Macroporous adsorption resin for decoloring sugar as well as preparation method and application of macroporous adsorption resin

Abstract

The invention belongs to the technical field of functional resin, and particularly relates to macroporous adsorption resin for sugar decolorization and a preparation method and application thereof.The preparation method of the macroporous adsorption resin for sugar decolorization comprises the following steps that water, a dispersing agent and a polymerization inhibitor are mixed, and a water phase is obtained; mixing a monomer, an initiator and a pore-foaming agent to obtain an oil phase; mixing the water phase and the oil phase, standing, shaping, carrying out polymerization reaction, and removing the pore-foaming agent to obtain matrix white balls; the monomer comprises at least one of divinylbenzene, styrene and methyl acrylate; in the oil phase, the mass ratios of the monomer, the initiator and the pore-foaming agent are respectively 36.38%-41.5%, 0.34%-0.45% and 58.05%-63.19%; and mixing the matrix white balls and Lewis acid, and carrying out a post-crosslinking reaction to obtain the macroporous adsorption resin for sugar decoloration. The synthesis process is low in equipment requirement, simple and convenient to operate, low in cost and environment-friendly; and the prepared product has high decolorization rate and can be regenerated.

Description

Technical Field

[0001] The present invention belongs to the technical field of functional resins, and particularly relates to a macroporous adsorption resin for sugar decolorization, its preparation method and application. Background Art

[0002] With the improvement of people's living standards, the requirement level for food has also increased. For example, compared with sucrose or fructose, functional sugars are more inclined to be used as additives to add sweetness to food. Functional sugars mainly include functional oligosaccharides, functional dietary fibers and functional sugar alcohols, which can reduce the impact of sugar in food on special populations.

[0003] A large amount of pigment impurities are easily present in the preparation process of functional sugars. For example, natural pigments such as flavonoids, chlorophyll, lutein, etc. are often removed by methods such as activated carbon adsorption or filtration. However, activated carbon has a high specific surface area and small pore size, and it has a good adsorption effect on small molecule pigments, but a poor adsorption effect on macromolecular natural pigments, and it is easy to fall off during the adsorption process, further causing pollution, and it is not suitable for directly decolorizing functional sugars. Summary of the Invention

[0004] Therefore, the purpose of the present invention is to provide a macroporous adsorption resin for sugar decolorization, its preparation method and application. The macroporous adsorption resin for sugar decolorization has a good effect on removing functional sugar pigments, and the preparation process has less harm.

[0005] For this reason, the present invention provides the following technical solutions.

[0006] The present invention provides a preparation method of a macroporous adsorption resin for sugar decolorization, including the following steps: S1: Mix water, a dispersant and an inhibitor to obtain an aqueous phase; mix a monomer, an initiator and a pore-forming agent to obtain an oil phase; mix the aqueous phase and the oil phase, let it stand, shape, carry out a polymerization reaction, and remove the pore-forming agent to obtain a matrix white ball; the monomer includes at least one of divinylbenzene, styrene, and methyl acrylate; in the oil phase, the mass ratios of the monomer, the initiator and the pore-forming agent are 36.38% - 41.5%, 0.34% - 0.45%, and 58.05% - 63.19% respectively; S2: Mix the matrix white ball and a Lewis acid to carry out a post-crosslinking reaction to obtain a macroporous adsorption resin for sugar decolorization.

[0007] In the preparation method of the macroporous adsorption resin for sugar decolorization provided by the present invention, typically and non-limitingly: first completely dissolve the dispersant in water, and then add the inhibitor. In order to better dissolve the dispersant, the water can also be heated to 45 - 60 °C.

[0008] In the preparation method of the macroporous adsorption resin for sugar decolorization provided by the present invention, a suitable removal method can be selected according to the porogen used, as long as the porogen can be completely removed; typically and non-limitingly, the porogen in the matrix white balls can be removed by washing, including the following steps: boiling the matrix white balls with water, draining the washing liquid by suction, adding methylal to extract the porogen until no large oil flowers appear after adding water, and then washing with water until clean.

[0009] In the preparation method of the macroporous adsorption resin for sugar decolorization provided by the present invention, typically and non-limitingly, when mixing the matrix white balls and the Lewis acid, they can be stirred for 20 - 60 min for sufficient mixing; after the post-crosslinking reaction, it also includes the steps of cooling, pickling, alcohol washing, and water washing, specifically including: washing the obtained macroporous adsorption resin with hydrochloric acid with a pH of 1 - 4 for 2 - 4 times, 15 - 20 min each time, to wash away the Lewis acid, then washing with methanol for 2 - 4 times, 15 - 20 min each time, to wash away the solvent used for swelling, and finally washing with water until neutral, followed by solid-liquid separation.

[0010] Optionally, after the S2, it further includes S3, mixing the macroporous adsorption resin for sugar decolorization and sulfuric acid to carry out a sulfonation reaction to obtain a sulfonated macroporous adsorption resin for sugar decolorization. The sulfonation reaction can connect strong acidic functional groups to the macroporous adsorption resin for sugar decolorization, enhancing the acidic environment inside the internal pores of the macroporous adsorption resin for sugar decolorization, which is more conducive to the removal of pigments. When methyl acrylate is used in the monomer, methyl acrylate can provide weak acid functional groups, thereby providing a weak acidic environment for the internal pores of the macroporous adsorption resin for sugar decolorization. In this case, the step of the sulfonation reaction can be omitted; when methyl acrylate is not used in the monomer, using the sulfonation reaction to provide an acidic environment for the internal pores of the macroporous adsorption resin for sugar decolorization can further improve the removal effect of the macroporous adsorption resin for sugar decolorization on natural pigments.

[0011] In the preparation method of the macroporous adsorption resin for sugar decolorization provided by the present invention, typically and non-limitingly, after the sulfonation reaction, it also includes the steps of water washing, alcohol washing, and water washing, specifically including: after cooling the prepared macroporous adsorption resin for sugar decolorization, slowly adding water for water washing, washing with methanol for 2 - 4 times, 15 - 20 min each time, to wash away the solvent used for swelling, and finally washing with water until neutral, followed by solid-liquid separation.

[0012] Optionally, in the aqueous phase, the mass ratios of water, dispersant, and inhibitor are 94.45% - 99.50%, 0.45% - 5.50%, and 0.0001% - 0.05% respectively.

[0013] Optionally, in the oil phase, the mass ratios of divinylbenzene, styrene, and methyl acrylate are 28.20% - 41.5%, 0 - 5.64%, and 0 - 4.15% respectively.

[0014] Optionally, the mass of the aqueous phase accounts for 65.35% to 72.5% of the sum of the masses of the aqueous phase and the oil phase.

[0015] Optionally, in the step S1, the standing time is 5 to 10 min.

[0016] Optionally, in the step S1, the polymerization reaction includes 2 to 3 heating processes.

[0017] Optionally, in the step S1, the shaping step includes controlling the particle size of the spherical beads by the stirring rate; optionally, the stirring rate is 100 to 250 r / min.

[0018] Optionally, in the step S1, it further includes the step of screening the particle size of the matrix white beads; optionally, the particle size range of the screened matrix white beads is 0.3 to 0.8 mm. Typically and non-limitingly, for example, a 0.315 mm and a 0.8 mm sieve can be used to screen out the matrix white beads with the required particle size.

[0019] Optionally, when the polymerization reaction includes 2 heating processes, the first heating is to raise the temperature to 73 to 78 °C within 15 to 30 min and keep the temperature for 3 to 4 h, and the second heating is to continue to raise the temperature to 80 to 85 °C within 15 to 30 min and keep the temperature for 3 to 4 h; or, when the polymerization reaction includes 3 heating processes, the first heating is to raise the temperature to 73 to 78 °C within 15 to 30 min and keep the temperature for 3 to 4 h, the second heating is to continue to raise the temperature to 80 to 85 °C within 15 to 30 min and keep the temperature for 3 to 4 h, and the third heating is to continue to raise the temperature to 88 to 90 °C within 15 to 30 min and keep the temperature for 4 to 6 h. The appropriate segmented heating process can make the polymerization reaction proceed more fully and further improve the mechanical properties of the obtained macroporous adsorption resin.

[0020] Optionally, in the step S1, after screening the particle size of the matrix white beads, it further includes the step of drying the matrix white beads.

[0021] Optionally, in the step S2, the mass of the Lewis acid accounts for 15% to 20% of the sum of the masses of the matrix white beads and the Lewis acid.

[0022] Optionally, in the step S2, the temperature of the post-crosslinking reaction is 80 to 100 °C and the time is 2 to 12 h.

[0023] Optionally, in the step S2, it further includes the step of drying the obtained macroporous adsorption resin for sugar decolorization.

[0024] Optionally, in step S3, the mass of the macroporous adsorption resin for sugar decolorization accounts for 79.5% - 87.5% of the sum of the mass of the macroporous adsorption resin for sugar decolorization and sulfuric acid; optionally, the mass of the macroporous adsorption resin for sugar decolorization accounts for 79.5% - 82.9% of the sum of the mass of the macroporous adsorption resin for sugar decolorization and sulfuric acid.

[0025] Optionally, in step S3, the mass concentration of sulfuric acid is 93% - 98%.

[0026] Optionally, in step S3, the temperature of the sulfonation reaction is 70 - 85°C and the time is 1 - 3 h; optionally, the temperature of the sulfonation reaction is 80 - 85°C and the time is 1 - 3 h.

[0027] Optionally, after drying the matrix white balls with the screened particle size in step S1, in step S2, before mixing the matrix white balls and the Lewis acid, there is also a step of swelling the matrix white balls; optionally, the swelling step includes mixing the matrix white balls with a solvent and stirring for swelling for 1 - 3 h.

[0028] Optionally, after drying the macroporous adsorption resin for sugar decolorization in step S2, in step S3, before mixing the macroporous adsorption resin for sugar decolorization and sulfuric acid, there is also a step of swelling the macroporous adsorption resin for sugar decolorization; optionally, the swelling step includes mixing the macroporous adsorption resin for sugar decolorization with a solvent and stirring for swelling for 1 - 3 h.

[0029] Optionally, the solvent includes at least one of 1,2 - dichloroethane and nitrobenzene.

[0030] Optionally, the mass - to - volume ratio of the matrix white balls to the solvent is 1 g: 3.7 - 6.4 mL.

[0031] Optionally, the mass - to - volume ratio of the macroporous adsorption resin for sugar decolorization to the solvent is 1 g: 5 - 6.3 mL.

[0032] Optionally, the dispersant includes at least one of sodium chloride, gelatin, and sodium carboxymethylcellulose.

[0033] Optionally, the inhibitor includes methylene blue.

[0034] Optionally, the initiator includes at least one of benzoyl peroxide and azobisisobutyronitrile.

[0035] Optionally, the pore - forming agent includes at least one of toluene, liquid paraffin, methylcyclohexane, and tert - amyl alcohol. Among them, liquid paraffin refers to paraffin oil, also known as liquid paraffin, which is a colorless and odorless mixture obtained from the fractional distillation of crude oil and mainly composed of hydrocarbons such as n - docosane and n - octacosane.

[0036] Optionally, the Lewis acid includes at least one of zinc chloride, ferric chloride, aluminum chloride, and stannic chloride.

[0037] The present invention provides a macroporous adsorption resin for sugar decolorization prepared by the above preparation method; optionally, the average pore diameter of the macroporous adsorption resin for sugar decolorization is 5.3 - 7.4 nm.

[0038] The present invention provides the application of the above macroporous adsorption resin for sugar decolorization in the functional sugar decolorization process; optionally, the functional sugar includes at least one of resistant dextrin, maltose, and xylose.

[0039] The beneficial effects of the present invention are as follows:

[0040] The preparation method of the macroporous adsorption resin for sugar decolorization provided by the present invention includes the following steps: S1: Mix water, a dispersant, and an inhibitor to obtain an aqueous phase; mix a monomer, an initiator, and a pore-forming agent to obtain an oil phase; mix the aqueous phase and the oil phase, let it stand, shape it, carry out a polymerization reaction, and remove the pore-forming agent to obtain a matrix white ball; the monomer includes at least one of divinylbenzene, styrene, and methyl acrylate; in the oil phase, the mass ratios of the monomer, the initiator, and the pore-forming agent are 36.38% - 41.5%, 0.34% - 0.45%, and 58.05% - 63.19% respectively; S2: Mix the matrix white ball and a Lewis acid to carry out a post-crosslinking reaction to obtain a macroporous adsorption resin for sugar decolorization. The equipment requirements for the synthesis process of this preparation method are low, the operation is simple, the cost is low, there is no need for highly toxic operations, and it is environmentally friendly; the macroporous adsorption resin for sugar decolorization prepared has a relatively high decolorization rate, can be regenerated, and can reduce the loss of products in the decolorization process. The dispersant and the inhibitor are used in combination, which can reduce the surface tension of water, make the oil phase easy to disperse into small oil droplets, and can be adsorbed on the surface of the oil droplets to protect them from merging and sticking when they touch each other. Through the post-crosslinking reaction, the specific surface area of the obtained macroporous adsorption resin for sugar decolorization is increased, and its adsorption capacity is increased. The specific oil phase components make the macroporous adsorption resin for sugar decolorization prepared in the present invention have a suitable specific surface area and pore diameter, can better adsorb macromolecular natural pigments; and at the same time have certain mechanical properties, which can support multi-cycle reuse.

[0041] The present invention provides the application of the above macroporous adsorption resin for sugar decolorization in the functional sugar decolorization process. Since pigment substances are usually easily ionized under alkaline conditions, they are more easily adsorbed in acidic solutions. Most of the macromolecular natural pigments in functional sugar production are in an ionized state, and it is best to adsorb them in an acidic environment. The macroporous adsorption resin for sugar decolorization provided by the present invention can provide an acidic environment inside the pores, which is beneficial to the removal of macromolecular natural pigments in functional sugar production. Detailed implementation manners

[0042] The following examples are provided for a better understanding of the present invention, but are not intended to limit the best mode of implementation, nor to limit the content and protection scope of the present invention. Any product identical or similar to the present invention obtained by anyone under the inspiration of the present invention or by combining the features of the present invention with other prior arts shall fall within the protection scope of the present invention.

[0043] If no specific experimental steps or conditions are specified in the examples, the conventional experimental steps or conditions described in the literature in the field can be used. If no manufacturer is specified for the reagents or instruments used, they are all conventional reagent products that can be obtained commercially.

[0044] Experimental drugs:

[0045] Divinylbenzene (purity 80%) and styrene were purchased from Shanghai MacLean Biochemical Technology.

[0046] Toluene and liquid wax were purchased from Tianjin Damao Chemical.

[0047] Zinc chloride, ferric chloride, aluminum chloride: purchased from Aladdin.

[0048] Methyl acrylate, methylcyclohexane, sulfuric acid, and tert-amyl alcohol were purchased from Sinopharm Reagent.

[0049] Benzoyl peroxide and azobisisobutyronitrile were purchased from Maclean.

[0050] Example 1

[0051] This embodiment provides a macroporous adsorption resin for sugar decolorization and a preparation method thereof, comprising the following steps:

[0052] (1) Add 1.5 g of gelatin and 1.5 g of sodium carboxymethyl cellulose to 500 g of water, heat to 55° C., add 25 g of sodium chloride and 3 ml of methylene blue (mass concentration of 1‰, the same below) after complete dissolution to obtain an aqueous phase; fully mix 75 g of divinylbenzene (80%), 0.75 g of azobisisobutyronitrile, 100 g of toluene, and 30 g of liquid wax to obtain an oil phase, add the oil phase to the aqueous phase, let stand for 5 min, adjust the stirring rate at any time according to the material conditions, and maintain it between 130 and 230 r / min as a whole, so that the particle size of the obtained sphere is visually observed to be between 0.3 and 1 mm, and then carry out a polymerization reaction, gradually heat to 78° C. within 30 min and keep warm for 4 h, then heat to 85° C. for 30 min and keep warm for 4 h, continue to heat to 90° C. for 30 min and keep warm for 4 h, and then cool to obtain a matrix white sphere. Boil the base white ball with water, drain the water washing liquid, add methylal to extract the porogen, add until no large pieces of oil appear after adding water, wash with water, and then screen to obtain the spheres with a particle size of 0.315-0.8mm, and dry.

[0053] (2) Take 35 g of the dried matrix white balls obtained in (1), add 130 ml of 1,2-dichloroethane, stir and swell at room temperature for 2 h, add 7 g of anhydrous aluminum trichloride, stir for 30 min, then raise the temperature to 80 °C in the next 30 min, and keep the temperature for 2 h for post-crosslinking reaction; cool down, wash twice with hydrochloric acid with a pH of 1 for 20 min each time to wash away the aluminum trichloride, wash three times with methanol for 20 min each time to wash away 1,2-dichloroethane, and finally wash with water until neutral, separate the solid and liquid to obtain the macroporous adsorption resin, and dry it.

[0054] (3) Take 35 g of the macroporous adsorption resin obtained in (2), add 220 ml of 1,2-dichloroethane, stir and swell at room temperature for 2 h, then slowly add 5 ml of 98 wt.% sulfuric acid, raise the temperature to 80 °C in 30 min, and keep the temperature for 2 h for sulfonation reaction; cool down, slowly add water for water washing, then wash three times with methanol for 20 min each time to wash away 1,2-dichloroethane, and finally wash with water until neutral, separate the solid and liquid to obtain the sulfonated macroporous adsorption resin for sugar decolorization.

[0055] Example 2

[0056] This example provides a macroporous adsorption resin for sugar decolorization and its preparation method, including the following steps:

[0057] (1) Add 3.5 g of gelatin to 500 g of water, raise the temperature to 55 °C, and after complete dissolution, add 3 ml of methylene blue to obtain the aqueous phase; mix 75 g of divinylbenzene (80%), 10 g of methyl acrylate, 15 g of styrene, 1 g of dibenzoyl peroxide, 90 g of toluene, 35 g of tert-amyl alcohol, and 40 g of methylcyclohexane thoroughly to obtain the oil phase, add the oil phase to the aqueous phase, let it stand for 5 min, adjust the stirring rate at any time according to the material situation, and keep it between 130 and 230 r / min as a whole, so that the obtained sphere diameter is visually between 0.3 and 1 mm, then carry out the polymerization reaction, gradually raise the temperature to 78 °C in 30 min and keep the temperature for 4 h, raise the temperature to 85 °C in the next 30 min and keep the temperature for 4 h, continue to raise the temperature to 90 °C in 30 min and keep the temperature for 4 h, and then cool down to obtain the matrix white balls. Boil the matrix white balls with water to remove the pore-forming agents toluene, tert-amyl alcohol, and methylcyclohexane, drain the washing liquid, and wash with water until clean. Then screen to obtain spheres with a particle size within 0.315 - 0.8 mm, and dry them.

[0058] (2) Take 65 g of the dried matrix white balls obtained in (1), add 325 ml of nitrobenzene, stir and swell at room temperature for 2 h, add 13 g of ferric chloride, stir for 30 min, then raise the temperature to 100 °C in the next 30 min, and keep the temperature for 8 h for post-crosslinking reaction; cool down, wash twice with hydrochloric acid with a pH of 1 for 20 min each time to wash away the ferric chloride, wash three times with methanol for 20 min each time to wash away the nitrobenzene, and finally wash with water until neutral, separate the solid and liquid to obtain the macroporous adsorption resin for sugar decolorization.

[0059] Example 3

[0060] This embodiment provides a macroporous adsorption resin for sugar decolorization and a preparation method thereof, comprising the following steps:

[0061] (1) Add 2g gelatin and 2g sodium carboxymethyl cellulose to 500g water, heat to 55°C, add 3ml methylene blue after it is completely dissolved to obtain an aqueous phase; 80g divinylbenzene (80%), 10g methyl acrylate, 10g styrene, 1g dibenzoyl peroxide, 90g toluene, and 50g tert-amyl alcohol, mix thoroughly to obtain an oil phase, add the oil phase to the aqueous phase, let stand for 10min, adjust the stirring rate at any time according to the material conditions, and maintain it between 130 and 230r / min as a whole, so that the particle size of the obtained ball is between 0.3 and 1mm by visual observation, and then carry out polymerization reaction, gradually heat to 78°C within 30min and keep it warm for 4h, then heat to 85°C for 30min and keep it warm for 4h, and then cool to obtain a base white ball. Add water to the base white ball and boil it to remove the porogen toluene and tert-amyl alcohol, drain the water washing liquid, and wash with water. After screening, spheres with a particle size of 0.315 to 0.8 mm are obtained and dried.

[0062] (2) Take 40 g of the dried white ball obtained in (1), add 255 ml of 1,2-dichloroethane and stir to swell at room temperature for 2 h, add 8 g of zinc chloride and stir for 30 min, then heat to 80°C for 30 min and keep warm for 12 h to perform post-crosslinking reaction; cool, wash twice with hydrochloric acid at pH 4 for 20 min each time to wash away the zinc chloride, wash three times with methanol for 20 min each time to wash away the 1,2-dichloroethane, and finally wash with water until neutral, separate the solid and liquid, and obtain a macroporous adsorption resin for sugar decolorization.

[0063] Example 4

[0064] This embodiment provides a macroporous adsorption resin for sugar decolorization and a preparation method thereof, comprising the following steps:

[0065] (1) Add 1.5 g of gelatin and 1.5 g of sodium carboxymethyl cellulose to 500 g of water, heat to 55° C., add 25 g of sodium chloride and 3 ml of methylene blue after complete dissolution to obtain an aqueous phase; fully mix 75 g of divinylbenzene (80%), 0.75 g of azobisisobutyronitrile, 100 g of toluene, and 30 g of liquid wax to obtain an oil phase, add the oil phase to the aqueous phase, let stand for 10 min, adjust the stirring rate at any time according to the material conditions, and maintain it between 130 and 230 r / min as a whole, so that the particle size of the obtained sphere is visually observed to be between 0.3 and 1 mm, and then carry out a polymerization reaction, gradually heat to 73° C. within 15 min and keep warm for 4 h, then heat to 80° C. for 15 min and keep warm for 4 h, continue to heat to 88° C. for 15 min and keep warm for 6 h, and then cool to obtain a matrix white sphere. Boil the base white ball with water, drain the water washing liquid, add methylal to extract the porogen, add until no large pieces of oil appear after adding water, wash with water, and then screen to obtain the spheres with a particle size of 0.315-0.8mm, and dry.

[0066] (2) Take 35 g of the dried white ball of the matrix obtained in (1), add 130 ml of 1,2-dichloroethane, stir and swell at room temperature for 3 h, add 8.7 g of anhydrous aluminum chloride, stir for 30 min, then heat to 80°C for 30 min and keep warm for 12 h to carry out post-crosslinking reaction; cool down, wash twice with hydrochloric acid at pH 1, each time for 20 min to wash away the aluminum chloride, wash three times with methanol, each time for 20 min to wash away the 1,2-dichloroethane, and finally wash with water until neutral, separate the solid and liquid to obtain a macroporous adsorption resin, and dry it.

[0067] (3) Take 35 g of the macroporous adsorption resin obtained in (2), add 220 ml of 1,2-dichloroethane, stir and swell at room temperature for 1 hour, then slowly add 5 ml of 98wt.% concentrated sulfuric acid, raise the temperature to 80°C for 30 minutes, and keep it at this temperature for 3 hours to carry out sulfonation reaction; cool down, slowly add water, wash with water, then wash with methanol 3 times, each time for 20 minutes to wash away 1,2-dichloroethane, and finally wash with water until neutral, separate the solid and liquid, and obtain the sulfonated macroporous adsorption resin for sugar decolorization.

[0068] Example 5

[0069] This embodiment provides a macroporous adsorption resin for sugar decolorization and a preparation method thereof, comprising the following steps:

[0070] (1) Add 1.5 g of gelatin and 1.5 g of sodium carboxymethyl cellulose to 500 g of water, heat it to 55° C., add 25 g of sodium chloride and 3 ml of methylene blue after it is completely dissolved to obtain an aqueous phase; fully mix 75 g of divinylbenzene (80%), 0.75 g of azobisisobutyronitrile, 100 g of toluene, and 30 g of liquid wax to obtain an oil phase, add the oil phase to the aqueous phase, let it stand for 10 min, adjust the stirring rate at any time according to the material conditions, and maintain it between 130 and 230 r / min as a whole, so that the particle size of the obtained sphere is visually observed to be between 0.3 and 1 mm, and then carry out a polymerization reaction, gradually heat it to 78° C. within 30 min and keep it warm for 3 h, then heat it to 85° C. for 30 min and keep it warm for 3 h, continue to heat it to 90° C. for 30 min and keep it warm for 4 h, and then cool it to obtain a matrix white sphere. Boil the base white ball with water, drain the water washing liquid, add methylal to extract the porogen, add until no large pieces of oil appear after adding water, wash with water, and then screen to obtain the spheres with a particle size of 0.315-0.8mm, and dry.

[0071] (2) Take 35 g of the dried white ball of the matrix obtained in (1), add 220 ml of 1,2-dichloroethane, stir and swell at room temperature for 1 h, add 6.2 g of anhydrous zinc chloride, stir for 30 min, then heat to 100°C for 30 min and keep warm for 2 h to carry out post-crosslinking reaction; cool down, wash twice with hydrochloric acid of pH 1, each time for 20 min to wash away the zinc chloride, wash three times with methanol, each time for 20 min to wash away the 1,2-dichloroethane, and finally wash with water until neutral, separate the solid and liquid to obtain a macroporous adsorption resin, and dry it.

[0072] (3) Take 41 g of the macroporous adsorption resin obtained in (2), add 210 ml of 1,2-dichloroethane, stir and swell at room temperature for 3 h, then slowly add 5 ml of 93 wt.% concentrated sulfuric acid, raise the temperature to 85°C for 30 min, and keep it at this temperature for 1 h to carry out sulfonation reaction; cool down, slowly add water, wash with water, then wash with methanol 3 times, each time for 20 min to wash away 1,2-dichloroethane, and finally wash with water until neutral, separate the solid and liquid, and obtain the sulfonated macroporous adsorption resin for sugar decolorization.

[0073] Example 6

[0074] This embodiment provides a macroporous adsorption resin for sugar decolorization and a preparation method thereof, comprising the following steps:

[0075] (1) Add 1.5 g of gelatin and 1.5 g of sodium carboxymethyl cellulose to 500 g of water, heat it to 55° C., add 25 g of sodium chloride and 3 ml of methylene blue after it is completely dissolved to obtain an aqueous phase; fully mix 75 g of divinylbenzene (80%), 0.75 g of azobisisobutyronitrile, 100 g of toluene, and 30 g of liquid wax to obtain an oil phase, add the oil phase to the aqueous phase, let it stand for 10 min, adjust the stirring rate at any time according to the material conditions, and maintain it between 130 and 230 r / min as a whole, so that the particle size of the obtained sphere is visually observed to be between 0.3 and 1 mm, and then carry out a polymerization reaction, gradually heat it to 78° C. within 30 min and keep it warm for 3 h, then heat it to 85° C. for 30 min and keep it warm for 3 h, continue to heat it to 90° C. for 30 min and keep it warm for 4 h, and then cool it to obtain a matrix white sphere. Boil the base white ball with water, drain the water washing liquid, add methylal to extract the porogen, add until no large pieces of oil appear after adding water, wash with water, and then screen to obtain the spheres with a particle size of 0.315-0.8mm, and dry.

[0076] (2) Take 35 g of the dried white ball of the matrix obtained in (1), add 220 ml of 1,2-dichloroethane, stir and swell at room temperature for 1 h, add 6.2 g of anhydrous zinc chloride, stir for 30 min, then heat to 100°C for 30 min and keep warm for 2 h to carry out post-crosslinking reaction; cool down, wash twice with hydrochloric acid of pH 1, each time for 20 min to wash away the zinc chloride, wash three times with methanol, each time for 20 min to wash away the 1,2-dichloroethane, and finally wash with water until neutral, separate the solid and liquid to obtain a macroporous adsorption resin, and dry it.

[0077] (3) Take 59 g of the macroporous adsorption resin obtained in (2), add 210 ml of 1,2-dichloroethane, stir and swell at room temperature for 3 h, then slowly add 5 ml of 93 wt.% concentrated sulfuric acid, raise the temperature to 70°C for 30 min, and keep it at this temperature for 3 h to carry out sulfonation reaction; cool down, slowly add water, wash with water, then wash with methanol 3 times, each time for 20 min to wash away 1,2-dichloroethane, and finally wash with water until neutral, separate the solid and liquid, and obtain the sulfonated macroporous adsorption resin for sugar decolorization.

[0078] Example 7

[0079] This embodiment provides a macroporous adsorption resin for sugar decolorization and a preparation method thereof, comprising the following steps:

[0080] (1) Add 2 g of gelatin and 1 g of sodium carboxymethylcellulose to 540 g of water, heat up to 55 °C, and after complete dissolution, add 3 ml of methylene blue to obtain the aqueous phase; mix 82 g of divinylbenzene (80%), 11 g of methyl acrylate, 12 g of styrene, 1 g of benzoyl peroxide, 90 g of toluene, and 90 g of tert-amyl alcohol thoroughly to obtain the oil phase. Add the oil phase to the aqueous phase, let it stand for 5 min, and adjust the stirring rate according to the material situation at any time, maintaining it between 130 and 230 r / min overall, so that the obtained sphere diameter is visually between 0.3 and 1 mm. Then carry out the polymerization reaction, gradually heat up to 73 °C within 15 min and keep it warm for 4 h, then heat up to 80 °C within 15 min and keep it warm for 4 h, and then cool down to obtain the matrix white balls. Boil the matrix white balls with water to remove the porogenic agents toluene and tert-amyl alcohol, drain the washing liquid by suction, and wash it with water until clean. Then sieve to obtain spheres with a diameter within 0.315 - 0.8 mm and dry them.

[0081] (2) Take 32 g of the dried matrix white balls obtained in (1), add 150 ml of 1,2-dichloroethane, stir and swell at room temperature for 3 h, add 8 g of stannic chloride, stir for 30 min, then heat up to 100 °C within 30 min, and keep it warm for 2 h for the post-crosslinking reaction; cool down, wash with hydrochloric acid with a pH of 4 twice, 20 min each time, to wash away stannic chloride, wash with methanol three times, 20 min each time, to wash away 1,2-dichloroethane, and finally wash with water until neutral, separate the solid and liquid to obtain the macroporous adsorption resin for sugar decolorization.

[0082] Comparative Example 1

[0083] This comparative example provides a macroporous adsorption resin for sugar decolorization and its preparation method. Compared with Example 3, the only difference is that in the oil phase of step (1), there are 90 g of divinylbenzene (80%), 10 g of methyl acrylate, 10 g of styrene, 1 g of benzoyl peroxide, 80 g of toluene, and 50 g of tert-amyl alcohol.

[0084] Comparative Example 2

[0085] This comparative example provides a macroporous adsorption resin for sugar decolorization and its preparation method. Compared with Example 2, the only difference is that in the oil phase of step (1), there are 75 g of divinylbenzene (80%), 5 g of methyl acrylate, 10 g of styrene, 1 g of benzoyl peroxide, 90 g of toluene, 40 g of tert-amyl alcohol, and 45 g of methylcyclohexane.

[0086] Comparative Example 3

[0087] This comparative example provides a macroporous adsorption resin for sugar decolorization and its preparation method. Compared with Example 6, the only difference is that in the oil phase of step (1), there are 65 g of divinylbenzene (80%), 0.5 g of azobisisobutyronitrile, 100 g of toluene, and 40 g of liquid paraffin.

[0088] Comparative Example 4

[0089] This comparative example provides a macroporous adsorption resin for sugar decolorization and its preparation method. Compared with Example 6, the only difference is that the aqueous phase in step (1) is: 1.5 g of gelatin and 1.5 g of sodium carboxymethylcellulose are added to 500 g of water, heated to 55 °C, and after complete dissolution, 25 g of sodium chloride is added to obtain the aqueous phase.

[0090] Test Example 1

[0091] Self-made resistant dextrin was used for testing. The preparation method of the resistant dextrin is as follows: Hydrochloric acid was added to corn starch at a mass ratio of 6% and gelatinized at 160 °C for 3 hours. After the reaction, hydrolysis was carried out at pH = 3 and 90 °C for 2 hours to obtain a fluid with a concentration of about 75%. After dilution with water to a concentration of 50%, it was reserved. At this time, the resistant dextrin slurry was a bright orange transparent liquid, and the pigments were mainly carotenoids and lutein.

[0092] 50 mL of the final products prepared in each example and comparative example, as well as the competing product resin (D941, purchased from Piaoyi Pure Resin (Shanghai) Co., Ltd.), were respectively placed in the same filling column. The outer diameter of the filling column was 25 mm, the inner diameter was 20 mm, and the length was 300 mm. The above-mentioned reserved resistant dextrin slurry was passed through at a flow rate of 1 BV / h. The light transmittance and product concentration were detected according to the standard T / GDL 1-2019, as shown in Tables 1-3.

[0093] Table 1

[0094]

[0095] Table 2

[0096]

[0097]

[0098] Table 3

[0099]

[0100] As can be seen from Tables 1 to 3, at the outlet of 4BV, after the sugar concentration stabilizes, the light transmittance of the final product provided in the embodiments of the present invention is above 65%, which is higher than that of the competing resins and the final products provided in the comparative examples. The macroporous adsorption resin for sugar decolorization provided in the embodiments of the present invention has a good decolorization effect. Moreover, in Examples 1, 2, and 4, while improving the decolorization effect, the sugar concentration can still be maintained at 50%. In Examples 3, 5, 6, and 7, while achieving a significant improvement in the decolorization effect, the sugar concentration only decreases slightly. The light transmittance of the competing resin is only 62.9%, and the highest light transmittance in the comparative examples is only 55.2%, and the sugar concentration in the comparative examples is relatively low. Therefore, the products prepared without using the raw materials and ratios provided in the present invention do not have a good functional sugar decolorization effect.

[0101] Test Example 2

[0102] Take the resistant dextrin slurry prepared in Test Example 1, fill Example 1 and the competing product into the packed column with the same specifications as in Test Example 1, connect Example 1 and the competing product in series with two columns at a flow rate of 2BV / h, and conduct tests for two cycles. The specific regeneration method is as follows: after the adsorption is completed, the remaining liquid in the column is discharged until it is flush with the upper surface of the absorbent cotton pressed above the same resin column; pass 2BV of pure water through the column at a flow rate of 2BV / h to wash away the remaining liquid (if the product concentration at one end of this part of the liquid is greater than 5%, this part of the liquid can be considered to be returned to the front-end inlet); desorb with 3BV of 4% sodium hydroxide aqueous solution at a flow rate of 1BV / h, and then pass 1BV of pure water through the column at a flow rate of 20BV / h after completion; regenerate with 2BV of 2% dilute hydrochloric acid at a flow rate of 1BV / h, and after completion, wash with water at a flow rate of 2BV / h until the pH is greater than 5 (the water consumption at this flow rate is 4BV), and then it can be used in the next cycle. The light transmittance, absorbance and product concentration are detected according to the standard T / GDL 1-2019, as shown in Tables 4 and 5.

[0103] Table 4

[0104]

[0105] Table 5

[0106]

[0107]

[0108] As shown in Tables 4 and 5, from the overall effect of the two cycles, the macroporous adsorption resin for sugar decolorization provided by the present invention has a better sugar decolorization effect than the decolorization resins on the market, a higher decolorization rate, can be regenerated, has less sugar concentration loss, and can achieve efficient separation of pigments in resistant dextrin.

[0109] Test Example 3

[0110] Refer to GB / T 19587-2017 "Determination of Specific Surface Area of Solid Materials by Gas Adsorption BET Method" to conduct BET detection on the final products obtained in Examples 1 to 3, measure their specific surface areas, and further calculate their average pore diameters based on the BET results. The obtained results are shown in Table 6. It can be seen that the macroporous adsorption resin in the present invention has a large specific surface area and appropriate pore diameters.

[0111] Table 6

[0112] Sample <![CDATA[Specific surface area (m 2 / g)]]> Average pore size (nm) Example 1 748.2 6.7 Example 2 714.3 7.3 Example 3 839.5 6.8

[0113] Obviously, the above examples are only for clear illustration and not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or variations can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. And the obvious changes or variations derived therefrom are still within the protection scope of the present invention.

Claims

1. A preparation method of a macroporous adsorption resin for sugar decolorization, characterized in that, It includes the following steps: S1: Mix water, a dispersant, and an inhibitor to obtain an aqueous phase; mix a monomer, an initiator, and a pore-forming agent to obtain an oil phase; mix the aqueous phase and the oil phase, let it stand, shape it, carry out a polymerization reaction, and remove the pore-forming agent to obtain a matrix white ball; The monomer includes at least one of divinylbenzene, styrene, and methyl acrylate; In the oil phase, the mass ratios of the monomer, the initiator, and the pore-forming agent are 36.38% - 41.5%, 0.34% - 0.45%, and 58.05% - 63.19% respectively; S2: Mix the matrix white ball and a Lewis acid to carry out a post-crosslinking reaction to obtain a macroporous adsorption resin for sugar decolorization.

2. The preparation method according to claim 1, characterized in that, After S2, there is also S3, where the macroporous adsorption resin for sugar decolorization and sulfuric acid are mixed to carry out a sulfonation reaction to obtain a sulfonated macroporous adsorption resin for sugar decolorization.

3. The preparation method according to claim 1 or 2, characterized in that, In the aqueous phase, the mass ratios of water, the dispersant, and the inhibitor are 94.45% - 99.50%, 0.45% - 5.50%, and 0.0001% - 0.05% respectively; And / or, in the oil phase, the mass ratios of divinylbenzene, styrene, and methyl acrylate are 28.20% - 41.5%, 0 - 5.64%, and 0 - 4.15% respectively; And / or, the mass of the aqueous phase accounts for 65.35% - 72.5% of the sum of the masses of the aqueous phase and the oil phase; And / or, in S1, the standing time is 5 - 10 min; And / or, in S1, the polymerization reaction includes 2 - 3 heating processes; And / or, in S1, the shaping step includes controlling the sphere diameter by the stirring rate; optionally, the stirring rate is 100 - 250 r / min; And / or, in S1, there is also a step of screening the particle size of the matrix white ball; optionally, the screened particle size range of the matrix white ball is 0.3 - 0.8 mm.

4. The preparation method according to claim 3, wherein, When the polymerization reaction includes 2 heating processes, the first heating is to raise the temperature to 73 - 78 °C within 15 - 30 min and keep it warm for 3 - 4 h, and the second heating is to continue raising the temperature to 80 - 85 °C within 15 - 30 min and keep it warm for 3 - 4 h; Or, when the polymerization reaction includes 3 heating processes, the first heating is to raise the temperature to 73 - 78 °C within 15 - 30 min and keep it warm for 3 - 4 h, the second heating is to continue raising the temperature to 80 - 85 °C within 15 - 30 min and keep it warm for 3 - 4 h, and the third heating is to continue raising the temperature to 88 - 90 °C within 15 - 30 min and keep it warm for 4 - 6 h; And / or, in S1, after screening the particle size of the matrix white ball, there is also a step of drying the matrix white ball; And / or, in S2, the mass of the Lewis acid accounts for 15% - 20% of the sum of the masses of the matrix white ball and the Lewis acid; And / or, in S2, the temperature of the post-crosslinking reaction is 80 - 100 °C and the time is 2 - 12 h; And / or, in S2, there is also a step of drying the obtained macroporous adsorption resin for sugar decolorization.

5. The preparation method according to any one of claims 2 to 4, characterized in that, In S3, the mass of the macroporous adsorption resin for sugar decolorization accounts for 79.5% - 87.5% of the sum of the mass of the macroporous adsorption resin for sugar decolorization and sulfuric acid; optionally, the mass of the macroporous adsorption resin for sugar decolorization accounts for 79.5% - 82.9% of the sum of the mass of the macroporous adsorption resin for sugar decolorization and sulfuric acid; and / or, in S3, the mass concentration of sulfuric acid is 93% - 98%; and / or, in S3, the temperature of the sulfonation reaction is 70 - 85 °C, and the time is 1 - 3 h; optionally, the temperature of the sulfonation reaction is 80 - 85 °C, and the time is 1 - 3 h.

6. The preparation method according to claim 5, characterized in that, After drying the matrix white balls with the selected particle size in S1, in S2, before mixing the matrix white balls and the Lewis acid, there is also a step of swelling the matrix white balls; optionally, the swelling step includes mixing the matrix white balls with a solvent and stirring for swelling for 1 - 3 h; and / or, after drying the macroporous adsorption resin for sugar decolorization in S2, in S3, before mixing the macroporous adsorption resin for sugar decolorization and sulfuric acid, there is also a step of swelling the macroporous adsorption resin for sugar decolorization; optionally, the swelling step includes mixing the macroporous adsorption resin for sugar decolorization with a solvent and stirring for swelling for 1 - 3 h.

7. The preparation method according to claim 6, characterized in that, The solvent includes at least one of 1,2-dichloroethane and nitrobenzene; and / or, the mass-to-volume ratio of the matrix white balls to the solvent is 1 g : 3.7 - 6.4 mL; and / or, the mass-to-volume ratio of the macroporous adsorption resin for sugar decolorization to the solvent is 1 g : 5 - 6.3 mL.

8. The preparation method according to any one of claims 1 to 7, characterized in that, The dispersant includes at least one of sodium chloride, gelatin, and sodium carboxymethylcellulose; and / or, the inhibitor includes methylene blue; and / or, the initiator includes at least one of benzoyl peroxide and azobisisobutyronitrile; and / or, the pore-forming agent includes at least one of toluene, liquid paraffin, methylcyclohexane, and tert-amyl alcohol; and / or, the Lewis acid includes at least one of zinc chloride, ferric trichloride, aluminum trichloride, and tin tetrachloride.

9. A macroporous adsorption resin for sugar decolorization prepared by the preparation method according to any one of claims 1 to 8; optionally, the average pore diameter of the macroporous adsorption resin for sugar decolorization is 5.3 - 7.4 nm.

10. An application of the macroporous adsorption resin for sugar decolorization according to claim 9 in the functional sugar decolorization process; optionally, the functional sugar includes at least one of resistant dextrin, maltose, and xylose.

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