CN113214531B - Hydrophobic/hydrophilic interpenetrating network resin and preparation and application thereof - Google Patents

Abstract

The invention discloses a method for refining and decoloring xylose mother liquor by utilizing hydrophobic/hydrophilic interpenetrating network resin, which comprises the following steps: (1) adding the oil phase mixture into the water phase to prepare macroporous resin; (2) swelling the prepared macroporous resin, putting the swollen macroporous resin into a polyvinyl alcohol solution, reacting, washing with water, extracting a pore-forming agent, and drying to obtain the double-hydrophobic interpenetrating network resin; (3) and (3) adding a trimethylamine hydrochloride solution into the interpenetrating network resin prepared in the step (2) to carry out amination reaction, and washing with water to neutrality after leaching to obtain the hydrophobic/hydrophilic type interpenetrating network resin. The hydrophobic/hydrophilic interpenetrating network resin prepared by the invention has stable adsorption performance, decolouring rate of xylose mother liquor of more than 97 percent, strong selectivity, reducing sugar retention rate of more than 99 percent, simple operation, good effect and low cost.

Description

A kind of hydrophobic/hydrophilic interpenetrating network resin and its preparation and application

technical field

The invention relates to the technical field of resin preparation, in particular to a hydrophobic/hydrophilic interpenetrating network resin and its preparation and application.

Background technique

Functional sugar has the functions of low calorie, can provide nutrition, promote the improvement of physiological function, and improve human immunity. It is mainly represented by functional sugar alcohol, functional dietary fiber and functional oligosaccharide. Among the functional sugar alcohols, xylitol is the most representative substance, which is generally prepared by catalytic hydrogenation of xylose in industry. The biomass used to produce reduced xylose includes straw agricultural and forestry wastes, core-shell agricultural and forestry wastes, and agricultural and forestry stems and tubers, among which straw agricultural and forestry wastes account for the largest proportion.

The xylose hydrolyzate is obtained by dilute acid hydrolysis or enzymatic hydrolysis of agricultural and forestry waste, and then xylose is produced by refining, concentration and crystallization. During this process, a large amount of remaining dark brown viscous liquid, namely xylose mother liquor, will be produced. If calculated by mass fraction, the xylose mother liquor contains 40% to 52% of xylose, 25% to 32% of arabinose, 10% to 18% of glucose, 10% to 16% of galactose and 3% to 32% of impurities. 7%. Because the xylose mother liquor contains a large amount of reducing monosaccharides and the color is darker, the xylose contained cannot be crystallized or separated and recovered by chromatography. It can only be sold to caramel color enterprises at the price of 10% of the crystalline xylose, which greatly reduces the production of xylose. economic benefits. In view of this, effectively removing the color source in the xylose mother liquor, fully recovering the reduced monosaccharide components in the mother liquor, and improving the production efficiency of xylose are the issues that the functional sugar industry must pay attention to.

Pigment in xylose mother liquor can be removed by activated carbon adsorption, membrane separation, ion exchange resin and other methods.

Activated carbon is a highly aromatized carbonaceous material with well-developed internal pore structure and large specific surface area, which can effectively and selectively eliminate inhibitors in the hydrolyzate. It will not affect the concentration of sugar liquid in the downstream section, and is an important decolorizing agent in the field of sugar production at home and abroad. CN107893132A discloses a production method and device for xylose, which uses lignocellulose such as corn cob and bagasse as raw materials to obtain xylose hydrolyzed liquid through acid hydrolysis, decolorized by activated carbon, and then passes through chromatographic and nanofiltration membrane to carry out the second phase of the hydrolyzed liquid. Secondary removal of impurities and decolorization. However, the process is relatively complicated, and after the hydrolyzate is decolorized by activated carbon, it needs to be purified twice by a nanofiltration membrane.

Membrane separation based on pore size sieving mechanism is a new application of decolorization and purification of sugar liquid. Under the action of driving force (such as pressure difference, concentration difference, potential difference), some substances pass through the membrane layer, and some substances are trapped to realize the composition. Recovery or feed liquid concentration. This technology avoids the consumption of acid or activated carbon in the decolorization process, and avoids a large amount of phase transition energy in the evaporative concentration process during the concentration process. CN111440903A discloses a process and system for using corncob to produce xylose products. The pretreated xylose hydrolyzate is subjected to continuous chromatographic separation and reverse osmosis concentration treatment, and then sent to nanofiltration membrane equipment for decolorization and degumming treatment. The obtained sugar Liquid transmittance is 65% to 75%. Although the method and the device used in the method can effectively remove acid, there are many processes and complicated operations, and the pigments and sugar components cannot be removed well.

Ion exchange resin is a synthetic spherical polymer with certain exchangeable functional groups on its surface; when its surface is in contact with a solution, due to the action of surface energy, the solute aggregates on the solid-liquid surface to generate adsorption It has the advantages of stable mechanical strength, dual effects of ion exchange and adsorption, and good regeneration performance. It is the mainstream method of refining and decolorization in the field of sugar production. The ion exchange resin has a suitable pore size and appropriate functional groups, and can remove the colored substances by chemical adsorption and physical adsorption (such as hydrophobic interaction, π-π stacking, etc.) with the pigment in the sugar solution. At the same time, the ion exchange resin can also adsorb other impurities (such as salts, organic acids, etc.), so that the purity of the sugar solution after decolorization is improved.

CN 103614435 A discloses a method for preparing xylo-oligosaccharide from bagasse, wherein a crude xylan solution is obtained by enzymatic hydrolysis, and a purified sugar solution is obtained through a decolorization and desalination system in which an activated carbon column and an anion and cation exchange column are connected in series. However, the method requires a series of activated carbon columns, which has the problem of solid waste treatment, and the problem of sugar loss in desalination and decolorization is not studied, and the performance degradation of the regenerated resin is not given.

To sum up, although the conventional decolorization and purification methods can effectively remove pigments, inorganic ions, etc., they have obvious shortcomings, such as low decolorization rate, poor selectivity, high sugar loss rate, decolorizing agent, etc. As artificially designed and tunable ion exchange resins, they have always been regarded as the most potential decolorizing media, but the key issue is the adsorption capacity of specific compounds. The pigment in the xylose mother liquor has both a hydrophilic part and a hydrophobic structure. The commonly used decolorizing resin has a single structure, low adsorption capacity and poor selectivity for pigment. Therefore, the design and synthesis of xylose mother liquor decolorization resin with high adsorption capacity and strong selectivity is the focus of research in this field.

SUMMARY OF THE INVENTION

In view of the deficiencies of the prior art, the present invention provides a hydrophobic/hydrophilic interpenetrating network resin and its preparation and application. The hydrophobic/hydrophilic type interpenetrating network resin prepared by the invention has stable adsorption performance, decolorization rate to xylose mother liquor can reach more than 97%, strong selectivity, retention rate of reducing sugar is more than 99%, simple operation, good effect, low cost.

The technical scheme of the present invention is as follows:

A preparation method of sparse/hydrophilic interpenetrating network resin, the preparation method comprises the steps:

(1) adding the oil phase mixture to the water phase to carry out suspension polymerization, after washing with water, extracting the porogen, and drying to obtain a macroporous resin;

(2) After swelling the macroporous resin prepared in step (1), put it into a polyvinyl alcohol solution, and heat up to 80-90° C. while stirring, after the reaction, wash with water, extract the porogen, and dry to obtain a double-hydrophobic type Interpenetrating network resin;

(3) adding trimethylamine hydrochloride solution to the double-hydrophobic interpenetrating network resin prepared in step (2) to carry out amination reaction, then rinsed with HCl solution, washed with water until neutral, and finally rinsed with NaOH solution, washed with water To neutrality, a sparse/hydrophilic interpenetrating network resin is obtained.

Further, in step (1), the mass ratio of the oil phase mixture to the water phase is (0.5-1):(2-3).

Further, in step (1), the oil phase mixture is composed of monomer, porogen and initiator, and the mass ratio of monomer, porogen and initiator is 1:(2～3):(0.005～ 0.02).

Further, the monomer is divinylbenzene; the porogen is composed of toluene, xylene and n-heptane, and the mass ratio of toluene, xylene and n-heptane is (1-3): (1-3) : 1; the initiator is dibenzoyl peroxide.

Further, in step (1), the water phase is composed of polyvinyl alcohol and NaCl solution, the mass concentration of polyvinyl alcohol in the water phase is 0.5-2%; the mass concentration of NaCl in the water phase is 2-5%.

Further, in step (1), the suspension polymerization method is as follows: adding the oil phase mixture to the water phase according to the mass ratio, while stirring at 140-170 r/min, the temperature is raised to 90-98 ℃ at 20-30 ℃/h Then, the reaction is performed at a constant temperature for 5 to 8 hours; the water washing is to use water at 70 to 80° C. for 2 to 5 times.

Further, in step (1) and step (2), the extraction of the porogen is carried out in a Soxhlet extractor, and the reagent used is one or more of acetone and petroleum ether; the drying temperature is 40 ℃ ～60℃, drying time is 10～15h.

Further, in step (2), the reagent used for the swelling is composed of a porogen and a monomer; the mass ratio of the porogen to the monomer is (1.5-3):1, and the monomer is composed of glycidyl methacrylate ester and triallyl isocyanurate, the mass ratio of glycidyl methacrylate, triallyl isocyanurate and the macroporous resin prepared in step (1) is (7～9):( 1-3): 10, the porogen is composed of butyl acetate and n-heptane, and the mass ratio of butyl acetate and n-heptane is (2-4): 1; the swelling time is 15-24 h; the The mass concentration of the polyvinyl alcohol solution is 0.5-2%; the stirring speed is 100-150r/min; the heating speed is 1-3°C/min; the reaction time is 10-15h; the Washing with water is 2 to 5 times using water at 70 to 80°C.

Further, in step (3), the mass concentration of the trimethylamine hydrochloride solution is 40-60%; the temperature of the amination reaction is 70-90° C., and the reaction time is 9-12 h; the molar mass of the HCl solution is The concentration is 0.5-1.5mol/L; the molar concentration of the NaOH solution is 0.5-1.5mol/L; the leaching time is 1-3h.

A kind of application of described sparse/hydrophilic interpenetrating network resin, described sparse/hydrophilic interpenetrating network resin can be used for decolorization of xylose mother liquor, and the concrete method is:

(1) The prepared sparse/hydrophilic interpenetrating network resin is loaded into an adsorption column with an aspect ratio of (15～25):1;

(2) the xylose mother liquor is filtered to remove insoluble impurities, and the xylose mother liquor is diluted with water to 25～30°Bx;

(3) Take 15-20 BV of the xylose mother liquor pretreated in step (2) and pass it through the adsorption column prepared in step (1) at a flow rate of 1 to 4 BV/h at a working temperature of 40 °C, and collect the xylose mother liquor passing through the adsorption column ;

(4) desorb and regenerate the resin with eluent;

The eluent is an aqueous solution composed of NaOH solution and absolute ethanol in a volume ratio of (4 to 6): 1, and the mass concentration of the NaOH solution is 1 to 3%; the consumption of the eluent is 3 to 5 BV; The desorption flow rate is 3-6 BV/h.

The beneficial technical effects of the present invention are:

(1) The hydrophobic/hydrophilic interpenetrating network resin prepared by the present invention has stable adsorption performance, and uses hydrophobic (or π-π stacking), electrostatic, hydrogen bonding and other effects to adsorb color sources, which greatly improves the resin's ability to absorb wood. Adsorption capacity of pigment substances in sugar mother liquor. The decolorization rate of sugar solution can reach more than 97%, and the selectivity is strong, and the retention rate of reducing sugar is more than 99%, which overcomes the shortcomings of traditional decolorizing resins, and effectively solves the problems of low decolorization rate, poor selectivity and weak anti-pollution ability of commonly used resins. and other defects.

(2) the sparse/hydrophilic interpenetrating network resin of the present invention is easy to regenerate, and the eluent uses sodium hydroxide with a lower concentration, the acid-base consumption is low, and the regeneration performance is good, and the decolorization rate is still more than 5 times after recycling It is maintained at more than 95%, which provides a new alternative adsorption and decolorization medium for the decolorization and purification of xylose mother liquor.

(3) The present invention overcomes some deficiencies in the prior art, has moderate specific surface area, suitable pore size distribution, and can better reduce the loss of sugar in the refining process, with simple operation, good effect and low cost.

Description of drawings

Fig. 1 is the infrared spectrum diagram of the hydrophobic/hydrophilic interpenetrating network resin prepared in Example 1 of the present invention.

2 is a pore size distribution diagram of the hydrophobic/hydrophilic interpenetrating network resin prepared in Example 1 of the present invention.

Fig. 3 is the ultraviolet spectrum before and after decolorization of xylose mother liquor by the resin prepared in Example 2 of the present invention.

Fig. 4 is the adsorption isotherm of the phobic/hydrophilic interpenetrating network resin prepared in Example 2 of the present invention to the pigment in the xylose mother liquor.

Fig. 5 is the adsorption kinetics of the hydrophobic/hydrophilic interpenetrating network resin prepared in Example 3 of the present invention to the pigment in the xylose mother liquor.

Fig. 6 is the repeated use result of decolorization of xylose mother liquor by the hydrophobic/hydrophilic interpenetrating network resin prepared in Example 3 of the present invention.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

Example 1

A sparse/hydrophilic interpenetrating network resin, the preparation method of the network resin comprising the following steps:

The oil phase mixture composed of monomers, porogens and initiators with a mass ratio of 1:2:0.005 was added to the water phase containing 0.5% polyvinyl alcohol and 2% NaCl to carry out suspension polymerization, wherein the oil phase mixture was mixed with water The mass ratio of the phase is 0.5:2, the monomer is divinylbenzene, the porogen is toluene, xylene and n-heptane, the mass ratio of toluene, xylene and n-heptane is 1:1:1, and the initiator is perylene glycol. Dibenzoyl oxide. The suspension polymerization is as follows: while stirring at 140 r/min, the temperature is raised to 90° C. at a speed of 20° C./h, and then the reaction is performed at a constant temperature for 5 hours. After the reaction, wash twice with hot water at 70°C, use a Soxhlet extractor to extract the porogen, the solvent used is acetone, and dry at 40°C for 10 hours to obtain a macroporous resin; The reagent is composed of monomer and porogen; the mass ratio of porogen to monomer is 1.5:1, the monomer is composed of glycidyl methacrylate and triallyl isocyanurate, methacrylate is glycidyl The mass ratio of glyceride, triallyl isocyanurate and macroporous resin is 9:1:10, the porogen is composed of butyl acetate and n-heptane, and the mass ratio of butyl acetate and n-heptane is 2: 1. A polyvinyl alcohol solution with a mass concentration of 0.5% was added, and the temperature was raised to 80 °C at 1 °C/min while stirring at 100 r/min, reacted for 10 h, washed twice with 70 °C hot water, and used a Soxhlet extractor to extract the porogen. The solvent used is acetone, and finally dried at 40°C for 10 h to obtain a hydrophobic/hydrophilic interpenetrating network resin; 40% trimethylamine hydrochloride solution is added to the prepared hydrophobic/hydrophilic interpenetrating network resin solution to carry out amination reaction , react at 70°C for 9h, rinse with 0.5mol/L HCl for 1h, wash with water until neutral, rinse with 0.5mol/L NaOH for 1h, and wash with water until neutral to obtain a sparse/hydrophilic interpenetrating network resin.

The prepared sparse/hydrophilic interpenetrating network resin is 15:1 with a height-diameter ratio, loaded into an adsorption column, the xylose mother liquor is filtered to remove insoluble impurities, and the xylose mother liquor is diluted with water to 25 ° Bx to obtain pretreated xylose. Mother liquor, the pretreated 15BV xylose mother liquor is passed through the adsorption column at a flow rate of 1BV/h at a working temperature of 40 °C, the decolorized xylose mother liquor is collected, its absorbance (A _450nm ) is measured, and the decolorization rate and reducing sugar retention are calculated. The eluent was 1% NaOH solution and absolute ethanol, the volume ratio was 4:1, the resin was desorbed and regenerated at a flow rate of 3BV/h, and the amount of eluent was 3BV.

Example 2

A sparse/hydrophilic interpenetrating network resin, the preparation method of the network resin comprising the following steps:

The oil phase mixture composed of monomers, porogens and initiators with a mass ratio of 1:2.5:0.015 was added to the water phase containing 1.5% polyvinyl alcohol and 4% NaCl for suspension polymerization, wherein the oil phase mixture was mixed with water The mass ratio of the phase is 0.75:2.5, the monomer is divinylbenzene, the porogen is toluene, xylene and n-heptane, the mass ratio of toluene, xylene and n-heptane is 2:2:1, and the initiator is perylene glycol. Dibenzoyl oxide. The suspension polymerization is as follows: while stirring at 155 r/min, the temperature is raised to 94° C. at a rate of 25° C./h, and then the reaction is performed at a constant temperature for 6 hours. After the reaction, wash with 75 ℃ hot water for 3 times, use a Soxhlet extractor to extract the porogen, the solvent used is petroleum ether, and dry at 50 ℃ for 13 hours to obtain a macroporous resin; The reagent used consists of monomer and porogen; the mass ratio of porogen to monomer is 2:1, the monomer consists of glycidyl methacrylate and triallyl isocyanurate, methacrylic acid The mass ratio of glycidyl ester, triallyl isocyanurate and macroporous resin is 8:2:10, the porogen is composed of butyl acetate and n-heptane, and the mass ratio of butyl acetate and n-heptane is 3 :1. A polyvinyl alcohol solution with a mass concentration of 1.5% was added, and the temperature was raised to 85°C at 2°C/min while stirring at 125 r/min, reacted for 13 hours, washed with 75°C hot water for 3 times, and used a Soxhlet extractor to extract the porogen. The solvent used is petroleum ether, and finally dried at 50°C for 13 hours to obtain a hydrophobic/hydrophilic interpenetrating network resin; 50% trimethylamine hydrochloride solution is added to the prepared hydrophobic/hydrophilic interpenetrating network resin to carry out amination reaction , reacted at 80°C for 11h, rinsed with 1.0mol/L HCl for 2h, washed with water until neutral, rinsed with 1.0mol/L NaOH for 2h, and washed with water until neutral to obtain a sparse/hydrophilic interpenetrating network resin.

The prepared sparse/hydrophilic interpenetrating network resin is 20:1 with a height-diameter ratio, loaded into an adsorption column, the xylose mother liquor is filtered to remove insoluble impurities, and the xylose mother liquor is diluted with water to 27.5 ° Bx to obtain pretreated xylose Mother liquor, the pretreated 17BV xylose mother liquor was passed through the adsorption column at a flow rate of 3BV/h at a working temperature of 40 °C, the decolorized xylose mother liquor was collected, its absorbance (A _450nm ) was measured, and the decolorization rate and reducing sugar retention were calculated. The eluent was 2% NaOH solution and absolute ethanol, the volume ratio was 5:1, the resin was desorbed and regenerated at a flow rate of 5BV/h, and the amount of eluent was 4BV.

Example 3

A sparse/hydrophilic interpenetrating network resin, the preparation method of the network resin comprising the following steps:

The oil phase mixture composed of monomers, porogens and initiators with a mass ratio of 1:3:0.02 was added to the water phase containing 2% polyvinyl alcohol and 5% NaCl for suspension polymerization, wherein the oil phase mixture was mixed with water. The mass ratio of the phase is 1:3, the monomer is divinylbenzene, the porogen is toluene, xylene and n-heptane, the mass ratio of toluene, xylene and n-heptane is 3:3:1, and the initiator is perylene glycol. Dibenzoyl oxide. The suspension polymerization is as follows: while stirring at 170 r/min, the temperature is raised to 98° C. at a speed of 30° C./h, and then the reaction is performed at a constant temperature for 8 hours. After the reaction, wash with 80°C hot water for 5 times, use a Soxhlet extractor to extract the porogen, the solvent used is petroleum ether, and dry at 60°C for 15h to obtain a macroporous resin; the prepared macroporous resin is swollen for 24h, and then swollen. The reagent used is composed of porogen and monomer; the mass ratio of porogen to monomer is 3:1, the monomer is composed of glycerol methacrylate and triallyl isocyanurate, and methacrylic acid is shrunk The mass ratio of glyceride, triallyl isocyanurate and macroporous resin is 7:3:10, the porogen is composed of butyl acetate and n-heptane, and the mass ratio of butyl acetate and n-heptane is 4: 1. A polyvinyl alcohol solution with a mass concentration of 2% was added, and the temperature was raised to 90 °C at 3 °C/min while stirring at 150 r/min, reacted for 15 h, washed with 80 °C hot water for 5 times, and used a Soxhlet extractor to extract the porogen. The solvent used is petroleum ether, and finally dried at 60°C for 15 hours to obtain a hydrophobic/hydrophilic interpenetrating network resin; 60% trimethylamine hydrochloride solution is added to the prepared hydrophobic/hydrophilic interpenetrating network resin to carry out amination reaction , reacted at 90°C for 12h, rinsed with 1.5mol/L HCl for 3h, washed with water until neutral, rinsed with 1.5mol/L NaOH for 3h, and washed with water until neutral to obtain a sparse/hydrophilic interpenetrating network resin.

The prepared sparse/hydrophilic interpenetrating network resin is 25:1 with a height-diameter ratio, loaded into an adsorption column, the xylose mother liquor is filtered to remove insoluble impurities, and the xylose mother liquor is diluted with water to 30 ° Bx to obtain pretreated xylose Mother liquor, pass the pretreated 20BV xylose mother liquor through the adsorption column at a working temperature of 40°C at a flow rate of 4BV/h, collect the decolorized xylose mother liquor, and measure its absorbance (A _450nm ), calculate the decolorization rate and reducing sugar Retention rate, the eluent is 3% NaOH solution and absolute ethanol, the volume ratio is 6:1, the resin is desorbed and regenerated at a flow rate of 6BV/h, and the amount of eluent is 5BV.

Comparative Example 1

A kind of macroporous resin, its preparation method comprises the steps:

The oil phase mixture composed of monomers, porogens and initiators with a mass ratio of 1:2.5:0.015 was added to the water phase containing 1.5% polyvinyl alcohol and 4% NaCl for suspension polymerization, wherein the oil phase mixture was mixed with water The mass ratio of the phase is 0.75:2.5, the monomer is divinylbenzene, the porogen is toluene, xylene and n-heptane, the mass ratio of toluene, xylene and n-heptane is 2:2:1, and the initiator is perylene glycol. Dibenzoyl oxide. The suspension polymerization is as follows: while stirring at 155 r/min, the temperature is raised to 94° C. at a rate of 25° C./h, and then the reaction is performed at a constant temperature for 6 hours. After the reaction, wash with 75 ℃ hot water for 3 times, use a Soxhlet extractor to extract the porogen, the solvent used is petroleum ether, and dry at 50 ℃ for 13 hours to obtain a macroporous resin.

The prepared macroporous resin is loaded into an adsorption column with a height-to-diameter ratio of 20:1, the xylose mother liquor is filtered to remove insoluble impurities, the xylose mother liquor is diluted with water to 27.5 ° Bx to obtain a pretreated xylose mother liquor, and the pretreated 17BV wood The sugar mother liquor was passed through the column bed at a working temperature of 40°C at a flow rate of 3BV/h, the decolorized xylose mother liquor was collected, and its absorbance (A _450nm ) was measured.

Comparative Example 2

Polymethacrylic acid strong base resin, its preparation method comprises the steps:

A 2:1 mass ratio of porogen to monomer was prepared, the monomer was composed of glycidyl methacrylate and triallyl isocyanurate, glycidyl methacrylate and triallyl isocyanurate The mass ratio of the acid ester is 8:2, the porogen is composed of butyl acetate and n-heptane, the mass ratio of butyl acetate and n-heptane is 3:1, put into a polyvinyl alcohol solution with a mass concentration of 1.5%, While stirring at 125 r/min, the temperature was raised to 85 °C at 2 °C/min, reacted for 13 h, washed with 75 °C hot water for 3 times, and then extracted the porogen using a Soxhlet extractor. The solvent used was petroleum ether, and dried to obtain polymethyl methacrylate. base glycidyl acrylate resin; add 50% trimethylamine hydrochloride solution to the prepared resin for amination reaction, react at 80 °C for 11 h, rinse with 1.0 mol/L HCl for 2 h, wash with water until neutral, and use 1.0 mol/L HCl for 11 h. Rinse with 1 L NaOH for 2h, and wash with water until neutral to obtain a hydrophilic strong base resin.

The prepared resin is loaded into an adsorption column with a height-to-diameter ratio of 20:1, the xylose mother liquor is filtered to remove insoluble impurities, the xylose mother liquor is diluted with water to 27.5°Bx to obtain a pretreated xylose mother liquor, and the pretreated 17BV xylose The mother liquor was passed through the column bed at a working temperature of 40 °C at a flow rate of 3 BV/h, the decolorized xylose mother liquor was collected, and the absorbance at 450 nm was measured.

Comparative Example 3

The commercially available 201×7 resin was loaded into the adsorption column with a height-to-diameter ratio of 20:1, the xylose mother liquor was filtered to remove insoluble impurities, and the xylose mother liquor was diluted with water to 27.5°Bx to obtain the pretreated xylose mother liquor. The 17BV xylose mother liquor was passed through the column bed at a working temperature of 40°C at a flow rate of 3BV/h, the decolorized xylose mother liquor was collected, and the absorbance at 450 nm was measured.

Comparative Example 4

The sugar activated carbon powder is loaded into the adsorption column with a height-to-diameter ratio of 20:1, the xylose mother liquor is filtered to remove insoluble impurities, the xylose mother liquor is diluted with water to 27.5 ° Bx to obtain a pretreated xylose mother liquor, and the pretreated 17BV xylose is mixed. The mother liquor was passed through the column bed at a working temperature of 40 °C at a flow rate of 3 BV/h, the decolorized xylose mother liquor was collected, and the absorbance at 450 nm was measured.

Test case:

The pore size, particle size and other properties of the hydrophobic/hydrophilic interpenetrating network resin prepared in Example 1-3 and the resin prepared in Comparative Example 1-2 were tested by using an automatic specific surface area and void analyzer. The test results are shown in Table 1. shown.

Determination of decolorization rate and sugar retention rate of xylose mother liquor:

Collect the xylose mother liquor before and after decolorization in embodiment 1-3 and comparative example 1-4, utilize ultraviolet spectrophotometer to measure the absorbance (A _450nm ) of xylose mother liquor before and after decolorization, calculate decolorization rate by absorbance, the calculation formula of decolorization rate is as follows Formula (1) is shown.

In the formula, A ₀ is the absorbance value of the xylose mother liquor before decolorization at 450 nm, and A is the absorbance value of the xylose mother liquor after decolorization at 450 nm.

Collect the xylose mother liquor before and after decolorization in Example 1-3 and Comparative Example 1-4, utilize high performance liquid chromatography to measure the sugar content of the xylose mother liquor before and after decolorization, calculate the sugar retention rate, and the calculation formula is shown in the following formula (2) :

In the formula, C ₀ is the sugar content before decolorization, C is the sugar content after decolorization, and the unit is mg/mL.

The measurement results of the decolorization rate and sugar retention rate of the xylose mother liquor are shown in Table 1.

Table 1

The infrared spectrum of the hydrophobic/hydrophilic interpenetrating network resin prepared in Example 1 of the present invention, as shown in Figure 1, the interpenetrated polydivinylbenzene/polyglycidyl methacrylate aminated resin (PDVB /PMATAM) infrared spectrum not only retains the characteristic absorption peak of polydivinylbenzene (PDVB), but also has the characteristic absorption peak of carbonyl at 1728cm- ¹ , and a broad peak at 3500cm ^-1 , which is -OH The stretching vibration absorption peak at 1058 cm ^-1 is the CN bond generated after the resin amination reaction, indicating that the prepared resin has the properties of the polydivinylbenzene resin (PDVB) network (i.e. the hydrophobic interaction , π-π stacking effect), and has the properties of the resin (PMATAM) network after amination of polyglycidyl methacrylate (ie, electrostatic, hydrogen bonding, etc.). It shows that the hydrophobic/hydrophilic interpenetrating network resin prepared in the present application can adsorb substances with hydrophobic structure in pigments (such as pigments with benzene ring structure) through hydrophobic interaction and π-π stacking interaction, and can also adsorb pigments with hydrophobic structure through electrostatic interaction and π-π stacking interaction. , hydrogen bond and other functions to adsorb organic acids, furfural and other substances in sugar liquid. Therefore, the resin has strong decolorization ability and large adsorption capacity. In addition, the specific surface area of the hydrophobic/hydrophilic interpenetrating network resin prepared by the present invention is moderate, and the reducing sugar component can be well retained. The total sugar content of the xylose mother liquor before decolorization is 288.9mg/mL, including glucose 34.7mg/mL, arabinose 52mg/mL, xylose 202.2mg/mL, and the total sugar content of the xylose mother liquor after decolorization> 287mg/mL, wherein , glucose 34.4mg/mL, arabinose 51.7mg/mL, xylose 202mg/mL.

Fig. 2 is the pore size distribution diagram before and after the interpenetration of the hydrophobic/hydrophilic interpenetrating network resin prepared in Example 1 of the application. It can be seen from Figure 2 that the pore size of the prepared resin is mostly distributed in the mesopore range, and contains abundant micropores. The special pore structure makes the resin have strong decolorization ability and high sugar retention rate.

Fig. 3 is the UV contrast diagram before and after decolorization of the xylose mother liquor by the resin prepared in Example 2 of the present invention. As can be seen from the figure, the absorbance of the decolorized xylose mother liquor in the range of 400-600 nm has a significant decrease.

Fig. 4 is the adsorption isotherm of the sparse/hydrophilic interpenetrating network resin prepared in Example 2 to the pigment in the xylose mother liquor. As can be seen from the figure, the temperature rise is conducive to the adsorption of the resin, and the adsorption curve is more in line with the Langmuir model.

Fig. 5 is the adsorption kinetics of the sparse/hydrophilic interpenetrating network resin prepared in Example 3 to the pigment in the xylose mother liquor, as can be seen from the figure, the decolorization rate of the sugar liquor in 10min has reached more than 90%, illustrating the present invention The adsorption rate of the prepared hydrophobic/hydrophilic interpenetrating network resin is extremely fast.

Figure 6 is the result of repeated use of the sparse/hydrophilic interpenetrating network resin prepared in Example 3 to decolorize the xylose mother liquor. As shown in the figure, after 5 times of recycling, the decolorization rate still remains above 95%, and the total The sugar retention rate is higher than 98%, which also shows that the resin structure is stable, repeatable and easy to regenerate.

Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Anyone who is familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, The protection scope of the present invention should be defined by the claims.

Claims (7)

1. a preparation method of sparse/hydrophilic type interpenetrating network resin, is characterized in that, described preparation method comprises the steps: (1) adding the oil phase mixture to the water phase to carry out suspension polymerization, after washing with water, extracting the porogen, and drying to obtain a macroporous resin; (2) After swelling the macroporous resin prepared in step (1), put it into a polyvinyl alcohol solution, and heat up to 80-90° C. while stirring, after the reaction, wash with water, extract the porogen, and dry to obtain a double-hydrophobic type Interpenetrating network resin; (3) adding trimethylamine hydrochloride solution to the interpenetrating network resin prepared in step (2) to carry out amination reaction, then rinsing with HCl solution, washing with water until neutrality, and finally rinsing with NaOH solution, washing with water until neutrality That is, a sparse/hydrophilic interpenetrating network resin is obtained; In step (1), the oil phase mixture is composed of monomer, porogen and initiator, and the mass ratio of monomer, porogen and initiator is 1:(2-3):(0.005-0.02); The monomer is divinylbenzene; the porogen is composed of toluene, xylene and n-heptane, and the mass ratio of toluene, xylene and n-heptane is: (1～3):(1～3):1 ; Described initiator is dibenzoyl peroxide; In step (2), the reagent used for the swelling is composed of a porogen and a monomer; the mass ratio of the porogen to the monomer is (1.5-3):1, and the monomer is composed of glycidyl methacrylate and triglyceride. Allyl isocyanurate is composed, and the mass ratio of glycidyl methacrylate, triallyl isocyanurate and the macroporous resin prepared in step (1) is (7-9): (1-3 ): 10, the porogen is composed of butyl acetate and n-heptane, and the mass ratio of butyl acetate to n-heptane is (2-4): 1; the swelling time is 15-24 h; the polyvinyl alcohol The mass concentration of the solution is 0.5-2%; the stirring speed is 100-150r/min; the heating speed is 1-3°C/min; the reaction time is 10-15h; Wash 2 to 5 times with water at 70 to 80 °C. 2 . The preparation method according to claim 1 , wherein in step (1), the mass ratio of the oil phase mixture to the water phase is (0.5～1):(2～3). 3 . 3. preparation method according to claim 1, is characterized in that, in step (1), described water phase is made up of polyvinyl alcohol and NaCl solution, and the mass concentration of polyvinyl alcohol in water phase is 0.5～2%; The mass concentration of NaCl in the phase is 2-5%; the suspension polymerization method is as follows: according to the mass ratio, add the oil-phase mixture to the water phase, and while stirring at 140-170 r/min, the temperature is raised to 90° C./h at 20-30° C. After ~98°C, constant temperature reaction is performed for 5-8 hours; the water washing is to use water at 70-80°C for 2 to 5 times. 4. preparation method according to claim 1, is characterized in that, in step (1) and step (2), described extraction porogen is carried out in Soxhlet extractor, and used reagent is acetone, petroleum ether One or more of the above; the drying temperature is 40～60℃, and the drying time is 10～15h. 5. The preparation method according to claim 1, wherein in step (3), the mass concentration of the trimethylamine hydrochloride solution is 40-60%; the temperature of the amination reaction is 70-90°C, The reaction time is 9-12 h; the molar concentration of the HCl solution is 0.5-1.5 mol/L; the molar concentration of the NaOH solution is 0.5-1.5 mol/L; the leaching time is 1-3 h. 6. A hydrophobic/hydrophilic interpenetrating network resin prepared by the preparation method according to any one of claims 1 to 5. 7. an application of the described sparse/hydrophilic type interpenetrating network resin of claim 6, is characterized in that, described sparse/hydrophilic type interpenetrating network resin can be used for the decolorization of xylose mother liquor, and concrete method is: (1) The prepared sparse/hydrophilic interpenetrating network resin is loaded into an adsorption column with an aspect ratio of (15～25):1; (2) the xylose mother liquor is filtered to remove insoluble impurities, and the xylose mother liquor is diluted with water to 25～30°Bx; (3) Take 15-20 BV of the xylose mother liquor pretreated in step (2) and pass it through the adsorption column of step (1) at a flow rate of 1-4 BV/h at a working temperature of 40°C, and collect the xylose mother liquor passing through the adsorption column.

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