Epoxy resin hollow microsphere as well as preparation method and application thereof

Abstract

The invention discloses epoxy resin hollow microspheres as well as a preparation method and application thereof, the epoxy resin hollow microspheres comprise the following raw material components: epoxy resin emulsion and a curing agent, the epoxy resin emulsion comprises 5-15 parts by weight of epoxy resin and 20-50 parts by weight of polyether polyol; and the curing agent is 2-5 parts by weight. The technical scheme is simple in preparation process, short in time consumption and good in repeatability; no toxic solvent is used, cost is low, and environmental protection is achieved; the particle size is 0.01-8.5 [mu] m, and in the application of chromatographic separation, the separation effect on high-molecular compounds is excellent, and the cost is relatively low.

Description

Technical Field

[0001] The invention relates to the preparation of a polymer material, in particular to an epoxy resin microsphere and a preparation method and application thereof. Background Art

[0002] Hollow microspheres are a type of core-shell particles with a special structure in which the core is air or other gases. Compared with other bulk materials, hollow microspheres have a smaller density and special mechanical, optical, electrical and other physical properties and application value. At present, the methods for preparing hollow microspheres mainly include template method, emulsion method, self-assembly method, etc. Organic polymer materials, inorganic materials, polymer / inorganic composite materials can all be used to prepare hollow microspheres.

[0003] Hollow structure polymer microspheres, also known as hollow microspheres, refer to special microspheres with single or multi-porous structures inside latex particles. Due to their special hollow structure, they have many special uses and properties. Compared with inorganic hollow structure materials, hollow polymer microsphere materials have low density, low price, easy modification or no modification required to combine with functional nanoparticles through active groups on the surface, etc. They have great application value in the fields of medicine, chemistry, materials science, etc. They are mainly used in drug controlled release capsules, adsorption materials, catalytic carriers, filling modified materials, etc.

[0004] Emulsion polymerization and suspension polymerization are traditional methods for preparing polymer microspheres. The particle size of microspheres prepared by emulsion polymerization is relatively small (less than 0.7 μm) and the post-processing operation is complicated; the particle size of microspheres prepared by suspension polymerization is relatively large (between 100 and 1000 μm), and the monodispersity of microspheres is generally difficult to control, which is only suitable for the preparation of polymethyl methacrylate, polystyrene and polyester microspheres. The reaction-induced phase separation method can be used to prepare microspheres with controllable particle size and excellent monodispersity, but when preparing epoxy resin microspheres with thermoplastic resin as the continuous phase, since most thermoplastic resins are polar materials, the viscosity is high in the molten state, and the intermolecular force is strong, the epoxy resin microspheres are not easy to elute.

[0005] Hseih et al. prepared micrometer-sized cross-linked epoxy resin microspheres by reaction-induced phase separation in epoxy resin / diphenyl sulfone / polymethyl methacrylate curing reaction system. Wu Yang et al. blended homemade polyester, epoxy resin and curing agent and prepared epoxy resin microspheres by reaction-induced phase separation, but the reproducibility was poor. Summary of the invention

[0006] In view of the shortcomings of the prior art described above, the purpose of the present invention is to provide a simple and efficient preparation method and use of epoxy resin hollow microspheres, the preparation process is simple, short in time, and has good repeatability; there is no toxic solvent, low cost, and green environmental protection; the particle size is between 0.01 and 8.5 μm, and the effect of separating polymer compounds in chromatographic separation is excellent and the cost is low.

[0007] To achieve the above-mentioned purpose and other related purposes, the first aspect of the present invention provides epoxy resin hollow microspheres, the raw material components of the epoxy resin hollow microspheres include epoxy resin emulsion and curing agent, the epoxy resin emulsion includes 5 to 15 parts by weight of epoxy resin and 20 to 50 parts by weight of polyether polyol; the curing agent is 2 to 5 parts by weight.

[0008] Preferably, the epoxy resin is a low-viscosity epoxy resin, and the epoxy value of the low-viscosity epoxy resin is 0.4-0.6 mol / 100 g. More preferably, it is 0.48-0.54 mol / 100 g. For example, it can be 0.4-0.45 mol / 100 g, 0.4-0.5 mol / 100 g, 0.5-0.55 mol / 100 g, or 0.55-0.6 mol / 100 g.

[0009] When low-viscosity epoxy resin is blended with polyether polyol, the interfacial tension is small, which is conducive to uniform mixing. The test method of the epoxy value is carried out in accordance with GB / T1677-2008.

[0010] Preferably, the polyether polyol comprises polytetramethylene glycol.

[0011] More preferably, the number average molecular weight of the polytetrahydrofuran polyol is 280-350, such as 280-290, 290-300, 300-310, 310-320, 320-330, 330-340, 340-350.

[0012] Preferably, the curing agent comprises polyetheramine.

[0013] More preferably, the number average molecular weight of the polyetheramine is in the range of 90 to 120, such as 90 to 100, 100 to 110, or 110 to 120.

[0014] Preferably, the epoxy resin includes one or more of bisphenol A epoxy resin, bisphenol F epoxy resin and bisphenol S epoxy resin.

[0015] More specifically, the raw material monomers of the epoxy resin may be one or more of bisphenol A, diphenol methane, phenol, mesitylene and epichlorohydrin.

[0016] Preferably, the particle size of the epoxy resin hollow microspheres is 0.01-8.5 μm. For example, it may be 0.01-0.6 μm, 0.6-1 μm, 1-2.3 μm, 2.3-2.8 μm, 2.8-3.5 μm, 3.5-4.2 μm, 4.2-6 μm, 6-7 μm, 7-8.5 μm. More preferably, it is 0.01-4 μm, for example, it may be 0.01-0.6 μm, 0.6-2 μm, 2-2.5 μm, 2.5-4 μm.

[0017] The second aspect of the present invention provides a method for preparing the above-mentioned epoxy resin hollow microspheres, comprising the following steps:

[0018] a) mixing epoxy resin and polyether polyol at a set temperature to obtain epoxy resin emulsion;

[0019] b) adding a curing agent to the epoxy resin emulsion and stirring the mixture evenly, and then putting the mixture into an oven for curing to obtain epoxy resin hollow microspheres.

[0020] Preferably, in step a), the set temperature is 40-70° C., such as 40-50° C., 50-55° C., 55-65° C., 65-70° C., and in a specific embodiment, 60° C. At this temperature, the epoxy resin and the polyether polyol are more easily dispersed and are conducive to mixing to form a uniform epoxy resin emulsion.

[0021] Preferably, in step a), the mixing time is 2 h to 4 h.

[0022] Preferably, in step b), the temperature of the epoxy resin emulsion is 30-50°C when the curing agent is added.

[0023] Preferably, in step b), the temperature of the oven is 50-100°C, such as 50-60°C, 60-70°C, 70-75°C, 75-85°C, 85-90°C, 90-100°C, and in a specific embodiment, 80°C.

[0024] Preferably, in step b), the stirring speed is 800-1000 r / min.

[0025] Preferably, in step b), after curing, acetone washing is used and drying is performed, and the drying temperature is 20-28° C. and the drying time is 48-60 hours. For example, the drying temperature can be 20° C., 21° C., 22° C., 23° C., 24° C., 25° C., 26° C., 27° C., 28° C., and in a specific embodiment, it is 25° C. The purpose of acetone washing is to remove other organic solvent impurities.

[0026] Preferably, in step b), the drying condition is drying in a vacuum environment. Vacuum drying has better drying efficiency and quality, which is conducive to the thorough drying of the microspheres. The polyether polyol is evaporated and removed during the drying process, so that the microspheres form a hollow structure.

[0027] The third aspect of the present invention provides a use of the above-mentioned epoxy resin hollow microspheres as a chromatographic filler for separating coumarin compounds in natural plant extracts.

[0028] Preferably, the natural plant is the root of Angelica dahurica.

[0029] Preferably, the coumarin compounds include one or more of simple coumarins, furanocoumarins, and pyranocoumarins.

[0030] More preferably, the coumarin compound is one or more of imperatorin, osthole and malvaceae lactone.

[0031] The smaller the particle size of the epoxy resin hollow microspheres used as chromatographic fillers, the higher the column efficiency, and the better the effect of chromatographic separation of coumarin compounds in natural plants. However, at the same time, the smaller the particle size, the greater the column pressure, the shorter the column life, and the higher the operating cost. The particle size of the epoxy resin hollow microspheres prepared by the present invention is controlled at 0.01 to 8.5 μm, which can improve the chromatographic separation effect of coumarin compounds in natural plants as much as possible while ensuring low operating costs.

[0032] As described above, the present invention provides an epoxy resin hollow microsphere and a preparation method and application thereof, which have the following beneficial effects:

[0033] (1) Compared with polymer hollow microspheres made of other materials, epoxy resin hollow microspheres have the advantages of heat resistance, solvent resistance, and high mechanical strength;

[0034] (2) The preparation process of the epoxy resin hollow microspheres of the present invention is relatively simple, with a short preparation cycle and good repeatability; the preparation process does not use, leave residues or emit toxic solvents, and the manufacturing cost is low and environmentally friendly; the particle size is between 0.01 and 8.5 μm, and the separation effect of coumarin compounds in natural plants in chromatographic separation applications is excellent, the operating cost is low, and the product life is long. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It shows an electron microscope image of epoxy resin hollow microspheres prepared in Example 1 of the present invention.

[0036] Figure 2 It shows the adsorption and desorption curves of the epoxy resin hollow microspheres prepared in Example 1 of the present invention.

[0037] Figure 3Shown is an electron microscope image of epoxy resin hollow microspheres prepared in Example 2 of the present invention.

[0038] Figure 4 It shows the adsorption and desorption curves of the epoxy resin hollow microspheres prepared in Example 2 of the present invention.

[0039] Figure 5 It shows an electron microscope image of epoxy resin hollow microspheres prepared in Example 3 of the present invention.

[0040] Figure 6 It shows the adsorption and desorption curves of the epoxy resin hollow microspheres prepared in Example 3 of the present invention.

[0041] Figure 7 Shown is an electron microscope image of epoxy resin hollow microspheres prepared in Example 4 of the present invention.

[0042] Figure 8 It shows the adsorption and desorption curves of the epoxy resin hollow microspheres prepared in Example 4 of the present invention.

[0043] Fig. 9 It shows the electron microscope image of the epoxy resin hollow microspheres prepared in Comparative Example 1 of the present invention.

[0044] Fig.10 It shows the adsorption and desorption curves of the epoxy resin hollow microspheres prepared in Comparative Example 1 of the present invention.

[0045] Fig.11 It shows the particle size analysis diagram of the epoxy resin hollow microspheres prepared in Examples 1 to 4 of the present invention and Comparative Example 1.

[0046] Fig.12 Shown is the standard sample separation diagram of imperatorin in the traditional Chinese medicine Angelica dahurica.

[0047] Fig.13 This is a diagram showing the separation effect when Example 1 of the present invention is applied.

[0048] Fig.14 This is a diagram showing the separation effect when Example 4 of the present invention is applied.

[0049] Fig.15 It shows the separation effect diagram when comparative example 1 of the present invention is applied. DETAILED DESCRIPTION

[0050] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0051] The invention uses polytetrahydrofuran polyol (PTG) with low melting viscosity and low interfacial tension when mixed with epoxy resin as the continuous phase of the blending system, and adopts a reaction-induced phase separation method to prepare epoxy resin hollow microspheres.

[0052] A specific method for preparing epoxy resin hollow microspheres is used in the following embodiments, comprising the following steps:

[0053] a) mixing 5 to 15 parts by weight of a low-viscosity epoxy resin and 20 to 50 parts by weight of polytetrahydrofuran polyol at 40 to 70° C. to obtain an epoxy resin emulsion, wherein the mixing time is 2 to 4 hours;

[0054] b) adding 2 to 5 parts by weight of a polyetheramine curing agent to the epoxy resin emulsion and stirring evenly until the emulsion becomes transparent and uniform, and then putting the emulsion into an oven for curing. After curing, washing the emulsion with acetone and drying the emulsion to obtain epoxy resin hollow microspheres.

[0055] In the following specific embodiments, the low viscosity epoxy resin includes one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, and bisphenol S epoxy resin. In the following more specific embodiments, the low viscosity epoxy resin is bisphenol A epoxy resin E-51.

[0056] In the following specific embodiments, the number average molecular weight of polytetrahydrofuran polyol is 280-350, and in a more specific embodiment, the number average molecular weight of polytetrahydrofuran is 305. Polytetrahydrofuran polyol acts as an emulsifier, which can make the low-viscosity epoxy resin and polytetrahydrofuran polyol uniformly mixed to form an emulsion system and keep the system stable.

[0057] Specifically, in the following specific embodiments, the number average molecular weight of the polyetheramine is 90-120, the total amine value is 8.0-9.0 meq / g; the primary amine accounts for more than 95% of the total amine value, the water content is up to 0.4%, the density is 0.9-1.0 g / ml at 25°C, and the viscosity is 9-10 mm 2 / s.

[0058] Preferably, in step b), the temperature of the epoxy resin emulsion when the curing agent is added is 30-50° C. If the initial temperature of adding the curing agent is too high, the curing rate will be slow.

[0059] Preferably, in step b), the stirring speed is 800-1000 r / min.

[0060] Preferably, in step b), the drying temperature is 20-28° C., and the drying time is 48-60 hours.

[0061] Preferably, in step b), the drying condition is drying in a vacuum environment.

[0062] However, those skilled in the art should understand that the above examples will not limit the scope of protection of the present application, and any technical solution that can achieve the technical effect of the present application is within the scope of protection required by the present application.

[0063] Example 1

[0064] This embodiment provides a method for preparing epoxy resin hollow microspheres, comprising the following steps:

[0065] a) 10 parts by weight of bisphenol A epoxy resin and 50 parts by weight of polytetrahydrofuran polyol (PTG) were uniformly mixed at 60° C. to obtain an epoxy resin emulsion.

[0066] b) When the temperature is 40°C, 3 parts by weight of polyetheramine is added to the epoxy resin emulsion, and the mixture is stirred with a magnetic stirring instrument at a speed of 900 r / min until it becomes transparent and uniform, and then placed in an oven at 80°C for curing. After curing, the mixture is washed with acetone and then placed in a vacuum oven at 25°C for drying for 48 hours to obtain epoxy resin hollow microspheres.

[0067] Figure 1 This is an electron microscope image of the epoxy resin hollow microspheres prepared in this example. Figure 2 This is the nitrogen adsorption-desorption curve diagram of this embodiment.

[0068] Depend on Figure 1 It can be seen that when the consumption of polytetrahydrofuran polyol (PTG) is 50 parts by weight, the obtained epoxy resin hollow microspheres have a small and uniform particle size and good dispersibility; Figure 2 It can be seen that the adsorption-desorption isotherm of the prepared epoxy resin microspheres is a type IV isotherm, which has a microporous structure and a pore size distribution of 5 to 10 nm.

[0069] Example 2

[0070] This embodiment provides a method for preparing epoxy resin hollow microspheres, comprising the following steps:

[0071] a) 10 parts by weight of bisphenol A epoxy resin and 40 parts by weight of polytetrahydrofuran polyol (PTG) were uniformly mixed at 60° C. to obtain an epoxy resin emulsion.

[0072] b) When the temperature is 40°C, 3 parts by weight of polyetheramine is added to the epoxy resin emulsion, and the mixture is stirred with a magnetic stirring instrument at a speed of 900 r / min until it becomes transparent and uniform, and then placed in an oven at 80°C for curing. After curing, the mixture is washed with acetone and then placed in a vacuum oven at 25°C for drying for 48 hours to obtain epoxy resin hollow microspheres.

[0073] Figure 3 This is an electron microscope image of the epoxy resin hollow microspheres prepared in this example. Figure 4 This is the nitrogen adsorption-desorption curve diagram of this embodiment.

[0074] Depend on Figure 3 It can be seen that when the consumption of polytetrahydrofuran polyol (PTG) is 40 parts by weight, the obtained epoxy resin hollow microspheres have a small and uniform particle size and good dispersibility; Figure 4 It can be seen that the adsorption-desorption isotherm of the prepared epoxy resin microspheres is a type IV isotherm, which has a microporous structure and a pore size distribution of 3 to 10 nm.

[0075] Example 3

[0076] This embodiment provides a method for preparing epoxy resin hollow microspheres, comprising the following steps:

[0077] a) 10 parts by weight of bisphenol A epoxy resin and 30 parts by weight of polytetramethylene glycol (PTG) were uniformly mixed at 60° C. to obtain an epoxy resin emulsion.

[0078] b) When the temperature is 40°C, 3 parts by weight of polyetheramine is added to the epoxy resin emulsion, and the mixture is stirred with a magnetic stirring instrument at a speed of 900 r / min until it becomes transparent and uniform, and then placed in an oven at 80°C for curing. After curing, the mixture is washed with acetone and then placed in a vacuum oven at 25°C for drying for 48 hours to obtain epoxy resin hollow microspheres.

[0079] Figure 5 This is an electron microscope image of the epoxy resin hollow microspheres prepared in this example. Figure 6 This is the nitrogen adsorption-desorption curve diagram of this embodiment.

[0080] Depend on Figure 5 It can be seen that when the dosage of polytetrahydrofuran polyol (PTG) is 30 parts by weight, the prepared epoxy resin hollow microspheres have a small and relatively uniform particle size and good dispersibility; Figure 6 It can be seen that the adsorption-desorption isotherm of the prepared epoxy resin microspheres is a type IV isotherm, which has a microporous structure and a pore size distribution of 3 to 20 nm.

[0081] Example 4

[0082] This embodiment provides a method for preparing epoxy resin hollow microspheres, comprising the following steps:

[0083] (a) 10 parts by weight of bisphenol A epoxy resin and 20 parts by weight of polytetramethylene glycol (PTG) were uniformly mixed at 60° C. to obtain an epoxy resin emulsion.

[0084] (b) When the temperature is 40°C, 3 parts by weight of polyetheramine is added to the epoxy resin emulsion, and the mixture is stirred with a magnetic stirring instrument at a speed of 900 r / min until it becomes transparent and uniform. The mixture is then placed in an oven at 80°C for curing. After curing, the mixture is washed with acetone and dried in a vacuum oven at 25°C for 48 hours to obtain epoxy resin hollow microspheres.

[0085] Figure 7 This is an electron microscope image of the epoxy resin hollow microspheres prepared in this example. Figure 8 This is the adsorption-desorption curve of nitrogen in this example.

[0086] Depend on Figure 7 It can be seen that when the consumption of polytetrahydrofuran polyol (PTG) is 20 parts by weight, the obtained epoxy resin hollow microsphere particle size is small; Figure 8 It can be seen that the adsorption-desorption isotherm of the prepared epoxy resin microspheres is a type IV isotherm, which is a mesoporous structure with a pore size distribution of 5 to 60 nm.

[0087] Example 5

[0088] This embodiment provides a method for preparing epoxy resin hollow microspheres, comprising the following steps:

[0089] a) 15 parts by weight of bisphenol A epoxy resin and 50 parts by weight of polytetrahydrofuran polyol (PTG) were uniformly mixed at 60° C. to obtain an epoxy resin emulsion.

[0090] b) When the temperature is 40°C, 3 parts by weight of polyetheramine is added to the epoxy resin emulsion, and the mixture is stirred with a magnetic stirring instrument at a speed of 900 r / min until it becomes transparent and uniform, and then placed in an oven at 80°C for curing. After curing, the mixture is washed with acetone and then placed in a vacuum oven at 25°C for drying for 48 hours to obtain epoxy resin hollow microspheres.

[0091] The epoxy resin hollow microspheres prepared in this embodiment have small and uniform particle sizes and good dispersibility; their adsorption-desorption isotherms are type IV isotherms, and they have a microporous structure with a pore size distribution of 3 to 10 nm.

[0092] Example 6

[0093] This embodiment provides a method for preparing epoxy resin hollow microspheres, comprising the following steps:

[0094] a) 5 parts by weight of bisphenol A epoxy resin and 50 parts by weight of polytetramethylene glycol (PTG) were uniformly mixed at 60° C. to obtain an epoxy resin emulsion.

[0095] b) When the temperature is 40°C, 3 parts by weight of polyetheramine is added to the epoxy resin emulsion, and the mixture is stirred with a magnetic stirring instrument at a speed of 900 r / min until it becomes transparent and uniform, and then placed in an oven at 80°C for curing. After curing, the mixture is washed with acetone and then placed in a vacuum oven at 25°C for drying for 48 hours to obtain epoxy resin hollow microspheres.

[0096] The epoxy resin hollow microspheres prepared in this embodiment have small and uniform particle sizes and good dispersibility; their adsorption-desorption isotherms are type IV isotherms, and they have a microporous structure with a pore size distribution of 5 to 8 nm.

[0097] Comparative Example 1

[0098] This embodiment provides a method for preparing epoxy resin hollow microspheres, comprising the following steps:

[0099] (a) 10 parts by weight of bisphenol A epoxy resin and 10 parts by weight of polytetramethylene glycol (PTG) were uniformly mixed at 60° C. to obtain an epoxy resin emulsion.

[0100] (b) When the temperature is 40°C, 3 parts by weight of polyetheramine is added to the epoxy resin emulsion, and the mixture is stirred with a magnetic stirring instrument at a speed of 900 r / min until it becomes transparent and uniform. The mixture is then placed in an oven for curing. After curing, the mixture is washed with acetone and dried in a vacuum oven at 25°C for 48 hours to obtain epoxy resin hollow microspheres.

[0101] Fig. 9 This is an electron microscope image of the epoxy resin hollow microspheres prepared in this comparative example. Fig.10 This is the nitrogen adsorption-desorption curve diagram of this comparative example.

[0102] Depend on Fig. 9 It can be seen that when the consumption of polytetrahydrofuran polyol (PTG) is 10 weight parts, the prepared epoxy resin hollow microsphere particle size is small; Fig.10 It can be seen that the adsorption-desorption isotherm of the prepared epoxy resin microspheres is a type IV isotherm, which is a mesoporous structure with a pore size distribution of 10 to 100 nm.

[0103] The epoxy resin hollow microspheres prepared in Examples 1 to 4 and Comparative Example 1 were tested for particle size using a laser particle size analyzer. The results are as follows: Fig.11 As shown. Fig.11 It can be seen that different amounts of polytetrahydrofuran polyol PTG will result in different particle sizes of epoxy resin hollow microspheres. Specifically, as the proportion of PTG in the blend gradually increases, the average particle size of the epoxy resin hollow microspheres decreases. When the amount of PTG is 50 parts, the average particle size of the microspheres is the smallest, and when the amount of PTG is 10 parts, the average particle size of the microspheres is the largest.

[0104] As shown in Examples 1 to 4, when the amount of PTG is 20 to 50 parts, the particle size of the microspheres ranges from 0.01 to 8.5 μm, and the monodispersity index of the epoxy resin hollow microspheres does not change significantly; as shown in Comparative Example 1, as the amount of PTG decreases, the particle size of the microspheres gradually increases, and the monodispersity index of the microsphere particle size gradually increases, indicating that the particle size distribution is becoming more and more uneven, which is consistent with the results of SEM observation. In summary, the technical solution can prepare epoxy resin hollow microspheres with a particle size within a certain range by controlling the proportion of PTG in the blend.

[0105] Application Example 1

[0106] The epoxy resin hollow microspheres prepared in Example 1 were used as chromatographic fillers for the chromatographic separation of imperatorin in the traditional Chinese medicine Angelica dahurica. The specific steps are as follows:

[0107] Take about 0.4g of Angelica dahurica powder, put it in a 50ml volumetric flask, add 45ml of methanol, and ultrasonically treat (power 300W, frequency 50kHz) for 1 hour. After cooling, add methanol to 50ml, shake well and filter. The filtrate is the sample solution.

[0108] The results of HPLC-UV analysis were as follows: Fig.13 shown.

[0109] Preparation of standard sample solution: Take an appropriate amount of imperatorin reference substance, weigh accurately, add methanol to make a solution containing 10 μg per 1 ml to obtain the standard sample solution.

[0110] The results of HPLC-UV analysis were as follows: Fig.12 The standard sample is used to locate the chromatographic peak type, and the chromatographic filler used in the standard sample is also the filler of Example 1.

[0111] from Fig.13 It can be clearly observed that the sample separated by the microspheres prepared in Example 1 can be separated normally, with a peak at 28.4 min, a peak asymmetry of 0.92, and a theoretical plate number of 6140. The theoretical plate number of a chromatographic column is one of the key parameters reflecting the separation ability of a chromatographic column, and is usually used to evaluate the effect of a certain separation technology. The higher the theoretical plate number, the better the separation effect.

[0112] Application Example 2

[0113] The epoxy resin hollow microspheres prepared in Example 4 were used for chromatographic separation of imperatorin in the Chinese medicine Angelica dahurica. The specific steps are as follows:

[0114] Take about 0.4g of Angelica dahurica powder, put it in a 50ml volumetric bottle, add 45ml of methanol, and ultrasonically treat (power 300W, frequency 50kHz) for 1 hour. After cooling, add methanol to 50ml, shake well and filter. The filtrate is the sample solution. Analyze by HPLC-UV, the results are as follows Fig.14 shown.

[0115] from Fig.14 It can be clearly observed that the sample separated by the microspheres prepared in Example 4 can be separated normally, with a peak at 24.79 min, a peak asymmetry of 0.89, and a theoretical plate number of 3210. The theoretical plate number of a chromatographic column is one of the key parameters reflecting the separation ability of a chromatographic column, and is usually used to evaluate the effect of a certain separation technology. The higher the theoretical plate number, the better the separation effect.

[0116] It can be seen from the theoretical plate numbers of Application Examples 1 and 2 that the separation effect of Application Example 1 is significantly better than that of Application Example 2, which indicates that the microspheres prepared by the technical solution of the present application are excellent when used as chromatographic fillers to separate coumarin compounds in natural plant extracts.

[0117] Application Example 3

[0118] The epoxy resin hollow microspheres prepared in Comparative Example 1 were used for the chromatographic separation of imperatorin in the Chinese medicine Angelica dahurica. The specific steps were exactly the same as those in Application Example 1. The results were as follows: Fig.15 shown.

[0119] from Fig.15 It can be clearly observed that when the microspheres prepared in Comparative Example 1 are used for separation, the sample cannot be separated normally.

[0120] Depend on Figures 13-15 It can be seen that when the amount of polytetrahydrofuran polyol used is too small, i.e., 10 parts by weight, the prepared hollow microspheres cannot normally separate imperatorin, while the hollow microspheres prepared by the technical solution provided by the present invention can successfully separate imperatorin, and have a high theoretical plate number and high column efficiency.

[0121] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A hollow epoxy resin microsphere, It is characterized in that The raw material components of the epoxy resin hollow microspheres include epoxy resin emulsion and curing agent. The epoxy resin emulsion includes 5 to 15 parts by weight of epoxy resin and 20 to 50 parts by weight of polyether polyol; the curing agent is 2 to 5 parts by weight.

2. The hollow microsphere according to claim 1, It is characterized in that The epoxy resin is a low-viscosity epoxy resin, and the epoxy value of the low-viscosity epoxy resin is 0.4-0.6 mol / 100g; And / or, the polyether polyol comprises polytetrahydrofuran polyol; and / or, the curing agent comprises polyetheramine; And / or, the epoxy resin includes one or more of bisphenol A epoxy resin, bisphenol F epoxy resin and bisphenol S epoxy resin.

3. The hollow microsphere according to claim 2, It is characterized in that The number average molecular weight of the polytetrahydrofuran polyol is 280 to 350; And / or, the number average molecular weight of the polyetheramine is 90-120.

4. The hollow microsphere according to claim 1, It is characterized in that The particle size of the epoxy resin hollow microspheres is 0.01 to 8.5 μm.

5. A method for preparing hollow microspheres according to any one of claims 1 to 4, It is characterized in that The steps include: a) mixing epoxy resin and polyether polyol uniformly at a set temperature to obtain epoxy resin emulsion; b) adding a curing agent to the epoxy resin emulsion and stirring evenly, and then putting the emulsion into an oven for curing to obtain epoxy resin hollow microspheres.

6. The preparation method according to claim 5, It is characterized in that In step a), the set temperature is 40-70°C.

7. The preparation method according to claim 5, It is characterized in that In step b), the temperature of the epoxy resin emulsion is 30-50° C. when the curing agent is added; And / or, in step b), the stirring speed is 800-1000 r / min; And / or, in step b), the temperature of the oven is 50-100°C.

8. The preparation method according to claim 5, It is characterized in that In step b), after curing, the product is washed with acetone and dried.

9. The preparation method according to claim 8, It is characterized in that In step b), the drying condition is drying in a vacuum environment; And / or, in step b), the drying temperature is 20-28° C. and the drying time is 48-60 hours.

10. Use of the hollow microspheres according to any one of claims 1 to 4 as chromatographic fillers for separation of coumarin compounds in natural plant extracts.

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