CN114832837B - Application of hydrophobically modified solid acid catalyst in cellulose acetate acetylation reaction - Google Patents

Application of hydrophobically modified solid acid catalyst in cellulose acetate acetylation reaction Download PDF

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CN114832837B
CN114832837B CN202210610750.5A CN202210610750A CN114832837B CN 114832837 B CN114832837 B CN 114832837B CN 202210610750 A CN202210610750 A CN 202210610750A CN 114832837 B CN114832837 B CN 114832837B
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solid
solid acid
cellulose acetate
cellulose
acid
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CN114832837A (en
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李力成
索娜
佘洁
吴臻煜
马娜
李倩倩
李小保
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Nanjing Forestry University
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Abstract

The invention relates to an application of a solid acid catalyst in cellulose acetate acetylation reaction, wherein the solid acid catalyst comprises solid acid and a modifying group; the modified group at least has a C1-C20 carbon chain, the contact angle of the solid acid catalyst to water is 120 degrees < theta <150 degrees, and the problems of low cellulose acetylation conversion rate and low reaction yield caused by poor interfacial binding force between the solid acid and cellulose in the prior art are solved by adopting the scheme of the invention.

Description

Application of hydrophobically modified solid acid catalyst in cellulose acetate acetylation reaction
Technical Field
The invention relates to the technical field of cellulose acetate acetylation reaction, in particular to application of a solid acid catalyst in cellulose acetate synthesis.
Background
Cellulose acetate has wide application, and is a large product with international competitive value. At present, concentrated sulfuric acid is mainly used as a catalyst in the production of cellulose acetate, and the method has the problems of large sewage yield, high energy consumption and the like because sulfuric acid cannot be separated from a reaction system, a large amount of water resources are consumed in the process, and technical innovation is needed to be carried out. Aiming at the problem, it is generally desired to replace liquid sulfuric acid with solid superacid in each field, and the solid superacid and a product system can be effectively separated and recycled, so that the waste water is reduced, and the production process is simplified.
At present, various solid superacids such as sulfuric acid-promoted metal oxide, mesoporous carbon-based solid sulfonic acid, acid resin and the like are reported to have the performance of catalyzing and synthesizing cellulose acetate, but the reaction system generally has the problem of low reaction rate, and the problems are particularly characterized by large solid superacids and long reaction time, which severely restrict the further development of the technology for catalyzing and synthesizing cellulose acetate by the solid superacids. Therefore, the technical staff have conducted a great deal of research, and developed many measures for improving the reaction performance of the solid superacid, such as preparation optimization of the solid superacid material, increasing the acid amount, nanocrystallizing the solid superacid material, expanding the pore size of the solid superacid, changing the acid position distribution of the solid superacid, and the like. At present, related researches are still in an experimental stage and have not been industrially applied.
From many classical heterogeneous reactions, such as Pickering interfacial catalysis, gas-liquid phase hydrogenation, photolysis of water, etc., it is known that if there is a significant difference in the properties between the reactants and the products, the reaction is affected by the interaction of each reactant with the catalyst surface. In the cellulose acetylation reaction process, a cellulose molecular chain is hydrophilic; as the reaction proceeds, the resulting cellulose acetate molecular chain becomes increasingly hydrophobic due to the substitution of hydroxyl groups by acetyl groups, and cellulose acetate may exhibit significant hydrophobic properties when the degree of substitution reaches 1.8. However, most solid superacids with strong reactivity, such as sulfuric acid-promoted metal oxides, have a surface that is strongly hydrophilic. According to interaction analysis, the interaction between the solid super acidic material and the low-substitution cellulose acetate is weak due to the surface property relation that the polarity difference between the solid super acidic material and the low-substitution cellulose acetate is large, so that the cellulose acetate molecular chain with low substitution degree is difficult to continuously react on the surface of the solid super acidic material.
Disclosure of Invention
The invention aims to provide an application of a solid acid catalyst in cellulose acetate acetylation reaction, wherein the solid acid catalyst comprises a solid acid and a modifying group; the modifying group has at least a carbon chain of C1-C20 and the solid acid catalyst has a contact angle to water of 120 ° < θ <150 °.
The cellulose acetylation reaction includes the step of mixing cellulose with an acetylating agent.
Technical effects
In general, in the solid acid catalytic reaction of cellulose acetate, since the molecular chain length of cellulose acetate as a raw material is large, the distance between the molecular chains of the modifier of the hydrophobically modified solid acid catalyst is far smaller than the length of cellulose acetate, which is generally thought to cause a steric hindrance effect, prevent adsorption of cellulose acetate on the surface of the solid acid catalyst, and result in low catalytic reaction efficiency, low substitution degree of the obtained cellulose acetate, and poor yield.
But through reasonable hydrophobic modification, the affinity between the solid acid catalyst and the intermediate of cellulose acetylation reaction is adjusted, so that the efficiency of cellulose acetylation reaction is greatly improved, and the effect is more obvious especially for sulfuric acid-promoted solid superacid with a specific structure.
Detailed Description
In order to make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention are described in more detail below in conjunction with the embodiments of the present invention. The described embodiments are, of course, some of the embodiments of the invention and should not be construed as limiting the scope of the invention.
The invention aims to provide an application of a solid acid catalyst in cellulose acetate acetylation reaction, wherein the solid acid catalyst comprises a solid acid and a modifying group; the modifying group has at least a carbon chain of C1-C20 and the solid acid catalyst has a contact angle to water of 120 ° < θ <150 °.
If the hydrophobicity is too strong, the contact angle is too large, the excessive modified groups can cover active sites, and the hydrophobicity is too strong, so that the affinity of the solid acid catalyst and cellulose is too weak, and the reaction resistance in the initial stage of the reaction is too large;
the kind of the solid acid catalyst is not particularly limited in the present application, and any known solid acid catalyst can be used in the present application without departing from the inventive concept of the present application, but it should be recognized that there is a difference in the hydrophobicizing modifying effect between different solid acid catalysts, which is related to the kind and performance of the solid acid catalyst. By way of illustrative example only, the solid acid catalyst is one or a mixture of a solid super acid, an acidic resin, an acidic molecular sieve solid acid, and a sulfonated carbon solid acid.
The acidic resin is a polymer resin material with acidity, especially containing-SO 3 H group resin material.
The acidic molecular sieve solid is silicon aluminum oxide with a pore structure, and after the silicon aluminum oxide is subjected to liquid acid ion exchange treatment, a plurality of OH groups coordinated with Al are generated on the surface of the silicon aluminum oxide, wherein protons can be dissociated, so that the whole material is weakly acidic.
The sulfonated carbon is a carbon material loaded with sulfur-containing substances, and contains-SO 3 H to be acidic.
It will be appreciated that the above materials are well known per se in the art and any known materials and satisfying the conditions capable of hydrophobicizing modification can be used in the present application without departing from the inventive concept of the present application.
Preferably, the solid acid catalyst is a solid super acid;
the solid superacid has higher acid strength and better catalytic efficiency for the acetylation reaction.
Preferably, the mass content ratio of the modifying group to the solid super acid is 0.01-10%, further preferably 0.1-8%, and more preferably 0.5-6%.
Preferably, M is one or more of Al, zr, ti, sn, fe.
It will be appreciated that the present application does not require any particular modification of the hydrophobically modified groups, and in principle, it is sufficient that the hydrophobicization modification of the solid acid catalyst is such that the hydrophilic and hydrophobic properties of the solid acid catalyst meet the requirements of the present application. By way of illustrative example only, and not by way of limitation of the scope of protection, the modifying group may be selected from one or more of silane coupling agents, titanate coupling agents, aluminate coupling agents, phosphate coupling agents, borate coupling agents.
The silane coupling agent can be one or more of butyl silane, epoxy silane, trimethyl silane, 2-chloroethyl silane, trichloroethyl silane, dodecyl silane, tetravinyl silane, octadecyl trichlorosilane, tetraethoxy silane, tertiary butyl trichlorosilane, methacryloxy silane, vinyl silane and ureido silane; the titanate coupling agent can be one or more of monoalkoxy titanate coupling agent, monoalkoxy pyrophosphoric acid ester type titanate coupling agent, integrated type titanate coupling agent and ligand type titanate coupling agent.
It will be appreciated that the above coupling agents are presented by way of example only, and that the specific manner of hydrophobically modification is not particularly critical to the present application and that any known manner of hydrophobically modification can be used in the present application without departing from the inventive concepts herein.
Preferably, the solid super acid is sulfuric acid-promoted solid super acid, and the sulfuric acid-promoted solid super acid is SO 4 2- /M x O y Wherein M is one or more of Al, zr, ti, sn, fe.
The mass content of sulfate radical in the sulfuric acid-promoted solid super acid is 0.1-10%, preferably 0.5-8%, and further preferably 1-5%.
In the application, the solid super acid is sulfuric acid-promoted solid super acid, and the molecular structure of the solid super acid is SO 4 2- /M x O y The sulfuric acid-promoted solid superacid is obtained by impregnating metal oxide with dilute sulfuric acid or sulfate and calcining at high temperature to form solid superacid with acid strength higher than 100% sulfuric acid by hundreds of times. The preparation method of the sulfuric acid-promoted solid superacid is known, and any known preparation method can be used in the present application, including but not limited to a hydrothermal method, a sol-gel method, a low-temperature aging method, and the like. In the molecule of the sulfuric acid-promoted solid super acid, M can be one or more than one of Al, zr, ti, sn, fe, and it is understood that the adjustment of the type of the metal oxide is still within the protection scope of the application on the basis of not departing from the inventive concept of the application.
As an embodiment, the sulfuric acid type solid super acid catalyst is loaded with active metals, including but not limited to one or more of Pt, au and Ag.
As one embodiment, the sulfuric acid type solidBulk super acid, niO and Al 2 O 3 The molecular sieve and the rare earth form a composite carrier; the composite support may extend the lifetime of the solid superacid to some extent, and it is understood that methods of forming the composite support are known and are not particularly limited in this application.
Compared with the traditional solid acid, the solid acid has the defects of low acid quantity, poor thermal stability and the like. The carbon-based solid acid has high acid density, adjustable pore structure, controllable surface wettability, unique thermo-mechanical stability and good chemical stability. However, the traditional carbon-based solid acid has the advantages of low specific surface area, low hydrophobicity, large mass transfer resistance, more steps, long period and certain limitation in severe condition application. More importantly, the time length of the catalytic cellulose acetylation reaction is nearly ten times or even tens times of that of the liquid sulfuric acid under the same condition, and the dosage is large.
Methods for hydrophobically modifying inorganic materials are known in the art. It will be appreciated that, without departing from the inventive concept of the present application, known powder hydrophobically modifying methods can be used in the present application to hydrophobically modify solid acid catalysts, by way of example and without any limitation to the scope of protection, by the process of hydrophobically modifying solid acid catalysts: dispersing solid super acid into a solvent, adding a modifier, stirring for reaction at a controlled temperature, cooling, filtering, washing, putting a filter cake mobile phone into an oven for drying, and grinding at room temperature to finally obtain a solid super acid sample.
In the above reaction, the solvent used may be one or more of trifluoroacetic acid, DMSO, DMF, ammonium hexamethylphosphonate, methanol, ethanol, acetic acid, isopropanol, pyridine, tetramethyl ethylenediamine, acetone, triethylamine, n-butanol, dioxane, methyl formate, tributylamine, methyl ethyl ketone, ethyl acetate, trioctylamine, dimethyl carbonate, isopropyl ether, n-butyl ether, trichloroethylene, diphenyl ether, dichloromethane, dichloroethane, carbon disulfide, cyclohexane, hexane, kerosene, petroleum ether, formamide, acetonitrile, tetrahydrofuran, diethyl ether, chloroform, benzene, toluene, and carbon tetrachloride.
In the reaction, the stirring temperature is between 20 ℃ below zero and 250 ℃ and the stirring time is between 1min and 36h; the drying temperature is 20-250 ℃.
The above process is merely an exemplary explanation of the preparation of the solid acid catalyst of the present application, and it is understood that the present application is not particularly limited to the above process parameters, and modifications of the above process by the skilled person based on actual needs are still considered to be within the scope of the present application.
The cellulose acetylation reaction comprises the following steps:
adding an acetylation reagent and cellulose into a reaction vessel according to a proportion, adding the solid acid catalyst, reacting for 1-5h at 50-120 ℃, and precipitating, filtering and washing to be neutral after the reaction is finished to obtain a product.
As one embodiment, the cellulose is alkali pretreated.
There is no particular requirement for the acetylating agent in the present application, and any known acetylating agent suitable for cellulose acetylating reaction can be used in the present application without departing from the inventive concept of the present application, including but not limited to one or more of acetic anhydride, acetyl chloride, acetic acid.
It is understood that any technical scheme for performing the acetylation reaction by using a multi-step reaction method is within the scope of the present application without departing from the inventive concept of the present application.
The present application is not particularly limited to the type of cellulose, and any cellulose known to be industrially valuable for performing an acetylation reaction can be subjected to an acetylation reaction using the method of the present application.
Surprisingly, because the generated cellulose molecular chain is hydrophobic due to the substitution of hydroxyl groups by acetyl groups in the cellulose acetylation reaction process, the binding force between the cellulose molecular chain and the surface super-hydrophilic solid acid catalyst is weakened, so that the capability of the solid acid serving as a catalyst for providing a reaction surface is weakened, and the reaction efficiency is further influenced. The present application is based on the recognition that by grafting a group having hydrophobicity on the surface of a superhydrophilic solid acid catalyst, the catalytic efficiency of the solid acid catalyst on cellulose acetylation reaction is greatly improved.
However, it must be recognized that since cellulose as a reaction raw material is hydrophilic, if the solid acid catalyst is modified so that the surface of the solid acid catalyst is too hydrophobic, the binding force between the cellulose and the solid acid catalyst becomes weak in the early stage of the reaction, and the cellulose acetylation reaction is also adversely affected.
Example 1
Preparation of modified sulfuric acid promoted solid superacid
Concentrated sulfuric acid and a carrier TiO 2 According to SO 4 2- With TiO 2 The mass ratio is 3:100, tiO 2 Mixing with deionized water with the ratio of 0.67g/mL, heating and stirring to be sticky; drying and roasting at 450 ℃ for 2 hours to obtain SO 4 2- /TiO 2 Sulfuric acid-promoted solid superacids. Then, octadecyl trichlorosilane was prepared as a 10% solution in octadecyl trichlorosilane in anhydrous toluene, and SO was added to the solution at a solid-to-liquid ratio of 1.0g/mL 4 2- /TiO 2 Powder, continuously and rapidly stirring at 25 ℃; after 1h, collecting powder by solid-liquid separation, then continuously flushing the powder with a large amount of anhydrous toluene, and drying by a baking oven to obtain the octadecyl trichlorosilane modified SO 4 2- /TiO 2 Solid superacid. The prepared reaction performance data of the solid superacid is obtained through the acetylation reaction evaluation of cellulose and acetic anhydride, and the specific reaction evaluation steps are shown in the following method.
Acetylation reaction
The microcrystalline cellulose and the solid super acid catalyst (the mass ratio is 2:1) are weighed and added into a three-neck flask, and then the molar ratio of the microcrystalline cellulose to the acetic acid is 1:6.8, adding the three-neck flask in proportion, firstly placing the three-neck flask in an oil bath pot at 45 ℃, continuously stirring for 2 hours, then, heating to 65 ℃, after the temperature of the solution in the flask is stable, adding acetic anhydride according to the proportion of microcrystalline cellulose to acetic anhydride of 0.25g/mL, and starting an acetylation reaction; after 2 hours of stable reaction, 0.01g/mL of a magnesium acetate/acetic acid mixed solution was added to the three-necked flask, and the mixture was taken out of the three-necked flask in an oil bath, and stirring was continued after the same volume of acetic acid was added. And (3) after the temperature of the three-neck flask is reduced to room temperature, centrifuging the mixture in the flask, pouring the collected clear liquid into deionized water, filtering out precipitate, flushing with a large amount of deionized water, stopping after the pH=7 of the filtrate at the bottom, and drying the precipitate in an oven to obtain the cellulose acetylation reaction product.
The substitution degree test method of the reaction product is according to the national standard HG/T3021-1999, and the main operation steps are as follows.
Crushing cellulose acetate, drying in an oven at 120-125 ℃ for 60min, weighing about 1.500g of dried cellulose acetate powder, adding the powder into a 250mL flask, and adding about 65mL of acetone to dissolve the cellulose acetate powder; next, 25.00mL of 1M NaOH solution was added and stirred for 3h; then, the wall and the bottle stopper were rinsed with 50mL of distilled water, and 25.00mL of 0.5. 0.5M H was added 2 SO 4 About 0.5mL of phenolphthalein reagent; titration was performed with 0.5M sodium hydroxide solution and V was recorded when the red color ceased to appear 1 The unit is mL. Performing blank experiment, repeating the above steps without adding vinegar tablet, and recording titration amount V of 0.500M sodium hydroxide solution 2 . The degree of substitution was calculated using the following formula:
Figure BDA0003671954170000091
Figure BDA0003671954170000092
wherein m is 1 The mass of the cellulose acetate powder used for the substitution degree test was 100g of the mass of acetic acid contained in cellulose acetate as AV; DS is the number of acetyl groups contained in each unit ring, and its upper limit is 3.
The product yield of the cellulose acetylation reaction is calculated according to the following formula:
Figure BDA0003671954170000101
wherein m is 2 For the mass, m, of cellulose acetate collected after the end of the reaction 3 Is the cellulose feeding amount before the acetylation reaction.
The octadecyltrichlorosilane modified SO is determined by the method 4 2- /TiO 2 The hydrophobic angle is 132.4 degrees, SO 4 2- /TiO 2 And octadecyltrichlorosilane modified SO 4 2- /TiO 2 The substitution degree of the cellulose acetate synthesized by catalysis is 2.22 and 2.76 respectively, and the yield of the cellulose acetate is 62.93 percent and 93.85 percent respectively.
Example 2
Preparation of modified sulfuric acid-promoted solid superacid:
zirconium oxychloride (ZrOCl) 2 ·8H 2 O) (national medicine group chemical reagent) as zirconium source for preparing Zr (OH) 4 . Zr (OH) 4 Roasting in a muffle furnace at 650 ℃ for 2h to obtain ZrO 2 Sulfuric acid and ZrO 2 According to SO 4 2- With ZrO 2 The mass ratio is 3: 100. ZrO (ZrO) 2 Mixing with deionized water with a ratio of 0.67g/mL, heating and stirring to be sticky, drying, and roasting at 450 ℃ for 2 hours to obtain SO 4 2- /ZrO 2 Sulfuric acid-promoted solid superacids. Then, a 6% vinyltriethoxysilane/ethyl acetate solution was prepared, and SO was added to the mixed solution at a solid-to-liquid ratio of 0.8g/mL 4 2- /ZrO 2 A powder; continuously and stably stirring at 40 ℃ for 12 hours, filtering, separating and collecting a solid sample, flushing with a large amount of ethyl acetate, and drying to obtain the vinyl triethoxysilane modified SO 4 2- /ZrO 2 。
The vinyltriethoxysilane modified SO was evaluated using the cellulose acetylation reaction conditions described in example 1 4 2- /ZrO 2 The hydrophobic angle was 129.2℃and SO 4 2- /ZrO 2 And vinyltriethoxysilane modified SO 4 2- /ZrO 2 The substitution degree of the cellulose acetate obtained by catalysis is 2.01 and 2.69, and the cellulose acetate yield is 53.72% and 87.34% respectively.
Example 3
Concentrated sulfuric acid and a carrier TiO 2 According to SO 4 2- With TiO 2 (Xuan Chengjing New Material Co., ltd.) the mass ratio was 2.5:100, tiO 2 Mixing with deionized water with the ratio of 0.67g/mL, heating and stirring to be sticky; drying and roasting at 450 ℃ for 2 hours to obtain SO 4 2- /TiO 2 Sulfuric acid-promoted solid superacids. Then, t-butyldimethylsilyl methyl isobutyl ketone was prepared as a 3% solution of t-butyldimethylsilyl chloride/methyl isobutyl ketone, and SO was added to the solution at a solid-to-liquid ratio of 0.64g/mL 4 2- /TiO 2 Powder, continuously and rapidly stirring at 50 ℃; after 4 hours, solid-liquid separation is carried out to collect powder, then a large amount of methyl isobutyl ketone is used for continuously flushing the powder, and the powder is dried by a baking oven to prepare the tertiary butyl dimethyl chlorosilane modified SO 4 2- /TiO 2 Solid superacid.
Tertiary butyl dimethyl chlorosilane modified SO as evaluated using cellulose acetylation reaction conditions described in example 1 4 2- /TiO 2 The hydrophobic angle is 132.5 degrees, SO 4 2- /TiO 2 And tertiary butyl dimethyl chlorosilane modified SO 4 2- /TiO 2 The substitution degree of the cellulose acetate obtained by the solid superacid catalysis is 2.08 and 2.72 respectively, and the yield of the cellulose acetate is 59.45 percent and 89.70 percent respectively.
Example 4
Preparation of SO 4 2- /La 2 O 3 HZSM-5, 1g La 2 O 3 And HZSM-5 in mass ratio of 1:10 is added into 100mL of 2M sulfuric acid, stirred for 3 hours at room temperature, dried and added into N 2 Calcining at 400 ℃ for 3 hours under the atmosphere. Weighing 3.3% of gamma-diethylenetriaminopropyl trimethoxysilane/acetone mixed solution, adding into a beaker, and adding SO according to the solid-to-liquid ratio of 0.6g/mL 4 2- /La 2 O 3 Stirring HZSM-5 powder continuously at 70 ℃ for 15h, and carrying out suction filtration, flushing and drying treatment to obtain the gamma-diethylenetriamine propyl trimethoxy silane modified SO 4 2- /La 2 O 3 /HZSM-5。
Evaluation with cellulose acetylation reaction conditions described in example 1, gamma-diethylenetriaminopropyl trimethoxysilane modified SO 4 2- /La 2 O 3 HZSM-5 hydrophobic angle of 130.3℃acidifying SO 4 2- /La 2 O 3 HZSM-5 and gamma-diethylenetriaminopropyl trimethoxysilane modified SO 4 2- /La 2 O 3 Cellulose acetate obtained by HZSM-5 catalysis has substitution degrees of 1.64 and 2.33, and cellulose acetate yields of 29.22% and 60.12%, respectively.
Example 5
Preparation of SO 4 2- /Fe 2 O 3 The sulfuric acid-promoted solid super acid is used for weighing methyltrichlorosilane and ethyl acetate to prepare a mixed solution with the concentration of 8% of modifier; the temperature of the mixed solution is reduced to 20 ℃, and then SO is added according to the solid-to-liquid ratio of 0.3g/mL 4 2- /Fe 2 O 3 A powder; after continuously and stably stirring for 4 hours, filtering, separating and collecting a solid sample, washing with a large amount of ethyl acetate, and drying to obtain the methyl trichlorosilane modified SO 4 2- /Fe 2 O 3 。
Methyl trichlorosilane modified SO was evaluated using the cellulose acetylation reaction conditions described in example 1 4 2- /Fe 2 O 3 The hydrophobic angle is 145.7 degrees, SO 4 2- /Fe 2 O 3 And methyltrichlorosilane modified SO 4 2- /Fe 2 O 3 The substitution degree of the cellulose acetate obtained by catalysis is 1.87 and 2.37 respectively, and the yield of the cellulose acetate is 34.42% and 65.35% respectively.
Example 6
A certain amount of ZSM-5 (the silicon-aluminum ratio is 25) is put into a muffle furnace to be roasted for 2 hours at 300 ℃, then soaked for a certain time by excessive 0.5mol/L sulfuric acid aqueous solution, and HZSM-5 powder is prepared after filtration, water washing and drying treatment. Weighing 6.25% isopropyl dioleate acyloxy (dioctyl phosphate acyloxy) titanate/isopropanol mixed solution, adding into a beaker, adding HZSM-5 powder according to a solid-to-liquid ratio of 0.18g/mL, continuously stirring at 60 ℃ for 3 hours, and after suction filtration, isopropanol flushing and drying treatment, collecting the powder which is the isopropyl dioleate acyloxy (dioctyl phosphate acyloxy) titanate modified HZSM-5.
The cellulose acetate substitution was 1.35 and 2.08, respectively, and cellulose acetate yields were 12.67% and 48.67%, respectively, using the cellulose acetylation reaction conditions described in example 1 to evaluate the modified HZSM-5 hydrophobic angle of isopropyl dioleate acyloxy (dioctyl phosphoryloxy) titanate, and the modified HZSM-5 catalyzed by HZSM-5 and isopropyl dioleate acyloxy (dioctyl phosphoryloxy) titanate.
Example 7
Preparation of SO 4 2- /Fe 2 O 3 -Al 2 O 3 -TiO 2 Solid superacid, al (NO) is weighed 3 ) 3 ·9H 2 O and Fe 2 (SO 4 ) 3 6H 2 O is dissolved in deionized water, and a proper amount of TiCl is removed under the cooling of ice water bath 4 Solution, and n (Fe): n (Al): n (Ti) =1: 2:2, adding into deionized water, mixing the 3 solutions, and dripping concentrated NH 3 H 2 And regulating the pH value of the solution to 8-9, and carrying out a large amount of precipitation, aging, suction filtration and drying. Grinding the solid powder, using H 2 SO 4 Soaking in solution, suction filtering, washing with deionized water, drying, and calcining at 500deg.C to obtain SO 4 2- /Fe 2 O 3 -Al 2 O 3 -TiO 2 Solid superacid. Then, gamma-methacryloxypropyl trimethoxysilane and isopropyl alcohol were prepared into a 7% strength gamma-methacryloxypropyl trimethoxysilane isopropyl alcohol solution, and Fe was added to the solution at a solid-to-liquid ratio of 0.4g/mL 2 O 3 -Al 2 O 3 -TiO 2 Powder, continuously and rapidly stirring at 15 ℃; after 3h, collecting powder by solid-liquid separation, then continuously flushing the powder with a large amount of isopropanol, and drying by a baking oven to obtain the gamma-methacryloxypropyl trimethoxy silane modified SO 4 2- /Fe 2 O 3 -Al 2 O 3 -TiO 2 Solid superacid.
Using the methods described in example 1Cellulose acetylation reaction conditions were evaluated, gamma-methacryloxypropyl trimethoxysilane modified SO 4 2- /Fe 2 O 3 -Al 2 O 3 -TiO 2 The hydrophobic angle is 129.3 degrees, SO 4 2- /Fe 2 O 3 -Al 2 O 3 -TiO 2 And gamma-methacryloxypropyl trimethoxysilane modified SO 4 2- /Fe 2 O 3 -Al 2 O 3 -TiO 2 The substitution degree of the cellulose acetate obtained by catalysis is 1.92 and 2.50 respectively, and the yield of the cellulose acetate is 53.20% and 79.42% respectively.
Example 8
Measuring vinyl triethoxysilane and acetone to prepare a vinyl triethoxysilane dispersion/acetone solution with the concentration of 5%, and then adding D005-T according to the solid-to-liquid ratio of 0.25 g/mL; after stirring continuously for 10h, washing the solid collected by suction filtration with acetone, and drying to obtain the vinyltriethoxysilane modified D005-T.
As evaluated by the cellulose acetylation reaction conditions described in example 1, vinyltriethoxysilane-modified resin catalyst D005-T had a hydrophobic angle of 122.2℃and resin catalysts D005-T and 3-aminopropyl trimethoxysilane-modified resin catalyst D005-T gave cellulose acetate having substitution degrees of 1.68 and 2.43, respectively, and cellulose acetate yields of 22.80% and 69.90%, respectively.
Example 9
The sulfonated carbon is prepared by mixing the active carbon and 4-benzene diazonium sulfonate (4-benzene diazonium sulfonate synthesized by diazotizing sulfanilic acid) with the molar mass of 100g/mol and 1M HCl, stirring for 12 hours at 20 ℃, filtering, washing with acetone and distilled water, and drying. Weighing octamethyl cyclotetrasiloxane and glycol ether to prepare a mixed solution with the concentration of 6% of the modifier; adding sulfonated carbon powder according to the solid-to-liquid ratio of 0.85g/mL at the temperature of 5 ℃; and (3) continuously and stably stirring for 0.5h, filtering, separating, collecting a solid sample, flushing with a large amount of glycol ether, and drying to obtain the octamethyl cyclotetrasiloxane modified sulfonated carbon.
The cellulose acetate catalyzed by the sulfonated carbon modified with octamethyl cyclotetrasiloxane had a hydrophobic angle of 128.5 ° and the sulfonated carbon modified with octamethyl cyclotetrasiloxane had substitution degrees of 2.04 and 2.58, respectively, with cellulose acetate yields of 28.20% and 70.32%, respectively, as evaluated by the cellulose acetylation reaction conditions described in example 1.
Example 10
Measuring isopropyl tri (dioctyl acyloxy) titanate and isopropanol to prepare an isopropyl tri (dioctyl acyloxy) titanate/isopropanol solution with the concentration of 12.5%, and then adding Amberlyst-15 according to the solid-to-liquid ratio of 0.82 g/mL; after stirring continuously for 2h, the solid collected by suction filtration is washed with isopropanol and dried to obtain Amberlyst-15 modified by isopropyl tri (dioctyl acyloxy phosphate) titanate.
The cellulose acetate substitution obtained by catalysis of Amberlyst-15 and Amberlyst-15 modified with isopropyl tri (dioctyl acyloxy phosphate) titanate was 1.20 and 2.03, respectively, with cellulose acetate yields of 9.01% and 50.75%, respectively, with Amberlyst-15 modified with isopropyl tri (dioctyl acyloxy phosphate) titanate having a hydrophobic angle of 145.9 ° as evaluated by the cellulose acetylation reaction conditions described in example 1.
Example 11
At 60 ℃, isopropyl di (acetoacetate) aluminate and propanol are measured to prepare an isopropyl di (acetoacetate) aluminate/propanol solution with the concentration of 3.5 percent, and then resin A-25 is added according to the solid-to-liquid ratio of 0.45 g/mL; after stirring continuously for 5 hours, washing the solid collected by suction filtration with propanol, and drying to obtain the methyl trichlorosilane modified resin A-25.
The cellulose acetylation reaction conditions described in example 1 were used to evaluate that isopropyl di (acetoacetate) aluminate-modified resin A-25 had a hydrophobic angle of 127.9℃and that the resin A-25 and methyltrichlorosilane-modified resin A-25 were catalyzed to give cellulose acetate substitution values of 1.42 and 1.98, respectively, with cellulose acetate yields of 17.52% and 48.43%, respectively.
Example 12
Preparation of SO 4 2- /Fe 2 O 3 -Al 2 O 3 -TiO 2 Solid superacid, al (NO) is weighed 3 ) 3 ·9H 2 O and Fe 2 (SO 4 ) 3 6H 2 O is dissolved in deionized water, and a proper amount of TiCl is removed under the cooling of ice water bath 4 Solution, and n (Fe): n (Al): n (Ti) =1: 2:2, adding into deionized water, mixing the 3 solutions, and dripping concentrated NH 3 H 2 And regulating the pH value of the solution to 8-9, and carrying out a large amount of precipitation, aging, suction filtration and drying. Grinding the solid powder, using H 2 SO 4 Soaking in solution, suction filtering, washing with deionized water, drying, and calcining at 500deg.C to obtain SO 4 2- /Fe 2 O 3 -Al 2 O 3 -TiO 2 Solid superacid. Then, vinyltriethoxysilane and butanone were prepared as a 3.5% strength vinyltriethoxysilane butanone solution, and Fe was added to the solution at a solid-to-liquid ratio of 0.33g/mL 2 O 3 -Al 2 O 3 -TiO 2 Powder, continuously and rapidly stirring at 20 ℃; after 24 hours, solid-liquid separation is carried out to collect powder, then a large amount of butanone is used for continuously flushing the powder, and then the powder is dried by a baking oven to prepare the vinyl triethoxysilane modified SO 4 2- /Fe 2 O 3 -Al 2 O 3 -TiO 2 Solid superacid.
The vinyltriethoxysilane modified SO was evaluated using the cellulose acetylation reaction conditions described in example 1 4 2- /Fe 2 O 3 -Al 2 O 3 -TiO 2 The hydrophobic angle was 122.5℃and SO 4 2- /Fe 2 O 3 -Al 2 O 3 -TiO 2 And vinyltriethoxysilane modified SO 4 2- /Fe 2 O 3 -Al 2 O 3 -TiO 2 The substitution degree of the cellulose acetate obtained by catalysis is 2.08 and 2.53 respectively, and the cellulose acetate yield is 57.82% and 84.56% respectively.
Example 13
Preparation of modified sulfuric acid-promoted solid superacid:
preparation of SO 4 2- /Fe 2 O 3 Sulfuric acid-promoted solid superacid: feCl is added 3 ·6H 2 O was dissolved in deionized water (250 ml), and ammonia was added and stirred until the final pH of the solution was adjusted to 9. Washing the precipitate with deionized water, drying at 100deg.C for 12 hr, and drying to obtain Fe (OH) 3 Roasting in a muffle furnace at 500 ℃ for 3 hours to form Fe 2 O 3 Cooling to room temperature, taking out, mixing sulfuric acid with carrier Fe 2 O 3 According to SO 4 2- With Fe 2 O 3 The mass ratio is 3:100, fe 2 O 3 Mixing with deionized water at a ratio of 0.67g/mL, heating and stirring to viscous state, drying, and calcining at 450 deg.C for 2 hr to obtain SO 4 2- /Fe 2 O 3 Sulfuric acid-promoted solid superacids. Then, weighing n-octyl trichlorosilane and propanol to prepare a mixed solution with the concentration of the modifier of 1.25%; the temperature of the mixed solution is reduced to 10 ℃, and then SO is added according to the solid-to-liquid ratio of 0.0375g/mL 4 2- /Fe 2 O 3 A powder; after continuously and stably stirring for 12 hours, filtering, separating and collecting a solid sample, flushing with a large amount of propanol, and drying to obtain n-octyl trichlorosilane modified SO 4 2- /Fe 2 O 3 。
N-octyl trichlorosilane modified SO was evaluated using the cellulose acetylation reaction conditions described in example 1 4 2- /Fe 2 O 3 The hydrophobic angle is 120.2 degrees, SO 4 2- /Fe 2 O 3 And n-octyl trichlorosilane modified SO 4 2- /Fe 2 O 3 The substitution degree of the cellulose acetate obtained by catalysis is 1.52 and 2.31 respectively, and the yield of the cellulose acetate is 19.23% and 57.37% respectively.
Example 14
Zirconium oxychloride (ZrOCl) 2 ·8H 2 O) (national medicine group chemical reagent) as zirconium source for preparing Zr (OH) 4 . Zr (OH) 4 Roasting in a muffle furnace at 650 ℃ for 2h to obtain ZrO 2 Sulfuric acid and ZrO 2 According to SO 4 2- With ZrO 2 The mass ratio is 2: 100. ZrO (ZrO) 2 And de-ionizedMixing with water at a ratio of 0.1g/mL, heating and stirring to viscous state, drying, and calcining at 450deg.C for 2 hr to obtain SO 4 2- /ZrO 2 Sulfuric acid-promoted solid superacids. Then, a 6% solution of tridecafluorooctyltriethoxysilane in toluene was prepared, and SO was added to the mixed solution at a solid-to-liquid ratio of 0.05g/mL 4 2- /ZrO 2 A powder; continuously and stably stirring at 80 ℃ for 12 hours, filtering, separating and collecting a solid sample, flushing with a large amount of toluene, and drying to obtain the decamethyl cyclopentasiloxane modified SO 4 2- /ZrO 2 。
Evaluation with cellulose acetylation reaction conditions described in example 1, tridecafluorooctyltriethoxysilane modified SO 4 2- /ZrO 2 The hydrophobic angle is 134.6 degrees, SO 4 2- /ZrO 2 And tridecafluorooctyltriethoxysilane modified SO 4 2- /ZrO 2 The substitution degree of the cellulose acetate obtained by catalysis is 1.93 and 2.75 respectively, and the yield of the cellulose acetate is 47.02% and 92.34% respectively.
Example 15
At 70 ℃, n-octyl trichlorosilane and toluene are measured to be prepared into a 3.5 percent n-octyl trichlorosilane dispersion/toluene solution, and then resin A-25 is added according to a solid-to-liquid ratio of 0.9 g/mL; after stirring continuously for 5 hours, the solid collected by suction filtration is washed by toluene, and the n-octyl trichlorosilane modified resin A-25 is prepared after drying.
The n-octyl trichlorosilane modified resin A-25 had a hydrophobic angle of 142.2℃and the resin A-25 and n-octyl trichlorosilane modified resin A-25 were evaluated by the cellulose acetylation reaction conditions described in example 1, and the final cellulose acetate obtained by the catalysis of both had substitution degrees of 1.37 and 2.02, respectively, and cellulose acetate yields of 13.36% and 49.31%, respectively.
Example 16
Measuring 4-chloromethyl phenyl trichlorosilane and diethyl ether to prepare a dispersion/diethyl ether solution with the concentration of 5%4-chloromethyl phenyl trichlorosilane at the temperature of 5 ℃, and then adding Amberlyst-15 according to the solid-to-liquid ratio of 0.1 g/mL; after stirring continuously for 1h, the collected solid was washed with diethyl ether and suction filtered, and dried to give Amberlyst-15 modified with 4-chloromethylphenyl trichlorosilane.
As evaluated by the cellulose acetylation reaction conditions described in example 1, 4-chloromethylphenyl trichlorosilane modified Amberlyst-15 had a hydrophobic angle of 127.8℃amberlyst-15 and 4-chloromethylphenyl trichlorosilane modified Amberlyst-15, and finally both catalyzed cellulose acetates had substitution degrees of 1.23 and 1.99, respectively, and cellulose acetate yields of 9.27% and 48.72%, respectively.
Comparative example 1:
weighing phosphotungstic acid (H) 3 PW 12 O 40 ·4H 2 O) was evaluated as a catalyst under the cellulose acetylation reaction conditions described in example 1, and the final catalysis gave a degree of substitution of cellulose acetate of 1.82 and a cellulose acetate yield of 32.2%.
Comparative example 2:
FeCS was weighed as a catalyst and evaluated according to the cellulose acetylation reaction conditions described in example 1, and the final catalysis gave a degree of substitution of cellulose acetate of 1.2 and a cellulose acetate yield of 13.7%.
Comparative example 3:
at 10 ℃, n-octyl trichlorosilane and toluene are measured to be prepared into a 3 percent n-octyl trichlorosilane dispersion/toluene solution, and FeCS is added according to the solid-to-liquid ratio of 0.25 g/mL; after continuously stirring for 2 hours, washing the solid collected by suction filtration by toluene, and drying to obtain the n-octyl trichlorosilane modified FeCS.
N-octyl trichlorosilane modified FeCS was evaluated using the cellulose acetylation reaction conditions described in example 1, and the final catalysis gave a cellulose acetate substitution of 1.57 and a cellulose acetate yield of 19.5%.
Comparative example 4:
measuring Fe 2 O 3 The final catalysis gave a degree of substitution of cellulose acetate of 1.02 and a cellulose acetate yield of 8.4% as catalyst evaluated under the cellulose acetylation reaction conditions described in example 1.
Comparative example 5:
the niobic tungstic acid was weighed as a catalyst and evaluated in accordance with the cellulose acetylation reaction conditions described in example 1, and the final catalysis gave a cellulose acetate substitution degree of 1.43 and a cellulose acetate yield of 17.9%.
Evaluation of SO using cellulose acetylation reaction conditions described in example 1 4 2- /Fe 2 O 3 And n-octyl trichlorosilane modified SO 4 2- /Fe 2 O 3 The substitution degree of the cellulose acetate obtained by the catalysis of the two is 2.07 and 2.22, and the yield of the cellulose acetate is 39.7 percent and 54.3 percent.
From the above examples and comparative examples, it can be obtained that only the modified sulfuric acid-promoting solid superacid can effectively improve the acetylation reaction efficiency of cellulose, and that neither the other solid superacids nor the modified solid superacids can effectively improve the acetylation reaction efficiency of cellulose.
To better demonstrate the trend of contact angle after hydrophobic modification with reaction efficiency, the results of examples 1-16 are as follows:
Figure BDA0003671954170000201
Figure BDA0003671954170000211
from the above examples, it can be seen that the hydrophobicization modification within a specific contact angle range is effective for improving the catalytic efficiency, and if the contact angle is too large or too small, the catalytic efficiency is adversely affected.

Claims (7)

1. Use of a solid acid catalyst in an acetylation reaction of cellulose acetate, wherein the solid acid catalyst comprises a solid acid and a modifying group; the modifying group has at least a carbon chain of C1-C20 and the solid acid catalyst has a contact angle to water of 120 ° < θ <150 °; the mass content ratio of the modifying group to the solid acid is 0.01-8%;
the cellulose acetylation reaction comprises the following steps: adding an acetylation reagent and cellulose into a reaction vessel according to a proportion, and adding the solid acid catalyst to perform a reaction;
the modifying group is one or more of phosphate, titanate, silane and aluminate.
2. The use of a solid acid catalyst according to claim 1 for cellulose acetate acetylation, wherein the solid acid is a sulfuric acid-promoted solid super acid having a molecular structure of SO4 2- /M x O y Wherein M is one or more of Al, zr, ti, sn, fe.
3. Use of a solid acid catalyst according to claim 1 in cellulose acetate acetylation reactions, characterized in that: the solid acid is an acidic resin.
4. Use of a solid acid catalyst according to claim 1 in cellulose acetate acetylation reactions, characterized in that: the solid acid is an acidic molecular sieve solid acid.
5. Use of a solid acid catalyst according to claim 1 in cellulose acetate acetylation reactions, characterized in that: the solid acid is a sulfonated carbon solid acid.
6. The use of a solid acid catalyst according to claim 1 in cellulose acetate acetylation, wherein the solid acid is a mixture of at least two of solid super acid, acid resin, acid molecular sieve solid acid, sulfonated carbon solid acid.
7. The use of a solid acid catalyst according to claim 2 in cellulose acetate acetylation, wherein the mass content of sulfate in the sulfuric acid-promoted solid superacid is 1-5%.
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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB372844A (en) * 1931-02-19 1932-05-19 Ruth Aldo Co Inc Improvements in or relating to the manufacture of cellulose acetate
JP2019214658A (en) * 2018-06-12 2019-12-19 国立大学法人北海道大学 Cellulose acetate, cellulose acetate fiber, cellulose acetate composition, manufacturing method of cellulose acetate, and manufacturing method of cellulose acetate composition

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN100492070C (en) * 2004-09-14 2009-05-27 富士胶片株式会社 Cellulose acylate film, polarizing plate, and liquid crystal display
CN104258911A (en) * 2014-08-29 2015-01-07 江苏科技大学 Preparation method of highly cross-linked macroporous/mesoporous solid acid catalyst
CN105642345B (en) * 2015-04-03 2018-08-10 江苏大学 A kind of preparation method of hydrophobic multi-stage porous solid acid-base bifunctional catalyst
CN107252697B (en) * 2017-06-27 2019-06-25 南京林业大学 A kind of high activity and high stability solid super-strong acid and preparation method thereof
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Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB372844A (en) * 1931-02-19 1932-05-19 Ruth Aldo Co Inc Improvements in or relating to the manufacture of cellulose acetate
JP2019214658A (en) * 2018-06-12 2019-12-19 国立大学法人北海道大学 Cellulose acetate, cellulose acetate fiber, cellulose acetate composition, manufacturing method of cellulose acetate, and manufacturing method of cellulose acetate composition

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