a titan-containing compound.

Description

DIRECT PROCESS FOR THE PRODUCTION OF CELLULOSE ESTERS DESCRIPTION OF THE INVENTION This invention relates to a process for the preparation of cellulose esters having a DS / AGU of between 0.1 and 3.0, where cellulose or cellulose derivative is in contact with an acylating reagent, a titanium-containing compound and a carboxamide diluent or a urea-based diluent. Cellulose esters (CE) are conventionally synthesized by the reaction of the cellulose with the anhydride or anhydrides corresponding to the desired ester group or groups, using the corresponding carboxylic acid as the diluent and the solvent of the product. In these processes, the reaction mixture is initially heterogeneous, due to the insolubility of cellulose in most organic solvents, including carboxylic acids. The reaction is terminated when the cellulose derivative has reached solution, and the viscosity of the desired solution has been reached. When the mixture becomes homogeneous, the cellulose is completely or almost completely acylated. Optionally, a large excess of the sulfuric acid catalyst can be used, in which case the product is a cellulose alkanoate sulfate. Selective cleavage of the sulfate groups can produce a cellulose alkanoate partially replaced. However, it is extremely difficult to remove a large DS (degree of substitution) of sulfate esters without simultaneously reducing the DP (degree of polymerization) of the cellulose ester to unacceptable levels. Thus, in conventional processes, the synthesis of partially substituted cellulose esters is carried out by hydrolysis of cellulose triesters, prepared by acylation catalyzed by mineral acid in a separate step, the desired level of substitution. Typically, hydrolysis in a mixture of water and carboxylic acid solvent results in looking for the substitution position (due to simultaneous, but slower, but slower acyl migration of the newly exposed hydroxyl groups by the carboxylic acid solvent) so that the products have an equilibrium distribution of ester substituents. The partially substituted cellulose ester has higher commercial value. They are used in coatings, where their higher solubility (compared to the triesters) and the hydroxyl group content (to facilitate crosslinking) are first class. In plastics, fibers and film applications, the ability to partially synthesize substituted EC allows control over thermal, mechanical and compatibility biodegradation. It is well known in the art that cellulose esters with long chain carboxylic acids could prepare with acylation with corresponding acid chlorides in pyridine, or less successfully, other solvents. This method was useful only for the synthesis of cellulose triesters. For example, see alm, et al., Ind. Eng. Chem. , 1951, 43, 684-688. U.S. Patent 2,705,710 describes DMAC as a solvent and sulfuric acid as a catalyst for preparing cellulose triacetate (a fully substituted ester - 2.9 DS Ac and 0.10 SD sulfate). The reaction described in this patent is carried out at 140 ° C and therefore, it is very fast. The disadvantage of the sulfuric acid technology of U.S. Patent 2,705,710 s is the need for a hydrolysis step to obtain partially substituted esters. • The use of ester titanate catalysts in carboxylic acid solvents is known in the literature. In U.S. Patent 2,976,277, it is disclosed that titanate esters are efficient catalysts for the acylation of cellulose with anhydrides such as acetic, propionic, butyric, or mixtures thereof, in a diluent (and the solvent for the product) . The diluent was the carboxylic acid corresponding to the anhydride or to one of the anhydrides in the case of the mixed esters, or an amide such as N, -dimethylformamide. This process produced cellulose esters soluble in high IV acetone (2.0-3.0).

Also, a large excess of the anhydrides were used (6-27 equivalents based on anhydroglucose). The direct synthesis of partially substituted SCs has also previously been taught by the acylation of cellulose in the solution as shown in U.S. Patent 2,976,277. The cellulose was first dissolved in a mixture of lithium chloride and an amide solvent (either l-methyl-2-pyrrolidinone (NMP) or N, N-dimethylacetamide (DMAC)), then it can be acylated with a carboxylic anhydride in the presence or absence of a catalyst to produce a CE partially or completely substituted only in the equivalents of the added anhydride. The cellulose esters with long chain carboxylic acids have been prepared in this form. So, in Carbohydrate Polymers. 22, 1-7, 1993, it is described that it is possible to react the cellulose in DMAC / LiCl solution with a variety of carboxylic acid chloride using amine catalysis, or alternatively carboxylic acids using dicyclohexylcarbodiimide catalysis to obtain cellulose esters with acids of chain length, up to 18 carbons (stearate) and DS from 0.1 to 2.5. Although this method has great flexibility in terms of the nature of the anhydride and DS of the product obtained, the need to dissolve the cellulose means that the reaction mixtures must be diluted (not more than 5% cellulose) and that the process is lengthened by the time it takes for the dissolution of cellulose. It is a practical necessity to develop a method to recycle expensive lithium chloride with high efficiency, whose method has not yet been described. The long chain cellulose esters (LCCE) (carbon chain length greater than 4) are known from the pioneering work of Malm as shown in Ind. Eng. Chem., 43, 684-691, 1951. Efforts to obtain LCCE by the reaction of the Cellulose with long-chain anhydrides in the carboxylic acid solvent with catalysis of mineral acid have not been successful because the rate of esterification is too slow and can not compete with the speed of the chain splitting. Only the other methods known in the literature involve the use of "boosters" such as chloroacetic anhydride, as described in U.S. Patent 1,880,808, and the reaction of regenerated cellulose with long-chain acid chlorides in pyridine or , as described in Ind. Enq. Chem. Res. 31, 2647-2651, 1991, pure. The reagents tend to be expensive, toxic and difficult to handle. Regenerated cellulose is expensive, as are acid chlorides, which also require construction reactors resistant to corrosion. Additionally, the Direct cellulose reaction with acid chloride under vacuum does not result in soluble, homogeneous products. LCCEs are of commercial interest, due to their lower processing temperatures, higher impact resistance, higher solubility in less polar solvents, the likelihood of greater compatibility of hydrophobic polymers, the potential for forming molded or extruded objects without the need for a plasticizer, and its potential utility as an associated thickener for water-based paints (by analogy with long-chain cellulose esters, such as hydrophobically modified hydroxyethylcellulose). It has also been described in US Pat. No. 2,705,710 that the activation of cellulose "with N, N-dialkylamides prior to conventional esterification (mineral acid and carboxylic anhydride) allows for the abraded esterification without excessive degradation. is a process for preparing cellulose triacetate with inherent viscosity in the range of 1.1 to 1.3 (less than that required for many current commercial applications). Clearly, there is a need in the art for a process whereby ECs less than full substitution can be prepared directly from cellulose. The process must be economical, practical and capable of industrial production. It must be possible with this process synthesize products which have a sufficiently high molecular weight for their commercial, particular application. It should be advantageous to be able to use long chain anhydrides in this process, so that the cellulose esters containing long chain ester groups can be obtained. It is essential that the products are sufficiently homogeneous, in such a way that they can be processed thermally and / or in solution, to be useful for film applications, coatings, plastics and other certain applications. It is advantageous to use a catalyst whose residues do not adversely affect the usefulness of the cellulose ester product, if they are not completely removed from the product. It is also advantageous to have the ability to control the DS product and the molecular weight by practical and predictable adjustments to process conditions. This invention relates to the preparation of cellulose esters (CE) of degree of substitution (DS) less than or equal to 3.0 by the reaction of cellulose in a carboxamide diluent or a urea-based diluent (optionally containing an additional cosolvent ) with an acylating reagent such as carboxylic acid anhydrides, using a titanium-containing species such as ester titanate as a catalyst.

More particularly, this invention relates to a process for preparing cellulose esters having a total DS / AGU of 0.1 to 3.0, the process comprising contacting the following: (i) a cellulose material, (ii) an amount solubilizer of a solvent system, comprising either a carboxamide diluent or a urea-based diluent, wherein the carboxamide portion of the carboxamide diluent comprises the structure: R4R5NCOCR6R7R8, wherein R4, R5, R6, R7 and R8 are selected independently of the group consisting of hydrogen, alkyl having from about 1 to about 20 carbon atoms, branched alkyl having from about 1 to about 20 carbon atoms, phenyl, naphthyl, alkenyl having from about 1 to about 20 carbon atoms. carbon and branched alkenyl having from about 1 to about 20 carbon atoms, and wherein the urea portion of the urea-based diluent comprises the structure: R9R10NCONR11R12, wherein R9, R10, R11 and R12 are independently selected from the group consisting of hydrogen, alkyl having from about 1 to about 20 carbon atoms, branched alkyl having from about 1 to about 20 carbon atoms; carbon, phenyl, naphthyl, alkenyl having from about 1 to about 20 carbon atoms, -and branched alkenyl having from about 1 to about 20 carbon atoms, (iii) an acylation reagent selected from the group consisting of (a) an acid chloride and optionally , an acid acceptor, (b) a carboxylic acid anhydride, (c) diketene, ketene, 2, 2, 6-trimethyl-4H-l, 3-dioxin-4-one and an acetoacetic acid ester, (d) an ester of a carboxylic acid, and combinations of one or more of (a) - (d), and (iv) a titanium-containing compound, wherein the components (i) and (ii) are in contact first and the components (iii) and (iv) are in contact with the contact product of components (i) and (ii), in any order. Preferably, the invention relates to a process for preparing cellulose esters with long chain carboxylic acids (containing more than 4 carbon atoms). The advantage of this process over the prior art include: that they are capable of using cellulose with a lower alpha content and a lower molecular weight, synthesis of cellulose esters of very high molecular weight, synthesis of cellulose esters, partially or completely substituted having a total of D.S. less than or equal to 3.0 with long chain carboxylic acids and, optionally, short chain acids, and partially substituted cellulose esters are obtained directly from the reaction mixture or by standard isolation techniques. These partially substituted cellulose esters have good solubility over a wide range of organic solvents and can have a high molecular weight. For the purpose of this invention, long chain should refer to more than 4 carbon atoms, while short chain should refer to 4 carbons or less. The process of the invention has wide utility for the direct, economic synthesis of cellulose esters for plastics, film, fiber and coatings applications. As used herein, "the term" degree of substitution "or" DS "or" DS / AGU "refers to the average number of acyl substituents per anhydroglucose ring of the cellulose polymer The present invention relates to a process for preparing a cellulose ester having a total DS / AGU of 0.1 to 3.0, preferably 2.0 to 3.0, # most preferred of 2.4 to 2.9, the process comprises contacting the following: (i) a material of cellulose, (ii) a solubilizing material of a solvent system comprising either a carboxamide diluent or a urea-based diluent, (iii) an acylation reagent selected from the group consisting of (a) an acid chloride, and optionally, an acid acceptor, (b) a carboxylic acid anhydride, (c) diketene, ketene, 2, 2, 6-trimethyl-4H-l, 3-dioxin-4-one, and an acetoacetic acid ester, (d) a carboxylic acid ester, and combinations of one or more of (a) - (d), and (iv) a titanium-containing compound. The components (i) and (ii) usually come into contact first and the components (iii) and (iv) are brought into contact with the product of contacting the components (i) and (ii), in any order. The cellulose esters produced by the invention generally comprise the following structure: n wherein R, R 'and R'1 are selected separately from the group consisting of: hydrogen, with the proviso that R, R', and R1 'are not all hydrogen simultaneously; acetoacetyl; and R1C = 0 wherein R1 is alkyl having from about 1 to about 30 carbons; carboxyalkyl of the structure (CH2) mCC > 2H, where m is from 2 to 6, preferably from 2 to 4; carboxyalkenyl of the structure CR2 = CR302H, wherein R2 and R3 are independently selected from the group consisting of hydrogen, methyl, branched alkyl having from about 1 to about 30 carbons, phenyl and naphthyl; alkenyl having from about 1 to about 30 carbon atoms and from one to three double bonds; and branched alkenyl having from about 1 to about 30 carbon atoms and having from one to three double bonds. For the branched carboxyalkenyl, alkenyl and alkenyl, the double bonds present may be in the cis or trans position. It is preferred that R, R 'and R "are independently selected from the group consisting of hydrogen, acetyl, propionyl and butyryl for the cellulose ester structure indicated above. Long chain esters are also preferred.

The carboxamide portion of the carboxamide diluent comprises the structure R4R5NCOCR6R7R8, wherein R4, R5, R6, R7 and R8 are independently selected from the group consisting of hydrogen, alkyl having from about 1 to about 20 carbon atoms, branched alkyl which it has from about 1 to about 20 carbon atoms, substituted phenyl, phenyl, substituted naphthyl, naphthyl, alkenyl having from about 1 to about 20 carbon atoms and branched alkenyl having from about 1 to about 20 carbon atoms. Examples of the carboxamide diluents are 1-methyl-2-pyrrolidinone (NMP), N, N-dimethylpropionamide, N, N-diethylacetamide, or N, N-dimethylacetamide (DMAC). The DMAC is particularly preferred. carboxamides such as succinimides, phthalimides or glutarimides can also be used as diluents. The urea portion of the urea-based diluent comprises the structure: R9R10NCONR11R12, wherein R9, R10, R11 and R12 are independently selected from the group consisting of hydrogen, alkyl having from about 1 to about 20 carbon atoms, branched alkyl having from about 1 to about 20 carbon atoms, phenyl, naphthyl, alkenyl having about 1 to about 20 carbon atoms, and branched alkenyl having from about 1 to about 20 carbon atoms. Urea compounds are also intended to fall within the scope of the general definition, are those in which one of R9 and R10 and one of R11 and R12 are joined to form a cyclic urea, such as N, N-dimethylimidazolidinone. The preferred urea compounds are those selected from the group consisting of urea and N, N-dimethylimidazolidinone. The N, N-dimethylimidazolidinone has the structure: Amino acids such as proline or glycine can also be used as diluents. The solvent to cellulose ratios used can vary within a moderately broad range. For the purposes of mushroom invention, examples of alkyl having from about 1 to about 20 carbon atoms are methyl, ethyl, propyl, butyl, hexyl, nonyl, hexadecyl and alkyl including alkyl substituted aryl such as benzyl, cycloalkyl such as cyclohexyl, etc. Examples of branched alkyl having from about 1 to about 20 carbon atoms are isopropyl, isobutyl, isononyl, butyl tertiary. Examples of alkenyl are propenyl, decenyl, pentacenyl, (&) -heptadec-8-enyl, and (Z, Z) -heptadecadi-8,11-enyl. Examples of branched alkenyl are pentadecenyl. Other activated acyl derivatives, such as acid chlorides, are also useful, - in the case of acid chlorides an acid acceptor such as pyridine, sodium bicarbonate or sodium acetate may also be optionally used. Acylation reagents can also include diketene, 2, 2, 6-trimethyl-4H-l, 3-dioxin-4-one (TKD), or an acetoacetic acid ester. As taught by Witzeman in Tetrahedron Letters, 1990, 3_1, 1401-1404, tert-butyl acetoacetate (tBAA) is especially suitable acetoacetate ester because it generates the reactive intermediate, acetylkethene at a high speed. Preferred acid chlorides are acetyl chloride, propionyl chloride, butyryl chloride, hexanoyl chloride, lauroyl chloride, palmitoyl chloride and stearoyl chloride. In the case of acid chlorides, an acid acceptor such as pyridine, sodium bicarbonate, or sodium acetate may optionally be used in combination with the acylating reagent. Preferred of this invention are the carboxylic anhydrides selected from the group consisting of acetic anhydride, propionic anhydride, butyric anhydride, hexanoic anhydride, nonanoic anhydride, lauric anhydride, palmitic anhydride and stearic anhydride. Preferred acylation reagents in this invention are esters of carboxylic acids, which are selected from the group consisting of the following acids: capric, lauric, palmitic, stearic, oleic, linoleic, linoleic, cyclohexanedicarboxylic, benzoic, substituted benzoic, phthalic, isophthalic and terephthalic. Acid acceptors useful within the context of this invention are selected from the group consisting of pyridine, triethylamine, sodium bicarbonate, and sodium acetate. The term "acid acceptor" is generally understood to refer to a basic material, such as a Le is base. Pyridine is a preferred acid acceptor. Preferred cellulose esters made by the processes of this invention include cellulose acetate, cellulose butyrate, cellulose propionate, cellulose acetate butyrate, cellulose acetate propionate, cellulose acetate hexanoate, cellulose acetate nonanoate, cellulose acetate laurate, cellulose palmitate, cellulose acetate stearate, cellulose nonanoate, cellulose hexanoate, cellulose hexanoate propionate, and cellulose nonanoate propionate. A variety of cellulose sources can be used for the practice of this invention. The sources of cellulose useful in the invention include hardwood pulp, softwood pulp, cotton linters, bacterial cellulose and regenerated cellulose. The practice of the present invention allows a wide variety of initial cellulose materials, temperatures, concentrations, titanium-containing species, carboxylic acid anhydrides, non-solvents, and reagent ratios, a wide variety of cellulose esters can be produced, depending on of the selected conditions. The temperature used for all aspects of the process of the invention are in the range of approximately 0 ° C to about 200 ° C, preferably of about 100 ° C, to about 180 ° C, and more preferably of 120 ° C to about 170 ° C. The products are isolated by methods known in the art, for example, by the addition of a non-solvent (often water) to the reaction mixture, and isolating the precipitated product by filtration and washing. In this invention, a combination of the compound of Ti / carboxamide or urea is employed, wherein the carboxamide or urea functions as an activating agent, diluent and a solvent. In the synthesis process of the invention, the molar ratio of component (iii): component (iv) is that amount that will result in desired DS / AGU under the chosen reaction conditions. Suitable conditions for the formation of cellulose esters can vary widely. Cellulose must first be activated by contact with the amide diluent. This can be done more simply by heating a suspension of the cellulose in the amide diluent at a temperature of 100-180 ° C., although it is also possible to perform activation by prolonged contact at room temperature. The reagent or acylation reagents are typically added all at once. The total amount of acylating reagents used can vary from 3 to 10 equivalents based on equivalents of anhydroglucose units, with 4 to 6 more preferred equivalents. Within this total, the proportion of each acylation reagent can be varied to achieve the ded DS of each substituent in the product. It is preferred that the amount of cellulose material present is from about 1.0 percent to about 50 percent, preferably from about 9.0 percent to about 28 percent, based on the weight of the carboxamide, and the amount of the compound it contains. titanium is from about 0.1 percent to about 20 percent, preferably from about 1.0 percent to about 10 percent, based on the weight of the cellulose material. The process of this invention usually includes the step of adding insolubilization of the cellulose ester by the addition of an amount of insolubilization of a non-solvent. It may also include the step of separating the insolubilized cellulose ester. The aforementioned non-solvents that are useful for the isolation of cellulose esters manufactured by this process will be specific to the particular material. The reaction solvents and any of the byproducts must be dissolved, but they must be non-solvent for the cellulose ester. Examples include methanol, ethanol, 2-propanol and water. The titanium-containing species useful as catalysts for this process are titanium compounds (IV). They can be titanic acid, titanate esters, tetra (amino) titanium compounds, or titanium (IV) compounds with a mixture of these substituents. Examples include tetra (2-propyl) titanate, titanic acid, tetra (1-propyl) titanate, tetra (1-butyl) titanate and tetra is (dimethylamino) titanium. The products of the process of this invention are useful for various purposes, such as plastics, films, fibers and coatings applications.

For the cellulose esters of this invention, the DS or DS / AGU can be determined by any method known in the art, for example, by proton NMR. This invention may be further illustrated by the following examples of the preferred embodiments thereof, although it will be understood that these examples are included solely for purposes of illustration and are intended to limit the scope of the invention unless specifically indicated in another. shape. The initial materials are commercially available unless otherwise described. All percentages are by weight unless otherwise described. EXAMPLES In the following examples, cellulose and DMAC solvent were added to a three-necked round bottom flask equipped with a mechanical stirrer, a thermometer, and a nitrogen inlet. The suspension is heated to 100 ° C under nitrogen, with stirring. Then the anhydride and the catalyst are added to the activated cellulose and the mixture is heated to the reaction temperature. Note that "equiv" below refers to reagent equivalents per anhydroglucose or cellulose unit. With the exceptions mentioned, the mixture was stirred at the reaction temperature until it was clear and uniform. Then the solution is cooled to 20-80 ° C. The mixture of reaction was in some cases. filtered to remove some residual fibers (sometimes the reaction mixture was diluted with acetone or with the amide diluent first to reduce the viscosity). The product was precipitated by adding the filtrate in drops to a non-solvent with vigorous agitation. The product was isolated by filtration, then suspended again in a non-solvent. This process was repeated two to five times as required to remove all impurities from the product. When the non-aqueous solvents were used, the suspension and the filtration processes are repeated twice more with water as the non-solvent, to avoid the plasticization and flow of the product during drying. The product was dried in a vacuum oven under nitrogen at 40-80 ° C. The yields cited in the examples are from well-characterized, isolated products. DS was determined by 1H NMR in d-6 DMSO or CDC13 containing several drops of trifluoroacetic acid (to displace any of the hydroxyl protons down the field), or by hydrolysis of the cellulose ester sample, followed by acid quantification carboxylic acids liberated by gas chromatography. Gel permeation chromatography used NMP as a solvent (reference polystyrene or absolute by GPC-V). The intrinsic viscosity was measured in NMP solution or DMSO (dimethyl sulfoxide). Differential scanning calorimetry (20 ° C / minute, second exploration, maximum temperature 240 ° C) was used to determine the thermal transitions. The titanium content was measured by ion cyclotron phosphorescence (ICP). The representative members of each family of materials were examined by infrared spectroscopy to confirm the identity of the product. All temperatures in degrees centigrade. EXAMPLE 1 The reagents cited in the following were subjected to the standard procedure described above under standard reaction conditions, except as described in the following. The results, in terms of identity of the desired cellulose ester, and key product analyzes, are also cited in the following, Natchez HVX Cellulose (hardwood cellulose pulp, available from International Paper Natchez, Mississippi) Anhydride Carboxylic Acetic anhydride Equivalents 6 Reaction temperature 120"c Diluent Amide DMAC gd Amide / gd? Cellulose 10 Catalyst Titanate tetra (2? Ro? Il) Equivalents O. 0171 Reaction time 4.3 hours Key Analysis DS (acetyl) = 2. 63, IV-3.40, GPC I = 107, 000, soluble in CHC I 3, acetone, acetic acid -, DMSO and NHP, titanium content = 29? Ppm.

This example demonstrates the direct synthesis of the cellulose of a high molecular weight cellulose acetate, partially substituted with good solubility in organic solvents. EXAMPLE 2 The reagents cited in the following were subjected to the standard procedure described above under standard reaction conditions, except as described in the following. The results, in terms of identity of the desired cellulose ester and key product analyzes, are also cited in the following.

Natchez HVX Cellulose Carboxylic Anhydride Propionic Anhydride Equivalents 4.5 Reaction Temperature 140'C Amide Diluent DMAC g Amide / g Cellulose 7 Catalyst Titanate tetra (2-propyl) Equivalents 0.0171 Reaction Time 8.5 hours Key Analysis DS (propionyl) = 2.46 # DS (acetyl) = on, iv * = 1.69, GPC Mn = 65,900, Tg = 156 * C, Tm = 23l'C, soluble in acetone, THF, acetic acid, CHCI-, DMSO and NMP, Ti content = 1630 ppm.

This example demonstrates the synthesis of a partially substituted semicrystalline acetate propionate of cellulose of relatively high molecular weight with good solubility in organic solvents, directly from cellulose. EXAMPLE 3 The reagents cited in the following were subjected to the standard procedure described above, under standard reaction conditions, except as described in the following. The results in terms of identity of the desired cellulose ester and key product analyzes are also cited in the following.

Natchez Cellulose HVX Carboxylic Anhydride Acetic anhydride Equivalents 6.00 Reaction Temperature 120 * C Amide Diluent 1-Methyl-2-pyrrolidinone (NMP) g Amide / g of Cellulose 10 Catalyst Titanate of tetra (2-propyl) Equivalents 0. 0171 Reaction Time 7.7 hours Key Analysis DS (acetyl) = 2.52, IV; solution too thick to measure, GPC Mn = 134, ooo, Tg = 2 oí 'c, soluble in acetic acid, DMSO and NMP.

This example demonstrates that NMP is also a useful solvent for the reaction, that the product of it has high molecular weight, is less soluble than that of DMAC, and has high viscosity in solution and that the reaction is slower in NMP than in DMAC . EXAMPLE 4 The reagents cited in the following were subjected to the standard procedure described above, under standard reaction conditions, except as described in the following. The results in terms of identity of the desired cellulose ester and key product analyzes are also cited in the following.

Cellulose Natchez HVX Carboxylic Anhydride Acetic anhydride Equivalents 6. 00 Reaction Temperature 120 'C Diluent Amide N, N-Dimethylformamide g Amide / g of Cellulose 10 Catalyst Titanate of tetra (2-propyl) Equivalents 0. 0171 Reaction Time 12. 8 hours Key Analysis DS (acetyl) = 2. 42, iv = 0. 95, GPC M, - = 64, 900, partially soluble in DMSO and mostly soluble in NMP, Tg = 194 c.

This example demonstrates that when DMF (N, N-dimethylformamide) is used as an amide diluent, the reaction is very low, and a cellulose acetate product of low solubility is obtained. EXAMPLE 5 The reagents cited in the following were subjected to the standard procedure described above, under standard reaction conditions, except as described in the following. The results in terms of identity of the desired cellulose ester and key product analyzes are also cited in the following. Viscocell Cellulose (hardwood cellulose pulp, available from International Paper in Natchez, Mississippi) Carboxylic Anhydride Propionic Anhydride Equivalents 6. 00 Reaction Temperature 140 * C Diluent Amide N, N-D imethylpropionamide g Amide / g Cellulose 10 Catalyst Titanate tetra (2-propyl) Equivalents 0. 0171 Reaction Time 8.6 hours Key Analysis DS (propionyl) - 2.71, DS (acetyl) = o. or, IV = 0. 94, GPC = 40, 100, Tg = 137 ° C, soluble in acetone, acetic acid, THF, CHCl 3, DMSO and NMP.

This example demonstrates that N, N-dimethylpropionamide is a suitable solvent for the propionylation of cellulose, using the Ti catalyst to obtain a partially substituted cellulose propionate. It will also be shown that acetyl in CAP (cellulose acetate propionate) can be this method, except with DMAC as a diluent originating from the acyl of DMAC. EXAMPLE 6 The reagents cited in the following were subjected to the standard procedure described above, under standard reaction conditions, except as described in the following. The results in terms of identity of the desired cellulose ester and key product analyzes are also cited in the following. Natchez HVX Cellulose Carboxylic Anhydride Propionic Anhydride Equivalents 4.50 Reaction Temperature 120"C Amide Diluent DMAC g Amide / g Cellulose Catalyst Tetra (2-propyl) Titanate Equivalents 0.0171 Reaction Time 17.3 hours Key Analysis DS (propionyl)« = 2.57 , DS (acetyl) - o., Iv = 1.80, GPC Mn = 80,700, Tg - = 152 * C, T ^ = - 229 * C, soluble in acetone, acetic acid THF, CHC13, DMSO and NMP.

This example shows that in DMAC at low temperature and high concentration, compared to the Example 2, a high molecular weight cellulose propionate product is obtained, but with a large reaction time. EXAMPLE 7 The reagents cited in the following were subjected to the standard procedure described above, under standard reaction conditions, except as described in the following. The results in terms of identity of the desired cellulose ester and key product analyzes are also cited in the following. Natchez HVX Cellulose Carboxylic Anhydride Propionic Anhydride Equivalents 4.50 Reaction Temperature 120 * C Carboxylic Acid Propionic Acid g Carboxylic Acid / g Cellulose 2.18 Amide Diluent DMAC g Amide / g Cellulose 2.62 Catalyst Titanate of tetra (2-propyl) Equivalents 0.0171 Reaction Time 28.9 hours Key Analysis DS (propionyl) = 2.65, DS (acetyl) = o.23, iv = 0.92, GPC Mn = 43,000, Tg = 128 * C, Tm = 206 * C, soluble in acetone, acetic acid THF, CHC13, DMSO and NMP.

This example demonstrates that when a combined amide diluent (DMAC) and a carboxylic acid are used, the esterification is slower (compared to example 6) and the CAP product has lower molecular weight. EXAMPLE 8 The reagents cited in the following were subjected to the standard procedure described above, under standard reaction conditions, except as described in the following. The results in terms of identity of the desired cellulose ester and key product analyzes are also cited in the following. Natchez HVX cellulose Carboxylic anhydride and hexanoic anhydride Equivalents 2.00 Carboxylic anhydride 2 Acetic anhydride Equivalents 2. 00 Reaction Temperature 140 'C Amide Diluent DMAC g Amide / g Cellulose 7 Catalyst Titanate tetra (2-p Equivalents 0. 0171 Reaction Time 9.2 hours Key Analysis DS (hexanoyl) = 0.75, DS (acetyl) =? .9i, iv = 1. 39, GPC Mn = 86, 500, Tg «- 149 * C.

This example demonstrates that it is possible to directly synthesize a partially substituted ester mixture, which contains a long chain of ester groups such as hexanoyl using a Ti catalyst in an amide diluent. EXAMPLE 9 The reagents cited in the following were subjected to the standard procedure described above, under standard reaction conditions, except as described in the following. The results in terms of identity of the desired cellulose ester and key product analyzes are also cited in the following. Natchez Cellulose HVX Carboxylic Anhydride 1 Acetic anhydride Equivalents 2. 00 Carboxylic anhydride 2 Hexanoic anhydride Equivalents 2. 00 Reaction Temperature 140"C Amide Diluent DMAC g Amide / g Cellulose 7 Catalyst Titanate tetra (2-r) Equivalents 0.0285 Reaction Time 9.0 hours Key Analysis DS (acetyl) = 1.84, DS (hexanoyl) = 0.73, IV = 1.40, GPC Mn = 32, 900, soluble in acetone, acetic acid, THF, CHCl3, DMSO and NMP, Tg = 153 * C.

This example demonstrates the direct synthesis from a cellulose of a mixed cellulose ester, high molecular weight, partially substituted, where one of the ester groups is a long chain ester, with good solubility in the organic solvents. EXAMPLE 10 The reagents cited in the following were subjected to the standard procedure described above, under standard reaction conditions, except as described in the following. The results in terms of identity of the desired cellulose ester and key product analyzes are also cited in the following. Natchez Cellulose HVX Carboxylic Anhydride Hexane Anhydride Equivalents 4. 50 Reaction Temperature 155 0 C Amide Diluent DMAC g Amide / g Cellulose 7. 00 Catalyst Titanate tetra (2-propyl) Equivalents 0. 0171 Reaction Time 5.7 hours Key Analysis n DSe 0. ? 12- > , DS (hexanoyl) = 2 .39, iv = 0. 94, GPC Mn = 32, 700, Tg = 119 * c, titanium content = 1850 ppm.

This example demonstrates direct synthesis from a cellulose of a mixed, partially substituted cellulose ester, where one of the ester groups is long chain carboxylic acid, by reaction with only the long chain acid anhydride in a DMAC diluent with a Ti catalyst. EXAMPLE 11 The reagents cited in the following were subjected to the standard procedure described above, under standard reaction conditions, except as described in the following. The results in terms of identity of the desired cellulose ester and the key product analyzes are also cited in the following, Natchez HVX Cellulose Carboxylic Anhydride 1 Acetic anhydride Equivalents 2.0 Carboxylic Anhydride 2 Nonanoic Anhydride Equivalents 2.0 Reaction Temperature 150 * C Amide Diluent DMAC g of Amide / g of Cellulose Catalyst Titanate of tetra (2-propyl) Equivalents O.0171 Reaction Time 7.9 hours Key Analysis DS (acetyl) = - 2.03, DS (nonanoiloj = o.70f iv = 1.18, GPC Mn - 44,500, soluble in acetone # acetic acid, THF, CHCl3, DMS? And NMP, Tg = 128 * C This example demonstrates the direct synthesis from a cellulose of a mixed, partially substituted cellulose ester, where one of the ester groups is a long chain ester, with good solubility in organic solvents. EXAMPLE 12 The reagents cited in the following were subjected to the standard procedure described above, under standard reaction conditions, except as described in the following. The results in terms of identity of the desired cellulose ester and key product analyzes are also cited in the following. Natchez Cellulose HVX Carboxylic Anhydride 1 Acetic anhydride Equivalents 2.0 Carboxylic Anhydride 2 Lauric Anhydride Equivalents 2.0 Reaction Temperature 150 ° C Amide Diluent DMAC g Amide / g Cellulose 5 Catalyst Titanate tetra (2-propyl) Equivalents 0.0342 Reaction Time 3.67 hours Key Analysis DS (acetyl) = 2.09, DS (lauroyl) = 0.81, IV «1.32, GPC n = 54,900, soluble in acetone, acetic acid, THF, CHCl3, DMSO and NMP, g = 122 * C.

This example demonstrates the direct synthesis from a cellulose of a mixed, partially substituted cellulose ester, where one of the ester groups is a long chain ester, with good solubility in organic solvents. EXAMPLE 13 The reagents cited in the following were subjected to the standard procedure described above, under standard reaction conditions, except as described in the following. The results in terms of identity of the desired cellulose ester and key product analyzes are also cited in the following. Natchez HVX Cellulose Carboxylic Anhydride 1 Acetic anhydride Equivalents 2.0 Carboxylic Anhydride 2 Palmitic Anhydride Equivalents 2.0 Reaction Temperature 145 ° C Amide Diluent DMAC g Amide / g Cellulose 20 Catalyst Titanate (2-propyl) titanate Equivalents 0.0171 Reaction Time 5.8 hours Key Analysis DS (acetyl) - 2.06, DS (palmitoyl) = 0.42, iv * = 0.29, GPC Mn = 33,400, soluble in acetone, acetic acid, THF, CHC13, DMSO NMP, Tg = 156 * C.

This example demonstrates the direct synthesis from a cellulose of a mixed cellulose ester, partially substituted, where one of the ester groups is a long chain ester, with good solubility in organic solvents. EXAMPLE 14 The reagents cited in the following were subjected to the standard procedure described above, under standard reaction conditions, except as described in the following. The results in terms of identity of the desired cellulose ester and key product analyzes are also cited in the following. Natchez HVX Cellulose Carboxylic Anhydride 1 Acetic anhydride Equivalents 2. or Carboxylic Anhydride 2 Hexane Anhydride Equivalents 2. o Reaction Temperature 14? 'C Amide Diluent DMAC g Amide / g Cellulose 7 - 67 Catalyst Titanium (IV) tetrakis (diethyl) lamino) Equivalents 0.0171 Reaction Time 16.8 hours Key Analysis DS (acetyl) = •? .9i, DS (hexanoyl) = o.83, iv = 1.49, GPC Mn = 40,7OO, soluble in acetone, acetic acid, HF, CHCl ,, DMSO, ethyl acetate, n-butyl acetate and NMP, Tg «= i42 * C This example demonstrates the direct synthesis from a cellulose of a mixed, partially substituted cellulose ester, where one of the ester groups is a long-chain ester, for use of an amino-titanium compound as a catalyst. EXAMPLE 15 The reagents cited in the following were subjected to the standard procedure described above, under standard reaction conditions, except as described in the following. The results in terms of identity of the desired cellulose ester and key product analyzes are also cited in the following.

Natcnez HVX cellulose. Carboxylic anhydride 1 Acetic anhydride Equivalents 2. 0 Carboxylic anhydride 2 Hexanoic anhydride Equivalents 2. 0 Reaction temperature 155 ° C Diluent Amide DMAC p t f *? Miria / p HÉ ».oli linca 7. 67 Catalyst Titanate of tetra (1-propyl) Equivalents 0. 0171 Reaction time 7. 7 hours Key Analysis DS (acetyl) = 1.84, DS (hexanoyl) = 0.79, iv = 1. 41, GPC Mn = 30, 600, soluble in acetone, acetic acid, and NMP, Tg «= 147 ° c.

This example demonstrates direct synthesis from a cellulose of a mixed, partially substituted cellulose ester, where one of the ester groups is a long chain ester, by use of an n-alkyl titanate compound as a catalyst. EXAMPLE 16 - Comparative Study The reagents cited in the following were subjected to the standard procedure described above, under standard reaction conditions, except as described in the following. The results in terms of identity of the desired cellulose ester and key product analyzes are also cited in the following. Cellulose Natchez HVX Carboxylic Anhydride Acetic anhydride Equivalents 6. 0 Reaction Temperature 120-140 'C Amide Diluent DMAC g Amide / g Cellulose 10. 0 Catalyst Zinc Acetate (II) Equivalents 0. 0171 Reaction Time 15.0 hours Results No reaction was observed during the course of 15 hours, starting at 120 ° C and increasing to 140 ° C after 5 hours.

This example demonstrates that Le is acids, based on zinc, do not catalyze the esterification of cellulose at reaction rates useful in amide diluents. EXAMPLE 17 - Comparative Study The reagents cited in the following were subjected to the standard procedure described in the above > under standard reaction conditions, except as described in the following. The results in terms of identity of the desired cellulose ester and key product analyzes are also cited in the following. Natchez Cellulose HVX Carboxylic Anhydride Acetic anhydride Equivalents 6. 0 Reaction Temperature 120-150 'C Amide Diluent DMAC g Amide / g Cellulose 7. 67 Catalyst Antimony Antimony (III) Equivalents 0.0171 Reaction Time ?? .6 hours Results No reaction was observed during the course of 11.6 hours, starting at 120 ° C and increasing to 140 ° C after 1.3 hours, then increasing to 150 ° C after 6 hours.

This example demonstrates that Lewis acids, based on antimony, do not catalyze the esterification of cellulose at reaction rates useful in amide diluents. EXAMPLE 18 - Comparative Study The reagents cited in the following were subjected to the standard procedure described above, under standard reaction conditions, except as described in the following. The results in terms of identity of the desired cellulose ester and key product analyzes are also cited in the following. Natchez HVX Cellulose Carboxylic anhydride Acetic anhydride Equivalents 6. 0 Reaction Temperature 120-145 * C Amide Diluent DMAC g Amide / g Cellulose 5. 0 Catalyst Germanium Oxide (IV) Equivalents 0.0171 Reaction Time 6.2 hours. Results 0 or be or reaction during the course of 6.2 hours, starting at 120 ° C and increasing "to 145 ° C after 2 hours.

This example demonstrates that Lewis acids, based on germanium, do not catalyze the esterification of cellulose at reaction rates useful in amide diluents. EXAMPLE 19 - Comparative Study The reagents cited in the following were subjected to the standard procedure described above, under standard reaction conditions, except as described in the following. The results in terms of identity of the desired cellulose ester and key product analyzes are also cited in the following. Natchez HVX Cellulose Carboxylic anhydride Acetic anhydride Equivalents 6. 0 Reaction Temperature 140-174"C DMAC Amide Diluent g Amide / g of Cellulose 10. 0 Catalyst Manganese Acetate (II) Equivalents 0. 0171 4.0 hours Reaction Time Results No reaction was observed during the course of 4.0 hours, starting at 140 ° C and increasing to 174 ° C after 1.2 hours.

This example demonstrates that Leis acids, based on manganese, do not catalyze the esterification of cellulose at reaction rates useful in amide diluents. EXAMPLE 20 • The reagents cited in the following were subjected to the standard procedure described above, under standard reaction conditions, except as described in the following. The results in terms of identity of the desired cellulose ester and key product analyzes are also cited in the following. Natchez HVX Cellulose Carboxylic anhydride Acetic anhydride Equivalents 6. 0 Reaction temperature 120 to C Diluent Urea N, N-Dimethylimidazolidinone g of Urea / g of Cellulose 7. 67 Catalyst Equivalents Titanate tetra (2-propyl) 0. 0171 Reaction time 6. 5 hours • Key Analysis DS (acetyl) = 2 .62, IV = 2. 60, GPC Mj. = 50, 000, Tg = i93 ° c, titanium content 449 ppm.

This example demonstrates that urea diluents are also useful for direct synthesis from a cellulose of a mixed high molecular weight cellulose ester, partially substituted by the use of an alkyl titanate compound as the catalyst. EXAMPLE 21 The reagents cited in the following were subjected to the standard procedure described in the above, under standard reaction conditions, except as described in the following. The results in terms of identity of the desired cellulose ester and key product analyzes are also cited in the following. Cellulose Placetate, a soft wood pulp commercially available from Rayonier Carboxylic Anhydride Propionic Anhydride Equivalents 4. 5 Reaction temperature 150 ° C Amide Diluent DMAC g of Amide / g of Cellulose 10. 0 Catalyst Titanate tetra (2-propyl) Equivalents 0.0171 Reaction Time 11.7 hours Key Analysis DS (acetyl) = 0.25, iv = 1. 64, GPC Mn = 36, 200, T = 147 ° C, Tm = 228 ° C.

This example demonstrates direct synthesis from high DP (polymerization degree), soft wood pulp cellulose from a high molecular weight cellulose acetate propionate, partially substituted by the use of an alkyl titanate compound as the catalyst. The invention has been described in detail with particular reference to its preferred embodiments, but it will be understood that variations and modifications may be made within the spirit and scope of the invention. In addition, all patents, patent applications (published or unpublished, foreign or national), references to literature or other publications cited in the foregoing are incorporated herein by reference to any disclosure pertinent to the practice of this invention.

Claims (55)

1. CLAIMS 1. A process for preparing cellulose esters having a total DS / AGU of 0.1 to 3.0, the process is characterized in that it comprises contacting the following: (i) a cellulose material, (ii) a solubilizing amount of a solvent system for the resulting cellulose esters comprising either a carboxamide diluent or a urea-based diluent, wherein the carboxamide portion of the carboxamide diluent comprises the structure: R4R5NCOCR ^ R7R8, wherein R4, R5, R6 , R7 and R8 are independently selected from the group consisting of hydrogen, alkyl having from about 1 to about 20 carbon atoms, branched alkyl having from about 1 to about 20 carbon atoms, phenyl, naphthyl, alkenyl having about 1 to about 20 carbon atoms and branched alkenyl having from about 1 to about 20 carbon atoms; and wherein the urea portion of the urea-based diluent comprises the structure: R9R10NCONR11R12, wherein R9, R10, R11 and R12 are independently selected from the group consisting of hydrogen, alkyl having from about 1 to about 20 carbon atoms, branched alkyl having from about 1 to about 20 carbon atoms, phenyl, naphthyl, alkenyl having from about 1 to about 20 carbon atoms and branched alkenyl having from about 1 to about 20 carbon atoms, (iii) a reactant of acylation selected from the group consisting of (a) an acid chloride and optionally, an acid acceptor, (b) a carboxylic acid anhydride, (c) diketene, ketene, 2, 2, 6-trimethyl-4H-1, 3-dioxin-4-one, and an acetoacetic acid ester, (d) an ester of a carboxylic acid, and combinations of one or more of (a) - (d), and (iv) a titanium-containing compound; wherein the components (i) and (ii) are in contact first and the components (iii) and (iv) are in contact with the product of contacting the components (i) and (ii), in any order .
2. 2. A process for preparing cellulose esters having a total DS / AGU of 0.1 to 3.0, the process is characterized in that it comprises contacting the following: (i) a cellulose material, (ii) a solubilizing amount of a solvent system for the resulting cellulose esters comprising a carboxamide diluent, wherein the carboxamide of the carboxamide diluent has the structure: R4R5NCOCR6R7R8, wherein R4, R5, R6, R7 and R8 are independently selected from the group consisting of hydrogen, alkyl having from about 1 to about 20 carbon atoms, branched alkyl having from about 1 to about 20 carbon atoms, phenyl, naphthyl, alkenyl having from about 1 to about 20 carbon atoms and branched alkenyl having from about 1 to about 20 carbon atoms; (iii) an acylation reagent selected from the group consisting of (a) an acid chloride and optionally an acid acceptor, (b) a carboxylic acid anhydride, (c) diketene, 2, 2, 6-trimethyl ketene -4H-1, 3-dioxin-4-one, and an acetoacetic acid ester, (d) an ester of a carboxylic acid, and combinations of one or more of (a) - (d), and (iv) a titanium-containing compound; wherein components (i) and (ii) are in contact first and components (iii) and (iv) are in contact with the product of contacting the components (i) and (ii), in any order.
3. 3. The process according to claim 2, characterized in that the cellulose esters comprise the structure: wherein R, R 'and R "are selected separately from the group consisting of: hydrogen, with the proviso that R, R' and R" are not all simultaneously hydrogen; acetoacetyl; and R1C = 0, wherein R1 is alkyl having from about 1 to about 30 carbons; carboxyalkyl of the structure (CH2) mC? 2H, where m is from 2 to 6; carboxyalkenyl of the structure, CR2 = CR3C02H, wherein R2 and R3 are independently selected from the group consisting of hydrogen, methyl, branched alkyl having from about 1 to about 30 carbons, phenyl and naphthyl; alkenyl having from about 1 to about 30 carbon atoms and from one to three double bonds or alkenyl branched having from about 1 to about 30 carbon atoms and having from one to three double bonds. The process according to claim 3, characterized in that the m of the carboxyalkyl is from 2 to 4. The process according to claim 3, characterized in that R, R 'and R "are independently selected from hydrogen , acetyl, propionyl and butyryl 6. The process according to claim 2, characterized in that the amount of the cellulose material is from about 1.0 percent to about 50 percent based on the weight of the carboxamide and the amount of the compound containing titanium is from about 0.1 percent to about 20 percent, based on the weight of the cellulose material 7. The process according to claim 2, characterized in that the amount of the cellulose material is about 9 percent. at about 28 percent, based on the weight of the carboxamide and the amount of the titanium-containing compound is from about 1.0 percent to about 10 percent, based on the weight of the cellulose material. 8. The process according to claim 2, characterized in that the total DS / AGU of the cellulose ester is from about 2.0 to about 3.0. 9. The process according to claim 2, characterized in that the total DS / AGU of the cellulose ester is from about 2.4 to about 2.9. The process according to claim 2, characterized in that the carboxamide diluent is selected from the group consisting of l-methyl-2-pyrrolidinone, N, N-dimethylpropionamide, N, N-diethylacetamide and N, N-di-ethylacetamide. 11. The process according to claim 2, characterized in that the carboxamides are selected from the group consisting of succinimides, phthalimides and glutarimides. 12. The process according to claim 2, characterized in that the acetoacetic acid ester is tert-butyl acetoacetate. 13. The process according to claim 2, characterized in that the carboxylic anhydride is selected from the group consisting of acetic anhydride, propionic anhydride, butyric anhydride, hexanoic anhydride, nonanoic anhydride, lauric anhydride, palmitic anhydride and stearic anhydride. 14. The process according to claim 2, characterized in that the esters of carboxylic acids are esters formed from the group consisting of the following acids: capric, lauric, palmitic, stearic, oleic, linoleic, linolenic, cyclohexanedicarboxylic, benzoic, substituted benzoic , phthalic, isophthalic and terephthalic. 15. The process according to claim 2, characterized in that the acid chloride is selected from the group consisting of acetyl chloride, propionyl chloride, butyryl chloride, hexanoyl chloride, lauroyl chloride, stearoyl chloride. 16. The process according to claim 2, characterized in that the acceptor acid is selected from the group consisting of pyridine, triethylamine, sodium bicarbonate and sodium acetate. 17. The process according to claim 2, characterized in that the acceptor acid is pyridine. The process according to claim 2, characterized in that the titanium-containing compounds are titanium (IV) compounds selected from the group consisting of titanic acid, titanate esters, tetra (amino) titanium compounds or mixtures thereof. 19. The process according to claim 2, characterized in that the titanium-containing compounds are selected from the group consisting of tetra (2-propyl) titanate, titanic acid, tetra (1-propyl) titanate, tetra (1-butyl) titanate and tetrakis (dimethylamino) titanium. The process according to claim 2, characterized in that the cellulose material is selected from the group consisting of hardwood pulp, soft wood pulp, cotton linters, bacterial cellulose and regenerated cellulose. 21. The process according to claim 2, characterized in that it is carried out at a temperature between about 0 ° C and about 200 ° C. 22. The process according to claim 2, characterized in that it is carried out at a temperature between about 100 ° C and about 180 ° C *. 23. The process in accordance with the claim 2, characterized in that it is carried out at a temperature between about 120 ° C and about 170 ° C. 24. The process according to claim 2, characterized in that it includes the additional step of insolubilizing the cellulose ester by the addition of an insolubilizing amount of a non-solvent. 25. The process according to claim 24, further characterized in that it comprises separating the insolubilized cellulose ester. 26. The process according to claim 25, characterized in that the non-solvent is methanol, ethanol, propanol, water or a mixture thereof. 27. A process for preparing cellulose esters having a total DS / AGU of 0.1 to 3.0, the process is characterized in that it comprises contacting the following: (i) a cellulose material, (ii) a solubilizing amount of a system of solvent for the resulting cellulose esters comprising a urea-based diluent, wherein the urea-based compound of the urea-based diluent has the structure: R9R10NCONR11R12, wherein R9, R10, R11 and R12 are independently selected from the group consisting of hydrogen, alkyl having from about 1 to about 20 carbon atoms, branched alkyl having from about 1 to about 20 carbon atoms, phenyl, naphthyl, alkenyl having from about 1 to about 20 carbon atoms. carbon and branched alkenyl having from about 1 to about 20 carbon atoms, (iii) an acylation reagent selected from the group consisting of (a) an acid chloride and optionally, an acid acceptor, (b) a carboxylic acid anhydride, (c) diketene, ketene, 2, 2, 6-trimethyl-4H-l, 3-dioxin-4-one, and an acetoacetic acid ester, (d) an ester of an carboxylic acid, 'and combinations of one or more of (a) - (d), and (iv) a titanium-containing compound; wherein the components (i) and (ii) are in contact first and the components (iii) and (iv) are in contact with the product contacting the components (i) and (ii), in any order. 28. The method according to claim 27, characterized in that the cellulose esters comprise the structure: wherein R, R 'and R "are selected separately from the group consisting of: hydrogen, with the proviso that R, R' and R "are not all simultaneously hydrogen, acetoacetyl; R1C = 0, wherein R1 is alkyl having about 1 at about 30 carbons; carboxyalkyl of the structure (Ci ^ ^ COjH, where m is from 2 to 6; carboxyalkenyl of the structure, CR2 = CR C02H, where R2 and R3 are independently selected from the group consisting of hydrogen or methyl, branched alkyl having about 1 to about 30 carbons, phenyl and naphthyl, alkenyl having from about 1 to about 30 carbon atoms and having from one to three double bonds, or branched alkenyl having from about 1 to about 30 carbon atoms and having from one to three double bonds 29. The process according to claim 28, characterized by the m of the carboxyalkyl is from 2 to 4. 30. The process according to the claim 28, characterized in that one of R9 and R10 and one of R11 and R12 are connected to form a cyclic urea. 31. The method of compliance with the claim 29, characterized in that R, R1 and R "are independently selected from hydrogen, acetyl, propionyl and butyryl 32. The process according to claim 28, characterized in that the amount of the cellulose material is from about 1.0 percent to about 50. percent based on the weight of the carboxamide and the amount of the titanium-containing compound is from about 0.1 percent to about 20 percent, based on the weight of the cellulose material. 33. The process according to claim 28, characterized in that the amount of the cellulose material is from about 9 percent to about 28 percent, based on the weight of the carboxamide and the amount of the titanium-containing compound is about 1.0 percent to about 10 percent, based on the weight of the cellulose material. 34. The process according to claim 28, characterized in that the total DS / AGU of the cellulose ester is from about 2.0 to about 3.0. 35. The process according to claim 28, characterized in that the total DS / AGU of the cellulose ester is from about 2.4 to about 2.9. 36. The process according to claim 28, characterized in that the urea-based compound is selected from the group consisting of urea and N, N-dimethylimidazolidinone. 37. The process according to claim 28, characterized in that the acetoacetic acid ester is tert-butyl acetoacetate. 38. The process according to claim 28, characterized in that the carboxylic anhydride is selected from the group consisting of acetic anhydride, propionic anhydride, butyric anhydride, hexanoic anhydride, nonanoic anhydride, lauric anhydride, palmitic anhydride and stearic anhydride. 39. The process in accordance with the claim 28, characterized in that the esters of carboxylic acids are selected from the group consisting of the following acids: capric, lauric, palmitic, stearic, oleic, linoleic, linolenic, cyclohexanedicarboxylic, benzoic, substituted benzoic, phthalic, isophthalic and terephthalic. 40. The process according to claim 28, characterized in that the acid chloride is selected from the group consisting of acetyl chloride, propionyl chloride, butyryl chloride, hexanoyl chloride, lauroyl chloride and stearoyl chloride. 41. The process according to claim 28, characterized in that the acceptor acid is selected from the group consisting of pyridine, triethylamine, sodium bicarbonate and sodium acetate. 42. The process in accordance with the claim 28, characterized in that the acceptor acid is pyridine. 43. The process according to claim 28, characterized in that the titanium-containing compounds are titanium (IV) compounds selected from the group consists of titanic acid, titanate esters, tetra (amino) titanium compounds or mixtures thereof. 44. The process according to claim 28, characterized in that the titanium containing compounds are selected from the group consisting of tetra (2-propyl) titanate, titanic acid, tetra (1-propyl) titanate, tetra titanate ( 1-butyl) and tetrakis (dimethylamino) titanium. 45. The process according to claim 28, characterized in that the cellulose material is selected from the group consisting of hardwood pulp, softwood pulp, cotton linters, bacterial cellulose and regenerated cellulose. 46. The process according to claim 28, characterized in that it is carried out at a temperature between about 0 ° C and about 200 ° C. 47. The process according to claim 28, characterized in that it is carried out at a temperature between about 100 ° C and about 180 ° C. 48. The process according to claim 28, characterized in that it is carried out at a temperature between about 120 ° C and about 170 ° C. 49. The process according to claim 28, characterized in that it includes the additional step of insolubilizing the cellulose ester by the addition of an insolubilizing amount of a non-solvent. 50. The process according to claim 49, further characterized in that it comprises separating the insolubilized cellulose ester. 51. The process according to claim 49, characterized in that the non-solvent is methanol, ethanol, propanol, water or a mixture thereof. 52. The process according to claim 1, 2 or 27, characterized in that after contacting, the resulting esterified cellulose is a partially esterified cellulose having a total DS / AGU of less than 3.0 and the partially esterified cellulose is not hydrolyzes during the contacting step or at a subsequent stage. 53. The process according to claims 1, 2 or 27, characterized in that the solvent system does not contain lithium chloride. 54. The process according to claims 1, 2 or 28, characterized in that after contact, the resulting esterified cellulose is a partially esterified cellulose, having a total DS / AGU of less than 3.0 and the partially esterified cellulose is not hydrolyzed during the contact or a subsequent stage. 55. The process according to claims 1, 2 or 28, characterized in that the solvent system does not contain lithium chloride.