CN114276228A - Preparation method of high-purity p-hydroxybenzoic acid - Google Patents
Preparation method of high-purity p-hydroxybenzoic acid Download PDFInfo
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- CN114276228A CN114276228A CN202111636025.7A CN202111636025A CN114276228A CN 114276228 A CN114276228 A CN 114276228A CN 202111636025 A CN202111636025 A CN 202111636025A CN 114276228 A CN114276228 A CN 114276228A
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Abstract
The invention relates to the technical field of organic synthesis, in particular to a preparation method of high-purity p-hydroxybenzoic acid.
Description
Technical Field
The invention relates to the technical field of organic synthesis, in particular to a preparation method of high-purity p-hydroxybenzoic acid.
Background
P-hydroxybenzoic acid (PHBA), also known as 4-hydroxybenzoic acid, is an organic compound having the molecular formula C7H6O3Molecular weight 138.13, melting point 214-217 ℃ and pure colorless fine crystalline or crystalline powder. The organic synthesis of p-hydroxybenzoic acid and important intermediates in the pharmaceutical and dye industries. The ester product synthesized by using p-hydroxybenzoic acid as raw material is widely used in various fields, and has high application value, for example, p-hydroxybenzoic acid can be used as synthetic liquid crystal polymer, p-hydroxybenzoic acid is reacted to synthesize p-hydroxybenzoic acid acetate, and then liquid crystal can be obtained after melting and solid phase polymerization.
Currently, the preparation method of p-hydroxybenzoic acid includes the following methods:
1. thermal rearrangement method of potassium salicylate, wherein the mass ratio of salicylic acid to potassium hydroxide is 1:1.1, the reaction temperature is 240 ℃, the reaction time is 70min, and then p-hydroxybenzoic acid can be prepared by a series of steps of decoloring, filtering, washing with water, drying and the like;
2. the carboxylation method of potassium phenoxide and carbon dioxide is characterized in that potassium phenoxide is used as a raw material, in the presence of a proper amount of potassium carbonate, hydrocarbon fuel oil is used as a medium, and the raw material and the carbon dioxide can directly synthesize the p-hydroxybenzoic acid under the pressure of 0.68-0.88Mpa and the temperature of 210-300 ℃;
3. supercritical carbon dioxide is used as reaction medium and reactant, carboxylation pressure is 8.5Mpa, time is 60min, temperature is 220 ℃, and stirring speed is 400 rpm. Because the supercritical carbon dioxide fluid has good solvent characteristics, the mass transfer and heat transfer of the reaction are greatly improved, thereby shortening the reaction time and improving the yield;
4. p-chlorobenzoic acid alkali fusion method;
5. the byproduct of saccharin production is p-toluenesulfonyl chloride.
Wherein, the p-chlorobenzoic acid alkali fusion method and the saccharin production byproduct p-toluenesulfonyl chloride method have limited raw material sources and high cost when synthesizing the p-hydroxybenzoic acid, and are not beneficial to industrial production. The processes for preparing p-hydroxybenzoic acid by the oxidation method of methyl cumene and the carboxylation method of potassium phenate and carbon dioxide are complex and the reaction conditions are difficult to control. In addition to the long reaction time required for the preparation of parahydroxybenzoic acid by the resin-catalyzed method, which is not suitable for mass production, the above-mentioned methods have low selectivity for the preparation of parahydroxybenzoic acid, easily produce a large amount of by-products, and the properties of the by-products are very similar to those of the target product parahydroxybenzoic acid, which is difficult to purify.
Disclosure of Invention
In order to solve the above problems, the present invention provides a method for preparing high-purity p-hydroxybenzoic acid. The method has the advantages of simple process, easy preparation and high purity of the prepared product.
The technical scheme adopted by the invention is as follows:
a preparation method of high-purity p-hydroxybenzoic acid comprises the following steps:
s1: preparation of the catalyst
Adding chloromethylated polystyrene into a 1, 4-dioxane solution to swell for 24-48h, transferring the swelled chloromethylated polystyrene into tetrabutyl ammonium iodide, adding beta-cyclodextrin and sodium iodide, adding the 1, 4-dioxane solution and distilled water, raising the temperature of a reaction system to 75-85 ℃, reacting for 28-36h, filtering, washing for 3-5 times by using water and acetone respectively, and drying the final product at 60-70 ℃ for 24h to obtain a catalyst;
s2: synthesis of p-hydroxybenzoic acid
Adding phenol, the catalyst prepared in S1 and copper powder into a sodium hydroxide solution, adding carbon tetrachloride, raising the reaction temperature to 70-85 ℃, reacting for 14-16h under stirring, carrying out suction filtration on the mixed solution after the reaction is finished, acidifying the obtained filtrate with hydrochloric acid, extracting for 3-5 times with a solvent to obtain an ether layer, washing the ether layer with water for 1-3 times, drying the ether layer with anhydrous sodium sulfate, distilling under normal pressure to remove the solvent, continuing to carry out reduced pressure distillation to obtain a crude product of p-hydroxybenzoic acid, and recrystallizing the crude product with anhydrous ethanol for 1-3 times to obtain a purified p-hydroxybenzoic acid.
Further, in S1, chloromethylated polystyrene was 15 g; 200ml of 1, 4-dioxane solution; tetrabutyl ammonium iodide is 0.12-0.16 mol; beta-cyclodextrin is 0.1-0.12 mol; sodium iodide is 0.015 mol; 200ml of 1, 4-dioxane solution; the amount of distilled water was 150 ml.
Further, in S2, the mass fraction of the sodium hydroxide solution is 20% -30%.
Further, in S2, the amount of sodium hydroxide solution added was 50 to 80 ml.
Further, in S2, the amount of copper powder added was 0.1 to 0.15 g.
Further, in S2, the charging ratio of phenol to carbon tetrachloride is 1: 2-4, wherein the addition amount of the catalyst is 15-20% of the total addition amount of phenol, carbon tetrachloride and the catalyst in parts by mass.
Further, in S2, the stirring rate was 400-800 rpm/min.
Further, in S2, the filtrate was acidified with hydrochloric acid to pH 2-3.
Further, in S2, the extraction solvent is diethyl ether or chloroform.
The invention has the following beneficial effects:
the preparation method of high-purity p-hydroxybenzoic acid provided by the application comprises the steps of firstly preparing a catalyst by using chloromethylated polystyrene and beta-cyclodextrin as raw materials, then adding the catalyst and a promoter copper powder into a solution of phenol, carbon tetrachloride and sodium hydroxide to synthesize the p-hydroxybenzoic acid, and preparing the high-purity p-hydroxybenzoic acid by controlling the proportion of the catalyst, the phenol and the carbon tetrachloride and carrying out multiple extraction and recrystallization, in particular, the preparation method can improve the product selectivity in the process of preparing the p-hydroxybenzoic acid and reduce the generation of byproducts by introducing the beta-cyclodextrin modified catalyst and the promoter copper powder, so as to improve the purity of the p-hydroxybenzoic acid, and simultaneously, in the post-treatment process of the product, the purity of the p-hydroxybenzoic acid is improved again by carrying out multiple extraction washing and multiple recrystallization, so that the finally prepared product has high purity, in addition, the whole preparation process is simple, easy to operate, mild in reaction condition, low in requirement on equipment and good in application prospect.
Drawings
FIG. 1 is a flow chart of the preparation in examples 1 to 5 of the present invention.
Detailed Description
In order that the invention may be more readily understood, reference will now be made to the following more particular description of the invention, examples of which are set forth below. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. These embodiments are provided so that this disclosure will be thorough and complete. The various starting materials used in the examples are, unless otherwise indicated, conventional commercial products.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.
The numerical values set forth in the examples of the present invention are approximations, not necessarily values. All values within the error range may be included without limiting to the specific values disclosed in the embodiments of the present invention, where the error or experimental conditions allow.
The numerical ranges disclosed in the examples of the present invention are intended to indicate the relative amounts of the components in the mixture and the ranges of temperatures or other parameters recited in the other method examples.
The preparation method of the high-purity p-hydroxybenzoic acid comprises the following steps:
s1: preparation of the catalyst
Adding chloromethylated polystyrene into a 1, 4-dioxane solution to swell for 24-48h, transferring the swelled chloromethylated polystyrene into tetrabutyl ammonium iodide, adding beta-cyclodextrin and sodium iodide, adding the 1, 4-dioxane solution and distilled water, raising the temperature of a reaction system to 75-85 ℃, reacting for 28-36h, filtering, washing for 3-5 times by using water and acetone respectively, and drying the final product at 60-70 ℃ for 24h to obtain a catalyst;
s2: synthesis of p-hydroxybenzoic acid
Adding phenol, the catalyst prepared in S1 and copper powder into a sodium hydroxide solution, adding carbon tetrachloride, raising the reaction temperature to 70-85 ℃, reacting for 14-16h under stirring, carrying out suction filtration on the mixed solution after the reaction is finished, acidifying the obtained filtrate with hydrochloric acid, extracting for 3-5 times with a solvent to obtain an ether layer, washing the ether layer with water for 1-3 times, drying the ether layer with anhydrous sodium sulfate, distilling under normal pressure to remove the solvent, continuing to carry out reduced pressure distillation to obtain a crude product of p-hydroxybenzoic acid, and recrystallizing the crude product with anhydrous ethanol for 1-3 times to obtain a purified p-hydroxybenzoic acid.
Further, in S1, chloromethylated polystyrene was 15 g; 200ml of 1, 4-dioxane solution; tetrabutyl ammonium iodide is 0.12-0.16 mol; beta-cyclodextrin is 0.1-0.12 mol; sodium iodide is 0.015 mol; 200ml of 1, 4-dioxane solution; the amount of distilled water was 150 ml.
Further, in S2, the mass fraction of the sodium hydroxide solution is 20% -30%.
Further, in S2, the amount of sodium hydroxide solution added was 50 to 80 ml.
Further, in S2, the amount of copper powder added was 0.1 to 0.15 g.
Further, in S2, the charging ratio of phenol to carbon tetrachloride is 1: 2-4, wherein the addition amount of the catalyst is 15-20% of the total addition amount of phenol, carbon tetrachloride and the catalyst in parts by mass.
Further, in S2, the stirring rate was 400-800 rpm/min.
Further, in S2, the filtrate was acidified with hydrochloric acid to pH 2-3.
Further, in S2, the extraction solvent is diethyl ether or chloroform.
The preparation method of the high-purity p-hydroxybenzoic acid provided by the application comprises the steps of firstly preparing a catalyst by using chloromethylated polystyrene and beta-cyclodextrin as raw materials, then adding the catalyst and a cocatalyst copper powder into phenol, carbon tetrachloride and a sodium hydroxide solution to synthesize the p-hydroxybenzoic acid, and preparing the high-purity p-hydroxybenzoic acid by controlling the proportion of the catalyst, the phenol and the carbon tetrachloride, extracting for many times and recrystallizing.
The following are specific examples of the present application:
example 1
S1: preparation of the catalyst
Adding 15g of chloromethylated polystyrene into 200ml of 1, 4-dioxane solution for swelling for 36h, transferring the swelled chloromethylated polystyrene into 0.12mol of tetrabutyl ammonium iodide, adding 0.1mol of beta-cyclodextrin and 0.015mol of sodium iodide, adding 200ml of 1, 4-dioxane solution and 150ml of distilled water, raising the temperature of a reaction system to 80 ℃ for reaction for 28h, filtering, washing water and acetone for 3 times respectively, and drying the final product in a vacuum oven at 60 ℃ for 24h to obtain the catalyst;
s2: synthesis of p-hydroxybenzoic acid
Adding 3g of phenol and 15% of the catalyst in the step 1 and 0.1g of copper powder into 50ml of 25% sodium hydroxide solution by mass, finally adding 6g of carbon tetrachloride, raising the reaction temperature to 70 ℃, starting stirring, wherein the stirring speed is 400rpm/min, reacting for 14h under the condition, carrying out suction filtration on the mixed solution after the reaction is finished, carrying out hydrochloric acid acidification on the obtained filtrate to control the pH to be 3, extracting for 3 times by using diethyl ether after acidification, washing the obtained ether layer for 1 time, drying the ether layer by using anhydrous sodium sulfate, distilling under normal pressure to remove the solvent, carrying out reduced pressure distillation to obtain a crude product of p-hydroxybenzoic acid, and carrying out absolute ethanol recrystallization on the crude product for 1 time to obtain a purified p-hydroxybenzoic acid.
Example 2
S1: preparation of the catalyst
Adding 15g of chloromethylated polystyrene into 200ml of 1, 4-dioxane solution for swelling for 24h, transferring the swelled chloromethylated polystyrene into 0.14mol of tetrabutyl ammonium iodide, adding 0.11mol of beta-cyclodextrin and 0.015mol of sodium iodide, adding 200ml of 1, 4-dioxane solution and 150ml of distilled water, raising the temperature of a reaction system to 80 ℃ for reaction for 36h, filtering, washing water and acetone for 4 times respectively, and drying the final product in a vacuum oven at 70 ℃ for 24h to obtain the catalyst;
s2: synthesis of p-hydroxybenzoic acid
Adding 3g of phenol, 16% of the catalyst in the step 1 and 0.1g of copper powder into 50ml of 20% sodium hydroxide solution by mass, finally adding 6g of carbon tetrachloride, raising the reaction temperature to 70 ℃, starting stirring at a stirring speed of 500rpm/min, and reacting for 14h under the conditions. And after the reaction is finished, carrying out suction filtration on the mixed solution, carrying out hydrochloric acid acidification on the obtained filtrate to control the pH to be 2.5, extracting for 3 times by using diethyl ether after acidification, washing the obtained ether layer with water for 1 time, drying the ether layer by using anhydrous sodium sulfate, distilling at normal pressure to remove the solvent, distilling under reduced pressure to obtain a crude product of the p-hydroxybenzoic acid, and recrystallizing the crude product with absolute ethyl alcohol for 1 time to obtain a purified product of the p-hydroxybenzoic acid.
Example 3
S1: preparation of the catalyst
Adding 15g of chloromethylated polystyrene into 200ml of 1, 4-dioxane solution for swelling for 48h, transferring the swelled chloromethylated polystyrene into 0.14mol of tetrabutyl ammonium iodide, adding 0.11mol of beta-cyclodextrin and 0.015mol of sodium iodide, adding 200ml of 1, 4-dioxane solution and 150ml of distilled water, raising the temperature of a reaction system to 80 ℃ for reaction for 36h, filtering, washing water and acetone for 4 times respectively, and drying the final product in a vacuum oven at 70 ℃ for 24h to obtain the catalyst;
s2: synthesis of p-hydroxybenzoic acid
To 60ml of 20% sodium hydroxide solution were added 3g of phenol, 18% of the catalyst of step 1 and 0.1g of copper powder, and finally 7g of carbon tetrachloride. Raising the reaction temperature to 80 ℃, starting stirring, enabling the stirring speed to be 500rpm/min, reacting for 16h under the condition, carrying out suction filtration on the mixed solution after the reaction is finished, carrying out hydrochloric acid acidification on the obtained filtrate to control the pH to be 3, extracting for 3 times by using chloroform after acidification, washing the obtained ether layer for 1 time, drying the ether layer by using anhydrous sodium sulfate, distilling at normal pressure to remove the solvent, distilling at reduced pressure to obtain a crude product of the p-hydroxybenzoic acid, and recrystallizing the crude product by using anhydrous ethanol for 1 time to obtain a purified product of the p-hydroxybenzoic acid.
Example 4
S1: preparation of the catalyst
Adding 15g of chloromethylated polystyrene into 200ml of 1, 4-dioxane solution for swelling for 24h, transferring the swelled chloromethylated polystyrene into 0.14mol of tetrabutyl ammonium iodide, adding 0.12mol of beta-cyclodextrin and 0.015mol of sodium iodide, adding 200ml of 1, 4-dioxane solution and 150ml of distilled water, raising the temperature of a reaction system to 80 ℃ for reaction for 36h, filtering, washing with water and acetone for 5 times respectively, and drying the final product in a vacuum oven at 70 ℃ for 24h to obtain the catalyst;
s2: synthesis of p-hydroxybenzoic acid
Adding 3g of phenol, 18% of the catalyst in the step 1 and 0.15g of copper powder into 50ml of 20% sodium hydroxide solution by mass, finally adding 9g of carbon tetrachloride, raising the reaction temperature to 80 ℃, starting stirring at the stirring speed of 400rpm/min, and reacting for 14h under the conditions. And after the reaction is finished, carrying out suction filtration on the mixed solution, carrying out hydrochloric acid acidification on the obtained filtrate to control the pH to be 2, extracting for 3 times by using diethyl ether after acidification, washing the obtained ether layer with water for 1 time, drying the ether layer by using anhydrous sodium sulfate, distilling under normal pressure to remove the solvent, distilling under reduced pressure to obtain a crude product of the p-hydroxybenzoic acid, and recrystallizing the crude product by using anhydrous ethanol for 1 time to obtain a purified product of the p-hydroxybenzoic acid.
Example 5
S1: preparation of the catalyst
Adding 15g of chloromethylated polystyrene into 200ml of 1, 4-dioxane solution for swelling for 48h, transferring the swelled chloromethylated polystyrene into 0.14mol of tetrabutyl ammonium iodide, adding 0.12mol of beta-cyclodextrin and 0.015mol of sodium iodide, adding 200ml of 1, 4-dioxane solution and 150ml of distilled water, raising the temperature of a reaction system to 80 ℃ for reaction for 36h, filtering, washing with water and acetone for 5 times respectively, and drying the final product in a vacuum oven at 70 ℃ for 24h to obtain the catalyst;
s2: synthesis of p-hydroxybenzoic acid
To 60ml of 25% sodium hydroxide solution were added 3g of phenol, 18% by weight of the catalyst of step 1 and 0.12g of copper powder, and finally 8g of carbon tetrachloride. The reaction temperature was raised to 80 ℃ and stirring was started at a rate of 600rpm/min, under which conditions 15h of reaction was allowed to occur. And after the reaction is finished, carrying out suction filtration on the mixed solution, carrying out hydrochloric acid acidification on the obtained filtrate to control the pH to be 2, extracting for 3 times by using diethyl ether after acidification, washing the obtained ether layer for 3 times by using water, drying the ether layer by using anhydrous sodium sulfate, distilling under normal pressure to remove the solvent, distilling under reduced pressure to obtain a crude product of the p-hydroxybenzoic acid, and recrystallizing the crude product by using anhydrous ethanol for 3 times to obtain a purified product of the p-hydroxybenzoic acid.
The purity of the products obtained in examples 1-5 above is shown in the following table:
| examples | Example 1 | Example 2 | Example 3 | Example 4 | Example 5 |
| Purity of | 96.5％ | 97.1％ | 99.3％ | 99.2％ | 99.5％ |
In the preparation method, firstly, the catalyst is prepared by using the chloromethylated polystyrene and the beta-cyclodextrin as raw materials, then the catalyst and the cocatalyst copper powder are added into the solution of phenol, carbon tetrachloride and sodium hydroxide to synthesize the p-hydroxybenzoic acid with high purity, and the p-hydroxybenzoic acid with high purity is prepared by controlling the proportion of the catalyst, the phenol and the carbon tetrachloride and carrying out multiple extraction and recrystallization, in particular, the preparation method can improve the product selectivity and reduce the generation of byproducts in the p-hydroxybenzoic acid preparation process by introducing the beta-cyclodextrin modified catalyst and the cocatalyst copper powder, and simultaneously, in the product post-treatment process, the purity of the p-hydroxybenzoic acid is improved again through multiple times of extraction washing and multiple times of recrystallization, so that the finally prepared product has high purity.
The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (9)
1. A preparation method of high-purity p-hydroxybenzoic acid is characterized by comprising the following steps:
s1: preparation of the catalyst
Adding chloromethylated polystyrene into a 1, 4-dioxane solution to swell for 24-48h, transferring the swelled chloromethylated polystyrene into tetrabutyl ammonium iodide, adding beta-cyclodextrin and sodium iodide, adding the 1, 4-dioxane solution and distilled water, raising the temperature of a reaction system to 75-85 ℃, reacting for 28-36h, filtering, washing for 3-5 times by using water and acetone respectively, and drying the final product at 60-70 ℃ for 24h to obtain a catalyst;
s2: synthesis of p-hydroxybenzoic acid
Adding phenol, the catalyst prepared in S1 and copper powder into a sodium hydroxide solution, adding carbon tetrachloride, raising the reaction temperature to 70-85 ℃, reacting for 14-16h under stirring, carrying out suction filtration on the mixed solution after the reaction is finished, acidifying the obtained filtrate with hydrochloric acid, extracting for 3-5 times with a solvent to obtain an ether layer, washing the ether layer with water for 1-3 times, drying the ether layer with anhydrous sodium sulfate, distilling under normal pressure to remove the solvent, continuing to carry out reduced pressure distillation to obtain a crude product of p-hydroxybenzoic acid, and recrystallizing the crude product with anhydrous ethanol for 1-3 times to obtain a purified p-hydroxybenzoic acid.
2. The method for preparing p-hydroxybenzoic acid with high purity according to claim 1, wherein in S1, chloromethylated polystyrene is 15 g; 200ml of 1, 4-dioxane solution; tetrabutyl ammonium iodide is 0.12-0.16 mol; beta-cyclodextrin is 0.1-0.12 mol; sodium iodide is 0.015 mol; 200ml of 1, 4-dioxane solution; the amount of distilled water was 150 ml.
3. The method for preparing p-hydroxybenzoic acid with high purity according to claim 1, wherein the mass fraction of sodium hydroxide solution in S2 is 20% -30%.
4. The method for preparing p-hydroxybenzoic acid with high purity according to claim 1, wherein the amount of sodium hydroxide solution added in S2 is 50-80 ml.
5. The method for preparing p-hydroxybenzoic acid with high purity according to claim 1, wherein the amount of copper powder added in S2 is 0.1 to 0.15 g.
6. The method for preparing high-purity p-hydroxybenzoic acid according to claim 1, wherein the feeding ratio of phenol to carbon tetrachloride in S2 is 1: 2-4, wherein the addition amount of the catalyst is 15-20% of the total addition amount of phenol, carbon tetrachloride and the catalyst in parts by mass.
7. The method for preparing high purity p-hydroxybenzoic acid according to claim 1, wherein the stirring rate in S2 is 400-800 rpm/min.
8. The method for preparing p-hydroxybenzoic acid with high purity according to claim 1, wherein in S2, the filtrate is acidified to pH 2-3 with hydrochloric acid.
9. The method for preparing p-hydroxybenzoic acid with high purity according to claim 1, wherein the extraction solvent in S2 is diethyl ether or chloroform.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI230151B (en) * | 1998-09-28 | 2005-04-01 | San Fu Chemical Co Ltd | Method of recovering p-hydroxybenzoic acid from the waste water from the process of producing p-hydroxybenzoic acid |
| CN102690195A (en) * | 2012-03-06 | 2012-09-26 | 江苏添鑫生物工程有限公司 | Para-hydroxybenzoic acid continuous production technique by liquid-phase method |
| CN113698286A (en) * | 2021-09-16 | 2021-11-26 | 宿迁思睿屹新材料有限公司 | Preparation method of p-hydroxybenzoic acid |
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- 2021-12-27 CN CN202111636025.7A patent/CN114276228A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI230151B (en) * | 1998-09-28 | 2005-04-01 | San Fu Chemical Co Ltd | Method of recovering p-hydroxybenzoic acid from the waste water from the process of producing p-hydroxybenzoic acid |
| CN102690195A (en) * | 2012-03-06 | 2012-09-26 | 江苏添鑫生物工程有限公司 | Para-hydroxybenzoic acid continuous production technique by liquid-phase method |
| CN113698286A (en) * | 2021-09-16 | 2021-11-26 | 宿迁思睿屹新材料有限公司 | Preparation method of p-hydroxybenzoic acid |
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| 庄玉贵等: "β-环糊精及脱氧胆酸的固载化研究", 《福建师范大学学报》, vol. 14, no. 3, pages 58 - 62 * |
| 张胜民等: "新型聚苯乙烯键联β－环糊精的制备及其催化羧化性能", 《湖北工学院学报》, vol. 11, no. 04, pages 56 - 58 * |
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