Polyhydroxy hyperbranched modified polymer and preparation method thereof
By preparing a multi-hydroxyl hyperbranched modified polymer, the problems of low density and easy softening of capsule wall material were solved, achieving high density and mechanical stability of capsules, ensuring effective release of contents and long shelf life.
Patent Information
- Application Number
- CN202510979637.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-16
- Publication Date
- 2025-11-18
AI Technical Summary
In the prior art, the capsule wall material for loading water-soluble contents is not dense and is prone to softening, making it difficult for the contents to be released, thus preventing the aroma of the contents from dissipating.
A method for preparing polyhydroxy hyperbranched modified polymers is adopted. By introducing ester groups into the polymer and reacting them with epoxy compounds, polyhydroxy hyperbranched polymers are formed. The strong polar hydrogen bonding between hydroxyl groups and the core material surface and the long aliphatic chain crosslinking of the polymer are utilized to improve the density and mechanical stability of the wall material.
It achieves high density and good mechanical stability of capsule wall material, ensuring that the contents are not easily leaked out, have a long shelf life, and are easy to break and release.
Smart Images
Figure BDA0005502551960000061 
Figure BDA0005502551960000141 
Figure BDA0005502551960000151
Abstract
Description
Technical Field
[0001] This invention relates to the field of capsule wall material technology, specifically to a multi-hydroxyl hyperbranched modified polymer and its preparation method. Background Technology
[0002] Capsules containing water-based fragrances use a wall material to fix the water-based contents within a sealed system. The contents are released by squeezing the capsule, thus eliminating odors, reducing irritation, enhancing aroma, refreshing the mind, and adding a pleasant sensation. The contents are generally classified as oil-soluble or water-soluble. Currently, the technology for preparing capsules with oil-soluble contents is very mature. Under the action of surfactants, the oil-soluble contents are dissolved in water to form an emulsion, which is then coaxially added dropwise to a crosslinking agent aqueous solution along with the capsule wall material solution. Typically, the capsule wall material is hydrophilic sodium alginate and a surfactant, and the crosslinking agent is calcium chloride. However, the technology for preparing capsules containing water-soluble contents is still immature. Currently, most capsules use sodium alginate and hydrophobic materials, combined with surfactants and other additives, to form the wall material, which then encapsulates the water-soluble contents. However, due to a certain degree of repulsion between the wall material and the water-soluble contents, the resulting capsules have poor stability.
[0003] The prior art discloses a cigarette filter flavor capsule, its preparation method, and a cigarette. The stability of the capsule is improved by using a polyelectrolyte membrane prepared from sodium alginate and chitosan as the wall material. However, the wall material of the capsule is not dense, and the water-based contents have a small loading capacity and are easy to seep out. The wall material is easy to soften and not easy to break, and the contents are not easy to release, resulting in the aroma of the contents of the aqueous solution not being able to diffuse. Summary of the Invention
[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defect of low density of the capsule wall material in the prior art, thereby providing a polyhydroxy hyperbranched modified polymer and its preparation method.
[0005] Another technical problem to be solved by the present invention is to overcome the defects of the prior art in which the capsule wall material is easy to soften and the contents are not easy to release, thereby providing a polyhydroxy hyperbranched modified polymer and its preparation method.
[0006] Therefore, on the one hand, the present invention provides a method for preparing a polyhydroxy hyperbranched modified polymer, comprising the following steps: in the presence of a first organic solvent and a catalyst, the polymer and 2-butene-1,4-diol diacetate are subjected to a polymerization reaction, acid hydrolysis, and a first solid-liquid separation to obtain an intermediate; in the presence of a second organic solvent and an initiator, the intermediate is reacted with an epoxy compound, and a second solid-liquid separation is performed to obtain a polyhydroxy hyperbranched modified polymer; wherein the polymer comprises natural rubber or synthetic rubber.
[0007] In some of these embodiments, the first organic solvent comprises tetrahydrofuran.
[0008] In some embodiments, the natural rubber includes at least one of natural rubber, gutta-percha, dandelion gum, smoked sheet gum, trefoil gum, and Malaysian gum.
[0009] In some embodiments, the synthetic rubber includes at least one of polybutadiene, polyisoprene, polybutadiene-styrene copolymer, and polybutadiene-isoprene copolymer.
[0010] In some embodiments, the catalyst comprises a ruthenium carbene complex catalyst, preferably, the catalyst comprises a second-generation Grubbs catalyst.
[0011] In some embodiments, the polymerization reaction between the polymer and 2-butene-1,4-diol diacetate takes 2-4 hours and the polymerization temperature is 80-120°C.
[0012] In some embodiments, after the polymerization of the polymer and 2-butene-1,4-diol diacetate, before acid hydrolysis, a termination reaction is included, which includes the step of adding a vinyl ether to the product after polymerization.
[0013] In some embodiments, the acidic substance in the acidolysis includes a hydrochloric acid solution with a concentration of 30-40 vol%. Preferably, the hydrochloric acid solution is an aqueous solution of hydrochloric acid.
[0014] In some embodiments, the first solid-liquid separation step includes precipitating the polymerization product with methanol and drying it.
[0015] In some embodiments, after acid hydrolysis and before a first solid-liquid separation, the step of refluxing the acid-hydrolyzed mixture is further included, and the refluxing time is 2-4 hours.
[0016] In some embodiments, the mass ratio of the polymer to 2-butene-1,4-diol diacetate is 10-35:0.5-5.5.
[0017] In some embodiments, the ratio of the polymer to the first organic solvent is 10-35:70-400, in g:mL.
[0018] In some embodiments, the second organic solvent comprises tetrahydrofuran.
[0019] In some embodiments, the initiator comprises an alkali organometallic compound, which includes at least one of potassium methoxide, sodium methoxide, and potassium tert-butoxide.
[0020] In some of these embodiments, the epoxy compound includes glycidyl ether.
[0021] In some embodiments, the mass ratio of the intermediate to the epoxide is 7-15:4-8.
[0022] In some embodiments, the reaction time of the intermediate and the epoxide is 8-12 hours, and the reaction temperature is 60-80°C.
[0023] In some embodiments, the secondary solid-liquid separation step includes precipitating the reaction product with an alcohol solvent, followed by drying, wherein the alcohol solvent includes methanol.
[0024] On the other hand, the present invention provides a polyhydroxy hyperbranched modified polymer, which is prepared by the above-described method for preparing polyhydroxy hyperbranched modified polymer.
[0025] In some embodiments, the weight percentage of hydroxyl groups in the polyhydroxy hyperbranched modified polymer is greater than or equal to 6%. Preferably, the weight percentage of hydroxyl groups in the polyhydroxy hyperbranched modified polymer is 40%, 50%, 52%, 60%, 65%, 80%, 85%, or 95%, or any range of two of these parameters.
[0026] Meanwhile, the present invention provides a capsule containing aqueous contents, the capsule comprising a wall material and a core material, the wall material comprising the above-mentioned polyhydroxy hyperbranched modified polymer.
[0027] In some embodiments, the present invention provides a method for preparing a capsule containing aqueous contents, comprising the following steps: forming an emulsion from the polyhydroxy hyperbranched modified polymer; forming a first mixture from the aqueous contents and a film-forming agent; forming a second mixture from a crosslinking agent; mixing the first mixture and the second mixture to form a gel ball; spraying the emulsion onto the surface of the gel ball; drying and curing to form a capsule.
[0028] In some embodiments, the aqueous contents include water-soluble plant extracts or water-soluble food flavoring substances.
[0029] In some embodiments, the aqueous contents further include an aqueous fragrance, which includes at least one of honey, sodium chloride, potassium sorbate, potassium citrate, alkaloids, volatile oils, tannins, sugars, amino acids, proteins, enzymes, and organic acids.
[0030] In some embodiments, the film-forming agent includes sodium alginate.
[0031] In some embodiments, the crosslinking agent comprises a metal ion salt, which includes at least one of calcium salt, iron salt, copper salt, magnesium salt, zinc salt, and aluminum salt, and at least one of calcium gluconate, zinc stearate, calcium isooctanoate, calcium oxalate, and calcium acetate.
[0032] In some embodiments, the concentration of the polyhydroxy hyperbranched polymer in the emulsion is 0.1-0.2 g / mL.
[0033] In some embodiments, the ratio of aqueous contents, film-forming agent and water in the first mixture is 0.05-6:0.05-1.5:0.4-6.5.
[0034] In some embodiments, the concentration of the crosslinking agent in the second mixture is 0.01-0.1 g / mL.
[0035] In some embodiments, the step of mixing the first mixture with the second mixture includes dropping the first mixture into the second mixture at a rate of 0.2-0.5 mL / s.
[0036] In some embodiments, the curing step includes curing with a UV lamp for 3-11 minutes.
[0037] The technical solution of this invention has the following advantages:
[0038] This invention provides a method for preparing a multi-hydroxyl hyperbranched modified polymer, comprising the following steps: in the presence of a first organic solvent and a catalyst, a polymer and 2-butene-1,4-diol diacetate are subjected to polymerization, acid hydrolysis, and a first solid-liquid separation to obtain an intermediate; in the presence of a second organic solvent and an initiator, the intermediate is reacted with an epoxy compound, followed by a second solid-liquid separation to obtain the multi-hydroxyl hyperbranched modified polymer; the polymer includes polymers of natural rubber or synthetic rubber. This invention utilizes 2-butene-1,4-diol diacetate to end-modify the polymer, introducing ester groups into the polymer. The polymer with ester groups generates hydroxyl groups during hydrolysis, and through multiple initiations and reactions with epoxy compounds, hyperbranching modification is achieved to obtain a multi-hydroxyl hyperbranched polymer.
[0039] The multi-hydroxyl hyperbranched modified polymer provided by this invention has terminal multi-hydroxyl hyperbranching. The polar hydroxyl groups on the inner surface of the wall material form a large number of strong polar hydrogen bonds with the polar core material surface, which play a role in encapsulating the core material and inhibiting the leakage of aqueous contents. The large number of double bonds in the long aliphatic chains of the polymer are solidified, and the double bonds between the free radical cross-linking molecular chains make the capsule wall material dense. Thus, the wall material of the water-based flavor capsule has high density, good mechanical stability and hand-squeezing brittleness, and the capsule is not easy to deteriorate and has a long shelf life. Detailed Implementation
[0040] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.
[0041] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.
[0042] Taking natural rubber as an example, formula (Ⅰ) is the synthetic route for polyhydroxy hyperbranched modified polymers.
[0043]
[0044] In the embodiments of the present invention, the molecular weight range of natural rubber is 100,000 Da to 1,000,000 Da.
[0045] Preparation Example 1
[0046] This preparation example provides a method for preparing a polyhydroxy hyperbranched modified polymer, the specific steps and parameters of which are as follows:
[0047] (1) Dissolve 28g of natural rubber (average molecular weight 100,000 Da) in 245mL of tetrahydrofuran, add 2.0g of 2-butene-1,4-diol diacetate and 0.2g of Grubbs second-generation catalyst, stir the reaction thoroughly for 3 hours, add 2mL of vinyl ether to terminate the polymerization, add 10mL of 36.5 vol% hydrochloric acid, reflux for 3 hours, pour in 500mL of methanol to precipitate the polymerization product, dry the solvent, and obtain the intermediate.
[0048] (2) Dissolve 11g of intermediate in 130mL of anhydrous and oxygen-free tetrahydrofuran, add 1.2g of potassium methoxide and 2g of glycidyl ether, stir slowly at 60℃ for 10 hours, pour into 250mL of methanol, precipitate and dry to obtain polyhydroxy hyperbranched polymer.
[0049] The molecular weight of the polyhydroxy hyperbranched polymer obtained in this preparation example was determined to be 45,000 Da and the molecular weight distribution was 2.5 by gel permeation chromatography. The weight percentage of hydroxyl groups in the polyhydroxy hyperbranched polymer obtained in this preparation example was 12.5% by nuclear magnetic resonance.
[0050] Preparation Example 2
[0051] This preparation example provides a method for preparing a polyhydroxy hyperbranched modified polymer, the specific steps and parameters of which are as follows:
[0052] (1) Dissolve 15g of Eucommia ulmoides gum (average molecular weight 160,000 Da) in 300mL of tetrahydrofuran, add 1.2g of 2-butene-1,4-diol diacetate and 0.14g of Grubbs second-generation catalyst, and stir thoroughly at 80℃ for 3 hours. Then, add 1.2mL of vinyl ether to terminate the polymerization, add 6.5mL of 36.5vol% hydrochloric acid, reflux for 3 hours, pour in 320mL of methanol to precipitate the polymer, and dry the solvent to obtain the intermediate.
[0053] (2) Dissolve 9.5g of intermediate in 6.7mL of anhydrous and oxygen-free tetrahydrofuran, add 0.65g of potassium methoxide and 5.3g of glycidyl ether, stir slowly at 80℃ for 10 hours, pour into 126mL of methanol, precipitate and dry to obtain polyhydroxy hyperbranched polymer.
[0054] The molecular weight of the hyperbranched polyhydroxy polymer obtained in this preparation example was determined to be 81,000 Da by gel permeation chromatography, and the molecular weight distribution was 2.2. The weight percentage of hydroxyl groups in the hyperbranched polyhydroxy polymer obtained in this preparation example was determined to be 6.5% by nuclear magnetic resonance.
[0055] Preparation Example 3
[0056] This preparation example provides a method for preparing a polyhydroxy hyperbranched modified polymer, the specific steps and parameters of which are as follows:
[0057] (1) 11 g of natural rubber (average molecular weight 1,000,000 Da) was dissolved in 176 mL of tetrahydrofuran. 0.9 g of 2-butene-1,4-diol diacetate and 0.1 g of Grubbs second-generation catalyst were added. After stirring thoroughly at 80 °C for 3 hours, 1.2 mL of vinyl ether was added to terminate the polymerization. 5.6 mL of 36.5 vol% hydrochloric acid was added, and the mixture was refluxed for 3 hours. 230 mL of methanol was then poured in to precipitate the polymer, and the solvent was dried. An intermediate was obtained.
[0058] (2) Dissolve 7g of intermediate in 89mL of anhydrous and oxygen-free tetrahydrofuran, add 0.8g of potassium methoxide and 4.1g of glycidyl ether. Stir slowly at 60℃ for 10 hours and then pour into 135mL of methanol. After precipitation, dry to obtain the polyhydroxy hyperbranched polymer.
[0059] The molecular weight of the polyhydroxy hyperbranched polymer obtained in this preparation example was 29,000 Da and the molecular weight distribution was 1.7, as determined by gel permeation chromatography. The weight percentage of hydroxyl groups in the polyhydroxy hyperbranched polymer obtained in this preparation example was 8.5%, as determined by nuclear magnetic resonance.
[0060] Preparation Example 4
[0061] This preparation example provides a method for preparing a polyhydroxy hyperbranched modified polymer, the specific steps and parameters of which are as follows:
[0062] (1) Dissolve 35g of smoked sheet rubber (average molecular weight 30000 Da) in 355mL of tetrahydrofuran, add 5.1g of 2-butene-1,4-diol diacetate and 0.22g of Grubbs second-generation catalyst, and stir thoroughly at 80℃ for 3 hours. Then, add 2.5mL of vinyl ether to terminate the polymerization, add 13mL of 36.5 vol% hydrochloric acid, reflux for 3 hours, pour in 650mL of methanol to precipitate the polymer, and dry the solvent to obtain the intermediate.
[0063] (2) Dissolve 15g of intermediate in 209mL of anhydrous and oxygen-free tetrahydrofuran, add 1.1g of potassium methoxide and 7.9g of glycidyl ether. Stir slowly at 60℃ for 10 hours and then pour into 309mL of methanol. After precipitation, dry to obtain the polyhydroxy hyperbranched polymer.
[0064] The molecular weight of the hyperbranched polyhydroxy polymer obtained in this preparation example was determined to be 33,000 Da and the molecular weight distribution was 2.0 by gel permeation chromatography. The weight percentage of hydroxyl groups in the hyperbranched polyhydroxy polymer obtained in this preparation example was 15.3% by nuclear magnetic resonance.
[0065] Preparation Example 5
[0066] This preparation example provides a method for preparing a polyhydroxy hyperbranched modified polymer, the specific steps and parameters of which are as follows:
[0067] (1) Dissolve 12.5 g of Glechoma hederacea (average molecular weight 100,000 Da) in 201 mL of tetrahydrofuran, add 1.7 g of 2-butene-1,4-diol diacetate and 0.18 g of Grubbs II catalyst, and stir thoroughly at 80 °C for 3 hours. Then, add 2 mL of vinyl ether to terminate the polymerization, add 6.8 mL of 36.5 vol% hydrochloric acid, reflux for 3 hours, pour in 410 mL of methanol to precipitate the polymer, and dry the solvent to obtain the intermediate.
[0068] (2) Dissolve 7.9g of intermediate in 108mL of anhydrous and oxygen-free tetrahydrofuran, add 1.0g of potassium methoxide and 5.1g of glycidyl ether. Stir slowly at 60℃ for 10 hours and then pour into 138mL of methanol. After precipitation, dry to obtain the polyhydroxy hyperbranched polymer.
[0069] The molecular weight of the hyperbranched polyhydroxy polymer obtained in this preparation example was determined to be 29,000 Da by gel permeation chromatography, and the molecular weight distribution was 1.6. The weight percentage of hydroxyl groups in the hyperbranched polyhydroxy polymer obtained in this preparation example was determined to be 21.3% by nuclear magnetic resonance.
[0070] Example 1
[0071] This embodiment provides a method for preparing capsules, with the specific steps and parameters as follows:
[0072] 5.7 g of the polyhydroxy hyperbranched polymer prepared in Preparation Example 1 was placed in 50 mL of deionized water to prepare an emulsion;
[0073] Dissolve 0.9g of the aqueous contents and 0.05g of sodium alginate in 0.56g of water to prepare aqueous solution A;
[0074] Prepare 2.1 mL of aqueous solution B by dissolving 0.05 g of cross-linking agent calcium glucose.
[0075] Solution A was slowly added to solution B via a syringe at a rate of 0.5 mL per second using a peristaltic pump to form gel beads. The emulsion was sprayed onto the surface of the gel beads, dried, cured under a UV lamp for 5 minutes, washed with deionized water, and dried at room temperature to obtain capsules.
[0076] Example 2
[0077] This embodiment provides a method for preparing capsules, with the specific steps and parameters as follows:
[0078] 7.3 g of the polyhydroxy hyperbranched polymer prepared in Example 2 was placed in 58 mL of deionized water to prepare an emulsion;
[0079] Dissolve 0.4g of the aqueous contents and 0.03g of sodium alginate in 0.45g of water to prepare aqueous solution A;
[0080] Prepare 1.1 mL of aqueous solution B by dissolving 0.03 g of crosslinking agent zinc stearate;
[0081] Solution A was slowly added to solution B via a syringe at a rate of 0.45 mL per second using a peristaltic pump to form gel beads. The emulsion was sprayed onto the surface of the gel beads, dried, cured under a UV lamp for 3 minutes, washed with deionized water, and dried at room temperature to obtain capsules.
[0082] Example 3
[0083] This embodiment provides a method for preparing capsules, with the specific steps and parameters as follows:
[0084] 3.7 g of the polyhydroxy hyperbranched polymer prepared in Preparation Example 3 was placed in 37 mL of deionized water to prepare an emulsion;
[0085] Dissolve 0.11g of the aqueous contents and 0.08g of sodium alginate in 0.56g of water to prepare aqueous solution A;
[0086] Prepare 1.9 mL of aqueous solution B using 0.034 g of the crosslinking agent calcium stearate;
[0087] Solution A was slowly added to solution B via a syringe at a rate of 0.47 mL per second using a peristaltic pump to form gel microspheres. The emulsion was sprayed onto the surface of the gel microspheres, dried, cured under a UV lamp for 5 minutes, washed with deionized water, and dried at room temperature to obtain capsules.
[0088] Example 4
[0089] This embodiment provides a method for preparing capsules, with the specific steps and parameters as follows:
[0090] 4g of the polyhydroxy hyperbranched polymer prepared in Example 5 was placed in 31mL of deionized water to prepare an emulsion.
[0091] Dissolve 0.9g of the aqueous contents and 0.07g of sodium alginate in 0.87g of water to prepare aqueous solution A;
[0092] Prepare a 1.9 mL aqueous solution B using 0.03 g of the cross-linking agent calcium isooctanoate;
[0093] Solution A was slowly added to solution B via a syringe at a rate of 0.29 mL per second using a peristaltic pump to form gel microspheres. The emulsion was sprayed onto the surface of the gel microspheres, dried, cured under a UV lamp for 7 minutes, washed with deionized water, and dried at room temperature to obtain capsules.
[0094] Example 5
[0095] This embodiment provides a method for preparing capsules, with the specific steps and parameters as follows:
[0096] 3.7 g of the polyhydroxy hyperbranched polymer prepared in Preparation Example 3 was placed in 37 mL of deionized water to prepare an emulsion;
[0097] Dissolve 1.6g of the aqueous contents and 0.11g of sodium alginate in 1.05g of water to prepare aqueous solution A;
[0098] Prepare 2.1 mL of aqueous solution B using 0.08 g of the crosslinking agent calcium oxalate;
[0099] Solution A was slowly added to solution B via a syringe at a rate of 0.33 mL per second using a peristaltic pump to form gel microspheres. The emulsion was sprayed onto the surface of the gel microspheres, dried, cured under a UV lamp for 11 minutes, washed with deionized water, and dried at room temperature to obtain capsules.
[0100] Example 6
[0101] This embodiment provides a method for preparing capsules, with the specific steps and parameters as follows:
[0102] 3.7 g of the polyhydroxy hyperbranched polymer prepared in Preparation Example 3 was placed in 37 mL of deionized water to prepare an emulsion;
[0103] Dissolve 3.4g of the aqueous contents and 1.4g of sodium alginate in 5.15g of water to prepare aqueous solution A;
[0104] Prepare a 5.3 mL aqueous solution B using 0.32 g of the crosslinking agent calcium isooctanoate;
[0105] Solution A was slowly added to solution B via a syringe at a rate of 0.21 mL per second using a peristaltic pump to form gel beads. The emulsion was sprayed onto the surface of the gel beads, dried, cured under a UV lamp for 7 minutes, washed with deionized water, and dried at room temperature to obtain capsules.
[0106] Example 7
[0107] This embodiment provides a method for preparing capsules, with the specific steps and parameters as follows:
[0108] 7.3 g of the polyhydroxy hyperbranched polymer prepared in Example 2 was placed in 58 mL of deionized water to prepare an emulsion;
[0109] Dissolve 4.9g of the aqueous contents and 0.21g of sodium alginate in 2.10g of water to prepare aqueous solution A;
[0110] Prepare a 2.5 mL aqueous solution B using 0.26 g of the crosslinking agent calcium acetate;
[0111] Solution A was slowly added to solution B via a syringe at a rate of 0.26 mL per second using a peristaltic pump to form gel microspheres. The emulsion was sprayed onto the surface of the gel microspheres, dried, cured under a UV lamp for 11 minutes, washed with deionized water, and dried at room temperature to obtain capsules.
[0112] Example 8
[0113] This embodiment provides a method for preparing capsules, with the specific steps and parameters as follows:
[0114] 6.8 g of the polyhydroxy hyperbranched polymer prepared in Preparation Example 4 was placed in 43 mL of deionized water to prepare an emulsion;
[0115] Dissolve 5.3g of the aqueous contents and 0.37g of sodium alginate in 6.11g of water to prepare aqueous solution A; prepare 4.9mL of aqueous solution B by dissolving 0.45g of the cross-linking agent calcium oxalate.
[0116] Solution A was slowly added to solution B via a syringe at a rate of 0.24 mL per second using a peristaltic pump to form gel microspheres. The emulsion was sprayed onto the surface of the gel microspheres, dried, cured under a UV lamp for 5 minutes, washed with deionized water, and dried at room temperature to obtain capsules.
[0117] Example 9
[0118] This embodiment provides a method for preparing capsules, with the specific steps and parameters as follows:
[0119] 3.7 g of the polyhydroxy hyperbranched polymer prepared in Preparation Example 3 was placed in 37 mL of deionized water to prepare an emulsion;
[0120] Dissolve 3.3g of the aqueous contents and 0.17g of sodium alginate in 5.87g of water to prepare aqueous solution A;
[0121] Prepare 3.4 mL of aqueous solution B by dissolving 0.13 g of cross-linking agent calcium glucose.
[0122] Solution A was slowly added to solution B via a syringe at a rate of 0.24 mL per second using a peristaltic pump to form gel microspheres. The emulsion was sprayed onto the surface of the gel microspheres, dried, cured under a UV lamp for 10 minutes, washed with deionized water, and dried at room temperature to obtain capsules.
[0123] Example 10
[0124] This embodiment provides a method for preparing capsules, with the specific steps and parameters as follows:
[0125] 3.7 g of the polyhydroxy hyperbranched polymer prepared in Preparation Example 1 was placed in 37 mL of deionized water to prepare an emulsion;
[0126] Dissolve 6g of the aqueous contents and 1.5g of sodium alginate in 6.5g of water to prepare aqueous solution A;
[0127] Prepare a 1 mL aqueous solution B by dissolving 0.5 g of the cross-linking agent calcium glucose.
[0128] Solution A was slowly added to solution B via a syringe at a rate of 0.24 mL per second using a peristaltic pump to form gel microspheres. The emulsion was sprayed onto the surface of the gel microspheres, dried, cured under a UV lamp for 10 minutes, washed with deionized water, and dried at room temperature to obtain capsules.
[0129] Comparative Example 1
[0130] This comparative example provides a method for preparing a capsule, with the same specific steps and parameters as in Example 1, except that an equal mass of natural gum is used to replace the polyhydroxy hyperbranched polymer prepared in Example 1.
[0131] Comparative Example 2
[0132] This comparative example provides a method for preparing a capsule, with the same specific steps and parameters as in Example 1, except that an equal mass of chitosan is used to replace the polyhydroxy hyperbranched polymer prepared in Example 1.
[0133] Experimental Example
[0134] The following parameters were tested for the capsules prepared in Examples 1-10 and Comparative Examples 1-2: weight percentage of aqueous contents, crush pressure (detected using a capsule crush pressure tester), weight retention rate at room temperature for 90 days (calculated by the ratio of the weight of the capsule after 90 days of storage at room temperature to the initial weight of the capsule), weight retention rate at room temperature for 180 days (calculated by the ratio of the weight of the capsule after 180 days of storage at room temperature to the initial weight of the capsule), diameter (measured using a digital caliper), roundness (measured using a roundness meter), presence of odor after crushing (ten volunteers with normal sense of smell were recruited to evaluate whether the capsules had an odor after crushing), total residual amount of non-crosslinking agent metal ions (GB 5009.74-2014), residual content of volatile organic solvents (GB 31604.8-2016), and residual content of chloride ions (GB / T 9729-2007). The results are shown in Table 1.
[0135] Table 1 Capsule Performance Testing
[0136]
[0137]
[0138] According to the data in Table 1, compared with Comparative Example 1 and Comparative Example 2, the present invention uses 2-butene-1,4-diol diacetate to modify the polymer, and then uses an epoxy compound to react to obtain a polyhydroxy hyperbranched modified polymer as the raw material for preparing capsules. The resulting capsules have high density, good mechanical stability and brittleness when squeezed, and the capsules are not easily deteriorated and have a long shelf life.
[0139] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.
Claims
1. A method for preparing a polyhydroxy hyperbranched modified polymer, characterized in that, Includes the following steps, In the presence of a first organic solvent and a catalyst, the polymer and 2-butene-1,4-diol diacetate undergo polymerization, acid hydrolysis, and a single solid-liquid separation to obtain an intermediate. In the presence of a second organic solvent and an initiator, the intermediate and epoxy compound are reacted, followed by a second solid-liquid separation to obtain a polyhydroxy hyperbranched modified polymer. The polymer includes natural rubber or synthetic rubber.
2. The method for preparing the polyhydroxy hyperbranched modified polymer according to claim 1, characterized in that, The first organic solvent includes tetrahydrofuran; and / or, The natural rubber includes at least one of natural rubber, gutta-percha, dandelion gum, smoked sheet rubber, trefoil gum, and Malaysian rubber; and / or, The synthetic rubber includes at least one of polybutadiene, polyisoprene, polybutadiene-styrene copolymer, and polybutadiene-isoprene copolymer; and / or The catalyst includes a ruthenium carbene complex catalyst, preferably a Grubbs second-generation catalyst.
3. The method for preparing the polyhydroxy hyperbranched modified polymer according to claim 2, characterized in that, The polymerization reaction between the polymer and 2-butene-1,4-diol diacetate takes 2-4 hours; and / or, Following the polymerization reaction of the polymer and 2-butene-1,4-diol diacetate, but before acid hydrolysis, a termination reaction is included, wherein the termination reaction comprises the step of adding a vinyl ether to the product after polymerization; and / or, The acidic substances in the acidolysis include a hydrochloric acid solution with a concentration of 30-40 vol%; and / or, The primary solid-liquid separation step includes precipitating the polymerization product with methanol, drying; and / or, After acid hydrolysis and before the first solid-liquid separation, the process further includes a step of refluxing the acid-hydrolyzed mixture for 2-4 hours; and / or, The mass ratio of the polymer to 2-butene-1,4-diol diacetate is 10-35:0.5-5.5; and / or, The ratio of the polymer to the first organic solvent is 10-35:70-400, in g:mL.
4. The method for preparing the polyhydroxy hyperbranched modified polymer according to claim 1, characterized in that, The second organic solvent includes tetrahydrofuran; and / or, The initiator comprises an alkali organometallic compound, which includes at least one selected from potassium methoxide, sodium methoxide, and potassium tert-butoxide; and / or, The epoxy compound includes glycidyl ether; and / or, The mass ratio of the intermediate to the epoxide is 7-15:4-8; and / or, The reaction time between the intermediate and the epoxide is 8-12 hours; and / or, The secondary solid-liquid separation step includes precipitating the reaction product with an alcohol solvent and drying it, wherein the alcohol solvent includes methanol.
5. A polyhydroxy hyperbranched modified polymer, characterized in that, It is prepared by the method for preparing the polyhydroxy hyperbranched modified polymer according to any one of claims 1-4.
6. The polyhydroxy hyperbranched modified polymer according to claim 5, characterized in that, The hydroxyl content of the polyhydroxy hyperbranched modified polymer is greater than or equal to 6 wt%.
7. A capsule containing aqueous contents, characterized in that, The capsule containing aqueous contents comprises a wall material and a core material, wherein the wall material comprises the polyhydroxy hyperbranched modified polymer as described in any one of claims 5-6.
8. A method for preparing a capsule containing aqueous contents as described in claim 7, characterized in that, Includes the following steps, The polyhydroxy hyperbranched modified polymer is formed into an emulsion, the aqueous contents and film-forming agent are formed into a first mixture, and the crosslinking agent is formed into a second mixture; The first mixture and the second mixture are mixed to form gel spheres. The emulsion is sprayed onto the surface of the gel spheres, dried, and solidified to form capsules.
9. The method for preparing a capsule containing aqueous contents according to claim 8, characterized in that, The aqueous contents include water-soluble plant extracts or water-soluble food flavoring substances; and / or, The film-forming agent includes sodium alginate; and / or, The crosslinking agent includes metal ion salts. The metal ion salt includes at least one selected from calcium salt, iron salt, copper salt, magnesium salt, zinc salt, and aluminum salt. The metal ion salt includes at least one of calcium gluconate, zinc stearate, calcium isooctanoate, calcium oxalate, and calcium acetate.
10. The method for preparing a capsule containing aqueous contents according to claim 9, characterized in that, The concentration of the polyhydroxy hyperbranched polymer in the emulsion is 0.1-0.2 g / mL; and / or, In the first mixture, the ratio of aqueous contents, film-forming agent, and water is 0.05-6:0.05-1.5:0.4-6.5; and / or, The concentration of the crosslinking agent in the second mixture is 0.01-0.1 g / mL; and / or, The step of mixing the first mixture with the second mixture includes adding the first mixture dropwise to the second mixture at a rate of 0.2-0.5 mL / s; and / or, The curing step includes curing with an ultraviolet lamp for a time of 3-11 minutes.