GB2071667A - Acetyl Derivatives of Cellulose - Google Patents
Acetyl Derivatives of Cellulose Download PDFInfo
- Publication number
- GB2071667A GB2071667A GB8107964A GB8107964A GB2071667A GB 2071667 A GB2071667 A GB 2071667A GB 8107964 A GB8107964 A GB 8107964A GB 8107964 A GB8107964 A GB 8107964A GB 2071667 A GB2071667 A GB 2071667A
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- Prior art keywords
- cellulose
- process according
- solution
- acetic anhydride
- derivative
- Prior art date
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- 239000001913 cellulose Substances 0.000 title claims abstract description 53
- 229920002678 cellulose Polymers 0.000 title claims abstract description 53
- 125000000218 acetic acid group Chemical group C(C)(=O)* 0.000 title claims abstract description 8
- WFDIJRYMOXRFFG-UHFFFAOYSA-N Acetic anhydride Chemical compound CC(=O)OC(C)=O WFDIJRYMOXRFFG-UHFFFAOYSA-N 0.000 claims abstract description 63
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical class OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 claims abstract description 57
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 claims abstract description 33
- FXHOOIRPVKKKFG-UHFFFAOYSA-N N,N-Dimethylacetamide Chemical compound CN(C)C(C)=O FXHOOIRPVKKKFG-UHFFFAOYSA-N 0.000 claims abstract description 28
- 238000000034 method Methods 0.000 claims abstract description 25
- 239000002904 solvent Substances 0.000 claims abstract description 15
- 239000003054 catalyst Substances 0.000 claims abstract description 12
- 238000006243 chemical reaction Methods 0.000 claims abstract description 10
- 229930040373 Paraformaldehyde Natural products 0.000 claims abstract description 7
- 229920002866 paraformaldehyde Polymers 0.000 claims abstract description 7
- 239000003513 alkali Substances 0.000 claims abstract description 5
- 229910052783 alkali metal Inorganic materials 0.000 claims abstract description 4
- 150000001875 compounds Chemical class 0.000 claims abstract description 4
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 claims description 14
- IAZDPXIOMUYVGZ-UHFFFAOYSA-N Dimethylsulphoxide Chemical compound CS(C)=O IAZDPXIOMUYVGZ-UHFFFAOYSA-N 0.000 claims description 11
- WSFSSNUMVMOOMR-UHFFFAOYSA-N Formaldehyde Chemical group O=C WSFSSNUMVMOOMR-UHFFFAOYSA-N 0.000 claims description 11
- 229960001760 dimethyl sulfoxide Drugs 0.000 claims description 11
- 238000006640 acetylation reaction Methods 0.000 claims description 10
- SCVFZCLFOSHCOH-UHFFFAOYSA-M potassium acetate Chemical group [K+].CC([O-])=O SCVFZCLFOSHCOH-UHFFFAOYSA-M 0.000 claims description 10
- 230000021736 acetylation Effects 0.000 claims description 9
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 8
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 claims description 6
- 238000002360 preparation method Methods 0.000 claims description 6
- QTBSBXVTEAMEQO-UHFFFAOYSA-M Acetate Chemical compound CC([O-])=O QTBSBXVTEAMEQO-UHFFFAOYSA-M 0.000 claims description 5
- 239000000203 mixture Substances 0.000 claims description 5
- 235000011056 potassium acetate Nutrition 0.000 claims description 5
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 claims description 4
- VZGDMQKNWNREIO-UHFFFAOYSA-N tetrachloromethane Chemical compound ClC(Cl)(Cl)Cl VZGDMQKNWNREIO-UHFFFAOYSA-N 0.000 claims description 4
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 claims description 3
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 2
- 238000009835 boiling Methods 0.000 claims description 2
- 125000002887 hydroxy group Chemical group [H]O* 0.000 claims description 2
- 125000005704 oxymethylene group Chemical group [H]C([H])([*:2])O[*:1] 0.000 claims description 2
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 claims 1
- 229910052751 metal Inorganic materials 0.000 claims 1
- 239000002184 metal Substances 0.000 claims 1
- 150000001242 acetic acid derivatives Chemical class 0.000 abstract description 3
- -1 alkali metal acetate Chemical class 0.000 abstract description 3
- 239000000835 fiber Substances 0.000 abstract description 3
- 235000010980 cellulose Nutrition 0.000 description 29
- 239000000047 product Substances 0.000 description 19
- JUJWROOIHBZHMG-UHFFFAOYSA-N Pyridine Chemical compound C1=CC=NC=C1 JUJWROOIHBZHMG-UHFFFAOYSA-N 0.000 description 12
- 235000019256 formaldehyde Nutrition 0.000 description 8
- XEKOWRVHYACXOJ-UHFFFAOYSA-N Ethyl acetate Chemical compound CCOC(C)=O XEKOWRVHYACXOJ-UHFFFAOYSA-N 0.000 description 7
- YMWUJEATGCHHMB-UHFFFAOYSA-N Dichloromethane Chemical compound ClCCl YMWUJEATGCHHMB-UHFFFAOYSA-N 0.000 description 6
- UMJSCPRVCHMLSP-UHFFFAOYSA-N pyridine Natural products COC1=CC=CN=C1 UMJSCPRVCHMLSP-UHFFFAOYSA-N 0.000 description 6
- HEDRZPFGACZZDS-UHFFFAOYSA-N Chloroform Chemical compound ClC(Cl)Cl HEDRZPFGACZZDS-UHFFFAOYSA-N 0.000 description 4
- XTHFKEDIFFGKHM-UHFFFAOYSA-N Dimethoxyethane Chemical compound COCCOC XTHFKEDIFFGKHM-UHFFFAOYSA-N 0.000 description 4
- RLSSMJSEOOYNOY-UHFFFAOYSA-N m-cresol Chemical compound CC1=CC=CC(O)=C1 RLSSMJSEOOYNOY-UHFFFAOYSA-N 0.000 description 4
- 239000000843 powder Substances 0.000 description 4
- 239000002244 precipitate Substances 0.000 description 4
- ZNQVEEAIQZEUHB-UHFFFAOYSA-N 2-ethoxyethanol Chemical compound CCOCCO ZNQVEEAIQZEUHB-UHFFFAOYSA-N 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 239000003960 organic solvent Substances 0.000 description 3
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 description 2
- HEDRZPFGACZZDS-MICDWDOJSA-N Trichloro(2H)methane Chemical compound [2H]C(Cl)(Cl)Cl HEDRZPFGACZZDS-MICDWDOJSA-N 0.000 description 2
- 239000003153 chemical reaction reagent Substances 0.000 description 2
- MVPPADPHJFYWMZ-UHFFFAOYSA-N chlorobenzene Chemical compound ClC1=CC=CC=C1 MVPPADPHJFYWMZ-UHFFFAOYSA-N 0.000 description 2
- 238000012505 colouration Methods 0.000 description 2
- 235000019439 ethyl acetate Nutrition 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- RYHBNJHYFVUHQT-UHFFFAOYSA-N 1,4-Dioxane Chemical compound C1COCCO1 RYHBNJHYFVUHQT-UHFFFAOYSA-N 0.000 description 1
- XIVUBGOYMBSEMA-UHFFFAOYSA-N 1,4-dioxane;methylsulfinylmethane Chemical compound CS(C)=O.C1COCCO1 XIVUBGOYMBSEMA-UHFFFAOYSA-N 0.000 description 1
- XVMSFILGAMDHEY-UHFFFAOYSA-N 6-(4-aminophenyl)sulfonylpyridin-3-amine Chemical compound C1=CC(N)=CC=C1S(=O)(=O)C1=CC=C(N)C=N1 XVMSFILGAMDHEY-UHFFFAOYSA-N 0.000 description 1
- LQVXSNNAFNGRAH-QHCPKHFHSA-N BMS-754807 Chemical compound C([C@@]1(C)C(=O)NC=2C=NC(F)=CC=2)CCN1C(=NN1C=CC=C11)N=C1NC(=NN1)C=C1C1CC1 LQVXSNNAFNGRAH-QHCPKHFHSA-N 0.000 description 1
- 239000002202 Polyethylene glycol Substances 0.000 description 1
- VMHLLURERBWHNL-UHFFFAOYSA-M Sodium acetate Chemical compound [Na+].CC([O-])=O VMHLLURERBWHNL-UHFFFAOYSA-M 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 125000004432 carbon atom Chemical group C* 0.000 description 1
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 1
- 229920002301 cellulose acetate Polymers 0.000 description 1
- 239000007806 chemical reaction intermediate Substances 0.000 description 1
- 238000004587 chromatography analysis Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- GNOIPBMMFNIUFM-UHFFFAOYSA-N hexamethylphosphoric triamide Chemical compound CN(C)P(=O)(N(C)C)N(C)C GNOIPBMMFNIUFM-UHFFFAOYSA-N 0.000 description 1
- 230000007062 hydrolysis Effects 0.000 description 1
- 238000006460 hydrolysis reaction Methods 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 238000002329 infrared spectrum Methods 0.000 description 1
- 235000015110 jellies Nutrition 0.000 description 1
- 239000008274 jelly Substances 0.000 description 1
- 125000004674 methylcarbonyl group Chemical group CC(=O)* 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 229920001223 polyethylene glycol Polymers 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 239000005373 porous glass Substances 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 235000017281 sodium acetate Nutrition 0.000 description 1
- GEHJYWRUCIMESM-UHFFFAOYSA-L sodium sulfite Chemical compound [Na+].[Na+].[O-]S([O-])=O GEHJYWRUCIMESM-UHFFFAOYSA-L 0.000 description 1
- 235000010265 sodium sulphite Nutrition 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 238000009987 spinning Methods 0.000 description 1
- 238000002211 ultraviolet spectrum Methods 0.000 description 1
- 239000003643 water by type Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08B—POLYSACCHARIDES; DERIVATIVES THEREOF
- C08B3/00—Preparation of cellulose esters of organic acids
- C08B3/06—Cellulose acetate, e.g. mono-acetate, di-acetate or tri-acetate
Landscapes
- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Biochemistry (AREA)
- Materials Engineering (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Polysaccharides And Polysaccharide Derivatives (AREA)
Abstract
A process is described for preparing acetyl derivatives of cellulose, comprising dissolving the cellulose in a solvent chosen among dimethylformamide and dimethylacetamide in the presence of paraformaldehyde, whereby a cellulose methylol derivative is formed, and thereafter treating said derivative in said solution with acetic anyhydride in the presence of a catalyst constituted by an alkali or earth alkali metal acetate or of a compound capable of forming such acetates by reaction with acetic anhydride. White products are obtained which may be easily isolated and used for making fibers or films or like products.
Description
SPECIFICATION
Acetyl Derivatives of Cellulose and Process for Their Preparation
The present invention refers to acetyl derivatives of cellulose and to a process for their preparation.
The derivatives which are an object of the present invention are distinguished from the acetyl celluloses known in the art both as to their structure and so as to their preparation and properties.
It is known to prepare cellulose solutions in organic solvents in the presence of formaldehyde or paraformaldehyde, in which solutions the cellulose is present in the form of a derivative which is normally considered as a methylol derivative and will thus be called in this description, although the
Applicant does not wish to be bound to any specific hypothesis as to its structure. For example, it is known to dissolve cellulose in paraformaldehyde and dimethylsulphoxide (DMSO) (Jour. Appl. Polym.
Sci. 20 3425-1976). The product which is formed is believed to be a monomethylol derivative of cellulose, prevalently substituted on the C6 carbon atom.
It is also known from previous patents and patent applications of this Applicant to prepare solutions of like methylol derivatives of cellulose in dimethylformamide (DMF) or dimethylacetamide (DMAC) or other solvents.
For example, such processes and products are described in our copending Italian patent applications No. 20540, 21844 A/78, 21922 A/78, 28527 A/78, 23349 A/79 and 23350 A/79.
An article of Jour. Polym. Sci.-Polymer Chemistry Ed., Vol. 16 1-11(1978), describes the acetylation of cellulose in solutions such as those previously mentioned, in DMSO and in the presence of paraformaldehyde, by means of acetic anhydride as reagent and pyridine as a catalyst. In such process the methylol derivative present in the solution becomes acetylated. The solution obtained is coloured from yellow to brown and a product coloured from yellow to orange may be precipitated therefrom with water. The cited article characterizes the acetylation product thus isolated and formulates the hypothesis that it contains acetylated methylol groups.
Said publication also underscores the importance of the formation of dimethylacetoxysulphonium acetates in the acetylation of cellulose and in its oxidation, accompanied by the formation of colour, which compounds are believed to be formed by reaction of acetic anhydride with DMSO and to act as reaction intermediates.
The present invention has the purpose of obtaining from methylol derivatives of cellulose dissolved in solvents, different from DMSO, acetylated products which are substantially free from colour, which provide white precipitates and may be employed to make fibers or like products, wherein a marked colouration constitutes an intolerable defect.
Such a result cannot be obtained by merely using solvents different from DMSO and applying the acetylation method described in the cited articles of Jour. Polym. Sci. The fact is that it is possible to acetylate with acetic anhydride and pyridine, cellulose solutions, for instance in DMF or DMAC in the presence of paraformaldehyde, obtained by the methods described in the previous patents and patent applications of this Applicant, but the resulting acetylated solutions are coloured from yellow to brown and yield precipitation products coloured from yellowish to orange, entirely similar to those obtained from solution in DMSO. The products obtained in this way are not easily isolated in the pure state and are not easily identified.Said results indicate that the acetylation with acetic anhydride and pyridine in any type of organic solvent in which a methylol derivative of cellulose is present, leads to the formation of an eccessive amount of by-products with attendant harmful colouration.
The present invention, on the contrary, solves the problem of obtaining white products, which are easily isolated and characterized and which can be used to make fibers or films or like products.
The process according to the invention is characterized in that a cellulose solution is prepared in a solvent chosen among DMF and DMAC, in the presence of paraformaldehyde, whereby a methylol derivative of cellulose is formed, according to the known art, and said derivative is acetylated with acetic anhydride in the presence of a catalyst constituted by an acetate of an alkali or earth-alkali metal or by a compound capable of forming such acetates by reaction with acetic anhydride. Preferred examples of such catalysts are the acetates, oxides and carbonates of alkali and earth-alkali metal, e.g.
potassium acetate.
The acetylation product obtained may be precipitated from the solution by adding an hydroxylated solvent thereto, e.g. a 1:1 mixture of water and a low boiling alcohol, such as methanol.
Said product, suitable freed from the solvents and dried, appears as a white powder, soluble in numerous organic solvents such as DMF, DMAC, DMSO dioxane, dimethylcellosolve, (Cellosolve is a
Registered Trade Mark), chloroform, methylene chloride, acetone, tetrahydrofurane, ethyl acetate, pyridine, N-methylpyrrolidone, m-cresol, etc.
Acetylated methylol and/or polyoxymethylene chains are present in said isolated products, possibly together with acetylated and free cellulosic hydroxyls, and the behaviour of said products to heating is considerably different from that of the products obtained with acetic anhydride and pyridine from solutions in DMSO. The difference in purity is underlined also by the ultraviolet spectrum, which does not not show the absorption at 214 and 327 nm cited in the aforementioned article of Jour.
Polym. Sci.
It is to be noted that if it is attempted to acetylate in similar way cellulose which is present as a methylol derivative in a solution in DMSO, brown products are obtained which are more or less degraded and quite similar to those obtained by operating with acetic anhydride and pyridine.
The critical factor for attaining the purpose of the invention, therefore, is not the solvent taken per se or the catalyst taken per se, but the critical combination of the two.
The products according to the invention are easily soluble in the wet or in the dry, due to their solubility in many spinning solvents, as listed hereinbefore, and are therefore suitable for direct industrial use.
The preferred conditions for carrying out the process are the following:
temperatures of the reaction between the cellulose methylol derivative in solution, and acetic anhydride: from 600C to 1 400C, and preferably from 900C to 1 200C; duration of the acetylation reaction: from 1 minute to 20 hours and preferably from 5 minutes to 90 minutes;
molar ratio CH2O/cellulose in the solution to be acetylated: from 1.5 to 15 and preferably from 2 to 5;
molar ratio acetic anhydride/cellulose: from 5 to 50 and preferably from 10 to 40;
quantity of catalyst, expressed as parts by weight referred to 100 parts of cellulose: from 0.1 to 50 and preferably from 1 to 30;
concentration of the solutions to be acetylated, expressed as percentages by weight of cellulose on the total weight of the solution: from 1 to 20 and preferably from 5 to 15;
final acetylation degree, expressed as the ratio of moles of acetic acid to anhydroglucosidic units: from 1 to 3 and preferably from 2 to 2.9.
A number of illustrative and non limitative examples of the invention will now be described.
Example 1
A solution of 0.3 g of potassium acetate in 30 g of acetic anhydride, with the addition a few drops of acetic acid, is added dropwise during about 15 min to 30 g of a cellulose solution in DMAC/(CH20)n, obtained according to one of the methods described e.g. in Italian patent application
No. 21922 /78 (CH2O % in the solution=8.4, cellulose % in the solution=9.5) and heated under efficient stirring and under inert gas to 600 C. A jelly may sometimes form during the addition of the reagent solution, but it charges into a solution when the temperature is raised from 600 to 1200. At the end of the reaction the resulting clear solution is cooled to room temperature and 60 ml of a 1:1 mixture of methanol and water are added, always under stirring.A white precipitate forms, which is filtered through a porous glass filter and is washed on said filter three times with a 1:1 mixture of methanol and water and once with methanol alone. The precipitate is dried firstly summarily under a vacuum at room temperature and then at 80--1000, always under a vacuum, until its weight becomes constant. 5.69 g of white powder are obtained. The mother waters, brought to dryness, yield 0.305 g of a water soluble residue. The white powder has the following analytical composition.
Acetate (hydrolysis) 6.78 (mequivalents/g)
Free CH2O (Na2SO3) absent
C 46.9%
H 5.8%
The molecular weight of the monomeric unit of the derivative may be calculated from the weight increase, referred to the cellulose initially present in the solution, said increase being 199.6%. The
result is: MW (monomeric)=323.
Based on-this datum, it is possibly to calculate the number of methylol and acetate groups per anhydroglucosidic unit(MS).
They are:
MS acetate 2.2
MS methylol 2.3
The white powder is soluble in DMF, DMAC, DMSO, dioxane, dimethylcellosolve, (Cellosolve is a
Registered Trade Mark), chloroform, methylene chloride, acetone, tetrahydrofurane, ethyl acetate, pyridine, n-methylpyrrolidone, m-cresol, and very slowly in acetic acid; it is insoluble in ethyl ether, methanol, water, carbon tetrachloride, chlorobenzene, cellosolve (Registered Trade Mark), polyethyleneglycol, (MW about 300) and in hexamethylphosphoramide.
The infrared spectrum of the precipitate product has a strong band at 955 cam~', which can be attributed to the oxymethylene group -CH2-0-, and bands at 1755, 1375, 1235 cam~' which can be attributed to the acetic ester group CH3-CO-0-.
The PMR spectrum in CDCl3 has a peak at 2.05 ppm, which can be attributed to the protons of the CH3CO groups and two peaks at 4.85 and 5.50 ppm, which can be attributed to the protons of the --OO-CHH,-O groups. No other significant peaks are noted. GPC chromatography shows that the product has maintained a polymeric structure.
Examples 2 to 7
The preparation method of Example 1 has been employed using several cellulose solutions in DMAC/(CH20)n or DMF/(CH20)n. Hereinafter some of the results obtained are listed, together with the characteristics of the starting solution.
Initial Solution Derivative
Solvent Cellulose % CH2O% MSacetate MSmethylol MWmonomer
2) DMAC 10.1 5.8 2.3 1.5 320
3) DMAC 10.2 9.0 2.3 2.1 336
4) DMAC 9.9 13.9 2.3 3.4 360
5) DMAC 10.5 6.6 2.4 1.4 305
6) DMAC 10.4 9.5 2.4 2.4 334
7) DMF 3.4 5.5 2.2 1.5 299
Examples 8-14 Examples 1-7 are repeated using double amounts of acetic anhydride and potassium acetate.
The results obtained are the following:
Initial Solution Derivative
Solvent Cellulose % CH2O% MSacetate MSmethylol MWmonomer
8) DMAC 10.0 7.0 2.6 2.3 338
9) DMAC 6.6 9.3 2.6 3.6 380
10) DMAC 10.0 8.0 2.7 2.7 357
11) DMAC 8.9 4.5 2.7 1.4 316
12) DMAC 2.25 2.8 2.7 3.2 371
13) DMAC 12.9 7.9 2.4 2.4 333
14) DMAC 8.1 15.1 2.7 4.9 423
Examples 15-18 The same conditions as in Example 1 have been used, but the amount of acetic anhydride has been doubled (60 g) and different catalysts have been used. The results are tabulated in the following table.
Initial Solution Derivative
Solvent Cellulose % CH2O% Catalyst MSacetate MSmethylol MWmonomer 15) DMAC 9.9 5.5 CH3COONa 0.50 9 2.5 1.5 311 16) DMAC 9.9 5.5 KOH,0.35 9 2.5 1.5 311 17) DMAC 9.9 5.5 (CH3COO)2CaO.97g 2.1 1.6 297 18) DMAC 9.9 5.5 CH3COOKO.60g 2.7 1.7 323
Examples 19-23 20 g of a cellulose solution in DMAC/(CH20)n obtained by one of the methods described e.g. in
Italian patent application No. 21922 A/78 (CH2O% in solution=6.72, cellulose % in solution=10.2) are treated in a manner analogous to that described in Example 1, but with variable amounts of acetic anhydride and potassium acetate, at variable temperatures and times.
In the following table the reaction conditions and the results obtained are tabulated.
Reaction Condition time Derivative g(CHgCO)2O gCH3COOK t0(0C) (min) MSacetate MSmethylol MWmonome 19) 40 0.4 120 60 2.72 1.99 336 20) 40 0.4 120 5 2.44 1.96 323 21) 40 0.4 80 480 2.45 1.87 321 22) 20 0.03 120 120 2.27 1.75 310 23) 40 0.01 130 60 2.28 1.52 303
Claims (19)
1. Process for the preparation of acetyl derivatives of cellulose, characterized in that the cellulose is dissolved in the presence of paraformaldehyde in a solvent chosen among dimethylformamide and dimethylacetamide, whereby a methylol derivative of cellulose is formed, and said derivative is treated in said solution with acetic anhydride in the presence of a catalyst constituted by an alkali or earthalkali metal acetate or of a compound capable of forming said acetate by reaction with acetic anhydride.
2. Process according to claim 1, characterized in that the catalyst is chosen in the group consisting of oxide and carbonate of alkali and earth-alkali metals.
3. Process according to claim 2, characterized in that the catalyst is potassium acetate.
4. Process according to any of claims 1 to 3, characterized in that the acetyl derivative produced is precipitated from the solution by adding a hydroxylated solvent thereto.
5. Process according to claim 4, characterized in that the hydroxylated solvent is a mixture of water and a low boiling alcohol.
6. Process according to any of claims 1 to 5, characterized in that the treatment of the solution of methylol derivative of cellulose with acetic anhydride is carried out at temperatures comprised between 600C and 1 400C.
7. Process according to any of claims 1 to 6, characterized in that the reaction between the cellulose methylol derivative solution and the acetic anhydride lasts from 1 minute to 20 hours.
8. Process according to any of claims 1 to 7, characterized in that the cellulose methylol derivative has a ratio of CH2O units to cellulose units from 1.5 to 1 5.
9. Process according to any of claims 1 to 8, characterized in that acetic anhydride is employed in a molar ratio with respect to the cellulose comprised between 5 to 50.
10. Process according to any of claims 1 to 9, characterized in that the catalyst is employed in amounts from 0.1 to 50 expressed as parts by weight referred to 100 parts of cellulose.
11. Process according to any of claims 1 to 10, characterized in that the concentration of the cellulose methylol derivative solution, expressed as weight percentage of cellulose with respect to the total weight of the solution, is comprised between 1 and 20.
12. Process according to any of claims 1 to 11, characterized in that the reaction of the cellulose methylol derivative with acetic anhydride is continued until a final acetylation degree from 1 to 3, expressed as moles of acetic acid per hydroglucosidic unit, has been attained.
1 3. Process for the preparation of acetyl derivatives of cellulose, substantially as described.
14. Acetyl derivatives of cellulose, essentially constituted by methylol acetylates, possibly in the presence of acetylated and free polyqxymethylene chains and cellulose hydroxyls, characterized by an acetylation degree comprised between 1 and 3, and by a white colour.
1 5. Acetylated derivatives of cellulose according to claim 14, characterized by their solubility in dimethylformamide, dimethylacetamide, dimethylsulphoxide, acetone, tetrahydrofurane, and the like, and by their insolubility in methanol, water, ethyl ether, carbon tetrachloride and the like.
1 6. Acetylated derivatives of cellulose according to claim 14 or 1 5, characterized by the fact that they comprise a number of oxymethylene groups per anhydroglucosidic unit comprised between 0.5 and 10 and a number of acetate groups per anhydroglucosidic unit comprised between 1 and 3.
1 7. Acetylated derivatives of cellulose according to any of claims 14 to 16, characterized by an average molecular weight of the monomeric unit comprised between 220 and 590.
18. Acetylated derivatives of cellulose, substantially as described.
19. Acetylated derivatives of cellulose, obtained by the process according to any of claims 1 to 13. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| IT8020784A IT8020784A0 (en) | 1980-03-19 | 1980-03-19 | ACETYLATED CELLULOSE DERIVATIVES AND PROCEDURE FOR THEIR PREPARATION. |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB2071667A true GB2071667A (en) | 1981-09-23 |
Family
ID=11172011
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8107964A Withdrawn GB2071667A (en) | 1980-03-19 | 1981-03-13 | Acetyl Derivatives of Cellulose |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JPS56141301A (en) |
| DE (1) | DE3111276A1 (en) |
| FR (1) | FR2478645A1 (en) |
| GB (1) | GB2071667A (en) |
| IT (1) | IT8020784A0 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1996020960A1 (en) * | 1994-12-30 | 1996-07-11 | Eastman Chemical Company | A direct process for the production of cellulose esters |
| CN108350089A (en) * | 2015-10-27 | 2018-07-31 | 株式会社Kri | Modified cellulose microfibre and its manufacturing method |
-
1980
- 1980-03-19 IT IT8020784A patent/IT8020784A0/en unknown
-
1981
- 1981-03-13 GB GB8107964A patent/GB2071667A/en not_active Withdrawn
- 1981-03-19 FR FR8105537A patent/FR2478645A1/en not_active Withdrawn
- 1981-03-19 JP JP4022281A patent/JPS56141301A/en active Pending
- 1981-03-19 DE DE19813111276 patent/DE3111276A1/en not_active Withdrawn
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1996020960A1 (en) * | 1994-12-30 | 1996-07-11 | Eastman Chemical Company | A direct process for the production of cellulose esters |
| CN108350089A (en) * | 2015-10-27 | 2018-07-31 | 株式会社Kri | Modified cellulose microfibre and its manufacturing method |
| US20180312609A1 (en) * | 2015-10-27 | 2018-11-01 | Kri, Inc. | Modified cellulose fine fibers and method for producing the same |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS56141301A (en) | 1981-11-05 |
| DE3111276A1 (en) | 1982-03-04 |
| FR2478645A1 (en) | 1981-09-25 |
| IT8020784A0 (en) | 1980-03-19 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |