CN107057091B - A kind of nylon-polymethyl methacrylate alloy microsphere and its preparation method and application - Google Patents

Abstract

The invention discloses a nylon-polymethyl methacrylate alloy microsphere, the alloy microsphere comprises nylon microsphere and polymethyl methacrylate; the content of the nylon microsphere in the alloy microsphere is 30-90wt %, the content of polymethyl methacrylate is 10-70wt%; the alloy microspheres use nylon microspheres as the skeleton, wherein the interior of the nylon microspheres is a through-hole structure, and the polymethyl methacrylate is uniformly dispersed in the Porous nylon microspheres exist in the pores, on the surface or both; the alloy microspheres are spherical or nearly spherical particles with a particle size of 1-100 μm. In the alloy microspheres proposed by the present invention, a large number of amide bonds and carboxyl groups and amino groups in the porous nylon microspheres are easy to form hydrogen bonds with the ester groups in polymethyl methacrylate, and the two components are cross-linked with each other to form an interpenetrating network Structure, without compatibilizer, has good compatibility.

Description

A kind of nylon-polymethyl methacrylate alloy microsphere and its preparation method and application

technical field

The invention relates to the technical field of polymer materials. More specifically, it relates to a nylon-polymethyl methacrylate alloy microsphere and its preparation method and application.

Background technique

Polyamide (PA), commonly known as nylon, is one of the five major engineering plastics. It belongs to the largest and most widely used variety of engineering plastics. It has high mechanical strength, good wear resistance and self-lubrication, and good impact toughness. It is widely used in automobiles and machinery. , electronics, construction, military industry, aerospace and other fields have a wide range of applications. With the needs of the progress of the times, rapid manufacturing technology has gradually come into view and is expected to replace traditional processing technology. As a new generation of rapid manufacturing technology, 3D printing technology has been hailed as the symbol of the third industrial revolution. Due to its excellent chemical stability and excellent mechanical properties, nylon is used as the main polymer consumable for 3D printing technology - Selective Laser Sintering (SLS). At present, most of the commercial nylon powders on the market are made by high temperature and high pressure method, such as PA2200 and PA3200GF of EOS Company, 3250MF, FS3400GF, PA3200 of Farsoon Hi-Tech, etc. The performance of these powders for laser sintered formed parts is indeed good, but still There are some disadvantages: For example, during the sintering process, the surface of the formed part will be rough due to the boundary effect caused by the melted particles and the unmelted particles; in addition, the polyamide powder will shrink to a certain extent during laser melting and cooling crystallization, which will affect the quality of the part. Dimensional stability.

Polymethyl methacrylate (PMMA) is a transparent polymer material with excellent optical and surface properties and good dimensional stability. Its good coloring property can also create a bright appearance, and the gloss of the parts is good. , feel delicate; however, PMMA surface hardness is small, poor wear resistance and other shortcomings limit its wider application. Therefore, the existing technology learns from each other and combines the advantages of PMMA and nylon to prepare a blend with the advantages of both. The physical blending method is mainly used to mix dry PA powder and PMMA materials in a high-speed mechanical mixer. , to obtain PMMA/PA12 composite powder, the molded product obtained by sintering the composite powder has a better smooth surface and better dimensional stability than the pure powder, but the composite powder obtained in this way has poor two-phase bonding and poor dispersion Uniform, low mechanical properties.

The present invention proposes a nylon-polymethyl methacrylate alloy microsphere, which adopts in-situ polymerization to make acrylic acid The monomer-like MMA is selectively polymerized in situ inside and on the surface of porous nylon microspheres to obtain PA/PMMA alloy powders with better dimensional stability, surface smoothness and mechanical properties.

Contents of the invention

One object of the present invention is to provide a nylon-polymethyl methacrylate alloy microsphere. In the alloy microspheres, PMMA is uniformly dispersed in the pores and/or surfaces of the porous nylon microspheres, and a large number of amide bonds, carboxyl groups and amino groups in PA easily form hydrogen bonds with the ester groups in PMMA, and the two components are crosslinked. It has an interpenetrating network structure, no compatibilizer is needed, and it has good compatibility.

Another object of the present invention is to provide a method for preparing nylon-polymethyl methacrylate alloy microspheres. The powder composed of alloy microspheres obtained by the preparation method proposed by the present invention is significantly different from the composite powder obtained by physical blending, and has the advantages of both PA and PMMA. Compared with single-component PA and PMMA, alloy microspheres have better Excellent mechanical properties, a certain light transmittance, and a decrease in water absorption.

The third object of the present invention is to provide an application of nylon-polymethyl methacrylate alloy microspheres.

In order to achieve the above-mentioned first object, the present invention adopts the following technical solutions:

A kind of nylon-polymethyl methacrylate alloy microsphere, described alloy microsphere comprises nylon microsphere and polymethyl methacrylate; In described alloy microsphere, the content of nylon microsphere is 30～90wt%, poly The content of methyl methacrylate is 10-70wt%.

Preferably, the alloy microspheres use nylon microspheres as the skeleton, wherein the interior of the nylon microspheres has a through-hole structure, which facilitates the in-situ polymerization of methyl methacrylate monomers inside and on the surface of the porous nylon microspheres, so that polymethyl Methyl acrylate is uniformly dispersed in the pores, the surface or both of the nylon microspheres. Nylon contains a large number of amide bonds, carboxyl groups and amino groups, and it is easy to form hydrogen bonds with the ester groups in PMMA. The two components are cross-linked with each other to form an interpenetrating network structure. It does not require a compatibilizer and has good compatibility.

Preferably, the alloy microspheres are spherical or nearly spherical particles with a particle size of 1-100 μm. The alloy microspheres are mainly made of nylon, which has high mechanical strength and toughness. They are filled with PMMA, so that the alloy shows good comprehensive mechanical properties and has excellent dimensional stability and appearance properties.

Preferably, the nylon microspheres are selected from nylon 6 microspheres, nylon 66 microspheres, nylon 12 microspheres, nylon 11 microspheres, nylon 1212 microspheres, nylon 612 microspheres, nylon 610 microspheres or nylon 1010 microspheres one or more of.

Preferably, the nylon microspheres have a specific surface area of 50-800 m ² /g, a porosity of 5%-85%, and a pore diameter of 0.05-10 μm.

In order to achieve the above-mentioned second purpose, the present invention adopts the following technical solutions:

A preparation method of nylon-polymethyl methacrylate alloy microspheres, comprising the steps of:

1) Add pore-containing nylon microspheres into a solvent, and stir at room temperature for 1 to 2 hours to obtain a uniform dispersion of nylon microspheres;

2) Add a catalyst to the nylon dispersion in step 1), pass in nitrogen to discharge oxygen, and when the temperature rises to 30-50°C, add methyl methacrylate monomer, stir and mix at room temperature, and then heat up to 20-100°C, After 6-48 hours of in-situ polymerization, the reaction is stopped, and the obtained product is filtered under reduced pressure, washed and dried to obtain nylon-polymethyl methacrylate alloy microspheres.

Preferably, the pore-containing nylon microspheres in step 1) are prepared by the dissolution-precipitation method in Chinese Patent Application No. 201510765814.9. In the dissolution-precipitation method, the nylon resin is first dissolved in a good solvent at 70°C to 90°C to form a stable transparent solution, then add a poor solvent containing dispersant PVP to it, precipitate, and post-treatment to obtain porous nylon microspheres with good dispersibility. Preferably, the good solvent used in the dissolution-precipitation method is formic acid solvent, and the mass ratio of nylon to formic acid solvent is 1:8-12; the poor solvent is ethanol solution, and the mass ratio of nylon to ethanol solution is 1:10-15.

Preferably, the solvent in step 1) is selected from one or more of deionized water, methanol, ethanol, isopropanol, n-butanol, and ethylene glycol. In the present invention, the solvent is used to keep the nylon microspheres uniformly dispersed without dissolving.

Preferably, the solvent in step 1) is a mixed solution of ethanol and deionized water, and the mass ratio of ethanol and water is 1:0.1-10; further, the mass ratio of ethanol and water is 1:1-10, 1:2~9, 1:3~8, 1:4~7, 1:5~6, etc.; more preferably, the mass ratio of ethanol to water is 1:0.1~9, 1:0.2~8, 1:0.3～7, 1:0.4～6, 1:0.5～5, 1:0.6～4, 1:0.7～3, 1:0.8～2, 1:0.9～1, etc.

Preferably, the amount of the solvent added in step 1) is 1 to 100 times the mass of the porous nylon microsphere; further, in some specific embodiments of the present invention, for example, the amount of the solvent added is 5-90 times, 5-80 times, 5-70 times, 5-60 times, 5-50 times, 5-40 times, 5-30 times, 5-20 times, 10-20 times the mass of nylon microspheres , 15 to 20 times, etc.; more preferably, the added amount of the solvent is 5 to 15 times, 8 to 15 times, 12 to 15 times, etc. of the mass of the porous nylon microsphere; further, the added amount of the solvent It is 5 to 12 times, 6 to 10 times, 7 to 10 times, 7 to 9 times, 8 to 9 times, etc. of the mass of the porous nylon microsphere.

Preferably, the catalyst described in step 2) is a water-soluble peroxide, which facilitates the catalytic reaction of methyl methacrylate monomer in aqueous solution to generate a polymer, and the catalyst is selected from one of hydrogen peroxide, ammonium persulfate or potassium persulfate One or more; Preferably, the catalyst described in step 2) is ammonium persulfate.

Preferably, the amount of catalyst added in step 2) is 0.1wt%-10wt% of the methyl methacrylate monomer.

Preferably, the amount of the methyl methacrylate monomer added in step 2) is 0.1 to 5 times that of the nylon microspheres containing holes.

Preferably, in step 2), the temperature of the heating reaction is 50-100° C., and the reaction time after heating is 6-24 hours.

A kind of nylon-polymethyl methacrylate alloy powder material, described powder material comprises nylon-polymethyl methacrylate alloy microsphere and antioxidant, the addition of described antioxidant is 0.05wt of alloy microsphere %~1wt%.

Preferably, the antioxidant is selected from one or both of antioxidant 2246, antioxidant 1010, antioxidant 168, antioxidant 1076, and antioxidant 1098; preferably, the antioxidant It is antioxidant 2246.

In order to achieve the above-mentioned third purpose, the present invention adopts the following technical solutions:

The application of a nylon-polymethyl methacrylate alloy microsphere in the fields of chromatographic separation and drug sustained release.

Application of a nylon-polymethyl methacrylate alloy powder material in the fields of functional coatings, electrostatic spraying, 3D printing-selective laser sintering.

Preferably, when the particle size of alloy microspheres in the alloy powder material is 20-90 μm, it is applied to 3D printing-selective laser sintering technology.

Preferably, when the particle size of alloy microspheres in the alloy powder material is 50-80 μm, it is applied to electrostatic spraying.

In the present invention, the acrylic monomer MMA is selectively polymerized in situ inside and on the surface of the porous nylon microsphere, and utilizes the intermolecular hydrogen bonding between a large number of amide bonds in the polyamide and the ester groups in the PMMA, so that the two The components are cross-linked and interact with each other, and the obtained nylon-polymethyl methacrylate alloy microspheres have the advantages of both PA and PMMA, and have better mechanical properties, and have a certain degree of light transmission, and the water absorption rate has decreased.

In addition, unless otherwise specified, any range described in the present invention includes any sub-range formed by the end value or any value between the end values and any value between the end value or any value between the end values.

The beneficial effects of the present invention are as follows:

(1) In the alloy microspheres proposed by the present invention, polymethyl methacrylate is evenly dispersed in the pores and/or surfaces of porous nylon microspheres, and a large amount of amide bonds and carboxyl groups and amino groups in PA are easily soluble with the ester groups in PMMA. Forming hydrogen bonds, the two components are cross-linked with each other to form an interpenetrating network structure, without compatibilizer, and have good compatibility.

(2) The composite powder composed of alloy microspheres proposed by the present invention is significantly different from the composite powder obtained by physical blending, and has the advantages of PA and PMMA. Compared with single-component PA and PMMA, alloy microspheres have better Excellent mechanical properties, a certain light transmittance, and a decrease in water absorption.

(3) The alloy powder has good fluidity and can be used in functional coatings, chromatographic separation, drug slow release, selective laser sintering and other fields; in the application of electrostatic spraying, the powder coating has good colorability and can create gorgeous colors , and sprayed products with good wear resistance; when alloy powder is used as a consumable in 3D printing-selective laser sintering technology, its surface is smooth and has significant dimensional stability, especially suitable for molded products, artwork and personalization Customization etc.

Detailed ways

In order to illustrate the present invention more clearly, the present invention will be further described below in conjunction with preferred embodiments. Those skilled in the art should understand that the content specifically described below is illustrative rather than restrictive, and should not limit the protection scope of the present invention.

Example 1

Preparation of porous nylon 6 microspheres:

Add 40g of nylon 6 pellets and 240ml of formic acid into the reaction kettle and heat up to 80°C, stir for 2 hours to fully dissolve the materials, then add 400ml of ethanol solution with a concentration of 10% g/ml polyvinylpyrrolidone (PVP-K30), and stir vigorously After standing still, the powder was precipitated. Suction filtration, washing with ethanol, and vacuum drying to obtain nylon 6 microspheres containing pores; the average particle diameter of the obtained nylon 6 microspheres is 60 μm, the specific surface area is 23 m ² /g, the porosity is 77%, the pore diameter is 0.1-2 μm, and the bulk density is 0.2 g/mL. Its melting temperature, thermal decomposition temperature, water absorption, tensile strength and other data are shown in Table 1.

Example 2

Preparation of porous nylon 12 microspheres:

Put 40g of nylon 12 pellets and 240ml of acetic acid into the reaction kettle and heat up to 100°C, stir for 2 hours to fully dissolve the materials, then add 400ml of ethanol solution with a concentration of 20% g/ml polyvinylpyrrolidone (PVP-K30), and stir vigorously After standing still, the powder was precipitated. Suction filtration, washing with ethanol, and vacuum drying to obtain nylon 12 microspheres containing pores; the obtained nylon 12 microspheres have a particle size of 60 μm, a specific surface area of 1.1 m ² /g, a porosity of 62%, a pore size of 0.1 to 4 μm, and a bulk density of 0.36 g /mL. Its melting temperature, thermal decomposition temperature, water absorption, tensile strength and other data are shown in Table 1.

Similarly, other pore-containing nylon 11 microspheres, nylon 1212 microspheres, nylon 612 microspheres, nylon 610 microspheres or nylon 1010 microspheres in the examples of the present invention are also prepared by the above-mentioned similar method. The particle size, specific surface area, porosity and pore size of the obtained porous nylon microspheres vary with different preparation methods and preparation conditions.

Example 3

The preparation of nylon 6/PMMA alloy microspheres, the steps are as follows:

Get 5g of nylon 6 porous microspheres and join 50g of water and ethanol solution with a mass ratio of 1:1, stir in a 150mL three-necked flask for 1h and mix to obtain a porous nylon microsphere dispersion; add 0.1g ammonium persulfate, pass Introduce nitrogen and discharge oxygen. When the temperature rises to 45°C, add 0.5g of methyl methacrylate monomer (MMA), then raise the temperature to 75°C and react for 24 hours to stop the reaction. The obtained product is filtered under reduced pressure, washed with ethanol and dried to obtain Nylon 6/PMMA alloy microspheres.

The particle size of the obtained nylon 6/PMMA alloy microspheres remains basically the same as that of the original porous nylon microspheres, and the melting temperature, thermal decomposition temperature, water absorption, tensile strength and other data are shown in Table 1.

Example 4

Preparation of Nylon 6/PMMA Alloy Microspheres

Take 5g of nylon 6 porous microspheres and add it to 50g of water and ethanol solution with a mass ratio of 1:1, stir and mix in a 150mL three-necked flask to obtain a porous nylon microsphere dispersion; add 0.1g of ammonium persulfate, pass through Nitrogen exhausts oxygen. When the temperature rises to 45°C, add 1g of methyl methacrylate monomer (MMA), then raise the temperature to 75°C and react for 24 hours. / PMMA alloy microspheres.

The particle size of the obtained nylon 6/PMMA alloy microspheres remains basically the same as that of the original porous nylon microspheres, and the melting temperature, thermal decomposition temperature, water absorption, tensile strength and other data are shown in Table 1.

Example 5

Preparation of Nylon 6/PMMA Alloy Microspheres

Take 5g of nylon 6 porous microspheres and add it to 50g of water and ethanol solution with a mass ratio of 1:1, stir and mix in a 150mL three-necked flask to obtain a porous nylon microsphere dispersion; add 0.1g of ammonium persulfate, pass through Nitrogen exhausts oxygen. When the temperature rises to 45°C, 5g of methyl methacrylate monomer (MMA) is added, and then the temperature is raised to 75°C for 24 hours to stop the reaction. The obtained product is filtered under reduced pressure, washed with ethanol and dried to obtain nylon 6 / PMMA alloy microspheres.

The particle size of the obtained nylon 6/PMMA alloy microspheres remains basically the same as that of the original porous nylon microspheres, and the melting temperature, thermal decomposition temperature, water absorption, tensile strength and other data are shown in Table 1.

Example 6

Preparation of Nylon 6/PMMA Alloy Microspheres

Take 5g of nylon 6 porous microspheres and add it to 50g of water and ethanol solution with a mass ratio of 1:1, stir and mix in a 150mL three-necked flask to obtain a porous nylon microsphere dispersion; add 0.1g of ammonium persulfate, pass through Nitrogen exhausts oxygen. When the temperature rises to 45°C, 10g of methyl methacrylate monomer (MMA) is added, and then the temperature is raised to 75°C for 24 hours to stop the reaction. / PMMA alloy microspheres.

The particle size of the obtained nylon 6/PMMA alloy microspheres remains basically the same as that of the original porous nylon microspheres, and the melting temperature, thermal decomposition temperature, water absorption, tensile strength and other data are shown in Table 1.

Example 7

Preparation of Nylon 6/PMMA Alloy Microspheres

Take 5g of nylon 6 porous microspheres and add it to 50g of water and ethanol solution with a mass ratio of 1:1, stir and mix in a 150mL three-necked flask to obtain a porous nylon microsphere dispersion; add 0.1g of ammonium persulfate, pass through Nitrogen exhausts oxygen. When the temperature rises to 45°C, 25g of methyl methacrylate monomer (MMA) is added, and then the temperature is raised to 75°C for 24 hours to stop the reaction. The obtained product is filtered under reduced pressure, washed with ethanol and dried to obtain nylon 6 / PMMA alloy microspheres.

The particle size of the obtained nylon 6/PMMA alloy microspheres remains basically the same as that of the original porous nylon microspheres, and the melting temperature, thermal decomposition temperature, water absorption, tensile strength and other data are shown in Table 1.

Comparative example 1

Get 5g of nylon 6 porous microspheres and join 50g of water and ethanol solution with a mass ratio of 1:1, stir in a 150mL three-necked flask for 1h and mix to obtain a porous nylon microsphere dispersion; add 0.1g ammonium persulfate, pass Introduce nitrogen to discharge oxygen. When the temperature rises to 45°C, add 50g of methyl methacrylate monomer (MMA), then raise the temperature to 75°C and react for 24 hours to stop the reaction. The product obtained is filtered under reduced pressure, washed with ethanol and dried to obtain nylon 6/ PMMA alloy microspheres.

The particle size of the obtained nylon 6/PMMA alloy microspheres remains basically the same as that of the original porous nylon microspheres, and the melting temperature, water absorption, tensile strength and other data are shown in Table 1.

Table 1 The properties of nylon 6/PMMA alloy microspheres with different PMMA contents

It can be seen from Table 1 that with the increase of PMMA content, the bulk density of alloy microspheres increases, the water absorption rate decreases slightly, the mechanical properties change little, and the thermal stability decreases. However, if the PMMA content is too low, the alloy exhibits the performance of polyamide and cannot achieve the required dimensional stability of the alloy. If the PMMA content is too high, the mechanical properties of the alloy will decrease and affect the actual use effect. However, if the alloy microspheres are obtained by physical blending, the combination of PMMA and nylon microspheres is not good, and the injection molding sample is prone to phase separation. There are data showing that nylon 6/PMMA alloy microspheres are prepared by physical blending. The mechanical properties are poor, and it is difficult to meet the performance requirements.

Comparative example 2

Nylon 6/PMMA alloy microspheres were prepared by physical blending, wherein the PMMA content was 30wt%. The performance indexes of the alloy microspheres are shown in Table 1.

Example 8-13

Repeat Example 3, the only difference is that the pore-containing nylon 6 microspheres are respectively changed into pore-containing nylon 12 microspheres, pore-containing nylon 11 microspheres, pore-containing nylon 1010 microspheres, pore-containing nylon 66 microspheres, pore-containing nylon 612 microspheres, pore-containing nylon 610 microspheres, and other conditions remain unchanged, and nylon/PMMA alloy microspheres were prepared. The performance indexes of alloy microspheres of different nylon types are shown in Table 2 below.

Comparative example 3

Take 50g of water and ethanol solution with a mass ratio of 1:1 in a 150mL three-necked flask, stir for 1 hour to mix to obtain a dispersion; add 0.1g of ammonium persulfate, pass through nitrogen to exhaust oxygen, and when the temperature rises to 45°C, add methacrylic acid Methyl ester monomer (MMA) 0.5g, then heated to 75 ° C for 24 hours to stop the reaction, the obtained product was filtered under reduced pressure, washed with ethanol and dried to obtain PMMA resin. The performance indexes of PMMA are shown in Table 2 below.

Table 2 Properties of PA/PMMA alloy microspheres of different nylons

As can be seen from this table, compared with pure PMMA and pure nylon, nylon is added PMMA to make alloy among the present invention, can improve the water absorption of polyamide, and can not influence its mechanical property

Examples 14-18

Example 3 was repeated, the only difference being that the reaction temperature was changed from 75°C to 50°C, 60°C, 80°C, 90°C, and 100°C respectively, and the rest of the conditions were unchanged, and the obtained nylon 6/PMMA alloy microspheres were prepared. The various properties of the prepared alloy microspheres are similar to those in Example 3, indicating that the properties of the prepared alloy microspheres change slightly in the range of the suitable reaction temperature of 50-100°C.

Comparative example 4-5

Take 5g of nylon 6 porous microspheres and add them to 50g of water and ethanol solution with a mass ratio of 1:1, stir in 150mL three-necked flasks A and B for 1h and mix to obtain a porous nylon microsphere dispersion; add 0.1g Ammonium persulfate, feed nitrogen to discharge oxygen, when the temperature rises to 45°C, add 0.5g of methyl methacrylate monomer (MMA), then heat up to 20°C and 200°C respectively, react for 24h, stop the reaction, and depressurize the obtained product Suction filtration, washing with ethanol and drying to obtain nylon 6/PMMA alloy microspheres. The prepared alloy is tested and found that the reaction is very slow at lower temperatures, the content of the synthesized PMMA is very small, and the performance index is similar to that of pure pore-containing nylon microspheres; while the alloy prepared at high temperature, the pore-containing nylon microspheres are partially dissolved to obtain If there is no dispersed microsphere structure, it becomes blocky, and the desired microsphere structure product cannot be obtained;

It can be seen from Comparative Examples 4-5 that the reaction temperature lower than 50°C or higher than 100°C is not conducive to the preparation of alloy microspheres.

Examples 19-23

Example 3 was repeated, the only difference being that 0.1 g of the catalyst was changed to 1 mg, 5 mg, 10 mg, 50 mg, and 0.5 g respectively, and the rest of the conditions remained unchanged, and the prepared nylon 6/PMMA alloy microspheres were obtained. The performances of the prepared alloy microspheres are similar to those of Example 3, and the performance of the prepared alloy microspheres changes slightly within the appropriate range of catalyst addition of 0.1 wt% to 10 wt% of the methyl methacrylate monomer.

Comparative example 6-7

Example 3 was repeated, the only difference being that 0.1 g of the catalyst was changed to 0 g and 0.1 mg respectively, and the rest of the conditions remained unchanged, and the obtained nylon 6/PMMA alloy microspheres were prepared. The performance of the obtained product is similar to that of pure nylon microspheres, indicating that no catalyst or too little catalyst will affect the formation of PMMA.

Example 24-25

Example 3 was repeated, the only difference being that the catalyst ammonium persulfate was changed to hydrogen peroxide and potassium persulfate respectively, and the rest of the conditions were unchanged, so as to prepare nylon 6/PMMA alloy microspheres. The performances of the obtained alloy microspheres are similar to those in Example 3, indicating that the two catalysts have good catalytic effects on the synthesis of PMMA.

Examples 26-30

Repeat Example 3, the only difference is that the reaction time is changed from 24h to 6h, 12h, 36h, 48h, 60h respectively, and the rest of the conditions are unchanged, and the obtained nylon 6/PMMA alloy microspheres are prepared. The properties of the prepared alloy microspheres are similar to those in Example 3, and the performance of the prepared alloy microspheres does not change much when the reaction time is at least 6h, but the reaction time is too long to increase the cost, so the present invention selects the reaction time of 6-24h.

Comparative example 8

Take 5g of nylon 6 porous microspheres and add 50g of water and ethanol solution with a mass ratio of 1:1 in a 150mL three-necked flask, stir for 1 hour to mix to obtain a dispersion; add 0.1g of ammonium persulfate, feed nitrogen to discharge oxygen, and heat When the temperature reaches 45°C, add 0.5g of methyl methacrylate monomer (MMA), then raise the temperature to 75°C and react for 5 hours to stop the reaction. .

The content of PMMA in the prepared alloy microspheres was detected to be low, indicating that the reaction time less than 6h was not conducive to obtaining the desired reaction product.

Examples 31-38

Repeat Example 3, the only difference is that the solvent quality 50g is changed to 5g, 10g, 25g, 40g, 60g, 150g, 300g, 500g respectively, and all the other conditions are constant, and the nylon 6/PMMA alloy microspheres are prepared, and the performance is as shown in the table 3.

Table 3 Properties of alloy microspheres under different solvent usage

As can be seen from Table 3, the quality of solvent used is within the range of 1 to 100 times that of nylon microspheres, and the properties of the alloy microspheres prepared are similar to those of Example 3. When the quality of solvent used is 5 to 12 times that of nylon microspheres Within the range of multiples, the properties of the prepared alloy microspheres are optimal. And if used solvent is less (comparative example 9) then easily make deposit stick into a block, powder dispersibility is poor; Solvent uses more (comparative example 10) then can make the PMMA content in the alloy lower and the PMMA that generates in the solution is easy Adsorbed on the surface of microspheres, resulting in uneven distribution of PMMA, affecting the performance of alloy microspheres.

Comparative example 9-10

Get 5g of nylon 6 porous microspheres and add 1g of water and ethanol solution with a mass ratio of 1:1 in a 150mL three-necked flask A; Put the ethanol solution in a 150mL three-necked flask B; stir for 1h to obtain a dispersion, add 0.1g of ammonium persulfate, pass in nitrogen to exhaust oxygen, and when the temperature rises to 45°C, add 0.5g of methyl methacrylate monomer (MMA), Then the temperature was raised to 75° C. for 1 hour, and then the reaction was stopped, and the obtained product was filtered under reduced pressure, washed with ethanol, and then dried to obtain PA/PMMA alloy microspheres.

It is tested that the alloy obtained in A is in the form of a block and no dispersed alloy microspheres can be obtained, indicating that too little solvent is not conducive to obtaining the desired reaction product.

It is detected that the content of PMMA in product B is more in the solution but less in the nylon microspheres, indicating that too much solvent affects the synthesis amount of PMMA in the alloy and affects the properties of the alloy.

Examples 39-43

Repeat Example 3, the only difference is that the mass ratio of solvent ethanol and deionized water 1:1 is changed to 1:0.1, 1:0.5, 1:2, 1:5, 1:10 respectively, and the remaining conditions remain unchanged. The obtained nylon 6/PMMA alloy microspheres. The various properties of the obtained alloy microspheres have a little change with the performance of Example 3. When the content of water in the solvent is greater than ethanol, the nylon microspheres are more easily broken, so too much aqueous solution in the solution is not conducive to obtaining alloy microspheres, and ethanol in the solvent More content has little effect on the properties of the alloy; but when the ratio of ethanol to aqueous solution in the solvent exceeds 1:10, it is not conducive to the miscibility of the catalyst in the solution, which in turn affects the preparation of alloy microspheres.

Comparative example 11-12

Take 5g of nylon 6-containing microspheres and add them to 50g of ethanol solution in a 150mL three-necked flask A, take 5g of nylon 6-containing microspheres and add them to a 50g aqueous solution in a 150mL three-necked flask B, stir for 1h and mix to obtain a dispersion; add 0.1g of ammonium persulfate, feed nitrogen to discharge oxygen, when the temperature rises to 45°C, add 0.5g of methyl methacrylate monomer (MMA), then raise the temperature to 75°C and react for 1 hour to stop the reaction, and the product obtained is subjected to vacuum filtration , washed with ethanol and dried to obtain PA/PMMA alloy microspheres.

After testing, the obtained product A is all nylon microspheres, indicating that PMMA cannot be synthesized when the solvent is pure ethanol; while the product B nylon microspheres are basically broken, and the alloy is flocculent, indicating that when the solvent is an aqueous solution, it is not conducive to obtaining the desired reaction product. .

Example 44

With 50 g of nylon 6/PMMA alloy microspheres obtained in Example 3, add antioxidant 2,2'-methylene bis-(4-methyl-6-tert-butylphenol) (antioxidant 2246) 0.1 g, Stir and mix in a vertical mixer for 1 hour, and pass through a 200-mesh sieve after the materials are evenly mixed, and can be directly used in 3D printing-selective laser sintering technology.

Example 45

With 50 g of nylon 6/PMMA alloy microspheres obtained in Example 3, add antioxidant 2,2'-methylene bis-(4-methyl-6-tert-butylphenol) (antioxidant 2246) 0.1 g, Stir and mix in a vertical mixer for 1 hour. After the materials are evenly mixed, pass through a 200-mesh sieve and can be directly used for electrostatic spraying.

Examples 46-49

Repeat Example 40, the only difference is that the antioxidant 2246 is changed to antioxidant 1010, antioxidant 168, antioxidant 1076, and antioxidant 1098 respectively, and the obtained alloy powder is sieved and can be directly used in electrostatic Spray coating or selective laser sintering techniques.

Example 50

Soak 50 g of the nylon 6/PMMA alloy microspheres obtained in Example 3 with 90-95% ethanol, stir continuously to remove air bubbles, and then pack into a column, elute with 3-4 times the volume of ethanol until the eluent is transparent and evaporated. Dries without residue. It is then eluted with 2-2.5 times the volume of 5% NaOH aqueous solution in turn, and finally eluted with distilled water until the pH is neutral. It is used as a stationary phase in column chromatography to separate proteins and flavonoids.

Example 51

The nylon/acrylic resin alloy microspheres obtained in Examples 1-43 can be further loaded with drug molecules by physical or chemical adsorption for drug sustained release research.

Conclusion: In the alloy microspheres prepared by the present invention, the porous nylon microspheres and polymethyl methacrylate are cross-linked by hydrogen bonds. Under the joint action of the two, the obtained nylon-polymethyl methacrylate alloy microspheres The ball has the advantages of both PA and PMMA, and has better mechanical properties, and has a certain degree of light transmission, and the water absorption rate has decreased. Wherein the PMMA content is too low and the alloy exhibits the performance of polyamide and cannot reach the effect that the desired alloy has dimensional stability, and the excessively high content will lead to the decline of the mechanical properties of the alloy and affect the actual use effect.

Apparently, the above-mentioned embodiments of the present invention are only examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those of ordinary skill in the art can also make It is not possible to exhaustively list all the implementation methods here, and all obvious changes or changes derived from the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims (3)

1. a kind of nylon-polymethyl methacrylate alloy microballoon preparation method, which comprises the steps of:

1) apertures nylon micro-sphere is added in solvent, 1 ~ 2h is stirred at room temperature and is mixed to get uniform nylon micro-sphere dispersion liquid；Institute The additional amount for stating solvent is 1 ~ 100 times of apertures nylon micro-sphere quality, and the solvent is ethyl alcohol and deionized water mixed solution, second The mass ratio of alcohol and water is 1:0.1~10；

2) catalyst is added in the nylon dispersion liquid into step 1), is passed through nitrogen discharge oxygen and adds when being warming up to 30 ~ 50 DEG C Enter methyl methacrylate monomer, mixing is stirred at room temperature, then be warming up to 50 ~ 100 DEG C, through stopping after home position polymerization reaction 6 ~ for 24 hours Reaction, obtains product and carries out decompression suction filtration, and drying obtains nylon-polymethyl methacrylate alloy microballoon, the first after washing The additional amount of base methacrylate monomer is 0.1 ~ 5 times of apertures nylon micro-sphere；

The catalyst is selected from one or more of hydrogen peroxide, ammonium persulfate or potassium peroxydisulfate.

2. a kind of nylon according to claim 1-polymethyl methacrylate alloy microballoon preparation method, feature exist In catalyst charge described in step 2 is 0.1 ~ 10wt% of methyl methacrylate monomer.

3. a kind of nylon that preparation method as described in claim 1 is prepared-polymethyl methacrylate alloy microballoon system The dusty material obtained, which is characterized in that the dusty material includes nylon-polymethyl methacrylate alloy microballoon and antioxygen Agent, the additional amount of the antioxidant are 0.05wt% ~ 1wt% of alloy microballoon；The antioxidant is selected from antioxidant 2246, antioxidant 1010, one or both of irgasfos 168, antioxidant 1076, antioxidant 1098.