CN108840955A - A method of preparing cellulose carbonic acid mixed carboxylic ester - Google Patents
A method of preparing cellulose carbonic acid mixed carboxylic ester Download PDFInfo
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- 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
- C08B3/16—Preparation of mixed organic cellulose esters, e.g. cellulose aceto-formate or cellulose aceto-propionate
Abstract
The invention discloses a kind of methods for preparing cellulose carbonic acid mixed carboxylic ester, include the following steps：1）Cellulose, organic base and organic solvent are mixed, CO is passed through into reaction system2The atmosphere for forming 0.1-8MPa pressure, reacts 0.5-10 hours at 20-80 DEG C, forms cellulose solution；2）To step 1）Alkyl halide is added in cellulose solution obtained, continues the CO in 0.1-8MPa pressure2Under atmosphere, 20-80 DEG C reaction 0.5-48 hours；3）Step 2）After reaction, CO is discharged2, acylating reagent is added into reaction solution, is reacted 0.1-10 hours at 20-100 DEG C；4）Step 3）After reaction, anti-solvent is added into reaction solution, deposit is filtered, washed and is dried after purification, obtains cellulose carbonic acid-mixed carboxylic ester material.What the present invention had prepared a kind of structure novel has carbonic acid-mixed carboxylic ester structure cellulose derivative, realizes cellulose specific derivatization in structure, is of great significance to the higher value application of cellulose.
Description
Technical field
The present invention relates to a kind of methods for preparing cellulose carbonic acid mixed carboxylic ester, belong to technical field of chemistry.
Background technique
Realize that efficient utilize of biomass resource helps to alleviate current energy crisis and environmental crisis.Wherein content
The most abundant is exactly cellulose, and as natural macromolecular material, repetitive unit is β-Isosorbide-5-Nitrae glycosidic bond, is not melted with insoluble
The characteristics of.To efficiently use to it, people develop a variety of methods and dissolve to it, including the processing of inorganic acid highly basic,
DMAc/LiCl system, NaOH/ urea system, ion liquid system etc. dissolve measure.Wherein explore DMAc/LiCl dissolution body
System more efficient (Marson G A, et al.Journal of Applied Polymer Science, 2015,74 (6):
1355-1360.), which is in intensive polar solvent, and the Cl ion and cellulose of inorganic salts form hydrogen bond, destroys fiber
High forces inside element, break up hydrogen bond network structure and realize dissolution；Ionic liquid such as 1- butyl -3- methylimidazole villaumite
(BMIMCl), 1- allyl -3- methylimidazole villaumite (BMIMCl), 1- ethyl-3-methylimidazole acetate (EMIMAC), to fibre
Dimension element has efficient dissolubility, but price is higher and recycling difficulty is the most important problem (Gericke faced at present
M,et al.Macromolecular Bioscience,2009,9(4):343.)；The NaOH/ urea that Zhang Lina academician proposes is molten
Enzymatic hydrolysis system, easy to operate and low in cost, the materials such as cellulose base hydrogel, aeroge, film prepared based on this system
It is of fine quality different, it is expected to realize industrial applications (Zhou J, et al.Polymer Chemistry, 2010,1 (10):1662-
1668.)。
Cellulose esters derivatization product mainly has cellulose acetate (CA), cellulose propionate (CP), cellulose butyrate (CB)
And cellulose acetate propionate (CAP), acetylbutyrylcellulose (CAB).CA is methylcellulose Acetylated and obtains have flexibility
Well, the features such as good luster, easily molded processing, it is widely used in coating, textile, cigarette filter, plastic products, packaging product
Deng.CP is that cellulose is propionating and obtain, and has the characteristics that transparent, high glaze, good weatherability properties, is widely used in automobile decoration
The neighborhoods such as part, electronic apparatus, sheet film.CB, CAP, CAB equally just have more excellent property, are widely used in film, spin
It knits, the fields such as plastics.
Relative to cellulose esters, people with regard to fewer and fewer, are melted into the research of cellulose carbonic ester because hydroxyl is derived
Carbonate group is not easy to, and introducing carbonic acid ester bond on cellulose at present, there are mainly three types of schemes, as shown in figure 12：Halogenated first
Acid esters reaction, carbonic ester transesterification, N, N'- carbonyl dimidazoles react (Elschner T, et al.Macromolecular
Bioscience,2015,15(6):735-746.).Haloformate is a kind of reagent of high activity, hydroxyl activate through phosgene and
Come, but have the shortcomings that it is many can not be ignored, such as use highly toxic phosgene, and its high activity with hold in hydroxyl reaction process
Many by-products easily generated are not efficient carbonic ester conversion pathway (Elschner T, et an al.Macromolecular
Bioscience,2014,14(2):161-165.)；The transesterification process of the carbonic ester of cellulose is mainly cellulose and carbonic acid two
The reaction of methyl esters, diethyl carbonate, this is a kind of method of current most study, has the characteristics that efficient, environmental protection, but universality
It is not high, can not prepare a variety of class formations cellulose carbonic ester (Khiari R, et al.Carbohydrate Polymers,
2017,163.)；Cellulose and N, N'- carbonyl dimidazoles reaction prepare carbonic ester, and this method generallys use the miaow of dissymmetrical structure
Oxazolyl carbonic ester can slough an imidazoles in the process with fibrin reaction, and then another part group is grafted on cellulose,
But this method operating process is cumbersome, needs first to synthesize imidazoles structural carbonate compound, and atom is uneconomical in reaction
(Elschner T.et al.Carbohydrate Polymers,2013,93(1):216-223.)。
It is recently proposed, is based under organic base environment, cellulose hydroxyl group and CO2Reaction generates the original of reversible poly ion liquid
Reason, realize cellulose activation and dissolving method (Yang.L., et al.Green Chem.2015,17,2758-
2763.Y.Yang.,et al.Green Chem.2014,16,3018–3023；Q.Zhang.,et al.,ChemSusChem
2013,6,593–596.)；And it is based on this system, Chinese patent 201310278276.1 and 2017108876489 is protected respectively
Using acid anhydrides and vinyl acetate as reaction reagent, the method for preparing cellulose esters；Chinese patent 201410503299.2 is protected simultaneously
The method of preparing cellulose graft polylactic acid derivative based on cellulose；And Chinese patent
2017108876898 protect the method for preparing cellulose proton type ionic liquid based on this dissolution strategy；China
Patent 2017114143308.9 protects the method for preparing novel cellulose carbonic ester with this dissolution system.The master of above-mentioned patent
It is characterized in cellulose, organic base and CO2Reaction generates cellulose carbonic acid monoesters anion, realizes the equal phased soln of cellulose,
Under halide compound environment, nucleophilic substitution occurs and prepares the cellulose derivative with structural carbonate, and can be with
Continue generation acylation reaction and obtain that there is carbonic acid-mixed carboxylic ester structure cellulose derivative, has to halide, acylating reagent
There is universality, the carbonic acid mixed carboxylic ester of various structures can be synthesized, is fiber as a kind of new cellulose dissolution system
The higher value application of element provides a strategy very well.
Summary of the invention
The object of the present invention is to provide a kind of methods for preparing cellulose carbonic acid mixed carboxylic ester.The present invention prepares
A kind of structure novel has carbonic acid-mixed carboxylic ester structure cellulose derivative, and it is special in structure to realize cellulose
Anisotropic derivatization is of great significance to the higher value application of cellulose.
Technical solution of the present invention：A method of cellulose carbonic acid mixed carboxylic ester is prepared, is included the following steps：
1) cellulose, organic base and organic solvent are mixed, CO is passed through into reaction system2Form 0.1-8MPa pressure
Atmosphere is reacted 0.5-10 hours at 20-80 DEG C, forms cellulose solution；
2) alkyl halide is added into cellulose solution made from step 1), continues the CO in 0.1-8MPa pressure2Under atmosphere,
20-80 DEG C reaction 0.5-48 hours；
3) step 2) after reaction, discharges CO2, acylating reagent is added into reaction solution, is reacted at 20-100 DEG C
0.1-10 hours；
4) step 3) after reaction, anti-solvent is added into reaction solution, is filtered, washed to deposit and does after purification
It is dry, obtain cellulose carbonic acid-mixed carboxylic ester material.
The method above-mentioned for preparing cellulose carbonic acid mixed carboxylic ester, the cellulose be microcrystalline cellulose, alpha-cellulose,
Cotton, wood pulps, bamboo pulp or from agricultural object stalk and crop seeds leather shell in the cellulose of resulting separation one
Kind or two or more mixture；Its structural formula is：
Wherein, 1<n<1000.
The method above-mentioned for preparing cellulose carbonic acid mixed carboxylic ester, in the step 1), cellulose, organic base and organic
The mass percent of cellulose in the mixture of solvent is 2-15wt%, and the mass percent of organic base is 2-20%, surplus
For organic solvent.
The method above-mentioned for preparing cellulose carbonic acid mixed carboxylic ester, in the step 2), the alkyl halide and fiber of addition
The molar ratio of hydroxyl is 0.05-4 on element:1.
The method above-mentioned for preparing cellulose carbonic acid mixed carboxylic ester, in the step 3), on acylating reagent and cellulose
The molar ratio of hydroxyl is 0.05-2:1.
The method above-mentioned for preparing cellulose carbonic acid mixed carboxylic ester, in the step 4), the anti-solvent is water or C1-
C3The volume ratio of lower aliphatic alcohols, anti-solvent and reaction solution is 0.5-10:1.
The method above-mentioned for preparing cellulose carbonic acid mixed carboxylic ester, the organic base are one of having structure or two
Kind or more mixture：
Wherein, n=1 or 2；M=1-6；R,R2、R3、R4And R5It is independent hydrogen, methyl or ethyl；R1It is independent hydrogen, first
Base, the alkyl of carbon atom 1-6, the ethyoxyl polyethylene glycol of carbon atom number 3-10, methoxy poly (ethylene glycol) base, carbon atom number 1-6
Hydroxylated alkyl groups or carbon atom number 4-8 polyethylene glycol groups.
The method above-mentioned for preparing cellulose carbonic acid mixed carboxylic ester, the organic solvent are dimethyl sulfoxide, N- methyl
Pyrrolidones, tetramethylguanidine, four base guanidine, N, N- dimethyl-imidazolinone, N,N-dimethylformamide, N, N- dimethylacetamide
Amine, N, N- diethyl acetamide, 2-Pyrrolidone, 2- piperazine ketone, epsilon-caprolactams, N, N- dimethyl propylene alkenyl urea, ring fourth
The mixture of one or both of sulfone or piperylene sulfone or more.
The method above-mentioned for preparing cellulose carbonic acid mixed carboxylic ester, the structure of the alkyl halide are one in having structure
Kind or two kinds or more of mixture：
(a) it is saturated halogenated alkane：XCnH2n+1, wherein：X=Cl, Br or I；1≤n≤20；The position of X does not limit, preferably position
It sets in end group；
(b) with the alkenyl halide or halogenated cycloalkane of a double bond：XCnH2n-1, wherein：X=Cl, Br or I；1≤n
≤20；The position of X does not limit, and optimum position is in end group；Containing there are two the alkenyl halide of double bond or halogenated cycloalkane：
XCnH2n-3, wherein：X=Cl, Br or I；1≤n≤20；The position of X does not limit, and optimum position is in end group；Containing there are three double bonds
Alkenyl halide or halogenated cycloalkane：XCnH2n-5, wherein：X=Cl, Br or I；1≤n≤20；The position of X does not limit, preferably position
It sets in end group；
(c) the halogenated alkynes containing three keys：XCnH2n-3, wherein：X=Cl, Br or I；1≤n≤5；The position of X is unlimited
Fixed, optimum position is in end group；
(d) halogenated aromatic substance：
Wherein：X=Cl, Br or I；R be the methyl of proton or any position, ethyl, propyl, isopropyl,
Methoxyl group, ethyoxyl, trifluoromethyl, nitro, cyano, aldehyde radical, methyl formate base, group-4 ethyl formate or trifluoromethoxy；
Wherein：R is the chloromethyl, bromomethyl or iodomethyl of any the position of substitution；
Wherein, R is the chloromethyl, bromomethyl or iodomethyl of any the position of substitution；
Wherein：X=Cl, Br or I；
(e) halogenated ester-based organic compound：
Wherein：X=Cl, Br or I；R is methyl, ethyl, n-propyl, isopropyl, normal-butyl, isobutyl group, uncle
Butyl or vinyl；
Wherein：X=Cl, Br or I；R is methyl, ethyl, n-propyl, isopropyl, normal-butyl, isobutyl group
Or tert-butyl；
Wherein：X=Cl, Br or I；R be methyl, ethyl, n-propyl, isopropyl, normal-butyl, isobutyl group or
Tert-butyl；
(f) halogen acid amide class compound：
Wherein：X=Cl, Br or I；R1And R2It is simultaneously proton, methyl or ethyl or R1And R2Arbitrarily
One is proton, another is methyl, ethyl, n-propyl, isopropyl, normal-butyl, isobutyl group or tert-butyl；
(g) halogenated nitrile-based compound：General formula is X- (CH2)nCN, wherein X=Cl, Br or I；1≤n≤5；
(h) halogenated epoxide：
Wherein X=Cl, Br or I；1≤n≤5；
(i) halogenated perfluoro alkane compound：XCH2(CF2)nCF3, wherein X=Cl, Br or I；0≤n≤10；
(j) fluoro benzene compound：
Wherein X=Cl, Br or I；
Wherein X=Cl, Br or I；R=H or F；
(k) halogenated polyethyleneglycol derivative：
X-CH2OCH3, wherein X=Cl, Br or I；
X-CH2CH2[OCH2CH2]nOCH3, wherein X=Cl, Br or I；0≤n≤5；
X-CH2CH2[OCH2CH2]nOCH2CH3, wherein X=Cl, Br or I；0≤n≤5；
(l) halogenated aldehyde, ketones derivant：
Wherein, X=Cl, Br or I；0≤n≤4；R is proton or methyl, ethyl, propyl, phenyl or naphthyl；
(m) double halogenated compounds：
Wherein, X=Cl, Br or I；0≤n≤10；
Wherein, X=Cl, Br or I；Wherein halomethyl is any the position of substitution；
Wherein, X=Cl, Br or I；0≤n≤10；
(m) halogenated tetrahydrofuran-compound：
Wherein：X=Cl, Br or I；
(o) halogenated adamantane compound：
The halogenated adamantane of 1-Wherein：X=Cl, Br or I；
The halogenated adamantane of 2-Wherein：X=Cl, Br or I；
(p) halogenated silane compounds：
Wherein, X=Cl, Br or I；R is proton or methyl, ethyl or propyl；
(q) halocarbonate compound：
Wherein, X=Cl, Br or I；R is proton or methyl, ethyl, propyl or phenyl.
The method above-mentioned for preparing cellulose carbonic acid mixed carboxylic ester, the acylating reagent be one of having structure or
Two kinds or more of mixture：
(a) it is saturated acid anhydrides：Wherein R is CnH2n+1Aliphatic group, carbon chain lengths are the carbon of 1≤n≤20
Chain number；
(b) alkene or cycloalkane acid anhydrides containing a double bond：Wherein R is CnH2n-1Unsaturated group,
Carbon chain lengths are the carbochain number of 1≤n≤20, and double bond and ring position do not limit；
(c) aromatic anhydride：
R is the methyl, ethyl, propyl, isopropyl, methoxyl group, ethyoxyl, fluoroform of proton or any one the position of substitution
Base, nitro, cyano, aldehyde radical, methyl formate base, group-4 ethyl formate or trifluoromethoxy；
(d) representative examples of saturated aliphatic carboxylic acid halides：Wherein X=Cl or Br；R is CnH2n+1Aliphatic group, carbon chain lengths 1
The carbochain number of≤n≤20；
(e) alkene or cycloalkane carboxylic acid halides containing a double bond：Wherein X=Cl or Br；R is CnH2n-1Group, carbon
Chain length is the carbochain number of 1≤n≤20；Double bond and ring position do not limit；
(f) containing there are two the alkene of double bond or the carboxylic acid halides of alkynes：Wherein X=Cl or Br；R is CnH2n-3Group, carbon
Chain length is the carbochain number of 1≤n≤20；Double bond and three key positions do not limit；
(g) aromatic series carboxylic acid halides：Wherein X=Cl or Br；R be proton or any one the position of substitution methyl,
Ethyl, propyl, isopropyl, methoxyl group, ethyoxyl, trifluoromethyl, nitro, cyano, aldehyde radical, methyl formate base, group-4 ethyl formate
Or trifluoromethoxy；
(h) vinyl acetate：
Wherein, R1=CnH2n+1, (18 >=n >=0)；R2=CnH2n-1, (18 >=n >=3)；R3=CnH2n-3, (18 >=n >=4)；
R4、R5、R6、R7And R8It is independent the alkyl of hydrogen, halogen or carbon atom number 1-6；n1=1-20.
Beneficial effects of the present invention
The present invention passes through the hydroxyl and CO under the conditions of organic base, on cellulose2Cellulose carbonic ester anion is formed, it should
Anion has good nucleophilic reactivity, in halogenated substance environment, it may occur that nucleophilic substitution forms cellulose carbonic ester knot
Structure；It is further continued for that acylating reagent is added, organic base present in substance system is good catalyst, can be acylated anti-with efficient catalytic
It answers, realizes the effect of organic functions catalysis in situ, finally prepare with carbonic acid-mixed carboxylic ester cellulose derivative.It should
Preparation method is novel and simple, and easy to operate, solvent etc. can be recycled, and the material structure finally prepared is novel and controllable,
Property is adjustable, and the content of present invention is of great significance for the higher value application of cellulose.
Detailed description of the invention
Fig. 1 is process flow chart of the invention；
Fig. 2 is cellulose and cellulose derivative FT IR spectrogram；
Fig. 3 is cellulose hexyl carbonic acid-acetic acid mixed ester1H NMR spectra；
Fig. 4 is cellulose hexyl carbonic acid-acetic acid mixed ester13C NMR spectra；
Fig. 5 is cellulose hexyl carbonic acid-propionic acid mixed ester1H NMR spectra；
Fig. 6 is cellulose hexyl carbonic acid-propionic acid mixed ester13C NMR spectra；
Fig. 7 is cellulose hexyl carbonic acid-butyric acid mixed ester1H NMR spectra；
Fig. 8 is cellulose hexyl carbonic acid-butyric acid mixed ester13C NMR spectra；
Fig. 9 is the DSC spectrogram of cellulose and cellulose derivative；
Figure 10 is the TGA spectrogram of cellulose and cellulose derivative；
Figure 11 is cellulose hexyl carbonic acid-acetic acid mixed ester GPC spectrogram；
Figure 12 is that tradition prepares cellulose carbonic ester approach.
Specific embodiment
Below with reference to embodiment, the present invention is further illustrated, but is not intended as the foundation limited the present invention.
The embodiment of the present invention
Need to illustrate that degree of substitution (Degree of Substitution) meaning, the calculation formula of degree of substitution are listed below：
DStotal=DSC+DSA(DSP or DSB)
Wherein DSC、DSA、DSP、DSB、DStatolBe respectively carbonate group in cellulose derivative, acetyl group, propiono,
The degree of substitution of bytyry and all substituent group summations；IH(3,4,5)、Iacetyl、Ipropinyl、IbutyrylAnd IAGURespectively represent hexane
Three methene protons in carbonic ester, the methyl proton of acetyl group, the methyl proton of propiono, the methyl proton of propiono and de-
The peak integration of all protons of water glucose unit (AGU)；Number 7,6,3 respectively indicates AGU, three methylene, methyl
Proton number.
Embodiment 1：
Weigh each 1.00g of different types of cellulose, respectively with 1,8- diazabicyclo [5.4.0] -7- endecatylene
(DBU) 2.812g and dimethyl sulfoxide (DMSO) 15.372g are added to inside reaction kettle, cover reaction kettle, charge and discharge CO2Circulation three
It is secondary, air is excluded, finally in the CO of 0.5Mpa2Atmosphere, 50 DEG C of conditions stir 3h, obtain homogeneous cellulose solution.Again by kettle
It is cooled to room temperature, (the ratio between molal quantity of-OH is 3 to the bromo hexane in situ that 2.6mL is added on bromohexane and cellulose：3), exist
4Mpa pressure reacts 12h under the conditions of 30 DEG C.After reaction, reaction kettle is opened, the acetic anhydride (acetic anhydride of 1.74mL is added
It is 3 with the ratio between the molal quantity of-OH original on cellulose：3), in 50 DEG C of reaction 3h.After, it is sunk using the water of 100mL
It forms sediment, washing filters 3 times, and freeze-drying obtains product.Product made from celluloses different in the present embodiment is detected, correlated results
As shown in the table：
Research of the table 1 to separate sources cellulose
| Number | Cellulose | DSC | DSA | DStotal |
| 1 | Microcrystalline cellulose | 1.27 | 0.56 | 1.83 |
| 2 | Cotton pulp cellulose | 1.18 | 0.50 | 1.68 |
| 3 | Bamboo pulp fiber element | 1.15 | 0.48 | 1.63 |
| 4 | Corn stover | 1.10 | 0.45 | 1.55 |
This example absolutely proves that the cellulose and corn stover for separate sources can prepare cellulose carbon
Acid-mixed carboxylic ester product absolutely proves that this patent has universality about cellulose type.
Embodiment 2：
Microcrystalline cellulose 1.00g is weighed, organic base 1,8- diazabicyclo [5.4.0] -7- endecatylene (DBU), three are taken
Ethamine (TEA) or 1,5- diazabicyclo [4.3.0] nonyl- 5- alkene (DBN), takes organic solvent dimethyl sulfoxide (DMSO), N, N-
Dimethylformamide (DMF) or N-Methyl pyrrolidone (NMP), respectively by one of microcrystalline cellulose, organic base and organic
It is added to inside reaction kettle after the mixing of one of solvent, covers reaction kettle, charge and discharge CO2Circulation three times, excludes air, finally exists
The CO of 0.5Mpa2Atmosphere, 50 DEG C of conditions stir 3h, obtain homogeneous cellulose solution.Kettle is cooled to room temperature, add in-place again
Entering the bromo hexane of 2.6mL, (the ratio between molal quantity of-OH is 3 on bromohexane and cellulose：3), under the conditions of 4Mpa pressure, 30 DEG C
React 12h.After reaction, reaction kettle is opened, acetic anhydride (acetic anhydride and the original-OH on cellulose of 1.74mL are added
The ratio between molal quantity is 3：3), in 50 DEG C of reaction 3h.After, it is precipitated using the water of 100mL, washing filters 3 times, is lyophilized
To product.Product made from organic bases different in the present embodiment and organic solvent is detected, correlated results is as shown in the table：
2 pairs of table different content of cellulose, the research of different organic bases and organic solvent
This example absolutely proves, for different cellulose concentration contents and the different own contents of strong organic base, and not
Same organic solvent, can prepare cellulose carbonic acid-mixed carboxylic ester.
Embodiment 3：
Microcrystalline cellulose 1.00g is weighed, 1,8- diazabicyclo [5.4.0] -7- endecatylene (DBU) 2.812g and two is taken
Methyl sulfoxide (DMSO) 15.372g, is added to inside reaction kettle, covers reaction kettle, charge and discharge CO2Circulation three times, excludes air, most
Afterwards in the CO of 0.5Mpa2Atmosphere, 50 DEG C of conditions stir 3h, obtain homogeneous cellulose solution.Kettle is cooled to room temperature again, it is former
Different alkyl halides (the ratio between molal quantity of-OH is adjustable on alkyl halide and cellulose) is added in position, reacts under certain condition.Reaction
After, reaction kettle is opened, adding the acetic anhydride of 1.74mL, (the ratio between the molal quantity of acetic anhydride and-OH original on cellulose is
3：3), in 50 DEG C of reaction 3h.After, it is precipitated using the water of 100mL, washing filters 3 times, and freeze-drying obtains product.And it is right
Product is detected respectively, and correlated results is as shown in the table：
Table 3 studies the reaction condition of alkyl halide
a：Alkyl halide and the molar ratio and reaction temperature of cellulose hydroxyl group, reaction time and CO2Pressure.
Total DS of part of product is more than 3, is to illustrate fibre caused by the error as existing for the degree of substitution calculation method
Three hydroxyls of dimension element are fully substituted.In order to characterize different degree of substitution cellulose derivative hot property, select number is
9,11,13 sample has done DSC test, sees attached drawing 9；It equally takes 9,11,13 sample to do GPC test, studies different degree of substitution
The change of molecular weight rule of product, is shown in attached drawing 11.
This example absolutely proves that alkyl halide and different halogens for different structure can prepare cellulose
Carbonic acid-mixed carboxylic ester, and change the condition of alkyl halide reaction such as：Temperature, time, CO2Pressure, it is available a series of to take
For the different product of degree, to realize controllable in structure, it is adjusted in nature.
Embodiment 4：
Microcrystalline cellulose 1.00g is weighed, 1,8- diazabicyclo [5.4.0] -7- endecatylene (DBU) 2.812g, two are taken
Methyl sulfoxide (DMSO) 15.372g, is added to inside reaction kettle, covers reaction kettle, charge and discharge CO2Circulation three times, excludes air, most
Afterwards in the CO of 0.5Mpa2Atmosphere, 50 DEG C of conditions stir 3h, obtain homogeneous cellulose solution.Kettle is cooled to room temperature again, it is former
Bromohexane 2.60mL is added in position, and (the ratio between molal quantity of-OH is 3 on bromohexane and cellulose：3), in 4Mpa pressure, 30 DEG C of conditions
Lower reaction 12h.After reaction, open reaction kettle, add different acylating reagents (it is original on acylating reagent and cellulose-
The ratio between molal quantity of OH is adjustable), it is reacted under the temperature and time of different acylations.After, it is sunk using the water of 100mL
It forms sediment, washing filters 3 times, and freeze-drying obtains product.Related experiment result is as shown in the table：
Research of the table 4 to acylating reagent
a:The molar ratio of acylating reagent and hydroxyl.
In order to determine cellulose carbonic acid-mixed carboxylic ester molecular structure, sample is characterized using FT IR and nuclear-magnetism method
5, the infrared figure of 7,8 chemical structure, pristine fibre element and three samples is shown in attached drawing 2；The nucleus magnetic hydrogen spectrum and carbon spectrogram of sample 5 are such as
Shown in attached drawing 3 and 4；The nucleus magnetic hydrogen spectrum and carbon spectrogram of sample 7 are as depicted in figures 5 and 6；The nucleus magnetic hydrogen spectrum and carbon spectrogram of sample 8 are such as
Shown in attached drawing 7 and 8.
The hot property of the cellulose derivative of different degree of substitution is characterized simultaneously, and the sample that number is 2,3,5 is selected to be DSC
Test, is shown in attached drawing 9；It selects the sample that number is 2,3,4,5 to do TGA test, sees attached drawing 10；2,3,5 sample is equally taken to do
GPC test studies the change of molecular weight rule of different degree of substitution product, sees attached drawing 11.
This example absolutely proves, for the acylating reagent of different structure, can prepare cellulose carbonic acid-carboxylic acid mixing
Ester, and change the condition of acylation reaction such as：Temperature, time, a series of different product of available degree of substitution, to realize
It is controllable in structure, it is adjusted in nature.
Embodiment 5：
To study influence of the different process for acylating to degree of substitution, the i.e. catalysis of one-step method original position organic functions and two step method
Extra catalyst catalysis method has equally carried out experimental study.
One-step method：Microcrystalline cellulose 1.00g is weighed, 1,8- diazabicyclo [5.4.0] -7- endecatylene (DBU) is taken
2.812g, dimethyl sulfoxide (DMSO) 15.372g, are added to inside reaction kettle, cover reaction kettle, charge and discharge CO2Circulation three times, is arranged
Except air, finally in the CO of 0.5Mpa2Atmosphere, 50 DEG C of conditions stir 3h, obtain homogeneous cellulose solution.It is again that kettle is cooling
To room temperature, (the ratio between molal quantity of-OH is 3 to the bromo hexane in situ that 2.6mL is added on bromohexane and cellulose：3) it, is pressed in 4Mpa
Power reacts 12h under the conditions of 30 DEG C.After reaction, reaction kettle is opened, adds the acetic anhydride of 2.6mL (according to acetic anhydride and original
Beginning hydroxyl molar ratio), 3h is reacted at 50 DEG C.After, it is precipitated using the water of 100mL, washing filters 3 times, is lyophilized
To product.
Two-step method：Microcrystalline cellulose 1.00g is weighed, 1,8- diazabicyclo [5.4.0] -7- endecatylene (DBU) is taken
2.812g, dimethyl sulfoxide (DMSO) 15.372g, are added to inside reaction kettle, cover reaction kettle, charge and discharge CO2Circulation three times, is arranged
Except air, finally in the CO of 0.5Mpa2Atmosphere, 50 DEG C of conditions stir 3h, obtain homogeneous cellulose solution.It is again that kettle is cooling
To room temperature, (the ratio between molal quantity of-OH is 3 to the bromo hexane in situ that 2.6mL is added on bromohexane and cellulose：3) it, is pressed in 4Mpa
Power reacts 12h under the conditions of 30 DEG C.It is precipitated with the methanol of 100mL, washing filters 3 times, and freeze-drying obtains product.Further according to core
The degree of substitution that magnetic calculates takes certain mass product to be dissolved in DMSO, calculates relative to original hydroxyl groups 3：The acetic anhydride of 3 moles, adds
Enter different catalyst and adjust different dosages, reacts 3h at 50 DEG C.After, it is precipitated using the water of 100mL,
Washing filters 3 times, and freeze-drying obtains product.Correlated results is as shown in the table：
Table 5 studies influence of the different acylation modes to degree of substitution
a:Indicate the derivative of one-step method preparation
Wherein DSC1And DSC2Indicate that the carbonic ester of first step product carbonic ester degree of substitution and final product takes in two-step method
Dai Du, DMAP, TEA, Py respectively indicate 4-dimethylaminopyridine, triethylamine and pyridine.This example illustrates one-step method and two-step method
All there is good catalytic activity to acylation reaction, but the activity of Py is most weak, the catalytic activity of DMAP is most strong.Portion of product it is total
DS is more than 3, is to illustrate that three hydroxyls of cellulose are taken completely caused by the error as existing for the degree of substitution calculation method
Generation.
Embodiment 6：
Microcrystalline cellulose 1.00g is weighed, 1,8- diazabicyclo [5.4.0] -7- endecatylene (DBU) 2.812g, two are taken
Methyl sulfoxide (DMSO) 15.372g, is added to inside reaction kettle, covers reaction kettle, charge and discharge CO2Circulation three times, excludes air, most
Afterwards in the CO of 0.5Mpa2Atmosphere, 50 DEG C of conditions stir 3h, obtain homogeneous cellulose solution.Kettle is cooled to room temperature again, it is former
Bromohexane 2.60mL is added in position, and (the ratio between molal quantity of-OH is 3 on bromohexane and cellulose：3), in 4Mpa pressure, 30 DEG C of conditions
Lower reaction 12h.After reaction, reaction kettle is opened, the acetic anhydride (molal quantity of acetic anhydride and original-OH on cellulose is added
The ratio between be 3：3), 3h is reacted at 50 DEG C.After, it is precipitated using the different anti-solvents of 100mL, washing filters 3 times, freezes
It is dry to obtain product.Related experiment result is as shown in the table：
Table 6 studies the influence of different anti-solvents
| Number | Anti-solvent | DSC | DSA | DStotal | Yield (%) |
| 1 | Water | 1.10 | 1.34 | 2.44 | 95 |
| 2 | Methanol | 1.02 | 1.40 | 2.42 | 93 |
| 3 | Ethyl alcohol | 1.31 | 1.20 | 2.51 | 96 |
| 4 | Isopropanol | 0.99 | 1.06 | 2.05 | 89 |
| 5 | The tert-butyl alcohol | 1.15 | 0.95 | 2.10 | 90 |
This example absolutely proves, for different anti-solvents, counter can be settled out cellulose carbonic acid-mixed carboxylic ester,
And it is all higher to the reproduction rate of product, illustrating different anti-solvents all has good effect.
Claims (10)
1. a kind of method for preparing cellulose carbonic acid mixed carboxylic ester, which is characterized in that include the following steps：
1) cellulose, organic base and organic solvent are mixed, CO is passed through into reaction system2The atmosphere of 0.1-8MPa pressure is formed,
It is reacted 0.5-10 hours at 20-80 DEG C, forms cellulose solution；
2) alkyl halide is added into cellulose solution made from step 1), continues the CO in 0.1-8MPa pressure2Under atmosphere, in 20-
80 DEG C reaction 0.5-48 hours；
3) step 2) after reaction, discharges CO2, acylating reagent is added into reaction solution, it is small that 0.1-10 is reacted at 20-100 DEG C
When；
4) step 3) after reaction, anti-solvent is added into reaction solution, is filtered, washed to deposit and dries after purification, obtains
Obtain cellulose carbonic acid-mixed carboxylic ester material.
2. the method according to claim 1 for preparing cellulose carbonic acid mixed carboxylic ester, it is characterised in that：The cellulose
For microcrystalline cellulose, alpha-cellulose, cotton, wood pulps, bamboo pulp or from agricultural object stalk and crop seeds leather shell point
From one of obtained cellulose or two or more mixture；Its structural formula is：
Wherein, 1<n<1000.
3. the method according to claim 1 for preparing cellulose carbonic acid mixed carboxylic ester, it is characterised in that：The step 1)
In, the mass percent of the cellulose in the mixture of cellulose, organic base and organic solvent is 2-15wt%, the matter of organic base
Amount percentage is 2-20%, and surplus is organic solvent.
4. the method according to claim 1 for preparing cellulose carbonic acid mixed carboxylic ester, it is characterised in that：The step 2)
In, the molar ratio of hydroxyl is 0.05-4 on the alkyl halide and cellulose of addition:1.
5. the method according to claim 1 for preparing cellulose carbonic acid mixed carboxylic ester, it is characterised in that：The step 3)
In, the molar ratio of hydroxyl is 0.05-2 on acylating reagent and cellulose:1.
6. the method according to claim 1 for preparing cellulose carbonic acid mixed carboxylic ester, it is characterised in that：The step 4)
In, the anti-solvent is water or C1-C3The volume ratio of lower aliphatic alcohols, anti-solvent and reaction solution is 0.5-10:1.
7. the method according to claim 1 for preparing cellulose carbonic acid mixed carboxylic ester, it is characterised in that：The organic base
For the mixture of one or both of having structure or more：
Wherein, n=1 or 2；M=1-6；R,R2、R3、R4And R5It is independent hydrogen, methyl or ethyl；R1Be independent hydrogen, methyl,
The alkyl of carbon atom 1-6, the ethyoxyl polyethylene glycol of carbon atom number 3-10, methoxy poly (ethylene glycol) base, carbon atom number 1-6 hydroxyl
The polyethylene glycol groups of base alkyl or carbon atom number 4-8.
8. the method according to claim 1 for preparing cellulose carbonic acid mixed carboxylic ester, it is characterised in that：It is described organic molten
Agent is dimethyl sulfoxide, N-Methyl pyrrolidone, tetramethylguanidine, four base guanidine, N, N- dimethyl-imidazolinone, N, N- dimethyl
Formamide, DMAC N,N' dimethyl acetamide, N, N- diethyl acetamide, 2-Pyrrolidone, 2- piperazine ketone, epsilon-caprolactams, N,
The mixture of one or both of N- dimethyl propylene alkenyl urea, sulfolane or piperylene sulfone or more.
9. the method according to claim 1 for preparing cellulose carbonic acid mixed carboxylic ester, it is characterised in that：The alkyl halide
Structure be one or both of having structure or more mixture：
(a) it is saturated halogenated alkane：XCnH2n+1, wherein：X=Cl, Br or I；1≤n≤20；The position of X does not limit, and optimum position exists
End group；
(b) with the alkenyl halide or halogenated cycloalkane of a double bond：XCnH2n-1, wherein：X=Cl, Br or I；1≤n≤20；
The position of X does not limit, and optimum position is in end group；Containing there are two the alkenyl halide of double bond or halogenated cycloalkane：XCnH2n-3,
In：X=Cl, Br or I；1≤n≤20；The position of X does not limit, and optimum position is in end group；Containing there are three the alkenyl halide of double bond or
The halogenated cycloalkane of person：XCnH2n-5, wherein：X=Cl, Br or I；1≤n≤20；The position of X does not limit, and optimum position is in end group；
(c) the halogenated alkynes containing three keys：XCnH2n-3, wherein：X=Cl, Br or I；1≤n≤5；The position of X does not limit,
Optimum position is in end group；
(d) halogenated aromatic substance：
Wherein：X=Cl, Br or I；R is methyl, ethyl, propyl, isopropyl, the methoxy of proton or any position
Base, ethyoxyl, trifluoromethyl, nitro, cyano, aldehyde radical, methyl formate base, group-4 ethyl formate or trifluoromethoxy；
Wherein：R is the chloromethyl, bromomethyl or iodomethyl of any the position of substitution；
Wherein, R is the chloromethyl, bromomethyl or iodomethyl of any the position of substitution；
Wherein：X=Cl, Br or I；
(e) halogenated ester-based organic compound：
Wherein：X=Cl, Br or I；R is methyl, ethyl, n-propyl, isopropyl, normal-butyl, isobutyl group, tert-butyl
Or vinyl；
Wherein：X=Cl, Br or I；R is methyl, ethyl, n-propyl, isopropyl, normal-butyl, isobutyl group or uncle
Butyl；
Wherein：X=Cl, Br or I；R is methyl, ethyl, n-propyl, isopropyl, normal-butyl, isobutyl group or tertiary fourth
Base；
(f) halogen acid amide class compound：
Wherein：X=Cl, Br or I；R1And R2It is simultaneously proton, methyl or ethyl or R1And R2Any one is
Proton, another is methyl, ethyl, n-propyl, isopropyl, normal-butyl, isobutyl group or tert-butyl；
(g) halogenated nitrile-based compound：General formula is X- (CH2)nCN, wherein X=Cl, Br or I；1≤n≤5；
(h) halogenated epoxide：
Wherein X=Cl, Br or I；1≤n≤5；
(i) halogenated perfluoro alkane compound：XCH2(CF2)nCF3, wherein X=Cl, Br or I；0≤n≤10；
(j) fluoro benzene compound：
Wherein X=Cl, Br or I；
Wherein X=Cl, Br or I；R=H or F；
(k) halogenated polyethyleneglycol derivative：
X-CH2OCH3, wherein X=Cl, Br or I；
X-CH2CH2[OCH2CH2]nOCH3, wherein X=Cl, Br or I；0≤n≤5；
X-CH2CH2[OCH2CH2]nOCH2CH3, wherein X=Cl, Br or I；0≤n≤5；
(l) halogenated aldehyde, ketones derivant：
Wherein, X=Cl, Br or I；0≤n≤4；R is proton or methyl, ethyl, propyl, phenyl or naphthyl；
(m) double halogenated compounds：
Wherein, X=Cl, Br or I；0≤n≤10；
Wherein, X=Cl, Br or I；Wherein halomethyl is any the position of substitution；
Wherein, X=Cl, Br or I；0≤n≤10；
(m) halogenated tetrahydrofuran-compound：
Wherein：X=Cl, Br or I；
(o) halogenated adamantane compound：
The halogenated adamantane of 1-Wherein：X=Cl, Br or I；
The halogenated adamantane of 2-Wherein：X=Cl, Br or I；
(p) halogenated silane compounds：
Wherein, X=Cl, Br or I；R is proton or methyl, ethyl or propyl；
(q) halocarbonate compound：
Wherein, X=Cl, Br or I；R is proton or methyl, ethyl, propyl or phenyl.
10. the method according to claim 1 for preparing cellulose carbonic acid mixed carboxylic ester, it is characterised in that：The acylation
Reagent is the mixture of one or both of having structure or more：
(a) it is saturated acid anhydrides：Wherein R is CnH2n+1Aliphatic group, carbon chain lengths are the carbochain number of 1≤n≤20；
(b) alkene or cycloalkane acid anhydrides containing a double bond：Wherein R is CnH2n-1Unsaturated group, carbochain
Length is the carbochain number of 1≤n≤20, and double bond and ring position do not limit；
(c) aromatic anhydride：
R is the methyl, ethyl, propyl, isopropyl, methoxyl group, ethyoxyl, trifluoromethyl, nitre of proton or any one the position of substitution
Base, cyano, aldehyde radical, methyl formate base, group-4 ethyl formate or trifluoromethoxy；
(d) representative examples of saturated aliphatic carboxylic acid halides：Wherein X=Cl or Br；R is CnH2n+1Aliphatic group, carbon chain lengths be 1≤n≤
20 carbochain number；
(e) alkene or cycloalkane carboxylic acid halides containing a double bond：Wherein X=Cl or Br；R is CnH2n-1Group, carbon chain length
Degree is the carbochain number of 1≤n≤20；Double bond and ring position do not limit；
(f) containing there are two the alkene of double bond or the carboxylic acid halides of alkynes：Wherein X=Cl or Br；R is CnH2n-3Group, carbon chain length
Degree is the carbochain number of 1≤n≤20；Double bond and three key positions do not limit；
(g) aromatic series carboxylic acid halides：Wherein X=Cl or Br；R be the methyl of proton or any one the position of substitution, ethyl,
Propyl, isopropyl, methoxyl group, ethyoxyl, trifluoromethyl, nitro, cyano, aldehyde radical, methyl formate base, group-4 ethyl formate or trifluoro
Methoxyl group；
(h) vinyl acetate：
Wherein, R1=CnH2n+1, (18 >=n >=0)；R2=CnH2n-1, (18 >=n >=3)；R3=CnH2n-3, (18 >=n >=4)；R4、R5、
R6、R7And R8It is independent the alkyl of hydrogen, halogen or carbon atom number 1-6；n1=1-20.
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