Regioselectively substituted cellulose esters

Abstract

This application discloses regioselectively substituted cellulose esters, films made from the regioselectively substituted cellulose esters, and methods for their preparation. The regioselectively substituted cellulose esters are synthesized using trifluoroacetic anhydride and cellulose with various acyl donors or acyl donor precursors.

Description

[Technical field]

[0001] FIELD OF THEINVENTION The present invention relates to the fields of cellulose chemistry, cellulose ester compositions, methods for making cellulose esters, and films made from cellulose esters. [Background technology]

[0002] 2. Background of the Invention Cellulose is a β-1,4-linked polymer of anhydroglucose. It is typically a high molecular weight polydisperse polymer that is insoluble in water and virtually all common organic solvents. The use of unmodified cellulose in wood or cotton products such as housing or fabrics is well known. Unmodified cellulose is also utilized in a variety of other applications, usually as films such as cellophane, fibers such as viscose rayon, or powders such as microcrystalline cellulose used in pharmaceutical applications. Modified cellulose, such as cellulose esters, is also widely utilized in a wide variety of commercial applications. Prog. Polym. Sci. 2001, 26, 1605-1688. Cellulose esters are generally prepared by first converting cellulose to a cellulose triester and then hydrolyzing the cellulose triester to the desired degree of substitution in an acidic aqueous medium. Hydrolysis of cellulose triacetate under these conditions produces a random copolymer that can be composed of eight monomers depending on the final degree of substitution. Macromolecules 1991, 24, 3050.

[0003] This application describes novel regioselectively substituted cellulose esters prepared by first treating cellulose with trifluoroacetic anhydride in trifluoroacetic acid, and then adding an acyl donor or an acyl donor precursor. Summary of the Invention

[0004] Summary of the Invention The present application discloses regioselectively substituted cellulose esters including: (i) Multiple R 1 -CO- substituents, and (ii) multiple hydroxyl substituents; Here, R at C2 position 1 -CO- substitution degree ("C2DS R1 ") is in the range of about 0.2 to about 1.0, C3rd place R 1 -CO- substitution degree ("C3DS R1 ") is in the range of about 0.2 to about 1.0, C6th place R 1 -CO- substitution degree ("C6DS R1 ") is in the range of about 0 to about 0.5, The degree of hydroxyl substitution is in the range of about 0 to about 2.6; R 1 (C 1-20 ) alkyl, halo(C 1-20 ) alkyl, (C 2-20 ) alkenyl, (C 3-7 ) cycloalkyl, (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 2 or a 5-20 membered heteroaryl containing 1-3 heteroatoms independently selected from oxygen, sulfur and nitrogen (heteroaryl is unsubstituted or substituted with 1-6 R 3 substituted with a aryl group; R 2 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) aryl or nitro; and R 3 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) aryl or nitro.

[0005] The present application also discloses regioselectively substituted cellulose esters, including: (i) Multiple R 1 -CO- substituent, (ii) Multiple R 4 -CO- substituent, (iii) multiple hydroxyl substituents; Here, R at C2 position 1 -CO- substitution degree ("C2DS R1 ") is in the range of about 0.2 to about 1.0, C3rd place R 1 -CO- substitution degree ("C3DS R1 ") is in the range of about 0.2 to about 1.0, C6th place R 1 -CO- substitution degree ("C6DS R1 ") is in the range of about 0 to about 0.5, C6th place R 4 -CO- substitution degree ("C6DS R4 ") is in the range of about 0.1 to about 1.0, The degree of hydroxyl substitution is in the range of about 0 to about 2.6. R 1 (C 1-20 ) alkyl, halo(C 1-20 ) alkyl, (C 2-20 ) alkenyl, (C 3-7 ) cycloalkyl, (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 2 or a 5-20 membered heteroaryl containing 1-3 heteroatoms independently selected from oxygen, sulfur and nitrogen (heteroaryl is unsubstituted or substituted with 1-6 R 3 substituted with a aryl group; R 2 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) aryl or nitro; R 3 (C1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) aryl or nitro; R 4 (C 1-20 ) alkyl, halo(C 1-5 ) alkyl, (C 2-20 ) alkenyl, (C 3-7 ) cycloalkyl, (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 5 or a monocyclic or bicyclic heteroaryl containing 1 to 3 heteroatoms independently selected from oxygen, sulfur and nitrogen (heteroaryl is unsubstituted or substituted with 1 to 6 R 6 substituted with a aryl group; R 5 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) aryl or nitro; and R 6 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) aryl or nitro.

[0006] The present application also discloses a film made from the regioselectively substituted cellulose ester disclosed herein.The present application also discloses a method for preparing the regioselectively substituted cellulose ester disclosed herein. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] Detailed Description In this specification and in the claims that follow, reference will be made to a number of terms which shall be defined to have the following meanings.

[0008] The singular forms "a," "an," and "the" include plural referents unless the context clearly indicates otherwise.

[0009] Values ​​can be expressed as "about" or "approximately" a specified number. Similarly, ranges can be expressed herein as from "about" a particular value, and / or to "about" or another particular value. When such a range is expressed, another embodiment includes from the one particular value and / or to the other particular value. Similarly, when values ​​are expressed as approximations, by use of the antecedent "about," it will be understood that the particular value forms another embodiment.

[0010] Optical films are commonly quantified in terms of birefringence, which is related to the refractive index, n. The refractive index typically ranges from 1.4 to 1.8 for polymers in general, and can be about 1.46 to 1.50 for cellulose esters. The higher the refractive index, the slower light waves will propagate through that given material.

[0011] For an unoriented, isotropic material, the index of refraction will be the same regardless of the polarization state of the incident light wave. When a material is oriented or otherwise anisotropic, the index of refraction becomes dependent on the direction of the material. For the purposes of this invention, there are three indices of refraction that are of interest: x , n y and n z and correspond to the machine direction ("MD"), transverse direction ("TD"), and thickness direction, respectively. As a material becomes more anisotropic (e.g., by stretching), the difference between the two indices of refraction increases. This difference is called "birefringence." There are many combinations of material orientation choices, resulting in different values ​​of birefringence. The two most common are planar birefringence (or "in-plane" birefringence), Δ e and thickness birefringence (or "out-of-plane" birefringence) Δ this defined as follows:

[0012] (1a)Δ e =n x -n y (1b)Δ th =n z -(n x +n y ) / 2

[0013] Birefringence Δ e is a measure of the relative in-plane orientation between the MD and TD directions and is dimensionless. In contrast, Δ th provides a measure of the orientation through the thickness relative to the average planar orientation.

[0014] Another term often used in reference to optical films is optical retardation R. R is simply the birefringence times the thickness d of the film in question. Thus,

[0015] (2a)R e = Δ e d=(n x -n y )d (2b)R th = Δ th d=[n z -(n x +n y ) / 2]d

[0016] Retardation is a direct measure of the relative phase shift between two orthogonal light waves and is typically reported in nanometers (nm). th The definition of R th Note that authors differ in how they calculate it, especially regarding the sign (+ / -).

[0017] Materials are also known to vary with respect to their birefringence / retardation behavior. For example, most materials, when stretched, exhibit a high index of refraction along the direction of stretching and a low index of refraction perpendicular to the stretching. This is because, at the molecular level, the index of refraction is typically high along the axis of the polymer chain and low perpendicular to the chain. These materials are commonly referred to as "positively birefringent" and represent most standard polymers, including cellulose esters, currently commercially available. It should be noted that positively birefringent materials can be used to create positively or negatively birefringent films or waveplates, as will be explained later.

[0018] To avoid confusion, the birefringence behavior of the polymer molecules themselves is called "intrinsic birefringence" and is a property of the polymer. From a materials optics perspective, intrinsic birefringence is a measure of the birefringence that would occur if the material were fully stretched with all chains perfectly aligned in one direction (for most polymers, this is a theoretical limit since perfect alignment is not possible). For the purposes of this invention, it also provides a measure of the sensitivity of a given polymer to a given amount of chain orientation. For example, a sample with high intrinsic birefringence will exhibit greater birefringence during film formation than a sample with low intrinsic birefringence, even if the relative stress levels in the film are roughly the same.

[0019] A polymer can have positive, negative or zero inherent birefringence. A negative inherent birefringence polymer exhibits a high refractive index in the direction perpendicular to the stretching direction (versus the parallel direction). Certain styrene-based and acrylic resins can have negative inherent birefringence behavior due to rather bulky side groups. Depending on the composition, some cellulose esters with aromatic ring structures can also exhibit negative inherent birefringence. In contrast, zero inherent birefringence is a special case, and represents a material with zero inherent birefringence, since it does not exhibit birefringence even when stretched. Such materials can be molded, stretched or otherwise stressed during processing without exhibiting optical retardation or distortion, and therefore may be ideal for certain optical applications.

[0020] The actual compensation films used in LCDs can take a variety of forms, including biaxial films, where all three refractive indices are different and there are two optic axes, and uniaxial films, which have only one optic axis where two of the three indices are identical. There are also other classes of compensation films where the optic axis is twisted or tilted through the thickness of the film (e.g., discotic films), but these are generally less important. In general, the types of compensation films that can be made are limited by the birefringent properties of the polymer (i.e., positive, negative, or zero intrinsic birefringence). The designation may be placed before or after the type of film (e.g., +A or A+). Some examples are given below:

[0021] In the case of uniaxial films, films having the following refractive indices are designated as "+A" optical films: (3a)n x >n y =n z "+A" Optical Film In such films, the refractive index is high in the x-direction (machine direction) of the film, and is approximately the same in magnitude in the y-direction and thickness direction (and n x (smaller than ). This type of film is also called a positive uniaxial crystal structure, with the optic axis aligned along the x-direction. Such films can be made by uniaxially stretching a material with positive intrinsic birefringence, for example using a film stretcher.

[0022] In contrast, an "-A" uniaxial film is defined as follows: (3b)n x <n y =n z "-A" Optical Film

[0023] Here, the refractive index in the x-axis is lower than in the other directions (where they are approximately equal). One way to make -A optical films is to stretch a polymer with negative intrinsic birefringence, or to coat a liquid crystal polymer with negative (intrinsic) birefringence onto a surface (e.g., using an underlying etched alignment layer) so that the molecules align in a preferred direction.

[0024] In terms of retardation, the ±A optical film is R e and R th There is the following relationship between (3c): (3c)R th =-R e / 2 "±A" Optical Film

[0025] Another class of uniaxial optical films are the C optical films, which can also be "+C" or "-C". The difference between C optical films and A optical films is that in C optical films, the inherent refractive index (or optic axis) lies through the thickness rather than in the plane of the film. Thus,

[0026] (4a)n z >n y =n x "+C" Optical Film (4b)n z <n y =n x "-C" Optical Film

[0027] C optical films can be produced by utilizing stresses created during solvent casting of the film. Tensile stresses are generally created in the plane of the film due to the constraint imposed by the casting belt. This is also an essentially equibiaxial stretch. These tend to align the chains in the plane of the film, resulting in -C or +C films for positive and negative intrinsic birefringent materials, respectively. Since many cellulose ester films used in displays are solvent cast and many are inherently positively birefringent, it is clear that solvent cast cellulose esters will usually only produce -C optical films. These films can also be uniaxially stretched to make +A optical films (assuming the initial cast retardation is very low).

[0028] In addition to uniaxial optical films, biaxially stretched films can also be used. Biaxial films have three refractive indices n x , n y and n zThis can be quantified in a variety of ways, including simply listing the n x ≠ n y ≠ n z .

[0029] Certain biaxially oriented films have unique optical properties that compensate for light leakage in a pair of crossed polarizers or in-plane switching ("IPS") mode liquid crystal displays. The optical films have a parameter N ranging from about 0.4 to about 0.9, or equal to about 0.5. z and Nz is defined as follows:

[0030] (5)N z =(n x -n z ) / (n x -n y )

[0031] This parameter gives the effective out-of-plane birefringence relative to the in-plane birefringence. z can be chosen to be approximately 0.5 when used as a compensation film for a pair of crossed polarizers. z is approximately 0.5, the corresponding out-of-plane retardation R th is approximately equal to 0.0 nm.

[0032] To illustrate the compensation effect of the optical film, the light transmittance or leakage of a pair of crossed polarizers with and without compensation films is calculated by computer simulation as follows.

[0033] "Degree of substitution" refers to the average number of substituents per anhydroglucose monomer of cellulose ester. Degree of substitution can refer to the substituents, such as acyl groups, attached to anhydroglucose monomer. Degree of substitution can also refer to the number of free hydroxyl groups on anhydroglucose monomer. Degree of substitution can specify the position on anhydroglucose monomer. For example, degree of substitution can be applied to C2, C3 or C6 position of anhydroglucose monomer (e.g., C2DS, C3DS, C6DS).

[0034] [ka]

[0035] Alternatively, the positional degree of substitution can be expressed by indicating the position before the term "degree of substitution" (eg, C2 degree of substitution or combined C2 and C3 degree of substitution).

[0036] "Degree of polymerization" refers to the number of glucose units that make up one polymer molecule.

[0037] Regioselectively substituted cellulose esters suitable for use in making optical films can include multiple alkyl-acyl and multiple aryl-acyl substituents. As used herein, the term "acyl substituent" refers to a group having the structure:

[0038] [ka] represents a substituent having the following formula:

[0039] Such acyl groups in cellulose esters are generally attached to the pyranose ring of cellulose via an ester bond (ie, via an oxygen atom).

[0040] As used herein, the term "alkyl-acyl" refers to an acyl substituent where "R" is an alkyl group. Often, the carbon units of the alkyl group are included, for example, (C 1-6 ) alkyl-acyl. Examples of alkyl-acyl groups include acetyl, propionyl, butyryl, and the like.

[0041] As used herein, the term "alkyl" refers to a hydrocarbon substituent. Alkyl groups suitable for use herein can be straight-chained, branched-chained or cyclic, and can be saturated or unsaturated. Often, the carbon units in an alkyl group are included, for example, (C 1-6 ) alkyl. Alkyl groups suitable for use herein include any (C 1-20 ), (C1-12 ), (C 1-5 ) or (C 1-3 In various embodiments, alkyl is C 1-5 In yet another embodiment, the alkyl group is a C 1-3 It may be a straight chain alkyl group. Examples of suitable alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl, decyl, dodecyl, cyclopentyl and cyclohexyl groups.

[0042] The acylating agent may be any known in the art for acylation of cellulose to produce cellulose esters. In one embodiment of the present invention, the acylating agent is one or more C1-C 20The carboxylic acid anhydride may be a straight or branched alkyl or aryl carboxylic acid anhydride, a carboxylic acid halide, a diketene, or an acetoacetate ester. Examples of carboxylic acid anhydrides include, but are not limited to, acetic anhydride, propionic anhydride, butyric anhydride, isobutyric anhydride, valeric anhydride, hexanoic anhydride, 2-ethylhexanoic anhydride, nonanoic anhydride, lauric anhydride, palmitic anhydride, stearic anhydride, benzoic anhydride, substituted benzoic anhydride, phthalic anhydride, and isophthalic anhydride. Examples of carboxylic acid halides include, but are not limited to, acetyl, propionyl, butyryl, hexanoyl, 2-ethylhexanoyl, lauroyl, palmitoyl, benzoyl, substituted benzoyl, and stearoyl halides. Examples of acetoacetates include, but are not limited to, methyl acetoacetate, ethyl acetoacetate, propyl acetoacetate, butyl acetoacetate, and tert-butyl acetoacetate. In one embodiment of the present invention, the acylating reagent is at least one C2-C9 linear or branched alkyl carboxylic anhydride selected from the group consisting of acetic anhydride, propionic anhydride, butyric anhydride, 2-ethylhexanoic anhydride, nonanoic anhydride, and stearic anhydride. The acylating reagent can be added after the cellulose is dissolved in the tetraalkylammonium alkyl phosphate. If desired, the acylating reagent can be added to the tetraalkylammonium alkyl phosphate before the cellulose is dissolved in the tetraalkylammonium alkyl phosphate. In another embodiment, the tetraalkylammonium alkyl phosphate and the acylating reagent can be added simultaneously to the cellulose to form the cellulose solution.

[0043] "Haloalkyl" refers to an alkyl substituent in which at least one hydrogen is replaced with a halogen group. The carbon units in the haloalkyl group are often included, for example, halo(C 1-6 ) alkyl. Haloalkyl groups can be straight or branched. Non-limiting examples of haloalkyl include chloromethyl, trifluoromethyl, dibromoethyl, and the like.

[0044] "Alkenyl" refers to an alkyl group of at least two carbon units containing at least one double bond. The carbon units in an alkenyl group are often included, for example (C 2-6 ) alkenyl. Alkenyl groups can be straight or branched. Non-limiting examples of alkenyl include ethenyl, allyl, 1-butenyl, and the like.

[0045] "Cycloalkyl" refers to a cyclic alkyl group having at least three carbon units. The carbon units in a cycloalkyl group are often included, for example, (C 3-8 ) cycloalkyl. Non-limiting examples of cycloalkyl include cyclopropyl, cyclobutyl, cyclohexyl, cycloheptyl, and the like.

[0046] "Aryl" means an aromatic carbocyclic group. An aryl group may be monocyclic or polycyclic. If one of the rings in a polycyclic ring system is aryl, the polycyclic ring system is considered aryl. In other words, not all of the carbocyclic rings in a polycyclic aryl group need be aromatic. Carbon units in an aryl group are often included, e.g., (C 6-20 ) aryl. Non-limiting examples of aryl include phenyl, naphthalenyl, 1,2,3,4-tetrahydronaphthalenyl, and the like.

[0047] "Heteroaryl" refers to an aryl in which at least one of the carbon units in the aryl ring is replaced with a heteroatom such as O, N, and S. The heteroaryl ring may be monocyclic or polycyclic. Often, units that form a heteroaryl ring system are included, for example, 5- to 20-membered ring systems. A 5-membered heteroaryl refers to a ring system having 5 atoms that form the heteroaryl ring. Non-limiting examples of heteroaryl include pyridinyl, quinolinyl, pyrimidinyl, thiophenyl, and the like.

[0048] "Alkoxy" refers to an alkyl-O- or alkyl group terminally attached to an oxygen group. Often, carbon units are included, e.g., (C1-6 ) alkoxy. Non-limiting examples of alkoxy include methoxy, ethoxy, propoxy, and the like.

[0049] "Haloalkoxy" refers to an alkoxy in which at least one hydrogen is replaced with a halogen. Often, a carbon unit is included, such as halo(C 1-6 )alkoxy. Non-limiting examples of haloalkoxy include trifluoromethoxy, bromomethoxy, 1-bromo-ethoxy, and the like.

[0050] "Halo" means halogen such as fluoro, chloro, bromo or iodo.

[0051] An "inverted A film" is a film that meets the following criteria: the in-plane retardation, measured at 589 nm, is in the range of about 100 nm to about 300 nm, and the R e 450 / R e 550 is less than 1, and R e 650 / R e 550 is over 1, R e 450, R e 550 and R e 650 is the in-plane retardation value of the film when measured at wavelengths of 450 nm, 550 nm and 650 nm, respectively.

[0052] An "inverse NRZ film" is a film that satisfies the following conditions: e ") ranges from about 100 nm to about 300 nm when measured at 589 nm, and the out-of-plane retardation ("R th ") is in the range of about -50 nm to about 0 nm, and R e 450 / R e 550 is less than 1, and R e 650 / R e 550 exceeds 1, where R e 450, R e 550 and R e 650 is the in-plane retardation value of the film when measured at wavelengths of 450 nm, 550 nm and 650 nm, respectively.

[0053] "NRZ film" means a film that meets the following criteria: Z =(n x -n z ) / (n x -n y )=0.5 N Z Use the value, or R th =[n z -(n x +n y ) / 2]*d=0 R th Use the value, where n x , n y and n z are the refractive indices of the film in the x, y, and z directions, respectively, and d is the film thickness.

[0054] As used herein, the term "chosen from" used in conjunction with "and" or "or" has the following meaning: A variable selected from A, B, and C means that the variable can be A alone, B alone, or C alone. The variables A, B, or C mean that the variable is A alone, B alone, C alone, a combination of A and B, a combination of B and C, a combination of A and C, or a combination of A, B, and C.

[0055] The cellulose ester prepared by the method of the present invention is useful in various applications.Those skilled in the art will understand that factors such as the type of acyl substituent, DS, MW and the type of cellulose ester copolymer significantly affect the physical properties of cellulose ester, so specific applications depend on the specific type of cellulose ester. Prog. Polym. Sci. 2001, 26, 1605-1688.

[0056] In yet another embodiment of the present invention, cellulose ester is used for coating applications.Examples of coating applications include, but are not limited to, automotive, wood, plastic or metal coating.Examples of cellulose esters suitable for coating applications include cellulose acetate, cellulose propionate, cellulose butyrate, cellulose acetate propionate, cellulose acetate butyrate or mixtures thereof.

[0057] In yet another embodiment of the present invention, cellulose ester is used in the application involving solvent casting of film.Examples of these applications include photographic film and protective and compensation film for liquid crystal display.Examples of cellulose ester that are preferred for use in solvent cast film applications include cellulose triacetate, cellulose acetate, cellulose propionate and cellulose acetate propionate.

[0058] In yet another embodiment of the present invention, the cellulose ester of the present invention can be used in the application involving solvent casting of film.Examples of such applications include photographic film, protective film for LCD and compensation film.Examples of the cellulose ester suitable for use in solvent casting film applications include, but are not limited to, cellulose triacetate, cellulose acetate, cellulose propionate and cellulose acetate propionate.

[0059] In one embodiment of the present invention, the film comprising the cellulose ester of the present invention is produced and used as protective film and compensation film for LCD.These films can be prepared by solvent casting as described in US Patent Application No. 2009 / 0096962 or melt extrusion as described in US Patent No. 8,344,134, both of which are incorporated in their entirety into the present invention to the extent that they do not contradict the description herein.

[0060] When used as a protective film, the film is typically laminated to either side of an oriented iodized PVOH polarizing film to protect the PVOH layer from scratches and moisture while also providing structural rigidity. When used as a compensation film (or plate), the film can be laminated with a polarizer stack or otherwise included between the polarizer and the liquid crystal layer. These compensation films can improve the contrast ratio, wide viewing angle, and color shift performance of LCDs. The reason for this important function is that in a typical pair of crossed polarizers used in LCDs, there is significant light leakage along the diagonal (leading to a low contrast ratio), especially as the viewing angle increases. It is known that various combinations of optical films can be used to correct or "compensate" for this light leakage. These compensation films must have a specific, well-defined retardation (or birefringence) value, which varies depending on the type or mode of liquid crystal cell used. This is because the liquid crystal cell itself also imparts a certain degree of undesirable optical retardation that needs to be corrected.

[0061] Compensation films are generally quantified in terms of birefringence, which is then related to the refractive index, n. For cellulose esters, the refractive index is approximately 1.46 to 1.50. For an unoriented, isotropic material, the refractive index will be the same regardless of the polarization state of the incident light wave. Once the material is oriented, or otherwise anisotropic, the refractive index will depend on the orientation of the material. For the purposes of this invention, n x , n y and n z There are three important refractive indices, denoted as Δ and Δ , which correspond to the MD, TD and thickness directions, respectively. As the material becomes more anisotropic (e.g., due to stretching), the difference between the two indices becomes larger. This difference in the indices is called the birefringence of the material for a particular combination of indices. There are many combinations of material orientation choices, and therefore a corresponding range of birefringence values. The two most common birefringence parameters are Δ e =n x -n y and Δ th =n z-(n x +n y Thickness birefringence (Δ th ) Birefringence Δ e is a measure of the relative in-plane orientation between MD and TD and is dimensionless. In contrast, Δ th provides a measure of the orientation through the thickness relative to the average planar orientation.

[0062] The optical retardation (R) is related to the birefringence by the film thickness (d); R e = Δ e d=(n x -n y )d;R th = Δ th d=[n z -(n x +n y ) / 2]. Retardation is a direct measure of the relative phase shift between two orthogonal light waves and is typically reported in nanometers (nm). th Please note that the definition of varies from author to author, especially with regard to the sign (±).

[0063] Materials are also known to vary with respect to their birefringence / retardation behavior. For example, most materials, when stretched, exhibit a high refractive index along the direction of stretching and a low refractive index perpendicular to the stretching. This is because, at the molecular level, the refractive index is typically high along the axis of the polymer chain and low perpendicular to the chain. These materials are commonly referred to as "positively birefringent" and represent most standard polymers, including all current conventional cellulose esters.

[0064] To avoid confusion, the birefringence behavior of the polymer molecules themselves is called "intrinsic birefringence" and is a property of the polymer. From a materials optics perspective, intrinsic birefringence is a measure of the birefringence that would occur if a material were fully stretched with all chains perfectly aligned in one direction (for most polymers, this is a theoretical limit since perfect alignment is not possible). For the purposes of this invention, it also provides a measure of the sensitivity of a given polymer to a given amount of chain orientation. For example, a sample with high intrinsic birefringence will exhibit greater birefringence during film formation than a sample with low intrinsic birefringence, even if the relative stress levels in the film are roughly the same.

[0065] A polymer can have positive, negative or zero inherent birefringence. A negative (intrinsic) birefringent polymer exhibits a higher refractive index in the direction perpendicular to the stretching direction (versus the parallel direction), and therefore also has a negative inherent birefringence. Certain styrene-based and acrylic resins are known to have negative inherent birefringence due to their rather bulky side groups. Depending on the composition, some cellulose esters with aromatic ring structures also exhibit negative inherent birefringence. In contrast, zero inherent birefringence is a special case, and represents a material with zero inherent birefringence, since it does not exhibit birefringence even when stretched. Such materials are ideal for optical applications, since they can be molded, stretched or otherwise stressed during processing without exhibiting optical retardation or distortion.

[0066] The actual compensation films used in LCDs can take a variety of forms, including biaxial films in which all three indices are different and there are two optic axes, and uniaxial films in which two of the three indices are the same and there is only one optic axis. There are also other classes of compensation films in which the optic axis is twisted or tilted through the thickness of the film (e.g., discotic films), but these are not as important to understanding the present invention. The important point is that the types of compensation films that can be made are limited by the birefringence properties of the polymer (i.e., positive, negative, or zero intrinsic birefringence).

[0067] Compensation films or plates can take many forms depending on the mode in which the LCD display device operates. For example, a C-plate compensation film is isotropic in the xy plane, and the plate can be positive (+C) or negative (-C). In the case of a +C plate, n x =n y <n z In the case of a -C plate, n x =n y >n z Another example is an A-plate compensation film that is isotropic in the yz direction. Again, the plate can be positive (+A) or negative (-A). For a +A plate, n x >n y =n z In the case of -A plate, n x <n y =n z It is.

[0068] In general, aliphatic cellulose esters have a R in the range of about 0 to about -350 nm at a film thickness of 60 μm. th Provide the value of the observed R th The most important factors affecting the DS are the type of substituent and OH Very low DS OH The films made using the cellulose mixed esters have R values ​​ranging from about 0 to about -50 nm. th The DS of cellulose mixed esters was 1.0. OH By significantly increasing R th It has been shown that larger absolute values ​​of cellulose acetate can be obtained. US Patent Application Publication No. 2009 / 0096962. Cellulose acetate is typically OH R ranges from about -40 to about -90 nm depending on the th Provide a value.

[0069] The cellulose ester of the present invention can be used to obtain the desired R eTo obtain the R value, the film must be stretched. The stretching conditions, such as stretching temperature, stretch type (uniaxial or biaxial), stretch ratio, preheat time and temperature, and post-stretch annealing time and temperature, can be adjusted to obtain the desired R value. e and R th can be achieved. The exact stretching conditions depend on the specific composition of cellulose ester, the amount and type of plasticizer, and the glass transition temperature of that particular composition. Thus, the specific stretching conditions can vary widely. The stretching temperature can range from 140°C to 190°C. The stretch ratio can range from 1.0 to 1.3 in the machine direction (MD) and from 1.1 to 1.8 in the TD. The preheat time can range from 10 to 300 seconds, and the preheat temperature can be the same as the stretching temperature. The postannealing time can range from 0 to 300 seconds, and the postannealing temperature can range from 10°C to 40°C lower than the stretching temperature. The thickness of the film depends on the thickness of the film before stretching and the stretching conditions. After stretching, the preferred film thickness is about 10 μm to about 200 μm. More preferred is when the film thickness is about 20 μm to about 100 μm. Even more preferably, the film has a thickness of about 25 μm to about 70 μm.

[0070] Regioselectively substituted cellulose esters The present invention discloses regioselectively substituted cellulose esters comprising: (i) a plurality of R 1 (ii) multiple hydroxyl substituents, where R 1 -CO- substitution degree ("C2DS R1 ") is in the range of about 0.2 to about 1.0, and the R 1 -CO- substitution degree ("C3DS R1 ") is in the range of about 0.2 to about 1.0, and the R 1 -CO- substitution degree ("C6DS R1 ") is in the range of about 0 to about 0.5, the degree of substitution of hydroxyl is in the range of about 0 to about 2.6, R 1 (C 1-20 ) alkyl, halo(C 1-20 ) alkyl, (C 2-20) alkenyl, (C 3-7 ) cycloalkyl, (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 2 or a 5-20 membered heteroaryl containing 1-3 heteroatoms independently selected from oxygen, sulfur and nitrogen (heteroaryl is unsubstituted or substituted with 1-6 R 3 substituted with R 2 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) aryl or nitro; R 3 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 ) alkoxy, halo, (C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) aryl or nitro.

[0071] In one embodiment, the degree of substitution of hydroxyl is in the range of about 0.5 to about 2.6. In one embodiment, the degree of substitution of hydroxyl is in the range of about 0.1 to about 2.6. In one embodiment, the degree of substitution of hydroxyl is in the range of about 0.2 to about 2.6. In one embodiment, the degree of substitution of hydroxyl is in the range of about 0.3 to about 2.6. In one embodiment, the degree of substitution of hydroxyl is in the range of about 0.4 to about 2.6.

[0072] In one embodiment of the regioselectively substituted cellulose ester, the weight average molecular weight ("M w In one embodiment of the regioselectively substituted cellulose ester, the weight average molecular weight ("M wIn one embodiment of the regioselectively substituted cellulose ester, the weight average molecular weight ("M w In one embodiment of the regioselectively substituted cellulose ester, the weight average molecular weight ("M w In one embodiment of the regioselectively substituted cellulose ester, the weight average molecular weight ("M w In one embodiment of the regioselectively substituted cellulose ester, the weight average molecular weight ("M w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0073] In one embodiment of the regioselectively substituted cellulose ester, R 1 is (C 1-20 ) alkyl, halo(C 1-20 ) alkyl or (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 2 substituted with a aryl group; and R 2 is (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) aryl or nitro. In one class of this embodiment, the weight average molecular weight ("M w In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 80,000 Da to about 250,000 Da. wIn one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0074] In one embodiment of the regioselectively substituted cellulose ester, R 1 (C 1-20 In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is selected from alkyl. w In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 80,000 Da to about 250,000 Da. w In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0075] In one embodiment of the regioselectively substituted cellulose ester, R 1 (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 2 substituted with R 2 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) aryl or nitro. In one class of this embodiment, the weight average molecular weight ("M w In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 80,000 Da to about 250,000 Da. wIn one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0076] In one embodiment of the regioselectively substituted cellulose ester, R 1 is selected from methyl, ethyl, propyl, 1-ethyl-pentyl-, phenyl, 3,4,5-trimethoxyphenyl, 2-naphthyl, benzothiophenyl, or heptadecanyl. In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is w In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 80,000 Da to about 250,000 Da. w In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0077] In one embodiment of the regioselectively substituted cellulose ester, R 1 -CO- substitution degree ("C6DS R1 In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 0 to about 0.3. w In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 80,000 Da to about 250,000 Da. w In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0078] In one class of this embodiment, R 1 is (C 1-20 ) alkyl, halo(C 1-20 ) alkyl or (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 2 substituted with R 2 is (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 In a subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is selected from aryl or nitro. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0079] In one class of this embodiment, R 1 (C 1-20 In a subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is selected from the group consisting of alkyl, aryl ... w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 150,000 Da. w" ) is in the range of about 100,000 Da to about 150,000 Da.

[0080] In one class of this embodiment, R 1 (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 2 substituted with R 2 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 In a subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is selected from aryl or nitro. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0081] In one class of this embodiment, R 1 is selected from methyl, ethyl, propyl, 1-ethyl-pentyl-, phenyl, 3,4,5-trimethoxyphenyl, 2-naphthyl, benzothiophenyl, or heptadecanyl. In a subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 250,000 Da. wIn one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0082] In one embodiment of the regioselectively substituted cellulose ester, R 1 -CO- substitution degree ("C6DS R1 In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 0 to about 0.1. w In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 80,000 Da to about 250,000 Da. w In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0083] In one class of this embodiment, R 1 is (C 1-20 ) alkyl, halo(C 1-20 ) alkyl or (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 2 substituted with R 2 is (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 In a subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is selected from aryl or nitro. wIn one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0084] In one class of this embodiment, R 1 (C 1-20 In a subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is selected from the group consisting of alkyl, aryl ... w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0085] In one class of this embodiment, R 1 (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 2 substituted with R 2 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 In a subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is selected from aryl or nitro. wIn one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0086] In one class of this embodiment, R 1 is selected from methyl, ethyl, propyl, 1-ethyl-pentyl-, phenyl, 3,4,5-trimethoxyphenyl, 2-naphthyl, benzothiophenyl, or heptadecanyl. In a subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0087] In one embodiment of the regioselectively substituted cellulose ester, R 1 -CO- substitution degree ("C6DS R1 In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 0 to about 0.08. w In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 80,000 Da to about 250,000 Da. wIn one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0088] In one class of this embodiment, R 1 is (C 1-20 ) alkyl, halo(C 1-20 ) alkyl or (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 2 substituted with R 2 is (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 In a subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is selected from aryl or nitro. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0089] In one class of this embodiment, R 1 (C 1-20 In a subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is selected from the group consisting of alkyl, aryl ... wIn one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0090] In one class of this embodiment, R 1 (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 2 substituted with R 2 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 In a subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is selected from aryl or nitro. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0091] In one class of this embodiment, R 1is selected from methyl, ethyl, propyl, 1-ethyl-pentyl-, phenyl, 3,4,5-trimethoxyphenyl, 2-naphthyl, benzothiophenyl, or heptadecanyl. In a subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0092] In one embodiment of the regioselectively substituted cellulose ester, R 1 -CO- substitution degree ("C6DS R1 In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 0 to about 0.06. w In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 80,000 Da to about 250,000 Da. w In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0093] In one class of this embodiment, R 1 is (C 1-20 ) alkyl, halo(C 1-20 ) alkyl or (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 2 substituted with R 2 is (C 1-6) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 In a subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is selected from aryl or nitro. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0094] In one class of this embodiment, R 1 (C 1-20 In a subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is selected from the group consisting of alkyl, aryl ... w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0095] In one class of this embodiment, R 1 (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 2 substituted with R 2 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 In a subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is selected from aryl or nitro. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0096] In one class of this embodiment, R 1 is selected from methyl, ethyl, propyl, 1-ethyl-pentyl-, phenyl, 3,4,5-trimethoxyphenyl, 2-naphthyl, benzothiophenyl, or heptadecanyl. In a subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0097] In one embodiment of the composition of matter, R 1 -CO- substitution degree ("C6DS R1 In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 0 to about 0.04. wIn one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 80,000 Da to about 250,000 Da. w In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0098] In one class of this embodiment, R 1 is (C 1-20 ) alkyl, halo(C 1-20 ) alkyl or (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 2 substituted with R 2 is (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 In a subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is selected from aryl or nitro. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0099] In one class of this embodiment, R 1 (C 1-20 In a subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is selected from the group consisting of alkyl, aryl ...w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0100] In one class of this embodiment, R 1 (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 2 substituted with R 2 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 In a subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is selected from aryl or nitro. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0101] In one class of this embodiment, R 1is selected from methyl, ethyl, propyl, 1-ethyl-pentyl-, phenyl, 3,4,5-trimethoxyphenyl, 2-naphthyl, benzothiophenyl, or heptadecanyl. In a subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0102] In one embodiment of the regioselectively substituted cellulose ester, R 1 (C 1-20 ) alkyl. In one embodiment of the regioselectively substituted cellulose ester, R 1 Halo(C 1-20 ) alkyl. In one embodiment of the regioselectively substituted cellulose ester, R 1 (C 2-20 ) alkenyl. In one embodiment of the regioselectively substituted cellulose ester, R 1 (C 3-7 ) cycloalkyl. In one embodiment of the regioselectively substituted cellulose ester, R 1 (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 2 substituted with R 2 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10) aryl or nitro. In one embodiment of the regioselectively substituted cellulose ester, R 1 is a 5-20 membered heteroaryl containing 1-3 heteroatoms independently selected from oxygen, sulfur and nitrogen (heteroaryl is unsubstituted or has 1-6 R 3 substituted with R 3 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) aryl or nitro.

[0103] In one embodiment of the regioselectively substituted cellulose ester, R 1 (C 1-20 ) alkyl, halo(C 1-20 ) alkyl, (C 2-20 ) alkenyl, (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 2 or a 5-20 membered heteroaryl containing 1-3 heteroatoms independently selected from oxygen, sulfur and nitrogen (heteroaryl is unsubstituted or substituted with 1-6 R 3 substituted with a group.

[0104] In one embodiment of the regioselectively substituted cellulose ester, R 1 is (C 1-20 ) alkyl, halo(C 1-20 ) alkyl or (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 2 substituted with R 2 is (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10) aryl or nitro.

[0105] In one embodiment of the regioselectively substituted cellulose ester, R 1 is selected from methyl, ethyl, propyl, 1-ethyl-pentyl-, phenyl, 3,4,5-trimethoxyphenyl, 2-naphthyl, benzothiophenyl or heptadecanyl.

[0106] In one embodiment of the regioselectively substituted cellulose ester, the regioselectively substituted cellulose ester comprises a plurality of R 4 Further containing a -CO- substituent, R 4 -CO- substitution degree ("C6DS R4 ") is in the range of about 0.1 to about 1.0, and R 4 (C 1-20 ) alkyl, halo(C 1-5 ) alkyl, (C 2-20 ) alkenyl, (C 3-7 ) cycloalkyl, (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 5 or a monocyclic or bicyclic heteroaryl containing 1 to 3 heteroatoms independently selected from oxygen, sulfur and nitrogen (heteroaryl is unsubstituted or substituted with 1 to 6 R 6 substituted with R 5 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) aryl or nitro; R 6 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) aryl or nitro.

[0107] In one class of this embodiment, R at the C2 position 4 -CO- substitution degree ("C2DS R4 ") is in the range of about 0 to about 0.5, where R 4 -CO- substitution degree ("C3DS R4 In a subclass of this class, the weight average molecular weight ("M") is in the range of about 0 to about 0.5. w In one subclass of this class, the weight average molecular weight ("M") is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") is in the range of about 80,000 Da to about 100,000 Da. w " ) is in the range of about 100,000 Da to about 250,000 Da.

[0108] In one class of this embodiment, R at the C2 position 4 -CO- substitution degree ("C2DS R4 ") ranges from about 0 to about 0.4, where R 4 -CO- substitution degree ("C3DS R4 In a subclass of this class, the weight average molecular weight ("M w In one subclass of this class, the weight average molecular weight ("M") ranges from about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") is in the range of about 80,000 Da to about 100,000 Da. w " ) is in the range of about 100,000 Da to about 250,000 Da.

[0109] In one class of this embodiment, R at the C2 position 4 -CO- substitution degree ("C2DS R4 ") ranges from about 0 to about 0.3, where R 4 -CO- substitution degree ("C3DS R4 In a subclass of this class, the weight average molecular weight ("Mw In one subclass of this class, the weight average molecular weight ("M") is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") is in the range of about 80,000 Da to about 100,000 Da. w " ) is in the range of about 100,000 Da to about 250,000 Da.

[0110] In one class of this embodiment, R at the C2 position 4 -CO- substitution degree ("C2DS R4 ") ranges from about 0 to about 0.2, where R 4 -CO- substitution degree ("C3DS R4 In a subclass of this class, the weight average molecular weight ("M w In one subclass of this class, the weight average molecular weight ("M") is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") is in the range of about 80,000 Da to about 100,000 Da. w " ) is in the range of about 100,000 Da to about 250,000 Da.

[0111] In one class of this embodiment, the weight average molecular weight ("M w " ) is in the range of about 80,000 Da to about 250,000 Da.

[0112] In one class of this embodiment, the weight average molecular weight ("M w " ) is in the range of about 80,000 Da to about 100,000 Da.

[0113] In one class of this embodiment, the weight average molecular weight ("M w " ) is in the range of about 100,000 Da to about 250,000 Da.

[0114] In one class of this embodiment, R 4 (C1-20 ) alkyl. In one class of this embodiment, R 4 Halo(C 1-5 ) alkyl.

[0115] In one class of this embodiment, R 4 (C 2-20 ) alkenyl.

[0116] In one class of this embodiment, R 4 (C 3-7 ) cycloalkyl.

[0117] In one class of this embodiment, R 4 (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 5 substituted with R 5 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) aryl or nitro.

[0118] In one class of this embodiment, R 4 is a monocyclic or bicyclic heteroaryl containing 1 to 3 heteroatoms independently selected from oxygen, sulfur and nitrogen, wherein the heteroaryl is unsubstituted or has 1 to 6 R 6 substituted with R 6 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) aryl or nitro.

[0119] In one class of this embodiment, R 4is selected from methyl, ethyl, propyl, 1-ethyl-pentyl-, phenyl, 3,4,5-trimethoxyphenyl, 2-naphthyl, benzothiophenyl, or heptadecanyl. In a subclass of this class, R 4 is methyl. In a subclass of this class, R 4 is ethyl. In a subclass of this class, R 4 is propyl. In a subclass of this class, R 4 is 1-ethyl-pentyl-. In a subclass of this class, R 4 is phenyl. In a subclass of this class, R 4 In one subclass of this class, R 4 is 2-naphthyl. In a subclass of this class, R 4 In a subclass of this class, R 4 is heptadecanyl.

[0120] In one embodiment, C6DS R1-CO- is less than 0.1. R1-CO- is less than 0.08. R1-CO- is less than 0.06. R1-CO- is less than 0.05. R1-CO- is less than 0.04. R1-CO- is less than 0.02.

[0121] In one embodiment, R 1 -CO- is selected from acetyl, propionyl, butanoyl, benzoyl, naphthoyl, 3,4,5-trimethoxybenzoyl, biphenyl-CO-, benzoyl-benzoyl or benzothiophenyl-CO-.

[0122] In one embodiment, R 1-CO- is propionyl. In one class of this embodiment, propionyl (i.e., R 1 The degree of substitution of propionyl at the C2 position (-CO- is propionyl) is about 1.0 to about 1.4, and the degree of substitution of propionyl at the C2 position ("C2DS Pr ") is 0.6-0.9, and the degree of substitution of propionyl at the C3 position ("C3DS Pr In one subclass of this class, the degree of substitution of propionyl at the C6 position ("C6DS") is about 0.3 to about 0.5. Pr " ) is less than 0.05.

[0123] In one embodiment, R 1 -CO- is a combination comprising benzoyl and naphthoyl. In one class of this embodiment, the degree of substitution of benzoyl is from about 0.2 to about 1.2, and the degree of substitution of naphthoyl is from about 0.8 to about 1.8.

[0124] In one class of this embodiment, the degree of substitution of benzoyl is from about 0.4 to about 0.8, the degree of substitution of naphthoyl is from about 1.2 to about 1.6, and the degree of substitution of the combination of benzoyl and naphthoyl at the C6 position is less than 0.05.

[0125] In one embodiment, R 1 -CO- is propionyl and (C 6-20 In one class of this embodiment, propionyl and (C 6-20 ) The degree of substitution at the C6 position of the aryl combination is less than 0.1.

[0126] In one embodiment, R 1 -CO- is a combination comprising propionyl and benzoyl. In one class of this embodiment, the degree of substitution of propionyl is from about 0.4 to about 0.7, the degree of substitution of benzoyl is from about 0.2 to about 0.5, and the degree of substitution at the C6 position of the combination of propionyl and benzoyl is less than 0.05.

[0127] In one class of this embodiment, the degree of substitution of propionyl is from about 1.1 to about 1.8, the degree of substitution of benzoyl is from about 0.1 to about 0.5, and the degree of substitution at the C6 position of the combination of propionyl and benzoyl is less than 0.05.

[0128] In one embodiment, R 1 -CO- is a combination comprising propionyl and naphthoyl. In one class of this embodiment, the degree of substitution of propionyl is in the range from 0.2 to 0.9, and the degree of substitution of naphthoyl is in the range from 0.4 to 1.4.

[0129] In one embodiment, R 1 -CO- is a combination comprising propionyl, or a 5-20 membered heteroaryl containing 1 to 3 heteroatoms independently selected from oxygen, sulfur, and nitrogen. In one class of this embodiment, the degree of substitution of propionyl is in the range of 0.2 to 0.4, and the degree of substitution of naphthoyl is in the range of 0.9 to 1.1.

[0130] In one embodiment, R1-CO- is propionyl and (C 6-20 ) alkyl-CO-.

[0131] In one embodiment, R 1 -CO- is acetyl and (C 6-20 In one class of this embodiment, the degree of substitution of acetyl is from about 0.7 to about 0.9, and (C 6-20 The degree of substitution of aryl-CO- is about 0.1 to about 0.5, and acetyl and (C 6-20 ) The degree of substitution at the C6 position of the aryl-CO- combination is less than 0.1.

[0132] In one embodiment, R 1-CO- is a combination including acetyl and 5-20 membered heteroaryl containing 1 to 3 heteroatoms independently selected from oxygen, sulfur, and nitrogen. In one class of this embodiment, the degree of substitution of acetyl is about 0.8 to about 1.1, the degree of substitution of 5-20 membered heteroaryl containing 1 to 3 heteroatoms independently selected from oxygen, sulfur, and nitrogen is about 0.1 to about 0.3, and the degree of substitution at the C6 position of the combination of acetyl and benzoyl is less than 0.1.

[0133] The present application also discloses regioselectively substituted cellulose esters comprising: (i) a plurality of R 1 (ii) a plurality of R 4 (iii) multiple hydroxyl substituents, where R 1 -CO- substitution degree ("C2DS R1 ") is in the range of about 0.2 to about 1.0, and R 1 -CO- substitution degree ("C3DS R1 ") is in the range of about 0.2 to about 1.0, and the R 1 -CO- substitution degree ("C6DS R1 ") is in the range of about 0 to about 0.5, and the R 4 -CO- substitution degree ("C6DS R4 ") is in the range of about 0.1 to about 1.0, the degree of substitution of hydroxyl is in the range of about 0 to about 2.6, R 1 (C 1-20 ) alkyl, halo(C 1-20 ) alkyl, (C 2-20 ) alkenyl, (C 3-7 ) cycloalkyl, (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 2 or a 5-20 membered heteroaryl containing 1-3 heteroatoms independently selected from oxygen, sulfur and nitrogen (heteroaryl is unsubstituted or substituted with 1-6 R 3 substituted with R 2 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6)Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) aryl or nitro; R 3 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) aryl or nitro; R 4 (C 1-20 ) alkyl, halo(C 1-5 ) alkyl, (C 2-20 ) alkenyl, (C 3-7 ) cycloalkyl, (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 5 or a monocyclic or bicyclic heteroaryl containing 1 to 3 heteroatoms independently selected from oxygen, sulfur and nitrogen (heteroaryl is unsubstituted or substituted with 1 to 6 R 6 substituted with R 5 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) aryl or nitro; R 6 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) aryl or nitro.

[0134] In one embodiment, the degree of substitution of hydroxyl is in the range of about 0.5 to about 2.6. In one embodiment, the degree of substitution of hydroxyl is in the range of about 0.1 to about 2.6. In one embodiment, the degree of substitution of hydroxyl is in the range of about 0.2 to about 2.6. In one embodiment, the degree of substitution of hydroxyl is in the range of about 0.3 to about 2.6. In one embodiment, the degree of substitution of hydroxyl is in the range of about 0.4 to about 2.6.

[0135] In one embodiment, R 1 -CO- is selected from acetyl, propionyl, butanoyl, benzoyl, naphthoyl, 3,4,5-trimethoxybenzoyl, biphenyl-CO-, benzoyl-benzoyl- or benzothiophene-CO-; R 4 -CO- is selected from acetyl, propionyl, butyryl, benzoyl, acetyl, naphthoyl, 3,4,5-trimethoxybenzoyl, biphenyl-CO-, benzoyl-benzoyl- or benzothiophene-CO-.

[0136] In one embodiment, C6DS R1-CO- is less than 0.1. R1-CO- is less than 0.08. R1-CO- is less than 0.06. R1-CO- is less than 0.05. R1-CO- is less than 0.04. R1-CO- is less than 0.02.

[0137] In one embodiment, R 1 -CO- is propionyl.

[0138] In one class of this embodiment, R 4 -CO- is (C 6-20 ) aryl-CO-.

[0139] In one class of this embodiment, R 4-CO- is pivaloyl and (C 6-20 In a subclass of this class, (C 6-20 ) Aryl-CO- is selected from benzoyl and naphthoyl. In one subsubclass of this subclass, the degree of substitution of pivaloyl is 0.6 to 0.9. 6-20 The degree of substitution of aryl-CO- is 0.2 to 0.5.

[0140] In one class of this embodiment, the degree of substitution of propionyl is from about 1.0 to about 1.4, the degree of substitution of propionyl at the C2 position is from 0.6 to 0.9, and the degree of substitution of propionyl at C3 is from about 0.3 to about 0.5.

[0141] In a subclass of this class, the degree of substitution of propionyl at the C6 position is less than 0.05. In a subsubclass of this subclass, the degree of substitution of pivaloyl is 0.6 to 0.9, and (C 6-20 The degree of substitution of aryl-CO- is 0.2 to 0.5.

[0142] In one subclass of this class, R 4 -CO- is (C 6-20 ) aryl-CO-.

[0143] In one subclass of this class, R 4 -CO- is pivaloyl and (C 6-20 In one sub-subclass of this subclass, (C 6-20 ) aryl-CO- is selected from benzoyl and naphthoyl. In one subsubsubclass of this subsubclass, the degree of substitution of pivaloyl is 0.6 to 0.9; 6-20 ) the degree of substitution of aryl-CO- is 0.2 to 0.5. In a subsubsubsubclass of this subsubsubclass, the degree of substitution of propionyl at the C6 position is less than 0.05. In a subsubsubsubsubclass of this subsubsubclass, the degree of substitution of pivaloyl is 0.6 to 0.9; 6-20The degree of substitution of aryl-CO- is 0.2 to 0.5.

[0144] In one embodiment, R 1 -CO- is a combination including benzoyl and naphthoyl.

[0145] In one class of this embodiment, R 4 -CO- is (C 1-6 ) alkyl-CO-.

[0146] In one subclass of this class, the degree of substitution of benzoyl is from about 0.2 to about 1.2, the degree of substitution of naphthoyl is from about 0.8 to about 1.8, (C 1-6 ) The degree of substitution of alkyl-CO- is less than 0.5.

[0147] In one subsubclass of this subclass, R 4 -CO- is propionyl.

[0148] In one embodiment, R 1 -CO- is a combination of propionyl and benzoyl.

[0149] In one class of this embodiment, R 4 -CO- is a combination of propionyl and benzoyl.

[0150] In one subclass of this class, the sum of the degrees of substitution of benzoyl at the combination positions C2 and C3 is 0.1-0.6, the degree of substitution of propionyl at the combination positions C2 and C3 is 0.5-1.4, the degree of substitution of benzoyl at the combination positions C6 is 0-0.8, and the degree of substitution of propionyl at the combination positions C6 is 0-1.0.

[0151] In a subsubclass of this subclass, the degree of substitution of benzoyl at C6 is 0.1-0.2 and the degree of substitution of propionyl at C6 is 0.4-0.8.

[0152] In one subclass of this class, the sum of the degrees of substitution of benzoyl at the combination positions C2 and C3 is 0.05-2.0, the degree of substitution of propionyl at the combination positions C2 and C3 is 0.5-1.4, the degree of substitution of benzoyl at the combination positions C6 is 0-0.8, and the degree of substitution of propionyl at the combination positions C6 is 0-1.0.

[0153] In a subsubclass of this subclass, the degree of substitution of benzoyl at C6 is 0.1-0.2 and the degree of substitution of propionyl at C6 is 0.4-0.8.

[0154] In one subclass of this class, the sum of the degrees of substitution of benzoyl at the combination positions C2 and C3 is 0.6-2.0, the degree of substitution of propionyl at the combination positions C2 and C3 is 0.5-1.4, the degree of substitution of benzoyl at the combination positions C6 is 0-0.8, and the degree of substitution of propionyl at the combination positions C6 is 0-1.0.

[0155] In a subsubclass of this subclass, the degree of substitution of benzoyl at C6 is 0.1-0.2 and the degree of substitution of propionyl at C6 is 0.4-0.8.

[0156] The present application also discloses regioselectively substituted trifluoroacetyl cellulose esters, including: (i) multiple trifluoroacetyl substituents, Here, the degree of substitution at the C2 position ("C2DS TFA ") is about 0 to about 0.1, Here, the degree of substitution at the C3 position ("C3DS TFA ") is about 0 to about 0.1, Here, the degree of substitution at the C6 position ("C6DS TFA ") is about 0.9 to about 1.0, Here, the regioselectively substituted trifluoroacetyl cellulose ester has a weight average molecular weight (M) in the range of about 50,000 Da to about 600,000 Da. w ").

[0157] In one class of embodiments, the C2DS TFA is about 0 to about 0.05, and C3DS TFA is about 0 to about 0.05. In one class of embodiments, the C2DS TFA is about 0 to about 0.02, and C3DS TFA is from about 0 to about 0.02. TFA is about 0 to about 0.01, and C3DS TFA is about 0 to about 0.02.

[0158] In one class of this embodiment, the regioselectively substituted cellulose esters have a weight average molecular weight ("M") in the range of about 50,000 Da to about 250,000 Da. w In one class of this embodiment, the regioselectively substituted cellulose ester has a weight average molecular weight ("M") in the range of about 50,000 Da to about 150,000 Da. w ").

[0159] film The present application discloses a film comprising a cellulose ester comprising: (i) a plurality of R 1 (ii) a plurality of R 4 (iii) multiple hydroxyl substituents, where R 1 -CO- substitution degree ("C2DS R1 ") is in the range of about 0.2 to about 1.0, and R 1 -CO- substitution degree ("C3DS R1 ") is in the range of about 0.2 to about 1.0, and the R 1 -CO- substitution degree ("C6DS R1 ") is in the range of about 0 to about 0.5, and the R 4 -CO- substitution degree ("C6DS R4 ") is in the range of about 0.1 to about 1.0, the degree of substitution of hydroxyl is in the range of about 0 to about 2.6, R 1 (C 1-20 ) alkyl, halo(C 1-20 ) alkyl, (C 2-20 ) alkenyl, (C 3-7) cycloalkyl, (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 2 or a 5-20 membered heteroaryl containing 1-3 heteroatoms independently selected from oxygen, sulfur and nitrogen (heteroaryl is unsubstituted or substituted with 1-6 R 3 substituted with R 2 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) aryl or nitro; R 3 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) aryl or nitro; R 4 (C 1-20 ) alkyl, halo(C 1-5 ) alkyl, (C 2-20 ) alkenyl, (C 3-7 ) cycloalkyl, (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 5 or a monocyclic or bicyclic heteroaryl containing 1 to 3 heteroatoms independently selected from oxygen, sulfur and nitrogen (heteroaryl is unsubstituted or substituted with 1 to 6 R 6 substituted with R 5 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) aryl or nitro; R 6 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) aryl or nitro.

[0160] In one embodiment, the degree of substitution of hydroxyl is in the range of about 0.5 to about 2.6. In one embodiment, the degree of substitution of hydroxyl is in the range of about 0.1 to about 2.6. In one embodiment, the degree of substitution of hydroxyl is in the range of about 0.2 to about 2.6. In one embodiment, the degree of substitution of hydroxyl is in the range of about 0.3 to about 2.6. In one embodiment, the degree of substitution of hydroxyl is in the range of about 0.4 to about 2.6.

[0161] In one embodiment of the regioselective cellulose ester, the weight average molecular weight ("M w In one embodiment of the regioselective cellulose ester, the weight average molecular weight ("M w In one embodiment of the regioselective cellulose ester, the weight average molecular weight ("M w In one embodiment of the regioselective cellulose ester, the weight average molecular weight ("M w In one embodiment of the regioselective cellulose ester, the weight average molecular weight ("M w In one embodiment of the regioselective cellulose ester, the weight average molecular weight ("M w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0162] In one embodiment of the regioselective cellulose ester, R 1 is (C 1-20 ) alkyl, halo(C 1-20 ) alkyl or (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 2 substituted with R 2 is (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) aryl or nitro. In one class of this embodiment, the weight average molecular weight ("M w In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 80,000 Da to about 250,000 Da. w In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0163] In one embodiment of the regioselective cellulose ester, R 1 (C 1-20 In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is selected from alkyl. w In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 80,000 Da to about 250,000 Da. w In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 80,000 Da to about 150,000 Da. w" ) is in the range of about 100,000 Da to about 150,000 Da.

[0164] In one embodiment of the regioselective cellulose ester, R 1 (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 2 substituted with R 2 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) aryl or nitro. In one class of this embodiment, the weight average molecular weight ("M w In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 80,000 Da to about 250,000 Da. w In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0165] In one embodiment of the regioselective cellulose ester, R 1 is selected from methyl, ethyl, propyl, 1-ethyl-pentyl-, phenyl, 3,4,5-trimethoxyphenyl, 2-naphthyl, benzothiophenyl, or heptadecanyl. In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is w In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 80,000 Da to about 250,000 Da. wIn one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0166] In one embodiment of the film, R at C6 1 -CO- substitution degree ("C6DS R1 In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 0 to about 0.3. w In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 80,000 Da to about 250,000 Da. w In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0167] In one class of this embodiment, R 1 is (C 1-20 ) alkyl, halo(C 1-20 ) alkyl or (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 2 substituted with R 2 is (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 In a subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is selected from aryl or nitro. wIn one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0168] In one class of this embodiment, R 1 (C 1-20 In a subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is selected from the group consisting of alkyl, aryl ... w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0169] In one class of this embodiment, R 1 (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 2 substituted with R 2 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 In a subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is selected from aryl or nitro. wIn one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0170] In one class of this embodiment, R 1 is selected from methyl, ethyl, propyl, 1-ethyl-pentyl-, phenyl, 3,4,5-trimethoxyphenyl, 2-naphthyl, benzothiophenyl, or heptadecanyl. In a subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0171] In one embodiment of the film, R at C6 1 -CO- substitution degree ("C6DS R1 In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 0 to about 0.1. w In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 80,000 Da to about 250,000 Da. wIn one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0172] In one class of this embodiment, R 1 is (C 1-20 ) alkyl, halo(C 1-20 ) alkyl or (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 2 substituted with R 2 is (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 In a subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is selected from aryl or nitro. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0173] In one class of this embodiment, R 1 (C 1-20 In a subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is selected from the group consisting of alkyl, aryl ... wIn one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0174] In one class of this embodiment, R 1 (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 2 substituted with R 2 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 In a subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is selected from aryl or nitro. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0175] In one class of this embodiment, R 1is selected from methyl, ethyl, propyl, 1-ethyl-pentyl-, phenyl, 3,4,5-trimethoxyphenyl, 2-naphthyl, benzothiophenyl, or heptadecanyl. In a subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0176] In one embodiment of the film, R at C6 1 -CO- substitution degree ("C6DS R1 In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of from about 0 to about 0.08. w In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 80,000 Da to about 250,000 Da. w In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0177] In one class of this embodiment, R 1 is (C 1-20 ) alkyl, halo(C 1-20 ) alkyl or (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 2 substituted with R 2 is (C 1-6 ) alkyl, halo(C1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 In a subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is selected from aryl or nitro. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0178] In one class of this embodiment, R 1 (C 1-20 In a subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is selected from the group consisting of alkyl, aryl ... w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0179] In one class of this embodiment, R 1 (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 2 substituted with R 2 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6)Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 In a subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is selected from aryl or nitro. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0180] In one class of this embodiment, R 1 is selected from methyl, ethyl, propyl, 1-ethyl-pentyl-, phenyl, 3,4,5-trimethoxyphenyl, 2-naphthyl, benzothiophenyl, or heptadecanyl. In a subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0181] In one embodiment of the film, R at C6 1 -CO- substitution degree ("C6DS R1 In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of from about 0 to about 0.06. wIn one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 80,000 Da to about 250,000 Da. w In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0182] In one class of this embodiment, R 1 is (C 1-20 ) alkyl, halo(C 1-20 ) alkyl or (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 2 substituted with R 2 is (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 In a subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is selected from aryl or nitro. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0183] In one class of this embodiment, R 1 (C 1-20In a subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is selected from the group consisting of alkyl, aryl ... w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0184] In one class of this embodiment, R 1 (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 2 substituted with R 2 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 In a subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is selected from aryl or nitro. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0185] In one class of this embodiment, R 1is selected from methyl, ethyl, propyl, 1-ethyl-pentyl-, phenyl, 3,4,5-trimethoxyphenyl, 2-naphthyl, benzothiophenyl, or heptadecanyl. In a subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0186] In one embodiment of the film, R at C6 1 -CO- substitution degree ("C6DS R1 In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of from about 0 to about 0.04. w In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 80,000 Da to about 250,000 Da. w In one class of this embodiment, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0187] In one class of this embodiment, R 1 is (C 1-20 ) alkyl, halo(C 1-20 ) alkyl or (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 2 substituted with R 2 is (C 1-6 ) alkyl, halo(C1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 In a subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is selected from aryl or nitro. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0188] In one class of this embodiment, R 1 (C 1-20 In a subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is selected from the group consisting of alkyl, aryl ... w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0189] In one class of this embodiment, R 1 (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 2 substituted with R 2 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6)Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 In a subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is selected from aryl or nitro. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0190] In one class of this embodiment, R 1 is selected from methyl, ethyl, propyl, 1-ethyl-pentyl-, phenyl, 3,4,5-trimethoxyphenyl, 2-naphthyl, benzothiophenyl, or heptadecanyl. In a subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose ester is w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") of the regioselectively substituted cellulose esters is in the range of about 80,000 Da to about 150,000 Da. w " ) is in the range of about 100,000 Da to about 150,000 Da.

[0191] In one embodiment of the film, R 1 (C 1-20 ) alkyl. In one embodiment of the composition of matter, R 1 Halo(C 1-20 ) alkyl. In one embodiment of the composition, R 1 (C2-20 ) alkenyl. In one embodiment of the composition of matter, R 1 (C 3-7 ) cycloalkyl. In one embodiment of the composition of matter, R 1 (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 2 substituted with R 2 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) aryl or nitro. In one embodiment of the composition of matter, R 1 is a 5-20 membered heteroaryl containing 1-3 heteroatoms independently selected from oxygen, sulfur and nitrogen (heteroaryl is unsubstituted or has 1-6 R 3 substituted with R 3 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) aryl or nitro.

[0192] In one embodiment of the film, R 1 (C 1-20 ) alkyl, halo(C 1-20 ) alkyl, (C 2-20 ) alkenyl, (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 2 or a 5-20 membered heteroaryl containing 1-3 heteroatoms independently selected from oxygen, sulfur and nitrogen (heteroaryl is unsubstituted or substituted with 1-6 R 3 substituted with a group.

[0193] In one embodiment of the film, R 1 is (C 1-20 ) alkyl, halo(C 1-20 ) alkyl or (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 2 substituted with R 2 is (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) aryl or nitro.

[0194] In one embodiment of the film, R 1 is selected from methyl, ethyl, propyl, 1-ethylpentyl-, phenyl, 3,4,5-trimethoxyphenyl, 2-naphthyl, benzothiophenyl or heptadecanyl.

[0195] In one embodiment of the film, the regioselectively substituted cellulose ester comprises a plurality of R 4 Further containing a -CO- substituent, R 4 -CO- substitution degree ("C6DS R4 ") is in the range of about 0.1 to about 1.0, and R 4 (C 1-20 ) alkyl, halo(C 1-5 ) alkyl, (C 2-20 ) alkenyl, (C 3-7 ) cycloalkyl, (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 5 or a monocyclic or bicyclic heteroaryl containing 1 to 3 heteroatoms independently selected from oxygen, sulfur and nitrogen (heteroaryl is unsubstituted or substituted with 1 to 6 R 6 substituted with R 5 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) aryl or nitro; R 6 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) aryl or nitro.

[0196] In one class of this embodiment, R at the C2 position 4 -CO- substitution degree ("C2DS R4 ") is in the range of about 0 to about 0.5, where R 4 -CO- substitution degree ("C3DS R4 In a subclass of this class, the weight average molecular weight ("M") is in the range of about 0 to about 0.5. w In one subclass of this class, the weight average molecular weight ("M") is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") is in the range of about 80,000 Da to about 100,000 Da. w " ) is in the range of about 100,000 Da to about 250,000 Da.

[0197] In one class of this embodiment, R at the C2 position 4 -CO- substitution degree ("C2DS R4 ") ranges from about 0 to about 0.4, where R 4 -CO- substitution degree ("C3DS R4 In a subclass of this class, the weight average molecular weight ("M w In one subclass of this class, the weight average molecular weight ("M") is in the range of about 80,000 Da to about 250,000 Da. wIn one subclass of this class, the weight average molecular weight ("M") is in the range of about 80,000 Da to about 100,000 Da. w " ) is in the range of about 100,000 Da to about 250,000 Da.

[0198] In one class of this embodiment, R at the C2 position 4 -CO- substitution degree ("C2DS R4 ") ranges from about 0 to about 0.3, where R 4 -CO- substitution degree ("C3DS R4 In a subclass of this class, the weight average molecular weight ("M w In one subclass of this class, the weight average molecular weight ("M") is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") is in the range of about 80,000 Da to about 100,000 Da. w " ) is in the range of about 100,000 Da to about 250,000 Da.

[0199] In one class of this embodiment, R at the C2 position 4 -CO- substitution degree ("C2DS R4 ") ranges from about 0 to about 0.2, where R 4 -CO- substitution degree ("C3DS R4 In a subclass of this class, the weight average molecular weight ("M w In one subclass of this class, the weight average molecular weight ("M") is in the range of about 80,000 Da to about 250,000 Da. w In one subclass of this class, the weight average molecular weight ("M") is in the range of about 80,000 Da to about 100,000 Da. w " ) is in the range of about 100,000 Da to about 250,000 Da.

[0200] In one class of this embodiment, the weight average molecular weight ("M w" ) is in the range of about 80,000 Da to about 250,000 Da.

[0201] In one class of this embodiment, the weight average molecular weight ("M w " ) is in the range of about 80,000 Da to about 100,000 Da.

[0202] In one class of this embodiment, the weight average molecular weight ("M w " ) is in the range of about 100,000 Da to about 250,000 Da.

[0203] In one class of this embodiment, R 4 (C 1-20 ) alkyl. In one class of this embodiment, R 4 Halo(C 1-5 ) alkyl.

[0204] In one class of this embodiment, R 4 (C 2-20 ) alkenyl.

[0205] In one class of this embodiment, R 4 (C 3-7 ) cycloalkyl.

[0206] In one class of this embodiment, R 4 (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 5 substituted with R 5 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) aryl or nitro.

[0207] In one class of this embodiment, R 4is a monocyclic or bicyclic heteroaryl containing 1 to 3 heteroatoms independently selected from oxygen, sulfur and nitrogen, wherein the heteroaryl is unsubstituted or has 1 to 6 R 6 substituted with R 6 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) aryl or nitro.

[0208] In one class of this embodiment, R 4 is selected from methyl, ethyl, propyl, 1-ethyl-pentyl-, phenyl, 3,4,5-trimethoxyphenyl, 2-naphthyl, benzothiophenyl, or heptadecanyl. In a subclass of this class, R 4 is methyl. In a subclass of this class, R 4 is ethyl. In a subclass of this class, R 4 is propyl. In a subclass of this class, R 4 is 1-ethyl-pentyl-. In a subclass of this class, R 4 is phenyl. In a subclass of this class, R 4 In one subclass of this class, R 4 is 2-naphthyl. In a subclass of this class, R 4 In a subclass of this class, R 4 is heptadecanyl.

[0209] In one embodiment of the film, the film is a uniaxial or biaxial optical film. In one class of this embodiment, the film is a uniaxial optical film. In one class of this embodiment, the film is a biaxial optical film.

[0210] In one embodiment, the film has a birefringence ("Δn") of about 0.007 to about 0.010 when measured at a wavelength of 589 nm. In one embodiment, the film has a Δn of about 0.008 to about 0.010 when measured at a wavelength of 589 nm. In one embodiment, the film has a Δn of about 0.009 to about 0.010 when measured at a wavelength of 589 nm.

[0211] In one embodiment, the film has a % haze less than about 0.9. In one embodiment, the film has a % haze less than about 0.8. In one embodiment, the film has a % haze less than about 0.7. In one embodiment, the film has a % haze less than about 0.6. In one embodiment, the film has a % haze less than about 0.5. In one embodiment, the film has a % haze less than about 0.4. In one embodiment, the film has a % haze less than about 0.3. In one embodiment, the film has a % haze less than about 0.2.

[0212] In one embodiment, the film is a C+ film, a C- film, an A+ film, or an A- film. In one class of this embodiment, the film is a C+ film. In one class of this embodiment, the film is a C- film. In one class of this embodiment, the film is an A+ film. In one class of this embodiment, the film is an A- film. In one class of this embodiment, the film is an A- film.

[0213] In one embodiment, the film is a C+ film, a C- film, an inverted A film, or an NRZ film.

[0214] In one class of this embodiment, the film is a C+ film. In a subclass of this class, the film has an out-of-plane retardation ("R th"") divided by the thickness of the film ("d") ranges from 0 to 20. In one subsubclass of this subclass, the films are uniaxially, biaxially, or 45 degree stretched.

[0215] In one class of this embodiment, the film is a C-film. In a subclass of this class, the film has an out-of-plane retardation ("R th ") divided by the thickness ("d") of the film ranges from 0 to about -12. In a subsubclass of this subclass, the films are uniaxially, biaxially, or 45 degree oriented. In a subclass of this class, the films have an out-of-plane retardation ("R th ") divided by the thickness ("d") of the film ranges from 0 to about -17. In a subsubclass of this subclass, the films are uniaxially, biaxially, or 45 degree oriented. In a subclass of this class, the films have an out-of-plane retardation ("R th ") divided by the thickness ("d") of the film ranges from -2 to about -17. In one subsubclass of this subclass, the films are uniaxially, biaxially, or 45 degree oriented. In one subclass of this class, the films have an out-of-plane retardation ("R th "") divided by the thickness of the film ("d") ranges from -5 to about -17. In one subsubclass of this subclass, the films are uniaxially, biaxially, or 45 degree stretched.

[0216] In one class of this embodiment, the film is an inverted A film. In a subclass of this class, the film is an R e 450 / R e 550<1 and R e 650 / R e 550>1, where R e 450, R e 550 and R e650 is the in-plane retardation measured at wavelengths of 450 nm, 550 nm, and 650 nm, respectively. In one subsubclass of this subclass, the in-plane retardation of the film measured at a wavelength of 589 nm ("R e ") is in the range of about 100 nm to about 300 nm. In one sub-sub-subclass of this sub-subclass, the films are uniaxially, biaxially, or 45 degree stretched.

[0217] In one class of this embodiment, the film is a NRZ film. In a subclass of this class, the film is a R e 450 / R e 550<1 and R e 650 / R e 550>1, where R e 450, R e 550 and R e 650 is the in-plane retardation measured at wavelengths of 450 nm, 550 nm, and 650 nm, respectively. In one subsubclass of this subclass, the in-plane retardation of the film measured at a wavelength of 589 nm ("R e In one sub-sub-subclass of this sub-subclass, the out-of-plane retardation ("R") of the film as measured at a wavelength of 589 nm is in the range of about 100 nm to about 300 nm. e ") ranges from about 0 nm to about -50 nm. In one sub-sub-sub-subclass of this sub-sub-subclass, the films are uniaxially, biaxially, or 45 degree stretched.

[0218] In one embodiment, the film disclosed above has an R th divided by the thickness of the film ("d") is in the range of -50 to 50. In one embodiment, the film disclosed above has an R th divided by the thickness of the film ("d") is in the range of -50 to 0. In one embodiment, the film disclosed above has an R thdivided by the thickness ("d") of the film is in the range of 0 to 50. In one embodiment, the film disclosed above has an R th divided by the thickness of the film ("d") is in the range of -20 to 20. In one embodiment, the film disclosed above has an R th divided by the thickness of the film ("d") is in the range of -20 to 0. In one embodiment, the film disclosed above has an R th divided by the thickness ("d") of the film is in the range of 0 to 20. In one embodiment, the film disclosed above has an R th divided by the thickness of the film ("d") is in the range of -15 to 15. In one embodiment, the film disclosed above has an R th divided by the thickness of the film ("d") is in the range of -15 to 0. In one embodiment, the film disclosed above has an R th divided by the thickness ("d") of the film is in the range of 0 to 15. In one embodiment, the film disclosed above has an R th divided by the thickness of the film ("d") is in the range of -10 to 10. In one embodiment, the film disclosed above has an R th divided by the thickness of the film ("d") is in the range of -10 to 0. In one embodiment, the film disclosed above has an R th R divided by the thickness of the film ("d") ranges from 0 to 10. In one embodiment, the film disclosed above has a R th In one embodiment, the film disclosed above has R th In one embodiment, the film disclosed above has an R thdivided by the thickness ("d") of the film is in the range of 0 to 5. In one embodiment, the film disclosed above has an R th divided by the thickness of the film ("d") is in the range of -3 to 3. In one embodiment, the film disclosed above has an R th divided by the thickness of the film ("d") is in the range of -3 to 0. In one embodiment, the film disclosed above has an R th divided by the thickness of the film ("d") is in the range of 0 to 3. In one embodiment, the film disclosed above has an R th divided by the thickness of the film ("d") ranges from -1 to 1. In one embodiment, the film disclosed above has an R th divided by the thickness of the film ("d") ranges from -1 to 0. In one embodiment, the film disclosed above has an R th divided by the thickness of the film ("d") is in the range of 0 to 1. In one embodiment, the film disclosed above has an R th divided by the thickness of the film ("d") is in the range of -0.5 to 0.5. In one embodiment, the film disclosed above has an R th divided by the thickness of the film ("d") is in the range of -0.5 to 0. In one embodiment, the film disclosed above has an R th divided by the film thickness ("d") is in the range of 0 to 0.5.

[0219] Any of the above-mentioned films can have a thickness in the range of about 40 to about 120 μm, in the range of about 40 to about 70 μm, or in the range of about 5 to about 20 μm. In this application, thickness and average thickness are used interchangeably. As used herein, "average thickness" refers to the average of at least three equally spaced measurements of the thickness of the optical film.

[0220] In various embodiments, additives such as plasticizer, stabilizer, UV absorber, antiblocking agent, slip agent, lubricant, dye, pigment, retardation adjuster, etc. may be mixed with the regioselectively substituted cellulose ester used in preparing the above optical film.Examples of these additives can be found in, for example, US Patent Application Publication No. 2009 / 0050842, US Patent Application Publication No. 2009 / 0054638 and US Patent Application Publication No. 2009 / 0096962, the contents of which are incorporated herein by reference.

[0221] Any of the above optical films can be made by solvent casting, melt extrusion, lamination or coating process. These procedures are generally known in the art. Examples of solvent casting, melt extrusion, lamination and coating process can be found in, for example, US Patent Application Publication Nos. 2009 / 0050842, 2009 / 0054638 and 2009 / 0096962, the contents of which are incorporated herein by reference. Further examples of solvent casting, melt extrusion, lamination and coating process for forming films can be found in, for example, US Patent Application Publication Nos. 4,592,885 and 7,172,713, and US Patent Application Publication Nos. 2005 / 0133953 and 2010 / 0055356, the contents of which are incorporated herein by reference.

[0222] The regioselectively substituted cellulose esters described herein can be used to produce the desired R e and R th The film can be stretched to help obtain the desired R value. By adjusting the stretching conditions such as stretching temperature, stretch type (uniaxial or biaxial), stretch ratio, preheat time and temperature, and post-stretch annealing time and temperature, the desired R value can be obtained. e and R thcan be achieved. The exact stretching conditions may depend on the particular composition of the regioselectively substituted cellulose ester, the amount and type of plasticizer, and the glass transition temperature of that particular composition. Thus, the particular stretching conditions may vary widely. In various embodiments, the stretching temperature may range from about 160 to about 210°C. Furthermore, the stretch ratio based on 1.0 in the machine direction ("MD") may range from about 1.3 to about 2.0 in the transverse direction ("TD"). The preheat time may range from about 10 to about 300 seconds, and the preheat temperature may be the same as the stretching temperature. The postannealing time may range from about 0 to about 300 seconds, and the postannealing temperature may range from about 10 to about 40°C lower than the stretching temperature. The thickness of the film may depend on the thickness of the film before stretching and the stretching conditions. After stretching, the thickness of the film may be about 1 μm to about 500 μm, about 5 μm to about 200 μm, or about 10 μm to about 120 μm.

[0223] In addition to optical properties, the films prepared from the regioselectively substituted cellulose esters described herein have other valuable features. Many conventional cellulose esters used in LCD displays have relatively high moisture absorption, which affects dimensional stability and changes the optical value of the film. The films prepared from the regioselectively substituted cellulose esters described herein have low moisture absorption, and the optical value of the film changes little at high humidity and temperature. Thus, in various embodiments, the regioselectively substituted cellulose esters can contain less than 2% moisture by weight, less than 1% moisture by weight, or less than 0.5% moisture by weight. In various other embodiments, the R of the cellulose ester film can be 0.01 to 0.01% by weight. e can be less than 4%, less than 1%, or less than 0.5% when stored for 240 hours at 60° C. and 100% relative humidity.

[0224] The regioselectively substituted cellulose ester described herein is surprisingly thermally stable, making it very useful for melt extrusion of film.Therefore, one aspect of the present invention relates to the regioselectively substituted cellulose ester that has a weight loss of less than 10% by thermogravimetric analysis at 330 ℃, 340 ℃ or 350 ℃.

[0225] As mentioned above, the optical films described herein can be used in LCDs. In particular, the optical films described above can be used as part or all of the compensation film of a polarizer stack of an LCD. As mentioned above, a polarizer stack generally includes two crossed polarizers disposed on either side of a liquid crystal layer. A compensation film can be disposed between the liquid crystal layer and one of the polarizers. In one or more embodiments, the single layer optical film described above can be used by itself as a compensation film (i.e., a waveplate) of an LCD. In such embodiments, the single layer optical film can be disposed between the liquid crystal layer and one of the polarizing filters of an LCD. In other embodiments, the -A optical film described above can be used in a compensation film (i.e., a waveplate) of an LCD. In such embodiments, the -A optical film can be disposed adjacent to at least one additional optical film, and such additional optical film can be a -C optical film. In yet other embodiments, the +C optical film described above can be used in a compensation film (i.e., a waveplate) of an LCD. In such embodiments, the +C optical film can be disposed adjacent to at least one additional optical film, and such additional optical film can be a +A optical film. In any of the above-described embodiments, LCDs prepared including the optical films described herein can be operated in an in-plane switching ("IPS") mode.

[0226] The optical compensation film described herein can also be used in OLEDs. For example, a QWP can be combined with a linear polarizer to form a circular polarizer. Placing a circular polarizer in front of an OLED device can reduce the ambient light reflected from the OLED metal electrode, improving display quality such as high contrast ratio and low color shift, especially when the QWP has near-ideal reverse dispersion.

[0227] The optical films described herein can also be used as circular polarizers. In particular, quarter wave plates can be prepared that include one or more of the above-mentioned optical films of the present invention that can be used to convert linearly polarized light to circularly polarized light. This aspect can be particularly valuable for use in circularly polarized three-dimensional ("3D") glasses and / or 3D media displays, such as televisions ("3D TVs"). Thus, in one or more embodiments, quarter wave plates can be prepared that include the single-layer optical films described above. In various other embodiments, quarter wave plates can be prepared that include the -A optical films described above. Such quarter wave plates can be applied to the glasses of a 3-D TV, such as on top of a polarizing stack. Furthermore, such quarter wave plates can be applied to the glasses of a 3D pair of glasses. In the case of 3-D glasses, the optical films can be applied such that the optical axis of one lens is perpendicular or substantially perpendicular to the optical axis of the other lens. As a result of the 3-D glasses, certain observed polarized light is blocked by one lens but passes through the other lens, leading to the observed 3D optical effect. In various embodiments, a quarter wave plate comprising one or more of the above-described optical films can be used in conjunction with at least one additional polarizer, which can be a linear polarizer.

[0228] Any of the disclosed films can be incorporated into a multilayer film. This application also relates to a multilayer film that includes any of the disclosed films of this application.

[0229] method The present application relates to a method for preparing regioselectively substituted cellulose esters having a combined degree of substitution of C2 and C3 ("(C2+C3)DS") ranging from about 0 to about 2.0 and a degree of substitution of C6 ("C6DS") ranging from about 0 to about 0.6, (1) contacting cellulose with about 1.4 equivalents to about 1.8 equivalents of trifluoroacetic anhydride ("TFAA") and about 0.1 equivalents to about 0.8 equivalents of one or more first carboxylic acids in a reaction medium in a suitable solvent; wherein the equivalents of TFAA and the first carboxylic acid are based on the total anhydroglucosyl units of the cellulose. A method is disclosed.

[0230] The solvent suitable for this method is any solvent that can dissolve or partially dissolve the starting cellulose or the cellulose ester formed during the reaction that produces the desired product.In one embodiment of this method, the suitable solvent is trifluoroacetic acid.

[0231] The acyl substituents contributing to the (C2+C3)DS and C6DS are acyl substituents derived from the first carboxylic acid or any acylating compound.

[0232] In one embodiment of this method, the C6DS is less than 0.4. In one embodiment of this method, the C6DS is less than 0.2. In one embodiment of this method, the C6DS is less than 0.1. In one embodiment of this method, the C6DS is less than 0.08. In one embodiment of this method, the C6DS is less than 0.06. In one embodiment of this method, the C6DS is less than 0.04. In one embodiment of this method, the C6DS is less than 0.02.

[0233] In one embodiment of this method, (2) further comprises adding 0.1 to 2.0 equivalents of one or more acyl donors, the equivalents of acyl donors being based on the total anhydroglucosyl units of the cellulose. In a class of this embodiment, the acyl donor is selected from a second carboxylic acid or an acid anhydride. In a subclass of this class, the acyl donor is a second carboxylic acid. In a subclass of this class, the acyl donor is an acid anhydride.

[0234] In one class of this embodiment, the acyl donor is added after at least 50% of the first carboxylic acid has been consumed. In a subclass of this class, the acyl donor is selected from the second carboxylic acid or an acid anhydride. In a subsubclass of this subclass, the acyl donor is the second carboxylic acid. In a subsubclass of this subclass, the acyl donor is an acid anhydride.

[0235] In one class of this embodiment, the acyl donor is added after at least 80% of the first carboxylic acid has been consumed. In a subclass of this class, the acyl donor is selected from the second carboxylic acid or an acid anhydride. In a subsubclass of this subclass, the acyl donor is the second carboxylic acid. In a subsubclass of this subclass, the acyl donor is an acid anhydride.

[0236] In one class of this embodiment, the acyl donor is added after at least 90% of the first carboxylic acid has been consumed. In a subclass of this class, the acyl donor is selected from the second carboxylic acid or anhydride. In a subsubclass of this subclass, the acyl donor is the second carboxylic acid. In a subsubclass of this subclass, the acyl donor is an acid anhydride.

[0237] In one embodiment of this method, the regioselectively substituted cellulose ester is a cellulose ester having a weight average molecular weight ("M") ranging from about 5,000 Da to about 250,000 Da. wIn one embodiment of this method, the regioselectively substituted cellulose ester has a weight average molecular weight ("M") in the range of about 25,000 Da to about 250,000 Da. w In one embodiment of this method, the regioselectively substituted cellulose ester has a weight average molecular weight ("M") in the range of about 50,000 Da to about 250,000 Da. w In one embodiment of this method, the regioselectively substituted cellulose ester has a weight average molecular weight ("M") in the range of about 80,000 Da to about 250,000 Da. w In one embodiment of this method, the regioselectively substituted cellulose ester has a weight average molecular weight ("M") in the range of about 100,000 Da to about 250,000 Da. w ").

[0238] In one embodiment of this method, the first carboxylic acid is R 1 -COOH,

[0239] Here, R 1 (C 1-20 ) alkyl, halo(C 1-20 ) alkyl, (C 2-20 ) alkenyl, (C 3-7 ) cycloalkyl, (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 2 or a 5-20 membered heteroaryl containing 1-3 heteroatoms independently selected from oxygen, sulfur and nitrogen (heteroaryl is unsubstituted or substituted with 1-6 R 3 substituted with a aryl group; Here, R 2 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) aryl or nitro; and Here, R 3 is (C1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) aryl or nitro.

[0240] In one embodiment of this method, the second carboxylic acid is R 1 -COOH,

[0241] Here, R 1 (C 1-20 ) alkyl, halo(C 1-20 ) alkyl, (C 2-20 ) alkenyl, (C 3-7 ) cycloalkyl, (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 2 or a 5-20 membered heteroaryl containing 1-3 heteroatoms independently selected from oxygen, sulfur and nitrogen (heteroaryl is unsubstituted or substituted with 1-6 R 3 substituted with a aryl group; Here, R 2 is (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) aryl or nitro; and Here, R 3 is (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) aryl or nitro.

[0242] In one embodiment of this method, the cellulose is softwood cellulose, hardwood cellulose, cotton linters cellulose or microcrystalline cellulose. In one embodiment of this method, the cellulose is Placetate F cellulose.

[0243] In one embodiment of this method, the reaction medium is set at a temperature in the range of about 20°C to about 80°C. In one class of this embodiment, the reaction medium is set at a temperature in the range of about 35°C to about 75°C. In one class of this embodiment, the reaction medium is set at a temperature in the range of about 0°C to about 20°C. In one class of this embodiment, the reaction medium is set at a temperature in the range of about 30°C to about 50°C. In one class of this embodiment, the reaction medium is set at a temperature in the range of about 50°C to about 80°C.

[0244] The present application relates to a method for preparing a regioselectively substituted cellulose ester having a C2 degree of substitution ("C2DS") of 0.01 to 1, a C3 degree of substitution ("C3DS") of 0.01 to 1, and a C6 degree of substitution ("C6DS") of about 0 to about 0.1, comprising: (1) contacting cellulose with about 0.5 to about 5.0 equivalents of trifluoroacetic anhydride ("TFAA") and 0.1 to 2.0 equivalents of one or more first acylating agents ("FAA") in a reaction medium including a suitable solvent to esterify at least a portion of the cellulose, thereby producing a regioselectively substituted cellulose ester; Herein, a method is disclosed in which the equivalents of TFAA and FAA are based on the sum of the anhydroglucosyl units of cellulose.

[0245] The acyl substituents contributing to (C2+C3)DS and C6DS are those derived from FAA or any other acylating compound added to the reaction medium.

[0246] Suitable solvent for this method is any solvent that can dissolve or partially dissolve the starting cellulose or the cellulose ester produced during the reaction that produces the desired product.In one embodiment of this method, suitable solvent is trifluoroacetic acid.

[0247] In one embodiment of this method, the C6DS is less than 0.4. In one embodiment of this method, the C6DS is less than 0.2. In one embodiment of this method, the C6DS is less than 0.1. In one embodiment of this method, the C6DS is less than 0.08. In one embodiment of this method, the C6DS is less than 0.06. In one embodiment of this method, the C6DS is less than 0.04. In one embodiment of this method, the C6DS is less than 0.02.

[0248] In one embodiment of this method, the TFAA is present at 0.5 equivalents to about 5.0 equivalents. In one embodiment of this method, the TFAA is present at 0.5 equivalents to about 3.0 equivalents. In one embodiment of this method, the TFAA is present at 0.5 equivalents to about 2.0 equivalents. In one embodiment of this method, the TFAA is present at 1.0 equivalents to about 2.0 equivalents.

[0249] In one embodiment of this method, the one or more FAAs are introduced after the introduction of the TFAA. In a class of this embodiment, the one or more FAAs and the TFAAs are added dissolved in a suitable solvent. In a subclass of this class, the suitable solvent is trifluoroacetic acid. In one embodiment of this method, the one or more FAAs are introduced before the introduction of the TFAA. In a class of this embodiment, the one or more FAAs and the TFAAs are added dissolved in a suitable solvent. In a subclass of this class, the suitable solvent is trifluoroacetic acid. In one embodiment of this method, the one or more FAAs and the TFAAs are introduced simultaneously. In a class of this embodiment, the one or more FAAs and the TFAAs are added dissolved in a suitable solvent. In a subclass of this class, the suitable solvent is trifluoroacetic acid.

[0250] In one embodiment of this method, the FAA is selected from an acid anhydride or an acid halide. In one embodiment of this method, the FAA is selected from a symmetric acid anhydride or a mixed acid anhydride. In one class of this embodiment, the mixed acid anhydride is generated in the reaction medium by addition of a carboxylic acid. In one embodiment of this method, the FAA is an acid halide.

[0251] In one embodiment, FAA is R 1a -C(O)OC(O)-R 1b and Here, R 1a and R 1b is independent (C 1-20 ) alkyl, halo(C 1-20 ) alkyl, (C 2-20 ) alkenyl, (C 3-7 ) cycloalkyl, (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 2 or a 5-20 membered heteroaryl containing 1-3 heteroatoms independently selected from oxygen, sulfur and nitrogen (heteroaryl is unsubstituted or substituted with 1-6 R 3substituted with a aryl group; Here, each R 2 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) aryl or nitro; and Here, each R 3 is (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) aryl or nitro.

[0252] In one embodiment, FAA is R 1a -C(O)X, Here, R 1 (C 1-20 ) alkyl, halo(C 1-20 ) alkyl, (C 2-20 ) alkenyl, (C 3-7 ) cycloalkyl, (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 2 or a 5-20 membered heteroaryl containing 1-3 heteroatoms independently selected from oxygen, sulfur and nitrogen (heteroaryl is unsubstituted or substituted with 1-6 R 3 substituted with a aryl group; Here, each R 2 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) aryl or nitro; Here, each R 3 is (C 1-6 ) alkyl, halo(C 1-6) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) aryl or nitro; and X is chloro, bromo or iodo.

[0253] In one embodiment of this method, the cellulose is hardwood cellulose, softwood cellulose, cotton linters cellulose or microcrystalline cellulose. In one embodiment of this method, the cellulose is Placetate F cellulose.

[0254] In one embodiment of this method, the reaction medium is set at a temperature in the range of about 20°C to about 80°C. In one class of this embodiment, the reaction medium is set at a temperature in the range of about 35°C to about 75°C. In one class of this embodiment, the reaction medium is set at a temperature in the range of about 0°C to about 20°C. In one class of this embodiment, the reaction medium is set at a temperature in the range of about 30°C to about 50°C. In one class of this embodiment, the reaction medium is set at a temperature in the range of about 50°C to about 80°C.

[0255] The present application relates to a method for preparing regioselectively substituted cellulose esters, comprising the steps of: (1) contacting cellulose with 0.5 to 5.0 equivalents of trifluoroacetic anhydride ("TFAA") and 0.1 to 2.0 equivalents of one or more first acylating agents ("FAA") in a first reaction medium comprising a first suitable solvent to esterify at least a portion of the cellulose, thereby producing an intermediate regioselectively substituted cellulose ester having a C2 degree of substitution ("C2DS") of 0.01 to 1, a C3 degree of substitution ("C3DS") of 0.01 to 1, and a C6 degree of substitution ("C6DS") of 0 to about 0.1; where the equivalents of TFAA and FAA are based on the sum of the anhydroglucosyl units of cellulose. (2) isolating the intermediate regioselectively substituted cellulose ester ("IRSCE"); and (3) contacting the intermediate regioselectively substituted cellulose ester with 0.1 to 2.0 equivalents of one or more second acylating agents ("SAA") in a second reaction medium comprising a second suitable solvent; Herein, a method is disclosed in which the equivalent of SAA is based on the sum of the anhydroglucosyl units of the IRSCE.

[0256] The acyl substituents contributing to the (C2+C3)DS and C6DS are acyl substituents derived from the FAA or any acylating compound added to the first reaction medium.

[0257] The first suitable solvent for this method is any solvent that can dissolve or partially dissolve the starting cellulose or the cellulose ester that is produced during the reaction that produces the desired product.In one embodiment of this method, the first suitable solvent is trifluoroacetic acid.

[0258] The second suitable solvent for this method is any solvent that can dissolve or partially dissolve starting cellulose or cellulose ester produced during reaction, and is inert to reaction.In one embodiment of this method, the second suitable solvent is selected from methyl ethyl ketone, tetrahydrofuran, dimethyl sulfoxide, 1,3-dimethyl-2-imidazolidinone, dimethylacetamide, dioxane, dimethylformamide, ethyl acetate, butyl acetate, trichloromethane, pyridine or dichloromethane.

[0259] In one embodiment of this method, the first suitable solvent is trifluoroacetic acid and the second suitable solvent is selected from methyl ethyl ketone, tetrahydrofuran, dimethyl sulfoxide, 1,3-dimethyl-2-imidazolidinone, dimethylacetamide, dioxane, dimethylformamide, ethyl acetate, butyl acetate, trichloromethane, pyridine, or dichloromethane.

[0260] In one embodiment of this method, the C6DS is less than 0.08. In one embodiment of this method, the C6DS is less than 0.06. In one embodiment of this method, the C6DS is less than 0.04. In one embodiment of this method, the C6DS is less than 0.02.

[0261] In one embodiment of this method, the TFAA is present at 0.5 equivalents to about 8.0 equivalents. In one embodiment of this method, the TFAA is present at 0.5 equivalents to about 6.0 equivalents. In one embodiment of this method, the TFAA is present at 0.5 equivalents to about 4.0 equivalents. In one embodiment of this method, the TFAA is present at 0.5 equivalents to about 3.0 equivalents. In one embodiment of this method, the TFAA is present at 0.5 equivalents to about 2.0 equivalents. In one embodiment of this method, the TFAA is present at 1.0 equivalents to about 2.0 equivalents.

[0262] In one embodiment of this method, the one or more FAAs are introduced after introducing the TFAAs in the TFA. In one embodiment of this method, the one or more FAAs are introduced before introducing the TFAAs in the TFA. In one embodiment of this method, the one or more FAAs and the TFAAs in the TFA are introduced simultaneously.

[0263] In one embodiment of this method, the FAA is selected from a symmetric acid anhydride or a mixed anhydride. In one embodiment of this method, the FAA is an acid halide.

[0264] In one embodiment of this method, the cellulose is hardwood cellulose, softwood cellulose, cotton linters cellulose or microcrystalline cellulose. In one embodiment of this method, the cellulose is Placetate F cellulose.

[0265] In one embodiment of this method, the first reaction medium is set at a temperature in the range of about 20° C. to about 80° C. In one class of this embodiment, the first reaction medium is set at a temperature in the range of about 35° C. to about 75° C. In one class of this embodiment, the first reaction medium is set at a temperature in the range of about 0° C. to about 20° C. In one class of this embodiment, the first reaction medium is set at a temperature in the range of about 30° C. to about 50° C. In one class of this embodiment, the first reaction medium is set at a temperature in the range of about 50° C. to about 80° C.

[0266] In one embodiment of this method, the second reaction medium is set at a temperature in the range of about 20°C to about 80°C. In one class of this embodiment, the second reaction medium is set at a temperature in the range of about 35°C to about 75°C. In one class of this embodiment, the second reaction medium is set at a temperature in the range of about 0°C to about 20°C. In one class of this embodiment, the second reaction medium is set at a temperature in the range of about 30°C to about 50°C. In one class of this embodiment, the second reaction medium is set at a temperature in the range of about 50°C to about 80°C.

[0267] Embodiment Embodiment 1. (i) Multiple R 1 -CO- substituents, and (ii) multiple hydroxyl substituents; where R at position C2 1 -CO- substitution degree ("C2DS R1 ") is in the range of about 0.2 to about 1.0, C3rd place R 1 -CO- substitution degree ("C3DS R1 ") is in the range of about 0.2 to about 1.0, C6th place R 1 -CO- substitution degree ("C6DS R1 ") is in the range of about 0 to about 0.5, The degree of hydroxyl substitution is in the range of about 0 to about 2.6; R 1 (C 1-20 ) alkyl, halo(C1-20 ) alkyl, (C 2-20 ) alkenyl, (C 3-7 ) cycloalkyl, (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 2 or a 5-20 membered heteroaryl containing 1-3 heteroatoms independently selected from oxygen, sulfur and nitrogen (heteroaryl is unsubstituted or substituted with 1-6 R 3 substituted with a aryl group; R 2 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) aryl or nitro; R 3 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) Regioselectively substituted cellulose esters selected from aryl or nitro.

[0268] Embodiment 2. C6DS R1-CO- 2. The regioselectively substituted cellulose ester of embodiment 1, wherein

[0269] Embodiment 3. R 1 3. The regioselectively substituted cellulose ester according to any one of embodiments 1 or 2, wherein -CO- is selected from acetyl, propionyl, butanoyl, benzoyl, naphthoyl, 3,4,5-trimethoxybenzoyl, biphenyl-CO-, benzoyl-benzoyl- or benzothiophenyl-CO-.

[0270] Embodiment 4. R 1The regioselectively substituted cellulose ester of any one of embodiments 1 or 2, wherein -CO- is propionyl.

[0271] Embodiment 5. The regioselectively substituted cellulose ester according to embodiment 4, wherein the degree of substitution of propionyl is about 1.0 to about 1.4, the degree of substitution of C2 of propionyl is 0.6 to 0.9, and the degree of substitution of C3 of propionyl is about 0.3 to about 0.5.

[0272] Embodiment 6. The regioselectively substituted cellulose ester of embodiment 5, wherein the C6 degree of substitution of propionyl is less than 0.05.

[0273] Embodiment 7. R 1 The regioselectively substituted cellulose ester of embodiment 1, wherein -CO- is a combination comprising benzoyl and naphthoyl.

[0274] Embodiment 8. The regioselectively substituted cellulose ester according to embodiment 7, wherein the degree of substitution of benzoyl is from about 0.2 to about 1.2, and the degree of substitution of naphthoyl is from about 0.8 to about 1.8.

[0275] EMBODIMENT 9. The regioselectively substituted cellulose ester according to embodiment 8, wherein the degree of substitution of benzoyl is about 0.4 to about 0.8, the degree of substitution of naphthoyl is about 1.2 to about 1.6, and the degree of substitution of the combination of benzoyl and naphthoyl at the C6 position is less than 0.05.

[0276] Embodiment 10. R 1 -CO is propionyl and (C 6-20 2. The regioselectively substituted cellulose ester of embodiment 1, wherein the combination comprises aryl.

[0277] Embodiment 11. Propionyl and (C 6-2011. The regioselectively substituted cellulose ester according to embodiment 10, wherein the substitution degree of the aryl combination at the C6 position is less than 0.1.

[0278] Embodiment 12. R 1 The regioselectively substituted cellulose ester of embodiment 1, wherein -CO- is a combination comprising propionyl and benzoyl.

[0279] Embodiment 13. The regioselectively substituted cellulose ester according to embodiment 12, wherein the degree of substitution of propionyl is about 0.4 to about 0.7, the degree of substitution of benzoyl is about 0.2 to about 0.5, and the degree of substitution of the combination of propionyl and benzoyl at C6 substitution is less than 0.05.

[0280] Embodiment 14. The regioselectively substituted cellulose ester according to embodiment 12, wherein the degree of substitution of propionyl is about 1.1 to about 1.8, the degree of substitution of benzoyl is about 0.1 to about 0.5, and the degree of substitution of the combination of propionyl and benzoyl at C6 substitution is less than 0.05.

[0281] EMBODIMENT 15. R 1 The regioselectively substituted cellulose ester of embodiment 1, wherein -CO- is a combination comprising propionyl and naphthoyl.

[0282] Embodiment 16. R 1 The regioselectively substituted cellulose ester of embodiment 1, wherein -CO- is a combination comprising propionyl, or a 5-20 membered heteroaryl containing 1 to 3 heteroatoms independently selected from oxygen, sulfur, and nitrogen.

[0283] EMBODIMENT 17. R 1 -CO- is propionyl and (C 6-202. The regioselectively substituted cellulose ester according to embodiment 1, wherein the combination comprises alkyl-CO-.

[0284] EMBODIMENT 18. R 1 -CO- is acetyl and (C 6-20 The regioselectively substituted cellulose ester according to embodiment 1, wherein the combination comprises aryl-CO-.

[0285] EMBODIMENT 19. The degree of acetyl substitution is about 0.7 to about 0.9, and (C 6-20 The degree of substitution of aryl-CO- is about 0.1 to about 0.5, and acetyl and (C 6-20 20. The regioselectively substituted cellulose ester of embodiment 18, wherein the degree of substitution at C6 substitution of the aryl-CO- combination is less than 0.1.

[0286] EMBODIMENT 20. R 1 The regioselectively substituted cellulose ester according to embodiment 1, wherein -CO- is a combination including acetyl and 5-20 membered heteroaryl containing 1-3 heteroatoms independently selected from oxygen, sulfur and nitrogen.

[0287] EMBODIMENT 21. The regioselectively substituted cellulose ester according to embodiment 20, wherein the degree of substitution of acetyl is about 0.8 to about 1.1, the degree of substitution of 5 to 20 membered heteroaryl containing 1 to 3 heteroatoms independently selected from oxygen, sulfur and nitrogen is about 0.1 to about 0.3, and the degree of substitution of C6 substitution of a combination of acetyl and benzoyl is less than 0.1.

[0288] EMBODIMENT 22. Weight average molecular weight (“M w 22. The regioselectively substituted cellulose ester according to any one of embodiments 1 to 21, wherein the molecular weight of the cellulose ester is in the range of about 50,000 Da to about 500,000 Da.

[0289] experiment Abbreviation AcOH is acetic acid, Ac2O is acetic anhydride, AcCl is acetyl chloride, aq. is aqueous, Bu2O is butanoic anhydride, BzOH is benzoic acid, Bz2O is benzoic anhydride, Bzt is benzothiephenyl C-CO-, BztOH is benzothiephenyl-COOH, BztCl is benzothiephenyl CO-Cl, °C is degrees Celsius, C2DS is the degree of substitution at the 2nd position of the anhydroglucose residue, C3DS is the degree of substitution at the 3rd position of the anhydroglucose residue, C6DS is the degree of substitution at the 6th position of the anhydroglucose residue, CIC is combustion ion chromatography, d is deuterated or heavy hydrogen, Da is Daltons, DCE is dichloroethane, DCM is dichloromethane, DEP is diethyl phthalate, DMAc is N,N-dimethylacetamide, DMAP is 4-dimethylaminopyridine, DMSO-d6 is hexadeuteriodimethylsulfoxide, min is minutes, equiv or eq. is equivalent, Et2O is ethyl ether, Ex is example, g is grams, GPC is gel permeation chromatography, h is hours, Int is intermediate, KOAc is potassium acetate, min is minutes, M wis weight average molecular weight, M is molar concentration, MEK is methyl ethyl ketone, MeOH is methanol, mg is milligram, MHz is megahertz, MIPK is methyl isopropyl ketone, mL or ml is milliliter, μL is microliter, mm is millimeter, mmHg is millimeter of mercury, N2 is nitrogen, NMR is nuclear magnetic resonance, Np is naphthyl, NpOH is 2-naphthoic acid, NpOH is 2-naphthoic acid, Np2O is 2-naphthoic anhydride, ppm is parts per million, Pr is propionyl, iPrOH is isopropyl alcohol, PrOH is propionic acid, PrO is propionic anhydride, RDS is relative degree of substitution, rt is room temperature, SM is starting material, TFA is trifluoroacetic acid, TFAA is trifluoroacetic anhydride, Tg is glass transition temperature, TMBz is 2,3,4-trimethoxybenzoyl, TMBzOH is 2,3,4-trimethoxybenzoic acid, TMBzCl is 2,3,5-trimethoxybenzoyl chloride, TPP is triphenyl phosphate, and wt% is weight percent.

[0290] Materials and Methods NMR characterization NMR characterization: Proton NMR data were acquired on a JEOL Model Eclipse-600 NMR spectrometer operating at 600 MHz. Sample tube size was 5 mm and sample concentration was approximately 20 mg / mL DMSO-d6. Each spectrum was recorded at 80 °C using 64 scans and a pulse delay of 15 seconds. One to two drops of trifluoroacetic acid-d were added to each sample to shift residual water out of the spectral region of interest. Chemical shifts are reported in ppm from tetramethylsilane with the central peak of DMSO-d6 (2.49 ppm) as an internal reference.

[0291] quantitative 13C NMR data were acquired on a JEOL Model GX-400 NMR spectrometer operating at 100 MHz. The sample tube size was 10 mm and the sample concentration was approximately 100 mg / mL DMSO-d6. Chromium(III) acetylacetonate was added to each sample at 5 mg / 100 mg cellulose ester as a relaxation agent. Each spectrum was typically recorded at 80 °C using 10,000 scans and a pulse delay of 1 second. Chemical shifts are reported in ppm from tetramethylsilane with the central peak of DMSO-d6 (39.5 ppm) as an internal reference.

[0292] The proton and carbon NMR assignments, the degree of substitution and the RDS of the various acyl groups of the cellulose esters were determined by adapting the procedures disclosed in US2012 / 0262650. The C2, C3 and C6DS were 13 The total DS of any substituent was determined by CNMR. 1 Determined by H NMR.

[0293] Molecular weight measurement For the cellulose esters described in this report, gel permeation chromatography analysis was performed in N-methylpyrrolidinone containing 1% by weight glacial acetic acid. The instrument consisted of an Agilent series 1100 liquid chromatography instrument. Instrument components included a degasser, an isocratic pump set at a flow rate of 0.8 ml / min, an autosampler with an injection volume of 50 microliters, a column oven set at 40°C, and a refractive index detector set at 40°C. The column set consisted of an Agilent PLgel 10 micron guard (7.5 x 50 mm) and mixed B (7.5 x 300 mm) column in series. Samples were prepared by weighing 25 mg into a 2-dram screw-cap vial and dissolving in 10 ml of solvent. Ten microliters of toluene was added as a flow rate marker. The instrument was calibrated with a series of 14 narrow molecular weight polystyrene standards ranging in molecular weight from 580 to 3,750,000. Instrument control and data acquisition / processing were performed using Agilent GPC software version 1.2 build 3182.29519. For the cellulose samples described in this report, gel permeation chromatography analysis was performed in N-methylpyrrolidinone / tributylmethylammonium dimethyl phosphate 70:30 by weight. The instrument consisted of an Agilent series 1100 liquid chromatography instrument. Instrument components included a degasser, an isocratic pump with a flow rate set at 0.5 ml / min, an autosampler with an injection volume of 50 microliters, a column oven set at 60°C, and a refractive index detector set at 40°C. The column set consisted of an Agilent PLgel 10 micron guard (7.5 x 50 mm) and mixed B (7.5 x 300 mm) column in series. Samples were prepared by weighing 12.5 mg into a 2-dram screw-cap vial and dissolving in 10 ml of solvent. 10 μL of toluene was added as a flow rate marker. The instrument was calibrated with a series of 14 narrow molecular weight polystyrene standards ranging from 580 to 3,750,000. Instrument control and data acquisition / processing were performed using Agilent GPC software version 1.2 build 3182.29519.

[0294] Dope preparation Solutions of cellulose esters for film preparation and manufacturing were made by adapting the procedures disclosed in US 2012 / 0262650.

[0295] General Procedure for Film Casting and Optical Film Analysis Dopes were made by mixing solvents (DCM, 10% MeOH in DCM, 10% acetone in DCM, 10% DCE in DCM, MEK or MIPK) and regioselective cellulose esters (8-12 wt%) and optional plasticizers (10 wt%, DEP or TPP). Films were then cast onto glass using a knife applicator and dried for 10 min at room temperature for DCM-based dopes or at 85 °C in a forced air oven for MEK- and MIPK-based dopes. The cast films were annealed in a forced air oven for 10 min at 100 °C and 120 °C, respectively, to remove residual solvent. Film thickness was measured using a Metricon Prism Coupler 2010 (Metricon Corp.) or a PosiTector 6000. Birefringence, optical dispersion and retardation were measured using an M-2000V ellipsometer (JA Woollam Co.). EXAMPLES

[0296] example Example 1: 6-Trifluoroacetyl-substituted cellulose A 1000 mL jacketed reaction kettle was equipped with a removable four-neck top. The top was fitted with an overhead stirring shaft, temperature probe, reflux condenser, and ground glass stopper. The reaction was connected to a Thermo Neslab RTE-7 temperature controller via rubber tubing and the set point was set at 25 °C. The reactor was charged with Placetate F cellulose pulp (20 g, 5 wt%). To a separate 500 mL graduated cylinder, TFA (337 g) was added, followed by TFAA (41.9 g). The resulting solution was then slowly poured into the reactor. The temperature controller was set to 60 °C and the materials were mixed with overhead stirring for approximately 75 minutes. The temperature controller was set to 50 °C and the reaction mixture was stirred for 35 minutes. The reaction mixture was poured into a beaker containing 2000 mL of anhydrous diethyl ether to precipitate the crude product. A homogenizer was used to disperse the precipitate to a uniform particle size, and the resulting solids were collected by vacuum filtration. The solid was rinsed on the filter with diethyl ether (2×200 mL) and then dried under vacuum at room temperature to give the title product. Analysis: Total DS: 1.1, C2DS: 0.03, C3DS: 0.1, C6DS: 1.0 and M w : 497,487.

[0297] Comparative Example 1. Cellulose-6-trifluoroacetate prepared according to Liebert using microcrystalline cellulose A 1000 mL jacketed reaction kettle was equipped with a removable four-neck top. An overhead stirring shaft was attached to the top. The reaction was connected to a Thermo Neslab RTE-7 temperature controller via rubber tubing and the set point was set to 25 °C. The reactor was charged with Alpha Aesar A17730 microcrystalline cellulose (10 g, 2.2 wt%). To another 500 mL graduated cylinder, TFA (297 g) was added, followed by TFAA (149 g). The resulting solution was then slowly poured into the reactor. The materials were mixed by overhead stirring at room temperature. After approximately 2-3 hours, the cellulose had completely dissolved and formed a clear viscous solution. The solution was mixed for 1 hour and the solution was poured into a beaker containing 1500 mL of anhydrous Et2O. The precipitate was dispersed to a uniform particle size using a homogenizer and the solids were collected using vacuum filtration. The solid was rinsed on the filter with diethyl ether (2×200 mL) and then dried under vacuum at room temperature to give the title compound. Analysis: Total DS: 1.2; C2DS 0.08; C3DS: 0.09; C6DS: 1.0; M w : 220,902.

[0298] Comparative Example 1 shows that the Liebert process produces cellulose esters with low selectivity at the C2 position but high selectivity at the C3 position. w is less than half of Example 1.

[0299] Comparative Example 2. Placetate F: Cellulose-6-trifluoroacetate prepared according to Liebert using cellulose pulp. A 1000 mL jacketed reaction kettle was equipped with a removable 4-neck top. The top was fitted with an overhead stirring shaft. The reaction was connected to a Thermo Neslab RTE-7 temperature controller via rubber tubing and the setpoint was set to 25 °C. The reactor was charged with Placetate F cellulose pulp (10 g, 2.2 wt%). To a separate 500 mL graduated cylinder, TFA (297 g) was added, followed by TFAA (149 g). The resulting solution was then slowly poured into the reactor. The materials were mixed at room temperature with overhead stirring. After 3 hours, the cellulose had not completely dissolved, instead forming a viscous, heterogeneous mass. This mixture was mixed for an additional hour before being transferred to a beaker containing anhydrous Et2O (1.5 L). The materials were dispersed to a uniform particle size using a homogenizer and the solids were collected using vacuum filtration. The solid was rinsed on the filter with diethyl ether (2×200 mL) and then dried under vacuum at room temperature to give the title compound. Analysis: Total DS 1.4; C2DS: 0.1; C3DS: 0.7; C6DS: 0.7; M w : 1,322,504.

[0300] Comparative Example 2 shows that the Liebert process is not effective for producing cellulose 6-trifluoroacetate from unmodified softwood pulp. Moreover, no significant molecular weight loss is observed under these conditions.

[0301] Determination of the optimal TFAA concentration for cellulose acylation The general procedure for determining the TFAA concentration is as follows: TFA and TFAA were added to a reaction vessel containing cellulose at room temperature, and the reaction was warmed to 60° C. The mixture was stirred until the cellulose was completely dissolved, and the temperature was reduced to 50° C., at which time 2.00 equivalents of Ac2O (per anhydroglucose unit of cellulose) were added, and the mixture was stirred overnight. Precipitation and polymer isolation provided the resulting cellulose acetate.

[0302] These preliminary studies are summarized in Table 1. The addition of 0.6 equivalents of TFAA reduced the total DSAc It was observed that the stoichiometry was 1.36, with a small amount of esterification at C6. This result indicated selective trifluoroacetylation at C6, although the acylation was not complete. However, it was gratifying to see that when 1.6 equivalents of TFAA was used, good acetylation at C2 and C3 was observed, with little substitution at C6. The effect of additional loading of TFAA was then examined to determine whether trifluoroacetylation was also selective towards C2 or C3, but adding 2.6 and 3.6 equivalents of TFAA was not expected to provide this additional selectivity. Ultimately, it was determined that 1.65 equivalents of TFAA was the ideal stoichiometry for selective trifluoroacetylation at C6, leaving C2 and C3 open for further functionalization.

[0303] [Table 1]

[0304] The results compare favorably with known methods for the acetylation of cellulose pulp (Table 2). Heterogeneous preparations of cellulose acetates, such as Eastman CA-320s, yield randomly substituted copolymers with acetyl groups distributed among C2, C3, and C6. Cellulose acetates prepared with the formic acid protocol developed by Buchanan (Example 13 of US9243072) provide CAs with significantly less substitution at C6 (DSC6=0.3). In contrast, polymers isolated by the TFA / TFAA protocol contain virtually no substitution at C6. For example, the cellulose acetate of Example 2 contains DS=0.05, while the remaining functional groups are exclusively concentrated at C2 and C3. Notably, Example 2 can be prepared with significantly higher molecular weights than Eastman CA 320S or Buchanan Example 13. These data indicate an improvement in the quality of cellulose esterification using the TFA / TFAA method.

[0305] [Table 2]

[0306] Example 2: Cellulose 2,3-acetate A 1000 mL jacketed reaction kettle was equipped with a removable 4-neck top. The top was fitted with an overhead stirring shaft, temperature probe, reflux condenser, and ground glass stopper. The reaction was connected to a Thermo Neslab RTE-7 temperature controller via rubber tubing and the set point was set at 25 °C. The reactor was charged with Placetate F cellulose pulp (20 g, 5 wt%). To a separate 500 mL graduated cylinder was added TFA (337 g), followed by TFAA (41.9 g). The resulting solution was then slowly poured into the reactor. The temperature controller was set to 60 °C and the materials were mixed with overhead stirring for approximately 75 minutes. The temperature controller was then set to 50 °C and the reaction mixture was stirred for 35 minutes. Subsequently, Ac2O (25.1 g, 2.00 equiv.) was added to the reaction mixture over 10 minutes via an overhead addition funnel. The resulting mixture was stirred for 12 hours. The dope was then precipitated by pouring into 3000 mL of deionized water to obtain the crude product. The crude product was broken down into uniform particle size by homogenization. The crude product was collected by filtration through a frit. The crude product was then suspended in 2000 mL of 5M KOAc (aq.) and slurried for 36 hours. The crude product was collected by filtration through a frit and washed successively with deionized water for 8 hours. The title compound was then dried in a ceramic dish at 60°C in vacuum for 12 hours. Analysis: Total DS Ac : 1.9, C2DS Ac : 0.9, C3DS Ac : 0.9, C6DS Ac : 0.05, Mw: 118,627 Da.

[0307] Except as stated in the table below, Synthesis of Example 2 Using the procedure In this way, Examples 3 to 5 were synthesized.

[0308] [Table 3]

[0309] Example 6: Cellulose-2,3-propionate A 1000 mL jacketed reaction kettle was equipped with a removable 4-neck top. The top was fitted with an overhead stirring shaft, temperature probe, reflux condenser, and ground glass stopper. The reactor was connected to a Thermo Neslab RTE-7 temperature controller via rubber tubing and the setpoint was set at 25 °C. The reactor was charged with Placetate F cellulose pulp (20 g, 5 wt%). A TFA / TFAA solution was prepared by adding TFAA (42.7 g) to TFA (337 g). The TFA / TFAA solution was then slowly poured into the reactor. The temperature controller was set to 60 °C and the reaction mixture was mixed with overhead stirring (75 min). The setpoint was then set to 50 °C. In a separate flask, PrOH (18.26 g, 2.0 equiv.) and TFA (30 mL) were stirred under a N2 atmosphere. TFAA (51.8 g, 2.0 equiv.) was added to the PrOH / TFA solution and the solution was stirred (45 min) to prepare the mixed anhydride mixture. The mixed anhydride mixture was added via an overhead addition funnel over 10 min and the resulting reaction mixture was stirred for 12 h. The dope was then precipitated by pouring into deionized water (3000 mL) to give the crude product. The crude product was broken down into a uniform particle size by homogenization. The crude product was collected by filtration through a frit and then the crude product was suspended in 5M KOAc(aq.) (2000 mL) and slurried for 36 h. The crude product was collected by filtration through a frit and washed successively with deionized water for 8 h. The title compound was obtained after the material was dried under vacuum (60° C.) for 12 h. Analysis: DS Pr : 2.0, C2DS Pr : 0.8, C3DS Pr : 0.9, C6DS Pr : 0.03, Mw: 163,340 Da.

[0310] Except as stated in the table below, The synthesis procedure of Example 6 Use By this, Examples 7 to 12 and Examples 58 to 61 were synthesized.

[0311] [Table 4]

[0312] Example 13: Cellulose 2,3-benzoate propionate The 1000 mL jacketed reaction kettle was equipped with a removable 4-neck top. The top was fitted with an overhead stirring shaft, temperature probe, reflux condenser, and ground glass stopper. The reaction vessel was connected to a Thermo Neslab RTE-7 temperature controller via rubber tubing and the set point was set at 25 °C. The reactor was charged with Placetate F cellulose pulp (20 g, 5 wt%). A solution of TFA / TFFA was prepared by adding TFAA (41.9 g) to TFA (337 g). The TFA / TFAA solution was then slowly poured into the reactor. The temperature controller was set to 60 °C and the reaction mixture was stirred with overhead stirring for approximately 75 minutes. The temperature controller was set to 50 °C and the reaction mixture was stirred for 35 minutes. Pr2O (8.02 g, 0.5 eq) was slowly added to the reaction mixture via an overhead addition funnel. During the addition of PrO, BzO (41.9 g, 1.50 equiv.) was added portionwise to the reaction mixture via a solid addition funnel. Both additions were complete after 10 min. The reaction mixture was stirred for 12 h. The dope was then precipitated by pouring into deionized water (3000 mL) to give the crude product. The crude product was broken down into a uniform particle size by homogenization. The crude product was collected by filtration through a frit. The solids were then resuspended in iPrOH and slurried for 30 min. The crude product was collected by filtration through a frit. The crude product was then suspended in 5M KOAc(aq.) (2000 mL) and stirred (36 h). The crude product was collected by filtration through a frit and washed successively with deionized water for 8 h. After drying in vacuum (60 °C) for 12 h, the title compound was obtained. Analysis: DS Bz : 0.9, DS Pr : 1.0, C2DS: 0.9, C3DS: 1.0: C6DS: 0.0, M w : 132,072 Da.

[0313] Except as stated in the table below, The synthesis procedure for Example 13 is as follows: Use In this way, Examples 14 to 16 were synthesized.

[0314] [Table 5]

[0315] Table 6 provides the degrees of substitution for Examples 14-16.

[0316] [Table 6]

[0317] Example 17: Cellulose 2,3-(2-naphthoate)propionate A 1000 mL jacketed reaction kettle was equipped with a removable 4-neck top. The top was fitted with an overhead stirring shaft, temperature probe, reflux condenser, and ground glass stopper. The reaction was connected to a Thermo Neslab RTE-7 temperature controller via rubber tubing and the set point was set at 25°C. The reactor was charged with Placetate F cellulose pulp (20 g, 5 wt%). To a separate 500 mL graduated cylinder was added TFA (337 g) followed by TFAA (41.9 g). The resulting solution was then slowly poured into the reactor. The temperature controller was set to 60°C and the materials were mixed by overhead stirring. After approximately 75 minutes the mixture formed a deep orange solution at which point the temperature controller was set to 50°C. While this process was taking place, a separate oven-dried 250 mL round bottom flask was charged with 2-NpOH (21.2 g, 1.0 equiv.) and TFA (60 mL) under nitrogen atmosphere and magnetic stirring. To this solution was slowly added TFAA (25.9 g, 1.0 equiv.) and the solution was stirred for 45 minutes until the slurry became homogenous. The reaction kettle was then fitted with two separate liquid addition funnels. One funnel contained the freshly prepared NpOH / TFAA solution and the second funnel contained PrO (4.8 g, 0.3 equiv.). The stopcocks of each funnel were opened and the liquids were added over approximately 10 minutes. The resulting mixture was stirred for 12 hours. The dope was then precipitated by pouring into deionized water (3000 mL) to give the product as a white solid. The solids were broken down into a uniform particle size by homogenization. The solids were collected by filtration through a frit. The crude product was then transferred to a cellulose thimble and extracted with MeOH using a Soxhlet apparatus for 7 hours. The crude product was then collected, suspended in 5M KOAc(aq.) (2000 mL) and slurried for 36 hours. The crude product was collected by filtration through a frit and washed successively with deionized water for 8 hours. After drying under vacuum (60° C.) for 12 hours, the title compound was obtained. Analysis: DS Np : 0.7, DS Pr : 0.6, C2DS: 0.7, C3DS: 0.4, C6DS: 0.07, Mw: 90,003 Da.

[0318] Except as stated in the table below, The synthesis procedure for Example 17 is as follows: Use In this way, Examples 18 to 20 were prepared.

[0319] [Table 7]

[0320] Table 8 provides the degree of substitution and molecular weight information for Examples 18-20.

[0321] [Table 8]

[0322] Example 21: Cellulose 2,3-(2-naphthoate)propionate A 1000 mL jacketed reaction kettle was equipped with a removable 4-neck top. The top was fitted with an overhead stirring shaft, temperature probe, reflux condenser, and ground glass stopper. The reaction was connected to a Thermo Neslab RTE-7 temperature controller via rubber tubing and the set point was set at 25°C. The reactor was charged with Placetate F cellulose pulp (20 g, 5 wt%). To a separate 500 mL graduated cylinder was added TFA (337 g) followed by TFAA (42.7 g). The resulting solution was then slowly poured into the reactor. The temperature controller was set to 60°C and the materials were mixed by overhead stirring. After approximately 75 minutes the mixture formed a deep orange solution at which point the temperature controller was set to 50°C. While this process was taking place, a separate oven-dried 250 mL round bottom flask was charged with 2-NpOH (25.5 g, 1.2 equiv.), PrOH (2.74 g, 0.3 equiv.) and TFA (60 mL) under N2 atmosphere with magnetic stirring. To this solution was slowly added TFAA (38.87 g, 1.5 equiv.) and the solution was stirred for 45 min, at which point the slurry became homogenous. The reaction kettle was then fitted with a liquid addition funnel. The funnel was then charged with the previously prepared mixture of acid anhydrides. The funnel was opened and the anhydride solution was added to the cellulose dope such that the addition was complete within 10 min. The resulting mixture was stirred for 12 h. The dope was poured into deionized water (3000 mL) to obtain the crude product. The crude product was broken down into uniform particle size by homogenization. The crude product was collected by filtration through a frit. The crude product was then transferred to a cellulose thimble and washed with MeOH for 7 h using a Soxhlet apparatus. The crude product was then collected, suspended in 5M KOAc(aq.) (2000 mL) and slurried for 36 h. The solids were collected by filtration through a frit and washed successively with deionized water for 8 h. After drying under vacuum (60° C.) for 12 h, the title compound was obtained. Analysis: DSN p : 1.3, DS Pr : 0.3, C2DS: 0.9, C3DS: 0.6, Mw: 124,916 Da.

[0323] Except as stated in the table below,The synthesis procedure of Example 21 is as follows: Use The examples in Table 9 were prepared by:

[0324] [Table 9]

[0325] Table 10 shows the degree of substitution and molecular weight information for Examples 22-29, 62-65, and 76-81. Acyl 1, Acyl 2, and Acyl 3 are the acyl substituents of Acid 1, Acid 2, and Acid 3, respectively.

[0326] [Table 10]

[0327] Example 30: Procedure for regioselective C6 propionylation of 2,3-substituted cellulose esters An oven-dried 500 mL jacketed round-bottom flask was charged with freshly dried (22 mmHg, 50 °C, 12 h) Example 58 (50 g, 8.9 wt % solids) with mechanical stirring under a nitrogen atmosphere. The reaction vessel was connected to a Thermo Neslab RTE-7 temperature controller via rubber tubing and the setpoint was set at 25 °C. To the flask was added DMAc (448 g), pyridine (61.6 g, 5.00 eq) and DMAP (1.90 g, 0.1 eq). The temperature controller was set to 50 °C and the mixture was stirred until the solids were dissolved (approximately 1-2 h) and the reaction mixture was cooled to room temperature. Pr2O (27.3 g, 1.35 eq) was then added via a liquid addition funnel (2 min). The mixture was stirred at room temperature for 12 h and the mixture was diluted with acetone (150 mL). The resulting mixture was poured into deionized water (3000 mL). The precipitated crude product was broken down to a uniform size by homogenization, and the crude product was collected on a coarse frit by vacuum filtration. The crude product was washed on the filter with MeOH (200 mL). The crude product was then washed successively with room temperature deionized water for 8 h. After drying under vacuum (60° C.) for 12 h, the title compound was obtained. Analysis: DS Pr :1.4; DS Bz:1.5; C2DS: 0.9; C3DS: 0.9; C6DS: 1.0; M w : 120,125 Da.

[0328] Example 31: Regioselective 2,3-substituted benzoate / 2-naphthoate propionate cellulose A 1000 mL jacketed reaction kettle was equipped with a removable 4-neck top. The top was fitted with an overhead stirring shaft, temperature probe, reflux condenser, and ground glass stopper. The reaction was connected to a Thermo Neslab RTE-7 temperature controller via rubber tubing and the set point was set at 25°C. The reactor was charged with Placetate F cellulose pulp (20 g, 5 wt%). To a separate 500 mL graduated cylinder was added TFA (337 g) followed by TFAA (41.9 g). The resulting solution was then slowly poured into the reactor. The temperature controller was set to 60°C and the materials were mixed by overhead stirring. After approximately 75 minutes the mixture formed a deep orange solution at which point the temperature controller was set to 50°C. The glass stopper of the reaction kettle was replaced with a plastic funnel and a mixture of Bz2O (27.8 g, 1.00 eq) and 2-Np2O (40.1 g, 1.00 eq) was added in small portions. The reaction was stirred for 12 hours at which time the dope was precipitated by pouring into 3000 mL of deionized water to give the product as a white solid. The solid was broken down into a uniform particle size by homogenization. The solid was collected by filtration through a frit. The solid was then transferred to a cellulose thimble and extracted with MeOH using a Soxhlet apparatus for 24 hours. The solid was then collected and suspended in 5M KOAc(aq.) (2000 mL) and stirred for 36 hours. The solid was collected by filtration through a frit and washed successively with deionized water for 8 hours. The solid was then dried under vacuum (60° C.) for 12 hours. Analysis: DS Np :1.4; DS Bz : 0.6; C2DS: 0.9; C3DS; 0.9; C6DS; 0.01; M W ;157,907 Da.

[0329] Except as stated in the table below, 31 synthesis steps Use The examples in Table 11 were prepared by:

[0330] [Table 11]

[0331] Example 32 An oven-dried 500 mL jacketed round-bottom flask was charged with freshly dried (50° C., 22.5 mmHg, 12 h) Example 31 (10 g, 8.9 wt % solids) with mechanical stirring under a N2 atmosphere. The reaction vessel was connected to a Thermo Neslab RTE-7 temperature controller via rubber tubing and the setpoint was set at 25° C. DMAc (93 g), pyridine (9.4 g, 5.00 eq) and DMAP (0.29 g, 0.1 eq) were added to the flask and the temperature controller was set at 50° C. to facilitate dissolution of the starting materials. Once complete dissolution of the cellulose ester was observed, the reaction was cooled to room temperature at which time Pr2O (0.93 g, 0.3 eq) was added dropwise via syringe over a period of approximately 2 minutes. The mixture was stirred at room temperature for 12 h at which time the reaction mixture was diluted with 100 mL of acetone. The resulting mixture was poured into water (2000 mL) to precipitate the crude product. The solids were broken down to a uniform size by homogenization and the solids were collected by vacuum filtration through a coarse frit. The solids were washed on the filter with 200 mL of MeOH (200 mL) and successively with water for 8 h. The solids were then dried under vacuum (60° C.) for 12 h. Analysis: DS Np : 1.4; DS Bz : 0.6;DS Pr : 0.3; C2DS: 0.9; C3DS: 0.9; C6DS: 0.3; M w ;166,868 Da.

[0332] Except as stated in the table below, Procedure for preparation of Example 32 Use The examples in Table 12 were prepared by:

[0333] [Table 12]

[0334] Table 13 provides the degree of substitution and molecular weight information for Examples 33-41.

[0335] [Table 13]

[0336] Example 42. Cellulose 2,3-benzoate A 1000 mL jacketed reaction kettle was equipped with a removable 4-neck top. The top was fitted with an overhead stirring shaft, temperature probe, reflux condenser, and ground glass stopper. The reaction was connected to a Thermo Neslab RTE-7 temperature controller via rubber tubing and the set point was set at 25°C. The reactor was charged with Placetate F cellulose pulp (50 g, 5 wt%). To a separate 500 mL graduated cylinder was added TFA (843 g) followed by TFAA (112 g). The resulting solution was then slowly poured into the reactor. The temperature controller was set to 60°C and the materials were mixed by overhead stirring. After approximately 75 minutes the mixture formed a deep orange solution at which point the temperature controller was set to 50°C. The glass stopper on the reaction kettle was replaced with a plastic funnel and Bz2O (125 g, 1.00 eq) was added in small portions. The reaction was stirred for 12 hours at which time the dope was precipitated by pouring into deionized water (3000 mL) to give the product as a white solid. The solids were broken down into a uniform particle size by homogenization. The solids were collected by filtration through a frit. The solids were then transferred to a beaker containing iPrOH (3000 mL) and slurried for 30 minutes. The solids were then collected by filtration through a coarse frit. The solids were then collected and suspended in 5M KOAc(aq.) (2000 mL) and the mixture was stirred for 36 hours. The solids were collected by filtration through a frit and washed successively with water for 8 hours. The solids were then dried under vacuum (60° C.) for 12 hours. Analysis: DS Pr : 0.0 ; DS Bz: 1.3 (appeared lower due to poor resolution in NMR solvent); C2DS: 0.8; C3DS: 0.9; C6DS: 0.02; M w : 129,434 Da.

[0337] Example 43. Cellulose 2,3-benzoate-6-propionate A 1000 mL jacketed round bottom flask was charged with freshly vacuum dried (22.5 mmHg, 50°C, 12 h) Example 42 (50 g, 8.9 wt% solids) under N2 atmosphere with mechanical stirring. The reaction vessel was connected to a Thermo Neslab RTE-7 temperature controller via rubber tubing and the set point was set at 25°C. DMAc (443 g), pyridine (55.9 g, 5.00 eq) and DMAP (1.73 g, 0.1 eq) were added to the flask and the temperature controller was set at 50°C. The mixture was stirred until the solids were dissolved (approximately 1-2 h). The reaction mixture was cooled to room temperature and Pr2O (18.38 g, 1.0 eq) was added dropwise (2 min). The mixture was stirred at room temperature for 12 h and the reaction mixture was diluted with acetone (200 mL). The resulting mixture was poured into deionized water (3000 mL). The precipitated crude product was broken down to a uniform size by homogenization, and the crude product was collected on a coarse frit by vacuum filtration. The crude product was washed on the filter with MeOH (200 mL) and then with a continuous stream of water at room temperature for 8 hours. After drying (22.5 mmHg, 60° C., 12 hours), the title compound was obtained. Analysis: DS Pr : 1.1; DS Bz : 2.1; C2DS: 1.0; C3DS: 1.0; C6DS: 0.8; M w : 139,604 Da; T g : 171.2 o C.

[0338] Except as stated in the table below, The preparative procedure of Example 43 was used to prepare the examples in Table 14.

[0339] [Table 14]

[0340] Table 15 provides degree of substitution information, molecular weight and glass transition temperature information for Examples 44-57.

[0341] [Table 15]

[0342] Example 67: Synthesis of cellulose 2,3-propionate-6-naphthoate pivalate Freshly dried (22 mmHg, 50°C, 12 h) Example 60 (20 g, 8.3 wt% solids) was added to an oven-dried 500 mL jacketed round-bottom flask under nitrogen atmosphere with mechanical stirring. The reaction vessel was connected to a Thermo Neslab RTE-7 temperature controller via rubber tubing and the set point was set to 25°C. DMAc (97 g) and pyridine (122 g) were added to the flask. The temperature controller was set to 50°C and the mixture was stirred until the solids were completely dissolved (approximately 1-2 h). The reaction mixture was then cooled to 20°C. In a separate vessel, 2-naphthyl chloride (6.55 g, 0.4 equiv.) was taken up in 15-20 mL of DMAc and magnetically stirred. Once the 2-naphthyl chloride was completely dissolved, the solution was added to the dissolved cellulose with vigorous stirring over a period of approximately 2 min. The reaction mixture was stirred at 20°C for 3-4 h. After this time, the reaction mixture was charged with pivaloyl chloride (9.31 g, 0.9 equiv.) over a period of 2 min with vigorous stirring. Once the addition was complete, the temperature controller was set to 35° C. and the resulting solution was stirred for at least 12 h. The reaction was then diluted with acetone (150 mL). The resulting mixture was poured into deionized water (3000 mL) and the precipitated crude product was broken down to a uniform size by homogenization. The resulting solids were collected by vacuum filtration through a coarse frit. The crude product was washed on the filter with two portions of iPrOH (2×200 mL). The crude product was then washed successively with room temperature deionized water for 8 h. After drying under vacuum (60° C.) for 12 h, the title compound was obtained.

[0343] Except as stated in the table below,The examples in Table 16 and the preparation procedure in Example 67 are Use It was prepared by

[0344] [Table 16]

[0345] Table 17 provides degree of substitution and molecular weight information for Examples 66-73 and 82-88.

[0346] [Table 17]

[0347] Preparation of Example 98: An oven-dried 500 mL jacketed 3-neck round bottom flask was transferred to a fume hood and attached to a hood stand. The flask was then purged under nitrogen while cooling. The flask was then fitted with a mechanical stirrer and adapter along with a positive pressure of nitrogen. The flask was then charged with Example 89 (20 grams) using a solids addition funnel. DMAc (50 mL) was added to the flask, followed by pyridine (150 mL). The reaction temperature was adjusted to 50° C. and the mixture was allowed to stir until complete dissolution of the cellulose ester was observed. The reaction temperature was adjusted to 25° C. and 2-benzothiophenecarbonyl chloride (10.3 g, 0.6 equiv.) was added over approximately 2 minutes. The reaction mixture was then held for 3 hours at which time pivaloyl chloride (8.1 g, 0.77 equiv.) was added dropwise over 2 minutes. The reaction mixture was then warmed to 40° C. and stirred for at least 12 hours. The resulting mixture was then diluted with 100 mL of acetone and poured into a beaker containing 2000 mL of deionized water to precipitate the white solids. The solids were broken down into uniform sizes by homogenization and collected by vacuum filtration through a coarse frit. The solids were washed twice on the filter with 200 mL of iPrOH. The solids were then washed successively with room temperature deionized water for 8 hours. The solids were then vacuum dried in a ceramic dish (22.5 mmHg, 60°C) for 12 hours. The product was 1 H NMR, 13Analyzed by C NMR, GPC and CIC: DSBz = 0.29, DSC2 = 0.83, DSC3=0.52, DSC6=0.96.

[0348] Except as stated in the table below, General Procedure B Use The following cellulose esters were prepared by the above procedure.

[0349] [Table 18]

[0350] Table 19 provides the degrees of substitution for the cellulose esters provided in Table 18.

[0351] [Table 19]

[0352] Table 20 provides additional degree of substitution information for Examples 98-103.

[0353] [Table 20]

[0354] Table 21 provides the degrees of substitution for Examples 104-109.

[0355] [Table 21]

[0356] film Table 22 provides films prepared using the general procedure for the preparation of films.

[0357] [Table 22]

[0358] The following films shown in Table 23 Except as stated in the table below, The disclosure procedure is as above. Use It was prepared by The films were prepared from the solvent MEK.

[0359] [Table 23]

[0360] [Table 24]

[0361] [Table 25]

[0362] Table 24 provides additional properties for the films in Table 23.

[0363] [Table 26]

[0364] [Table 27]

[0365] [Table 28]

[0366] The claims are not limited to the disclosed embodiments. The above-mentioned preferred embodiments of the present invention should be used only as examples, and should not be used in a limiting sense to interpret the scope of the present invention. Modifications to the above-mentioned exemplary embodiments can be easily made by those skilled in the art without departing from the spirit of the present invention.

[0367] The inventors hereby express their intention to rely on the doctrine of equivalents to determine and assess the reasonably fair scope of the invention relating to any device outside the literal scope of the invention without substantially departing from the literal scope of the invention as set forth in the following claims. (Aspect) (Aspect 1) (i) Multiple R 1 -CO- substituents, and (ii) multiple hydroxyl substituents; where R at position C2 1 -CO- substitution degree ("C2DS R1 ") is in the range of about 0.2 to about 1.0, C3rd place R 1 -CO- substitution degree ("C3DS R1 ") is in the range of about 0.2 to about 1.0, C6th place R 1 -CO- substitution degree ("C6DS R1 ") is in the range of about 0 to about 0.5, The degree of hydroxyl substitution is in the range of about 0 to about 2.6. R 1 (C 1-20 ) alkyl, halo(C 1-20 ) alkyl, (C 2-20 ) alkenyl, (C 3-7 ) cycloalkyl, (C 6-20 ) aryl (aryl is unsubstituted or has 1 to 6 R 2 or a 5-20 membered heteroaryl containing 1-3 heteroatoms independently selected from oxygen, sulfur and nitrogen (heteroaryl is unsubstituted or substituted with 1-6 R 3 substituted with a aryl group; R 2 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) aryl or nitro; R 3 (C 1-6 ) alkyl, halo(C 1-6 ) alkyl, (C 1-6 )Alkoxy, halo(C 1-6 ) alkoxy, halo, (C 3-7 ) cycloalkyl, (C 6-10 ) Regioselectively substituted cellulose esters selected from aryl or nitro. (Aspect 2) C6DS R1-CO- The regioselectively substituted cellulose ester of embodiment 1, wherein (Aspect 3) R 1 2. The regioselectively substituted cellulose ester according to embodiment 1, wherein -CO- is selected from acetyl, propionyl, butanoyl, benzoyl, naphthoyl, 3,4,5-trimethoxybenzoyl, biphenyl-CO-, benzoyl-benzoyl- or benzothiophenyl-CO-. (Aspect 4) R 1 The regioselectively substituted cellulose ester of embodiment 1, wherein -CO- is propionyl. (Aspect 5) The regioselectively substituted cellulose ester according to embodiment 4, wherein the degree of substitution of propionyl is from about 1.0 to about 1.4, the degree of substitution of C2 of propionyl is from 0.6 to 0.9, and the degree of substitution of C3 of propionyl is from about 0.3 to about 0.5. (Aspect 6) The regioselectively substituted cellulose ester according to embodiment 5, wherein the C6 degree of substitution of propionyl is less than 0.05. (Aspect 7) R 1 The regioselectively substituted cellulose ester of embodiment 1, wherein -CO- is a combination comprising benzoyl and naphthoyl. (Aspect 8) The regioselectively substituted cellulose ester according to embodiment 7, wherein the degree of substitution of benzoyl is from about 0.2 to about 1.2, and the degree of substitution of naphthoyl is from about 0.8 to about 1.8. (Aspect 9) The regioselectively substituted cellulose ester according to embodiment 8, wherein the degree of substitution of benzoyl is about 0.4 to about 0.8, the degree of substitution of naphthoyl is about 1.2 to about 1.6, and the degree of substitution of the combination of benzoyl and naphthoyl at the C6 position is less than 0.05. (Aspect 10) R 1 -CO- is propionyl and (C 6-20 2. The regioselectively substituted cellulose ester according to embodiment 1, wherein the combination comprises aryl. (Aspect 11) Propionyl and (C 6-20 11. The regioselectively substituted cellulose ester according to embodiment 10, wherein the substitution degree of the combination of aryls at the C6 position is less than 0.1. (Aspect 12) R 1 The regioselectively substituted cellulose ester of embodiment 1, wherein -CO- is a combination comprising propionyl and benzoyl. (Aspect 13) The regioselectively substituted cellulose ester according to embodiment 12, wherein the degree of substitution of propionyl is about 0.4 to about 0.7, the degree of substitution of benzoyl is about 0.2 to about 0.5, and the degree of substitution of the combination of propionyl and benzoyl at C6 substitution is less than 0.05. (Aspect 14) The regioselectively substituted cellulose ester according to embodiment 12, wherein the degree of substitution of propionyl is about 1.1 to about 1.8, the degree of substitution of benzoyl is about 0.1 to about 0.5, and the degree of substitution of the combination of propionyl and benzoyl at C6 substitution is less than 0.05. (Aspect 15) R 1 The regioselectively substituted cellulose ester according to embodiment 1, wherein -CO- is a combination comprising propionyl and naphthoyl. (Aspect 16) R 1 The regioselectively substituted cellulose ester according to embodiment 1, wherein -CO- is a combination including propionyl, or a 5-20 membered heteroaryl containing 1 to 3 heteroatoms independently selected from oxygen, sulfur, and nitrogen. (Aspect 17) R 1 -CO- is propionyl and (C 6-20 2. The regioselectively substituted cellulose ester according to embodiment 1, wherein the combination comprises alkyl-CO-. (Aspect 18) R 1 -CO- is acetyl and (C 6-20 The regioselectively substituted cellulose ester according to embodiment 1, wherein the aryl-CO- is a combination of the aryl-CO- and aryl-CO-. (Aspect 19) The degree of acetyl substitution is about 0.7 to about 0.9, and (C 6-20 The degree of substitution of aryl-CO- is about 0.1 to about 0.5, and acetyl and (C 6-20 20. The regioselectively substituted cellulose ester according to embodiment 18, wherein the degree of substitution at C6 substitution of the aryl-CO- combination is less than 0.1. (Aspect 20) R 1 The regioselectively substituted cellulose ester according to embodiment 1, wherein -CO- is a combination containing acetyl and a 5- to 20-membered heteroaryl containing 1 to 3 heteroatoms independently selected from oxygen, sulfur, and nitrogen. (Aspect 21) The regioselectively substituted cellulose ester according to embodiment 20, wherein the degree of substitution of acetyl is about 0.8 to about 1.1, the degree of substitution of 5-20 membered heteroaryl containing 1 to 3 heteroatoms independently selected from oxygen, sulfur and nitrogen is about 0.1 to about 0.3, and the degree of substitution of C6 substitution of a combination of acetyl and benzoyl is less than 0.1. (Aspect 22) Weight average molecular weight (“M w The regioselectively substituted cellulose ester according to embodiment 1, wherein the molecular weight of the cellulose ester is in the range of about 50,000 Da to about 500,000 Da. (Aspect 23) (i) Regioselectively substituted trifluoroacetyl cellulose esters containing multiple trifluoroacetyl substituents, Here, the degree of substitution at the C2 position ("C2DS TFA ") is about 0 to about 0.1, Degree of substitution at C3 position ("C3DS TFA ") is about 0 to about 0.1, Degree of substitution at C6 position ("C6DS TFA ") is about 0.9 to about 1.0, The regioselectively substituted trifluoroacetyl cellulose ester has a weight average molecular weight (M) ranging from about 50,000 Da to about 600,000 Da. w "). Regioselectively substituted trifluoroacetyl cellulose esters having the formula:

Claims

1. (i) a plurality of R １ a -CO- substituent, and (ii) multiple hydroxyl groups; where R at position C2 １ The degree of substitution of -CO- ("C2DS Ｒ１ ") is in the range of 0.2 to 1.0, C3rd place R １ The degree of substitution of -CO- ("C3DS Ｒ１ ") is in the range of 0.2 to 1.0, C6th place R １ Degree of substitution of -CO- ("C6DS Ｒ１ ") is greater than or equal to 0 and less than 0.1, The degree of hydroxyl substitution ranges from 0.9 to 2.6; R １ (C １－２０ ) alkyl, halo (C １－２０ ) alkyl, (C ２－２０ ) alkenyl, (C ３－７ ) cycloalkyl, (C ６－２０ ) aryl (aryl is unsubstituted or has 1 to 6 R ２ or a 5-20 membered heteroaryl containing 1-3 heteroatoms independently selected from oxygen, sulfur and nitrogen (heteroaryl is unsubstituted or substituted with 1-6 R ３ substituted with a aryl group; R ２ (C １－６ ) alkyl, halo (C １－６ ) alkyl, (C １－６ ) alkoxy, halo (C １－６ ) alkoxy, halo, (C ３－７ ) cycloalkyl, (C ６－１０ ) selected from aryl or nitro; R ３ (C １－６ ) alkyl, halo (C １－６ ) alkyl, (C １－６ ) alkoxy, halo (C １－６ ) alkoxy, halo, (C ３－７ ) cycloalkyl, (C ６－１０ ) Regioselectively substituted cellulose esters selected from aryl or nitro.

2. R １ 2. The regioselectively substituted cellulose ester of claim 1, wherein --CO-- is selected from acetyl, propionyl, butanoyl, benzoyl, naphthoyl, 3,4,5-trimethoxybenzoyl, biphenyl-CO-- or benzothiophenyl-CO--.

3. R １ 2. The regioselectively substituted cellulose ester of claim 1, wherein --CO-- is propionyl.

4. 4. The regioselectively substituted cellulose ester according to claim 3, wherein the degree of substitution of propionyl is 1.0 to 1.4, the degree of substitution of C2 of propionyl is 0.6 to 0.9, and the degree of substitution of C3 of propionyl is 0.3 to 0.

5.

5. The regioselectively substituted cellulose ester of claim 4, wherein the degree of C6 substitution of propionyl is less than 0.

05.

6. R １ 2. The regioselectively substituted cellulose ester of claim 1, wherein --CO-- is a combination comprising benzoyl and naphthoyl.

7. 7. The regioselectively substituted cellulose ester of claim 6, wherein the degree of substitution of benzoyl is from 0.2 to 1.2, and the degree of substitution of naphthoyl is from 0.8 to 1.

8.

8. The regioselectively substituted cellulose ester according to claim 7, wherein the degree of substitution of benzoyl is 0.4-0.8, the degree of substitution of naphthoyl is 1.2-1.6, and the degree of substitution of the combination of benzoyl and naphthoyl at the C6 position is less than 0.

05.

9. R １ -CO- is propionyl and R １ As (C ６－２０ 2. The regioselectively substituted cellulose ester of claim 1, wherein the aryl is a combination of:

10. Propionyl and R １ As (C ６－２０ 10. The regioselectively substituted cellulose ester of claim 9, wherein the degree of substitution at the C6 position of the aryl combination is less than 0.

1.

11. R １ 2. The regioselectively substituted cellulose ester of claim 1, wherein --CO-- is a combination comprising propionyl and benzoyl.

12. The regioselectively substituted cellulose ester of claim 11, wherein the degree of substitution of propionyl is 0.4 to 0.7, the degree of substitution of benzoyl is 0.2 to 0.5, and the degree of substitution of the combination of propionyl and benzoyl at C6 substitution is less than 0.

05.

13. The regioselectively substituted cellulose ester of claim 11, wherein the degree of substitution of propionyl is 1.1 to 1.8, the degree of substitution of benzoyl is 0.1 to 0.5, and the degree of substitution of the combination of propionyl and benzoyl at C6 substitution is less than 0.

05.

14. R １ 2. The regioselectively substituted cellulose ester of claim 1, wherein --CO-- is a combination comprising propionyl and naphthoyl.

15. R １ -CO- is propionyl, or R １ The regioselectively substituted cellulose ester according to claim 1, wherein R is a 5- to 20-membered heteroaryl having 1 to 3 heteroatoms independently selected from oxygen, sulfur and nitrogen.

16. R １ -CO- is propionyl and (C ６－２０ 2. The regioselectively substituted cellulose ester of claim 1, wherein the aryl group is a substituted cellulose ester.

17. R １ -CO- is acetyl and (C ６－２０ 2. The regioselectively substituted cellulose ester of claim 1, wherein the aryl-CO- is a combination of aryl-CO-.

18. The degree of acetyl substitution is 0.7 to 0.9, and (C ６－２０ The degree of substitution of aryl-CO- is 0.1 to 0.5, and acetyl and (C ６－２０ 20. The regioselectively substituted cellulose ester of claim 17, wherein the degree of substitution at C6 substitution of the aryl-CO- combination is less than 0.

1.

19. R １ -CO- is acetyl and benzoyl, and R １ The regioselectively substituted cellulose ester according to claim 1, which is a combination comprising: a 5- to 20-membered heteroaryl having 1 to 3 heteroatoms independently selected from oxygen, sulfur and nitrogen as the heteroaryl;

20. The degree of substitution of acetyl is 0.8 to 1.1, and R １ The regioselectively substituted cellulose ester according to claim 19, wherein the degree of substitution of 5-20 membered heteroaryl containing 1-3 heteroatoms independently selected from oxygen, sulfur and nitrogen is 0.1-0.3, and the degree of substitution of C6 substitution of acetyl and benzoyl combination is less than 0.

1.

21. Weight average molecular weight (“M ｗ 2. The regioselectively substituted cellulose ester of claim 1, wherein m is in the range of 50,000 Da to 500,000 Da.

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