WO2019148577A1 - Method for preparing microcapsule containing pure polyamine and microdroplet forming device thereof - Google Patents

Abstract

Disclosed is a method for preparing a microcapsule containing pure polyamine and a microdroplet forming device thereof. The method for preparing a microcapsule containing pure polyamine comprises preparing and stirring a reaction solution, preparing microdroplets of the polyamine and adding the same to the reaction solution to obtain a first stage microcapsule; washing the first stage microcapsule using a cleaning agent, and then drying to obtain the finished microcapsule. The microdroplet forming device can form pure polyamine microdroplets, thereby preparing microcapsules containing pure polyamine.

Description

Method for preparing microcapsule containing pure polyamine and micro droplet forming device thereof Technical field

The invention belongs to the field of microencapsulation, and in particular to a method for preparing microcapsules containing pure polyamines and a microdroplet device thereof.

Background technique

The microencapsulation technique is a technique for producing microcapsules containing a protective shell material and various functional core materials that are wrapped. These core materials become solid before being wrapped, and they become solid after being wrapped, so the use and disposal of these materials is more convenient after microencapsulation. When the substance is wrapped, it is isolated from the environment, which reduces its volatilization, masks its odor, enhances its stability, protects its active ingredients, and controls its release. Microencapsulation technology has been extensively and deeply studied by the academic community since its invention, and it has also been widely used in industry. Microcapsules can perform different functions depending on the permeability of the capsule wall. When the microcapsule wall is relatively tight, the microcapsules can be used to store various functional substances, such as repair liquid (US6518330B2), phase change energy storage material, flame retardant, etc.; and when the microcapsule wall has In the case of modulating permeability, it can be used as a carrier for sustained release or controlled release, such as drugs, antifouling agents, corrosion inhibitors and the like.

In order to meet the demand for the preparation of microcapsules containing different functions, various microencapsulation techniques have been developed over the past few decades. The conventional microencapsulation method can be roughly classified into three types according to the difference in the manner of generating small droplets/small particles for wrapping and the manner of forming the shell material, that is, physical methods, physicochemical compounding methods, and chemical methods. Among them, in-situ polymerization and interfacial polymerization are the two methods used most in the chemical method. In these two methods, whether it is oil-in-water or water-in-oil, when a stable emulsion is formed, the droplets in the emulsion can be The shell monomer in the system is encapsulated by polymer deposition on the oil/water interface.

However, although the microencapsulation technology has been very diverse so far, there are still some materials that cannot be wrapped by existing methods, such as polyamines. As a class of compounds containing two or more amino groups, organic polyamines are widely used as curing agents or chain extenders for epoxy resins, polyureas, nylons, and the like. However, since the molecular structure has both hydrophobic and hydrophilic moieties, organic polyamines can be dissolved in most polar or weakly polar solvents, such as water, benzene, toluene, and the like. Therefore, there is no way to emulsify a pure organic polyamine in a solvent to form a stable emulsion. In addition, because organic polyamines can react with many of the shell monomers used today or can affect their reaction, this high activity is also a reason for their microcapsules being very challenging.

Since polyamines have high activity for both epoxy groups and isocyanate groups, it has been tried for a long time to encapsulate polyamines to prepare self-healing materials. In the field of self-repair, microencapsulated epoxy-amine self-healing systems and microencapsulated isocyanate-amine rapid self-healing systems have attracted more and more attention. In order to manufacture the self-healing materials described above, a great deal of effort has been made in the academic community for the microencapsulation of polyamines. In addition to the use of hollow tubes to load polyamines to prepare self-healing materials, the researchers also prepared various other carriers to load polyamine curing agents, such as hollow polyurea resin (PUF) microcapsules, hollow glass beads (US9522843B2), and Hollow polypropylene cyanide nanofibers. After the preparation of these microcarriers, the polyamine-based curing agent is then loaded in these carriers. During the loading process, depending on the actual situation, you can choose to use vacuum to speed up the loading process. Although the above methods can be used to load polyamines for self-healing purposes, these methods are relatively complex. Li (Li) and others claimed that they successfully wrapped the polyether polyamine, Jeffamine D230, by solvent evaporation. At the same time, the two-component epoxy-amine self-repairing system based on the microcapsules and epoxy microcapsules showed a good repairing effect in the self-repairing epoxy resin. However, according to their report, the content of amine in the finally obtained microcapsules is very low. After optimizing the wrapping conditions, the highest content is only about 20% by weight. Researchers also used the Pickering emulsion method to encapsulate pure polyamines. Although microspheres containing polyamines were prepared, they obtained solid microspheres rather than microcapsules having a core-shell structure. At the same time, they did not further prepare self-healing materials based on such microcapsules to verify the applicability of the prepared pure polyamine-containing microcapsules. Using the rules for the partitioning of polyamines in water and low-polarity carbohydrate solvents, Li (Li) et al. and Yi et al. successfully encapsulated aqueous solutions of polyamines rather than pure polyamines. Since the microcapsule wall prepared by this method is very fragile, these researchers did not even remove the water in the microcapsule before further use of the microcapsule. Chen et al. successfully encapsulated aqueous solutions of diethylenetriamine (DETA) and triethylenetetramine (TETA) using a second complex emulsion produced by a very complex and sophisticated microfluidic device. Through the fine control of the microencapsulation process, this method can prepare microcapsules with uniform dimensions and uniform thickness of the capsule wall. Since the thermal stability of the polyacrylic acid capsule wall used is relatively good, the water in the capsule can be completely removed using a vacuum. Nevertheless, since the capsule wall of the capsule is thick and the original capsule contains a large proportion of moisture, the polyamine content in the final microcapsule is relatively low. In addition, self-healing epoxy resins prepared using such microcapsules are less than ideal for repairing fracture toughness because of the relatively high epoxy crosslink density cured using DETA or TETA.

As can be seen from the above, there is currently no method for preparing a microcapsule containing a pure polyamine having a core-shell structure, a high core material content, and a controllable core material composition. In addition, there is a dilemma for such polyamine-containing microcapsules, that is, in the self-healing application of the microcapsules, we hope that the higher the activity of the encapsulated amine, the better, but using the conventional method In the process of preparing such microcapsules, the more active the amine, the more difficult it is to be encapsulated. So it seems that if we want to wrap pure polyamines, we need to explore a new way to implement their packages. In this invention, we describe a composite process using a T-junction microfluidic device in combination with interfacial polymerization to achieve microencapsulation of pure polyamines.

Summary of the invention

The object of the present invention is to overcome the above problems and to provide a method for preparing microcapsules containing pure polyamines and a microdroplet device thereof, which can complete the preparation of pure polyamine microcapsules and provide a preparation for pure polyamines. A new method and a corresponding micro-dropletization device can well complete the micro-dropletization of pure polyamines.

The object of the invention is achieved by the following technical solution:

A method of preparing microcapsules containing pure polyamines, comprising the following preparation steps:

(1) arranging the reaction solution, and continuously stirring the reaction solution;

(2) micro-droplet treatment of the polyamine, and the micro-dropletized polyamine droplets are added to the reaction solution;

(3) heating the reaction solution to which the polyamine droplets are added to 40-60 ° C, and adjusting the stirring speed to maintain continuous stirring of the reaction solution, and obtaining the preliminary microcapsules after stirring for 2-6 hours;

(4) The primary microcapsules are washed with a cleaning agent, and after drying, the finished microcapsules are obtained.

The reaction solution described in the step (1) is a mixture of a diisocyanate monomer/prepolymer, a surfactant, a catalyst, and a nonpolar or weakly polar solvent which is insoluble or only slightly soluble in the polyamine. The weight ratio of diisocyanate monomer/prepolymer, surfactant and catalyst in each solute is 4-8:0.05-1:0-1, and each solute is insoluble or only slightly soluble in polyamine at 50ml. The non-polar or weakly polar solvent is combined, and the configured reaction solution is placed in a normal temperature environment and stirred at a rate of 80-180 r/min.

The diisocyanate monomer/prepolymer includes any one or more of hexamethylene diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, isophorone diisocyanate, and toluene diisocyanate. The composition may be formed by any one of hexamethylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate or toluene diisocyanate. a prepolymer dissolved in the reaction solution;

The surfactant is selected to be a surfactant capable of promoting the formation of an inverse emulsion;

The catalyst comprises any one of triethylenediamine, 2,4,6-tris(dimethylaminomethyl)phenol or dibutyltin dilaurate capable of promoting the reaction of a polyamine with an isocyanate monomer/prepolymer;

Non-polar or weakly polar solvents which are insoluble or only slightly soluble in polyamines include liquid aliphatic hydrocarbons having from 6 to 18 carbon atoms, cycloalkanes such as cyclohexane, cycloheptane, cyclooctane, cyclodecane. Any one or a mixture of any one or more of decalin.

The micro-droplet treatment in the step (2) is performed by using a micro-droplet device; the polyamine includes any one of an ethylenediamine polycondensate, a polyether amine, a fatty amine, a polyacrylamine, and an aromatic amine. Kind or a mixture of any one or more.

The heating method in step (3) is:

(31) The reaction solution to which the polyamine droplets were added was heated to 40 ° C, and stirred at a stirring speed of 200-250 r / min for 1 hour;

(32) Raise the temperature to 50 ° C, and stir at a stirring speed of 200-250 r / min for 2 hours;

(33) The temperature was raised to 60 ° C, and the preliminary microcapsules were obtained by stirring at a stirring speed of 200-250 r/min for 2 hours.

The cleaning process in step (4) is:

First, a cleaning agent is added to the preliminary microcapsules, and the mixture is stirred uniformly, and then allowed to stand until the solid precipitates, and the supernatant is removed, and the cleaning agent is repeatedly added for cleaning 3-6 times until the supernatant is clarified; Then, the clarified supernatant is removed, and the washed microcapsules are placed in the air until the cleaning agent is completely volatilized to obtain pure microcapsules;

The cleaning agent is a non-polar solvent, and the most preferred cleaning agent is pure cyclohexane.

A micro-dropleting device for preparing microcapsules containing pure polyamines, comprising a crude Teflon tube, inserted into a fine Teflon tube at any position except the ends of the first and last ends of the Teflon tube, and separately connected thereto Pumping device on the thick Teflon tube and the fine Teflon tube; wherein the pumping device connected to the thick Teflon tube is used for pumping out the co-current phase, and pumping out with the fine Teflon tube The device uses and pumps out a polyamine.

Preferably, the number of the fine Teflon tubes is one or more, and each of the fine Teflon tubes is independently connected with a pumping device, and the pumping device is a syringe or a metering pump; The phase is a solution in which a surfactant and a nonpolar or weakly polar solvent which is insoluble or only slightly soluble in the polyamine are mixed in a weight-to-volume ratio of 0.05-1 g: 50 ml.

A micro-dropleting device for preparing microcapsules containing pure polyamines, comprising a pumping device, a flat metal needle connected to the pumping device and vertically disposed, a metal conductor disposed directly below the flat metal needle, and a positive electrode A high-voltage power supply is connected between the flat metal needles and the negative electrode and the metal conductor; the distance between the flat metal needle and the metal conductor is 10-50 cm, and the voltage of the high-voltage power source is 5-15 KV.

A micro-dropletting device for preparing microcapsules containing pure polyamines, comprising a pressure tank with two conduits inserted at the top, one of which extends into the bottom of the pressure tank and the other conduit is placed on top of the pressure tank An atomizing nozzle connected to a conduit extending into the bottom of the pressure tank, and a gas cylinder connected to a conduit disposed at the top of the pressure tank; wherein the compressed gas in the gas cylinder is any non-acid gas.

Compared with the prior art, the present invention has the following advantages and beneficial effects:

(1) The method of the invention provides a brand-new idea, breaks through the bottleneck of the existing polyamine microcapsules, can well complete the production of pure polyamine microcapsules, and promotes the development of enterprises and industries. .

(2) The micro-dropletization device of the present invention has three different composition structures, and provides different setting modes for the enterprise, thereby facilitating selection according to actual needs during use, and greatly improving the flexibility of product use.

DRAWINGS

Figure 1 is a schematic view showing the structure of a first micro-dropletizing apparatus of the present invention.

2 is a schematic view showing the structure of a second micro-dropleting device of the present invention.

Fig. 3 is a schematic view showing the structure of a third micro-dropleting device of the present invention.

DESCRIPTION OF REFERENCE NUMERALS: 1, pumping device; 2, thick Teflon tube; 3, fine Teflon tube; 4, flat metal needle; 5, high voltage power supply; 6, metal conductor; 7, gas tank; Pressure tank; 9, atomizing nozzle.

Detailed ways

The present invention will be further described in detail below with reference to the embodiments, but the embodiments of the present invention are not limited thereto.

Example 1

This embodiment discloses a method for preparing a microcapsule containing a pure polyamine, comprising the following preparation steps:

(1) arranging the reaction solution, and continuously stirring the reaction solution;

The reaction solution is prepared by mixing a diisocyanate monomer/prepolymer, a surfactant, a catalyst, and a non-polar or weakly polar solvent which cannot dissolve or only dissolve a polyamine in a small amount, wherein each solute has two The weight ratio of isocyanate monomer/prepolymer, surfactant and catalyst is 6:0.05:0, and each solute is matched with 50ml of non-polar or weakly polar solvent which cannot dissolve or only dissolve the polyamine in a small amount. The configured reaction solution was placed in a normal temperature environment and stirred at a rate of 80-180 r/min.

Among them, the catalyst may not be used, that is, when the weight ratio of the catalyst therein is zero. The use of the catalyst is to further increase the formation speed of the outer shell of the polyamine droplets after entering the reaction solution, thereby further ensuring the rapid formation of the microcapsules.

The diisocyanate monomer/prepolymer includes any one or more of hexamethylene diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, isophorone diisocyanate, and toluene diisocyanate. The composition may be formed by any one of hexamethylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate or toluene diisocyanate. a prepolymer dissolved in the reaction solution;

The surfactant is selected to be a surfactant capable of promoting the formation of an inverse emulsion which is a polyoxyethylene polyhydroxystearate or a sorbitan fatty acid ester, the most preferred being span 80.

The catalyst comprises any one of triethylenediamine, 2,4,6-tris(dimethylaminomethyl)phenol or dibutyltin dilaurate capable of promoting the reaction of a polyamine with an isocyanate monomer/prepolymer;

Non-polar or weakly polar solvents which are insoluble or only slightly soluble in polyamines include liquid aliphatic hydrocarbons having from 6 to 18 carbon atoms, cycloalkanes such as cyclohexane, cycloheptane, cyclooctane, cyclodecane. Any one or a mixture of any one or more of decalin.

(2) micro-droplet treatment of the polyamine, and the micro-dropletized polyamine droplets are added to the reaction solution;

The micro-droplet treatment is performed by using a micro-droplet device; the polyamine includes any one or more of an ethylenediamine polycondensate, a polyether amine, a fatty amine, a polyacrylamide, and an aromatic amine. mixture.

After the polyamine is converted into micro droplets into the reaction solution, it will react rapidly with the diisocyanate monomer/prepolymer, and the polyamine on the surface of the microdroplet reacts with the diisocyanate monomer/prepolymer. The shell encloses the inner pure polyamine to prevent the internal polyamine from continuing to react with the diisocyanate monomer/prepolymer, thereby forming the desired polyamine microcapsules.

(3) heating the reaction solution to which the polyamine droplets are added to 40-60 ° C, and adjusting the stirring speed to maintain continuous stirring of the reaction solution, and obtaining the preliminary microcapsules after stirring for 2-6 hours;

The heating method is:

(31) The reaction solution to which the polyamine droplets were added was heated to 40 ° C, and stirred at a stirring speed of 200 r / min for 1 hour;

(32) Raise the temperature to 50 ° C, and stir at a stirring speed of 200 r / min for 2 hours;

(33) The temperature was raised to 60 ° C, and the preliminary microcapsules were obtained by stirring at a stirring speed of 200 r / min for 2 hours.

(4) The primary microcapsules are washed with a cleaning agent, and after drying, the finished microcapsules are obtained.

The cleaning process is:

First, a cleaning agent is added to the preliminary microcapsules, and the mixture is stirred uniformly, and then allowed to stand until the solid precipitates, and the supernatant is removed, and the cleaning agent is repeatedly added for cleaning 3-6 times until the supernatant is clarified; Then, the clarified supernatant is removed, and the washed microcapsules are placed in the air until the cleaning agent is completely volatilized to obtain pure microcapsules;

The cleaning agent is a non-polar solvent, and the most preferred cleaning agent is pure cyclohexane.

The content of the amine in the microcapsules produced by the method is about 80% by weight, and the thermal stability of the shell of the microcapsules is relatively good, and the thermal decomposition temperature is above 200 degrees Celsius.

Example 2

This embodiment differs from Embodiment 1 only in that:

The weight ratio of diisocyanate monomer/prepolymer, surfactant to catalyst in each solute was 8:1:1.

The stirring speed at the time of heating the reaction solution to which the polyamine droplets were added was 250 r/min.

Example 3

This embodiment differs from Embodiment 1 only in that:

The weight ratio of the diisocyanate monomer/prepolymer, surfactant and catalyst in each solute was 6:0.6:0.5.

The stirring speed at the time of heating the reaction solution to which the polyamine droplets were added was 225 r/min.

Example 4

As shown in FIG. 1 , this embodiment discloses a micro-dropleting device for preparing microcapsules containing pure polyamines, including a thick Teflon tube 2, inserted into the crude Teflon tube 2 except for the ends of the first and last ends. a fine Teflon tube 3, and a pumping device 1 separately connected to the thick Teflon tube 2 and the fine Teflon tube 3; wherein, the pumping device 1 connected to the thick Teflon tube 2 The pumping device 1 for pumping out the co-current phase and connected to the fine Teflon tube 3 is used to pump out the polyamine.

The number of the fine Teflon tubes 3 is one or more, and each of the fine Teflon tubes 3 is independently connected with a pumping device 1 , and the pumping device 1 is a syringe or a metering pump; The flow phase is a solution in which a surfactant and a nonpolar or weakly polar solvent which is insoluble or only slightly soluble in the polyamine are mixed in a weight-to-volume ratio of 0.05-1 g: 50 ml.

The liquid flow rate in the crude Teflon tube and the fine Teflon tube is controlled by the pumping device, and during the pumping process, the liquid flow rate in the crude Teflon tube is greater than that in the fine Teflon tube. The flow rate is such that the polyamine can become a microdroplet during the flow.

Example 5

As shown in FIG. 2, a micro-dropleting device for preparing microcapsules containing pure polyamines includes a pumping device 1, a flat metal needle 4 connected to the pumping device 1 and vertically disposed, and disposed at the flat metal a metal conductor 6 directly under the needle 4, and a high-voltage power source 5 in which the positive-electrode metal needle 4 is connected and the negative electrode is connected to the metal conductor 6; the distance between the flat metal needle 4 and the metal conductor 6 is 10-50 cm, and the high voltage The voltage of the power source 5 is 5-15 KV.

The polyamine will be charged when passing through the flat metal needle, and will approach the metal conductor under the action of the electric field, and then drip into the carrier disposed above the metal conductor to form microcapsules. To adjust the drip range of the microdroplets, the upper planar area of the metal conductor can be changed. To adjust the size of the microdroplets, it can be done by adjusting the pumping speed or the voltage value of the high voltage power supply.

Example 6

As shown in FIG. 3, a micro-dropleting apparatus for preparing microcapsules containing pure polyamines includes a pressure tank 8 with two conduits inserted at the top, one of which extends into the bottom of the pressure tank 8, and the other The conduit is disposed at the top of the pressure tank 8, an atomizing nozzle 9 connected to the conduit extending into the bottom of the pressure tank 8, and a gas cylinder 7 connected to the conduit disposed at the top of the pressure tank 8; wherein the gas tank 7 The compressed gas is any non-acid gas.

The compressed gas in the gas tank adopts a non-acid gas, which can ensure that the gas does not react with the polyamine, thereby ensuring the purity of the polyamine. The polyamine enters the atomizing nozzle through a conduit under the pressure of air pressure, and is micro dropletized by the atomizing nozzle. The size of the microdroplets can be changed by adjusting the size of the atomizing nozzle and the pressure of the cylinder.

As described above, the present invention can be well implemented.

Claims (10)

A method of preparing microcapsules containing pure polyamines, comprising the following preparation steps: (1) arranging the reaction solution, and continuously stirring the reaction solution; (2) micro-droplet treatment of the polyamine, and the micro-dropletized polyamine droplets are added to the reaction solution; (3) heating the reaction solution to which the polyamine droplets are added to 40-60 ° C, and adjusting the stirring speed to maintain continuous stirring of the reaction solution, and obtaining the preliminary microcapsules after stirring for 2-6 hours; (4) The primary microcapsules are washed with a cleaning agent, and after drying, the finished microcapsules are obtained. The method for preparing a microcapsule containing pure polyamine according to claim 1, wherein the reaction solution described in the step (1) is composed of a diisocyanate monomer/prepolymer, a surfactant, a catalyst, and A non-polar or weakly polar solvent which is insoluble or only slightly soluble in the polyamine, wherein the weight ratio of the diisocyanate monomer/prepolymer, surfactant and catalyst in each solute is 4-8: 0.05-1: 0-1, and each solute is combined with 50 ml of a non-polar or weakly polar solvent which cannot dissolve or only slightly dissolve the polyamine, and the configured reaction solution is placed in a normal temperature environment and Stir at a speed of 80-180 r/min. A method of preparing a microcapsule containing pure polyamine according to claim 2, wherein the diisocyanate monomer/prepolymer comprises hexamethylene diisocyanate, 4,4'-dicyclohexyl Any one or more of methane diisocyanate, isophorone diisocyanate, and tolylene diisocyanate, or hexamethylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, a prepolymer which is soluble in a reaction solution formed by any one of isophorone diisocyanate, diphenylmethane diisocyanate or toluene diisocyanate; The surfactant is selected to be a surfactant capable of promoting the formation of an inverse emulsion; The catalyst comprises any one of triethylenediamine, 2,4,6-tris(dimethylaminomethyl)phenol or dibutyltin dilaurate capable of promoting the reaction of a polyamine with an isocyanate monomer/prepolymer; Non-polar or weakly polar solvents which are insoluble or can only slightly dissolve polyamines include liquid aliphatic hydrocarbons having 6 to 18 carbon atoms, cycloalkanes such as cyclohexane, cycloheptane, cyclooctane, cyclodecane, Any one or a mixture of any one or more of decalin. The method for preparing a microcapsule containing pure polyamine according to claim 3, wherein the micro-droplet treatment in the step (2) is performed by using a micro-droplet device; the polyamine It includes any one or a mixture of any one or more of an ethylenediamine polycondensate, a polyether amine, a fatty amine, a polyacrylamine, and an aromatic amine. A method of preparing a microcapsule containing a pure polyamine according to claim 4, wherein the heating method in the step (3) is: (31) The reaction solution to which the polyamine droplets were added was heated to 40 ° C, and stirred at a stirring speed of 200-250 r / min for 1 hour; (32) Raise the temperature to 50 ° C, and stir at a stirring speed of 200-250 r / min for 2 hours; (33) The temperature was raised to 60 ° C, and the preliminary microcapsules were obtained by stirring at a stirring speed of 200-250 r/min for 2 hours. A method of preparing a microcapsule containing pure polyamine according to claim 5, wherein the cleaning process in the step (4) is: First, a cleaning agent is added to the preliminary microcapsules, and the mixture is stirred uniformly, and then allowed to stand until the solid precipitates, and the supernatant is removed, and the cleaning agent is repeatedly added for cleaning 3-6 times until the supernatant is clarified; Then, the clarified supernatant is removed, and the washed microcapsules are placed in the air until the cleaning agent is completely volatilized to obtain pure microcapsules; The cleaning agent is a non-polar solvent, and the most preferred cleaning agent is pure cyclohexane. A micro-dropleting device for preparing microcapsules containing pure polyamines according to any one of claims 1 to 6, characterized in that it comprises a thick Teflon tube (2) and a small Teflon tube (2) a fine Teflon tube (3) at any position except the ends of the first and last ends, and a pumping device (1) separately connected to the thick Teflon tube (2) and the fine Teflon tube (3); Wherein, the pumping device (1) connected to the thick Teflon tube (2) is used for pumping out the co-current phase, and the pumping device (1) connected to the fine Teflon tube (3) is pumped out Polyamine. A micro-dropleting device for preparing microcapsules containing pure polyamine according to claim 7, wherein the number of the fine Teflon tubes (3) is one or more, each fine A pumping device (1) is independently connected to the fluorotube (3), and the pumping device (1) is a syringe or a metering pump; the co-current phase is composed of a surfactant and cannot be dissolved or only trace A solution in which a non-polar or weakly polar solvent of a polyamine is mixed in a weight-to-volume ratio of 0.05 to 1 g: 50 ml. A micro-dropleting apparatus for preparing microcapsules containing pure polyamines according to any one of claims 1 to 6, characterized in that it comprises a pumping device (1) connected to the pumping device (1) A vertical flat metal needle (4), a metal conductor (6) disposed directly under the flat metal needle (4), and a high voltage connected to the positive flat metal needle (4) and a negative electrode connected to the metal conductor (6) The power source (5); the distance between the flat metal needle (4) and the metal conductor (6) is 10-50 cm, and the voltage of the high voltage power source (5) is 5-15 KV. A micro-dropleting apparatus for preparing microcapsules containing pure polyamines according to any one of claims 1 to 6, characterized in that it comprises a pressure tank (8) with two conduits inserted at the top, one of which is a catheter Extending into the bottom of the pressure tank (8), another conduit is placed at the top of the pressure tank (8), connected to the atomizing nozzle (9) that extends into the bottom of the pressure tank (8), and is placed under pressure A gas tank (7) connected to a conduit at the top of the tank (8); wherein the compressed gas in the gas tank (7) is any non-acid gas.

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