Method for modifying hydrophilic polyelectrolyte multilayer film on surfaces of hydrophobic polymer particles by using coating machine

Abstract

The invention relates to a method for modifying a hydrophilic polyelectrolyte multilayer film on the surfaces of polymer particles by using a coating machine, which comprises the following steps of: firstly, respectively preparing polyelectrolyte polymers with opposite charges into a polyelectrolyte polymer aqueous solution A and a polyelectrolyte polymer aqueous solution B; and alternately spraying the polyelectrolyte aqueous solution with opposite charges on the surfaces of polymer particles transferred in a coating machine pot by adopting a spraying method, cleaning redundant non-adsorbed polyelectrolyte polymer by using clear water, and adjusting the circulating spraying times of the polyelectrolyte solution A and the polyelectrolyte solution B to obtain the polymer particles. The number of layers of polyelectrolyte multilayer films on the surfaces of the hydrophobic polymer particles can be adjusted, so that the hydrophilicity of the surfaces of the polymer particles is controlled; the method has the advantages of simple operation, easy implementation and the like, and the prepared material can be used in the fields of coating, printing ink, spinning, papermaking and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer material preparation and molecular particle surface modification, and specifically provides a method for modifying a hydrophilic polyelectrolyte multilayer film on the surface of hydrophobic polymer particles by using a coating machine. Background Art

[0002] Polymer particles have been widely used in coatings, inks, cosmetics, food, medicine, and biotechnology due to their good chemical stability, mechanical properties, and processability. However, most polymer particles have hydrophobic surfaces, which leads to poor dispersibility and biocompatibility in aqueous solutions, severely limiting their application range. In order to overcome these problems, it is urgent to modify the surface of polymer particles to be hydrophilic.

[0003] Common hydrophilic modification methods include:

[0004] 1. Use chemical methods to change the surface chemical composition of polymer particles: for example, introduce hydrophilic groups through chemical grafting, copolymerization, etc.

[0005] 2. Use physical methods to change the chemical composition of the surface of polymer particles: for example, change the surface properties of polymer particles through plasma, gamma-ray irradiation, etc., so that they produce polar hydrophilic polar groups.

[0006] The above method changes the surface chemical composition of polymer particles so that the inert CC, CF etc. become polar functional groups, thereby dispersing more easily in the aqueous phase. But at the same time, due to the change of the surface chemical composition, its stability and processing properties in the environment will also change. It is a common solid material surface modification method to construct a hydrophilic polyelectrolyte multilayer film on the solid surface by self-assembly of water-soluble polyelectrolytes, which has the advantages of no need for complex instruments and equipment, simple operation, low cost and no selectivity to substrate, so it is widely used in sensors, electronic devices, lubricants and controlled drug release systems, anti-fog, anti-icing, anti-waxing coatings and other fields. In addition, since this method does not change the surface properties of the polymer itself, it can be made into polymer materials of different shapes using the same processing method as traditional polymers. At present, polyelectrolyte multilayer films have been successfully constructed on hydrophobic polymer blocks and film materials using methods such as dipping and spraying, and the coverage of hydrophilic polyelectrolyte multilayer films on its surface can be adjusted.

[0007] Due to the low surface tension of hydrophobic polymer particles, they cannot be wetted by water and are therefore difficult to disperse directly in the aqueous phase, which limits the application of layer-by-layer self-assembly methods for surface modification by polymer solution impregnation. Wang et al. recently used degassed water to successfully achieve aqueous dispersion of hydrophobic polymer particles, but the cost of converting ordinary water into degassed water by freeze-drying is high, and the economic efficiency needs to be improved (Chem. Commun., 2023, 59, 12479-12482). Summary of the invention

[0008] In order to overcome the problems existing in the prior art, the present invention proposes a method for modifying the surface of hydrophobic polymer particles with a polyelectrolyte multilayer film by a layer-by-layer self-assembly method using a coating machine. This method can overcome the shortcomings of the prior art, realize the modification of the hydrophilic polyelectrolyte multilayer film on the surface of the hydrophobic polymer particles and the regulation of its proportion, and increase the hydrophilicity of the surface without changing the inherent chemical properties of the surface of the hydrophobic polymer particles.

[0009] Specifically, the present invention provides a method for modifying a hydrophilic polyelectrolyte multilayer film on the surface of a hydrophobic polymer particle by using a coating machine. The method uses a coating machine to modify a hydrophilic polyelectrolyte multilayer film with n layers on the surface of a hydrophobic polymer particle by a layer-by-layer self-assembly method, wherein n is 1 to 100.

[0010] The method of the present invention has the advantages of simple operation, low cost, and easy large-scale preparation. The hydrophobic polymer particles modified with a hydrophilic polyelectrolyte multilayer film prepared by the method have good surface hydrophilicity. Under air conditions, the contact angle of water droplets on the surface is reduced from 60°-120° to less than 30°, which can effectively improve its dispersibility and biocompatibility in aqueous solution and expand its application range.

[0011] The method of modifying a hydrophilic polyelectrolyte multilayer film on the surface of a hydrophobic polymer particle by using a coating machine according to the present invention comprises the following steps:

[0012] Step 1: preparing polyelectrolyte polymers with opposite charges into polyelectrolyte polymer aqueous solution A and polyelectrolyte polymer aqueous solution B respectively, wherein the polyelectrolytes with opposite charges include polycation electrolytes and polyanion electrolytes;

[0013] Step 2: After loading the polymer particles with hydrophobic surfaces to be modified into the pot of the coating machine, spray the polyelectrolyte polymer aqueous solution A onto the surface of the polymer particles, wash with clean water, and wait for it to dry. This layer of polyelectrolyte polymer is recorded as a polyelectrolyte multilayer film with 1 modified layer on the surface of the hydrophobic polymer particles (n=1);

[0014] Step 3: spraying the polyelectrolyte polymer aqueous solution B onto the surface of the polymer particles, washing with clean water, and drying it. This layer of polyelectrolyte polymer is recorded as a polyelectrolyte multilayer film with two modified layers on the surface of the hydrophobic polymer particles (n=2);

[0015] Step 4: Repeat the process of step 2 and step 3, and achieve the purpose of modifying the surface of the hydrophobic polymer particles with a hydrophilic polyelectrolyte multilayer film with n layers by adjusting the spraying times of the polyelectrolyte solution and other conditions.

[0016] The polymer particles with surface modified polyelectrolyte multilayer films used in the present invention have a number of layers n of 1 to 100, preferably n of 1 to 50. After modification, the contact angle of water on the surface is reduced from the original 60°-120° to below 60°, and even reaches the super-hydrophilic standard of 10°. The solid content of the saturated solution of the modified hydrophilic polyelectrolyte polymer particles in the water phase is 1% to 80%, preferably 10% to 80%.

[0017] In the method described in the present invention, a polyelectrolyte multilayer film is modified on the surface of hydrophobic polymer particles by using a coating machine. In step 1, the polycationic electrolyte includes one or a mixture of polydiallyldimethylamine halide, polyethyleneimine, polyacrylic acid hydrochloride, and chitosan. The molecular weight of the polycationic electrolyte is 5,000 to 1,000,000, preferably 10,000 to 500,000. The concentration of the polycationic electrolyte polymer aqueous solution is 0.1 g / L to 20 g / L, preferably 0.5 g / L to 10 g / L, wherein the content of inorganic salt is 0-5 mol / L, preferably 0-1 mol / L.

[0018] The present invention describes a method for modifying a polyelectrolyte multilayer film on the surface of hydrophobic polymer particles using a coating machine. In step 1, the polyanion electrolyte includes one or more of sodium polystyrene sulfonate (PSS), sodium polyvinyl sulfonate (PVS), polyacrylic acid (PAA), polymethacrylic acid (PMA), sodium carboxymethyl cellulose (CMC-Na), polymethacrylic acid (PMAA), poly(2-vinylpyridine) (P2VP), poly(4-vinylpyridine) (PVP), polymaleic acid (PMA), polypeptides, proteins, DNA, hyaluronic acid, polymaleic acid, and sodium styrene sulfonate-maleic acid copolymer (PSS-MA). The molecular weight of the polyanion electrolyte is 2,000 to 1,000,000, preferably 6,000 to 200,000. The polyanion electrolyte polymer aqueous solution is 0.01 to 20 g / L, preferably 0.5 to 10 g / L, and the inorganic salt concentration contained is 0-5 mol / L, preferably 0 to 1 mol / L.

[0019] In the method for modifying a polyelectrolyte multilayer film on the surface of a hydrophobic polymer particle using a coating machine described in the present invention, in step 2, the surface hydrophobic polymer particles to be modified include the following polymers or copolymers thereof and derivatives thereof:

[0020] (i) General plastics: for example, polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS), acrylonitrile-butadiene-styrene copolymer (ABS), etc.;

[0021] (ii) Engineering plastics: for example, polycarbonate (PC), polyamides (such as nylon 6, nylon 66, nylon 610, etc.), polyoxymethylene (POM), saturated polyesters (such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), etc.), polyphenylene ether (PPO), etc.;

[0022] (III) Special plastics: for example, high-temperature nylon (such as polybutylene adipamide (PA46), polyphenylene sulfide (PPS), polysulfones (such as polysulfone (PSF), polyethersulfone (PES), polyarylsulfone (PASF); polyphenylene sulfone (PPSU)), polyimides (such as isophthalic polyimide (PI), polyetherimide (PEI), polyamideimide (PAI)), polyaryletherketone (such as polyetheretherketone (PEEK), polyetherketone (PEK)), liquid crystal polymer (LCP), etc.;

[0023] (iv) Barrier plastics: for example, polyvinyl alcohol (PVA), polyvinylidene chloride (PVDC), polyethylene naphthalate (PEN), etc.;

[0024] (V) Corrosion-resistant plastics: for example, polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyperfluoroethylene propylene (FEP), chlorinated polyether (CP), etc.;

[0025] (vi) Photoelectric resins: for example, polyaniline (PAn), polythiophene (PTh), polypyrrole (PPy), etc.;

[0026] (VII) Degradable plastics: for example, polylactic acid (such as polylactic acid (PLA), polyglycolic acid (PGA)), polyalkyl alkanoates (such as poly-3-hydroxybutyrate PHB), polyaliphatic esters (such as polybutylene succinate (PBS), polycaprolactone (such as poly-ε-caprolactone (PCL)), carbon dioxide copolymers (carbon dioxide-ethylene oxide copolymer (PPE)), etc.;

[0027] (VIII) Thermoplastic elastomers: for example, styrene-based (TPS) (such as styrene-butadiene-styrene block copolymer (SBS)), polyethylene-olefin copolymer (POE) and the like.

[0028] (IX) Other plastics: for example, thermosetting plastics (such as phenolic resin (PF), epoxy resin (EP), polymethyl methacrylate (PMMA)), cellulosic plastics (such as cellulose acetate (CA)), polyolefins (such as polybutene (PB)), etc.

[0029] (10) Rubber: for example, natural rubber, synthetic rubber (such as silicone rubber (SI), styrene-butadiene rubber (SBR)), etc.

[0030] The contact angle of water droplets on the surface of polymer particles is 60°~120°

[0031] In the method described in the present invention for modifying a polyelectrolyte multilayer film on the surface of hydrophobic polymer particles using a coating machine, the rotation speed of the coating machine used in step 2 and / or step 3 is 0-100 rad / min, preferably 10-30 rad / min; the temperature of the hot air used for drying is 20-100°C, preferably 40-80°C.

[0032] The present invention achieves the following technical effects: a method for modifying a hydrophilic polyelectrolyte multilayer film on the surface of a hydrophobic polymer particle by layer-by-layer self-assembly using a coating technology is provided. By regulating the thickness of the polyelectrolyte multilayer film, its surface hydrophilicity can be regulated while keeping the surface properties of the hydrophobic polymer particle unchanged. At the same time, the active groups of the outermost layer of the polyelectrolyte multilayer film, such as amino groups, carboxyl groups, etc., can be used for further modification. The above method not only changes the surface hydrophilicity of the polymer multilayer film, but also can use traditional polymer molding methods to process the polymer particles with the surface modified with the polyelectrolyte multilayer film into polymer materials of different shapes. The present invention solves the technical problem of modifying a hydrophilic polyelectrolyte multilayer film on the surface of a hydrophobic polymer particle that is difficult to disperse in water by using a layer-by-layer self-assembly method. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic structural diagram of the coating machine used in the present invention.

[0034] Figure numerals: 1-system emergency stop switch, 2-external heating switch, 3-internal heating switch, 4-air supply switch, 5-air volume adjustment knob, 6-deionized water injection rate knob, 7-solution A injection rate knob, 8-solution B injection rate knob, 9-hot air temperature adjustment control panel, 10-pot body rotation speed adjustment control panel, 11-deionized water tank, 12-solution A tank, 13-solution B tank, 14-hot air pipe, 15-coating pot, 16-washing drain switch, 17-drain port, 18-internal heater;

[0035] Figure 2 The flow chart of using a coating machine to modify polyelectrolyte multilayer films on the surface of polymer particles. DETAILED DESCRIPTION

[0036] In order to further understand the present invention, the preferred technical scheme of the present invention is described in detail with specific examples below. The reagents and raw materials used in the following examples and test examples are all industrial pure commodities, and the equipment used are all commonly used equipment and devices in the field. Figure 1 It is the structure diagram of the coating machine used in the present invention, such as Figure 1 As shown, the device used includes: a coating machine, a solution A tank 12 connected to the coating machine through a pipeline, a solution B tank 13, a deionized water tank 11 and an internal heater 18 connected to the coating machine through a hot air pipe 14. Figure 2 The flow chart of using a coating machine to modify polyelectrolyte multilayer films on the surface of polymer particles is as follows: Figure 2 As shown, step one: prepare polymer solutions A and B, steps two and three are spraying solutions A and B respectively, washing and drying, and step four repeats steps two and three to obtain a hydrophilic polyelectrolyte multilayer film with n modified layers on the surface of the hydrophobic polymer particles.

[0037] Example 1

[0038] Step 1: Use deionized water to prepare aqueous solution A of polycation electrolyte polyallyl dimethyl ammonium chloride (PDADMAC) and aqueous solution B of polyanion electrolyte polystyrene sulfonate (PSS). Wherein, polyelectrolyte aqueous solution A is an aqueous solution of polyallyl dimethyl ammonium chloride (PDADMAC) with a molecular weight of 100,000, a concentration of 1 g / L, and an inorganic salt concentration of 1 mol / L; polyelectrolyte aqueous solution B is an aqueous solution of polyanion electrolyte polystyrene sulfonate (PSS) with a molecular weight of 200,000, a concentration of 2 g / L, and an inorganic salt concentration of 0.5 mol / L.

[0039] Step 2: Pour 2500g of polytetrafluoroethylene polymer particles with a particle size of 0.1μm into the pot of the coating machine, spray 500mL of polyelectrolyte aqueous solution A onto the surface of the polymer particles at a rotation speed of 20rpm, rinse with deionized water, and then dry with hot air at 40°C to obtain hydrophobic polymer particles with n=1 layers of polyelectrolyte multilayer film modified on the surface.

[0040] Step 3: Spray 500 mL of polyelectrolyte aqueous solution B onto the surface of the polymer particles, rinse with deionized water, and then dry with hot air at 60° C. to obtain hydrophobic polymer particles with n=2 layers of polyelectrolyte multilayer films modified on the surface.

[0041] Step 4: Repeat the process of steps 2 and 3 for 5 times, that is, spray the polyelectrolyte aqueous solution A and the polyelectrolyte aqueous solution B alternately onto the surface of the polytetrafluoroethylene polymer particles for 5 times, and then polytetrafluoroethylene particles modified with n=10 layers of polyelectrolyte polymers can be obtained. Under air conditions, the contact angle of water droplets on its surface drops from 120° when it is not modified to 10°. The maximum solid content of its dispersion in the aqueous phase is 50%.

[0042] Example 2

[0043] Step 1: Use ultrapure water to prepare aqueous solution A of sodium polyacrylate (PAA) and aqueous solution B of polyetherimide (PEI). Polyelectrolyte aqueous solution A is a PAA aqueous solution with a molecular weight of 100,000, a concentration of 0.5 g / L, and an inorganic salt concentration of 1 mol / L. Polyelectrolyte aqueous solution B is a PEI aqueous solution with a molecular weight of 10,000, a concentration of 0.3 g / L, and an inorganic salt concentration of 1 mol / L.

[0044] Step 2: Pour 2500 grams of polystyrene polymer particles with a particle size of 1 μm into the container of a coating machine, spray 500 milliliters of polyelectrolyte aqueous solution A onto the surface of the polymer particles at a speed of 30 revolutions per minute, wash with clean water, and then dry with hot air at 40°C to obtain hydrophobic polymer particles with a surface modified with n=1 layers of polyelectrolyte multilayer film.

[0045] Step 3: Spray 600 ml of polyelectrolyte aqueous solution B onto the surface of the polymer particles, wash with clean water, and then dry with hot air at a temperature of 60° C. to obtain polymer particles modified with n=2 layers of polyelectrolyte multilayer membranes on the surface.

[0046] Step 4: Repeat the process of steps 2 and 3, and spray the polyelectrolyte aqueous solutions A and B alternately onto the surface of the polymer particles 6 times to obtain hydrophobic polymer particles modified with n=6 layers of polyelectrolyte multilayer films. Under air conditions, the contact angle of water droplets on its surface drops from 120° when it is not modified to 15°. The maximum solid content of its dispersion in the aqueous phase is 10%.

[0047] Example 3

[0048] Step 1: Use deionized water to prepare polycationic chitosan aqueous solution A and polyanionic electrolyte hyaluronic acid aqueous solution B. Polyionic electrolyte aqueous solution A is an aqueous solution of chitosan with a molecular weight of 100,000, a concentration of 1g / L, and an inorganic salt concentration of 1mol / L; polyionic electrolyte aqueous solution B is an aqueous solution of hyaluronic acid with a molecular weight of 10,000, a concentration of 1.5g / L, and an inorganic salt concentration of 1mol / L.

[0049] Step 2: Pour 1000g of polypropylene polymer particles with a particle size of 10μm and 1000g of epoxy resin polymer particles with a particle size of 10μm into a coating pan. At a rotation speed of 15rpm, spray 500mL of polyion electrolyte aqueous solution A onto the surface of the polymer particles, wash with deionized water, and then dry with hot air at 40°C to obtain hydrophobic polymer particles modified with n=1 layers of polyelectrolyte multilayer membrane on the surface.

[0050] Step 3: Spray 500 mL of polyion electrolyte aqueous solution B onto the surface of the polymer particles, wash with deionized water, and then dry with hot air at 60° C. to obtain hydrophobic polymer particles modified with n=2 layers of polyelectrolyte multilayer films on the surface.

[0051] Step 4: Repeat steps 2 and 3, spray polyelectrolyte aqueous solution A and polyelectrolyte aqueous solution B onto the surface of the hydrophobic polymer particles 7 times in sequence, and then hydrophobic polymer particles with n=7 layers of polyelectrolyte multilayer films modified on the surface can be obtained. The coverage of the polyelectrolyte multilayer film reaches 100% of the hydrophobic polymer particles. Under air conditions, the contact angle of water droplets on its surface drops from 100° when it is not modified to 25°. The maximum solid content of its dispersion in the aqueous phase is 0.8g / mL.

[0052] Example 4

[0053] Step 1: Use deionized water to prepare polyallylamine hydrochloride (PAH) aqueous solution A and polyacrylic acid (PAA) aqueous solution B respectively. Polyelectrolyte solution A is an aqueous solution of polyallylamine hydrochloride (PAH) with a concentration of 10 g / L, a molecular weight of PAH of 100,000, and an inorganic salt concentration of 1 mol / L; polyelectrolyte aqueous solution B is an aqueous solution of polyacrylic acid with a concentration of 8 g / L, a molecular weight of PAA of 100,000, and an inorganic salt ion concentration of 1 mol / L;

[0054] Step 2: Pour 1000g of polyvinyl chloride polymer particles with a particle size of 10μm and 1000g of epoxy resin polymer particles with a particle size of 10μm into the coating machine of the coating equipment. At a rotation speed of 15rpm, spray 500mL of polyelectrolyte solution A onto the surface of the polymer particles. Rinse the surface of the polymer particles with deionized water. Then dry the polymer particles with hot air at 40°C. That is, the polymer particles modified with hydrophilic polyelectrolyte multilayer membranes with the number of polyelectrolyte multilayer membrane layers n=1 are obtained.

[0055] Step 3: Spray 600 mL of polyelectrolyte aqueous solution B onto the surface of the polymer particles, wash with hydrophilic water, and then dry with hot air at 75° C. to obtain polymer particles modified with hydrophilic polyelectrolyte multilayers with the number of polyelectrolyte multilayers n=2.

[0056] Step 4: Repeat the process of steps 2 and 3 4 times, that is, spray the polyelectrolyte aqueous solution A and the polyelectrolyte aqueous solution B onto the surface of the polystyrene polymer particles 4 times in sequence, and then obtain polyelectrolyte polymer modified hydrophobic polymer particles with polyelectrolyte multilayer film layers n=8, and the contact angle of the surface is reduced from 100° to 20°. The maximum solid content of the dispersion in the aqueous phase is 70%.

[0057] Example 5

[0058] Step 1: Use deionized water to prepare an aqueous solution A of a polycation electrolyte polydiallyldimethylammonium chloride (PDADMAC), wherein the polyelectrolyte aqueous solution A is an aqueous solution of PDADMAC, with a concentration of 1 g / L, a molecular weight of PDADMAC of 100,000, and an inorganic salt ion concentration of 1 mol / L. Use deionized water to prepare an aqueous solution B of a polyanion electrolyte polyacrylic acid (PAA), wherein the polyelectrolyte aqueous solution B is an aqueous solution of PAA, with a concentration of 2 g / L, a molecular weight of PAA of 100,000, and an inorganic salt ion concentration of 1 mol / L.

[0059] Step 2: Pour 500g of polylactic acid (PLA) polymer particles with a particle size of 5μm and 1000g of polystyrene (PS) polymer particles with a particle size of 8μm into the pot of the coating machine. At a speed of 15rpm, spray 100mL of polyelectrolyte aqueous solution A onto the surface of the polymer particles. Wash the surface of the polymer particles with deionized water and then dry them with hot air at 40°C. That is, hydrophilic polyelectrolyte multilayer membrane-modified polymer particles with a polyelectrolyte multilayer membrane layer number n=1 are obtained.

[0060] Step 3: Spray 100 mL of polyelectrolyte aqueous solution B onto the surface of polymer particles. Wash the surface of polymer particles with deionized water, and then dry with hot air at 75° C. Obtain hydrophobic polymer particles modified with hydrophilic polyelectrolyte multilayer films with a polyelectrolyte multilayer film number n=2.

[0061] Step 4: Repeat the process of step 2 and step 3, spray the polyelectrolyte aqueous solution A and polyelectrolyte aqueous solution B onto the surface of the polymer particles in turn, and you can get the hydrophobic polymer particles modified by polyelectrolyte polymers with a polyelectrolyte multilayer film layer number n=4. In the air environment, the contact angle of water droplets on its surface drops from 95° to 30°. The maximum solid content of its dispersion in the water phase is 60%.

[0062] Example 6

[0063] Step 1: Use deionized water to prepare polycationic electrolyte polydiallyldimethylammonium chloride (PDADMAC) aqueous solution A and polyanionic electrolyte polypeptide aqueous solution B. Polyelectrolyte aqueous solution A is an aqueous solution of PDADMAC with a concentration of 1 g / L, a molecular weight of PDADMAC of 1 million, and an inorganic salt ion concentration of 1 mol / L. Polyelectrolyte aqueous solution B is a polypeptide aqueous solution with a concentration of 2 g / L, a molecular weight of polypeptide of 1 million, and an inorganic salt ion concentration of 1 mol / L.

[0064] Step 2: Pour 500g of polylactic acid particles with a particle size of 10μm and 100g of polylactic acid particles with a particle size of 5μm into a coating pan, spray 200mL of polyelectrolyte aqueous solution A onto the surface of the polylactic acid particles at a rotation speed of 150rpm, wash the surface of the polymer particles with clean water, and then dry with hot air at 45°C. That is, hydrophilic polyelectrolyte multilayer membrane-modified hydrophobic polymer particles with a polyelectrolyte multilayer membrane layer number n=1 can be obtained.

[0065] Step 3: Spray 200 mL of polyelectrolyte aqueous solution B onto the surface of the polymer particles, wash the surface of the polymer particles with clean water, and then dry with hot air at 60° C. Hydrophobic polymer particles modified with hydrophilic polyelectrolyte multilayers with a polyelectrolyte multilayer layer number n=2 are obtained.

[0066] Step 4: Repeat the process of step 2 and step 3, spray the polyelectrolyte aqueous solution A and polyelectrolyte aqueous solution B onto the surface of polypropylene polymer particles 4 times in sequence. Hydrophilic polyelectrolyte multilayer membrane modified hydrophobic polymer particles with polyelectrolyte multilayer membrane number n=8 can be obtained. The contact angle of water droplets on the surface decreases from 95° to 20°. The maximum solid content of the dispersion in the aqueous phase is 70%.

[0067] Example 7

[0068] Step 1: Use deionized water to prepare polyanion DNA aqueous solution A and polycation chitosan aqueous solution B respectively. Among them, polyelectrolyte aqueous solution A is an aqueous solution of DNA with a concentration of 5 g / L, a molecular weight of DNA of 200,000, and an inorganic salt concentration of 1 mol / L, and polyelectrolyte aqueous solution B is an aqueous solution of chitosan with a concentration of 10 g / L, a molecular weight of chitosan of 500,000, and an inorganic salt concentration of 1 mol / L.

[0069] Step 2. Pour 500 g of phenolic resin (PF) particles with a particle size of 50 μm into a coating pan, spray 100 mL of polyelectrolyte aqueous solution A onto the surface of the particles at a rotation speed of 25 rpm, rinse with clean water, and then dry with hot air at 40°C to obtain hydrophobic polymer particles modified with hydrophilic polyelectrolyte multilayers with a polyelectrolyte multilayer layer number n=1.

[0070] Step 3: Spray 100 mL of polyelectrolyte aqueous solution B onto the surface of polyphenylene sulfide particles, rinse with clean water, and then dry with hot air at 60° C. to obtain hydrophilic polyelectrolyte multilayer membrane-modified hydrophobic polymer particles with a polyelectrolyte multilayer membrane layer number n=2.

[0071] Step 4: Repeat the process of step 2 and step 3, spray the polyelectrolyte aqueous solution A and polyelectrolyte aqueous solution B onto the surface of polypropylene polymer particles 8 times in sequence, and then the polyelectrolyte polymer modified hydrophobic polymer particles with polyelectrolyte multilayer film layer number n=8 can be obtained. Under air conditions, the contact angle of water droplets on its surface decreases from 95° to 20°. The maximum solid content of its dispersion in the water phase is 70%.

[0072] Example 8

[0073] Step 1: Use deionized water to prepare a polycation electrolyte chitosan aqueous solution A and a polyanion electrolyte polymaleic acid (PMA) aqueous solution B. The polyelectrolyte aqueous solution A is a chitosan aqueous solution with a concentration of 0.5 g / L, a molecular weight of chitosan of 50,000, and an inorganic salt concentration of 0 mol / L; the polyelectrolyte aqueous solution B is a PMA aqueous solution with a concentration of 2 g / L, a molecular weight of PMA of 100,000, and an inorganic salt concentration of 1 mol / L.

[0074] Step 2: Pour 500g of phenolic resin (PF) polymer particles with a particle size of 10μm and 500g of polyphenylene sulfide polymer particles with a particle size of 5μm into the coating pot of the coating machine. Spray 120mL of polyelectrolyte aqueous solution A onto the surface of the polymer particles at a speed of 15rpm. Rinse with clean water and then dry with hot air at 50℃. That is, hydrophilic polyelectrolyte multilayer membrane modified hydrophobic polymer particles with a polyelectrolyte multilayer membrane layer number n=1 can be obtained.

[0075] Step 3: Spray 150 mL of polyelectrolyte aqueous solution B onto the surface of the polymer particles, rinse with clean water, and then dry with hot air at 60° C. to obtain hydrophobic polymer particles modified with hydrophilic polyelectrolyte multilayers with the number of polyelectrolyte multilayers n=2.

[0076] Step 4: Repeat the process of steps 2 and 3, and spray the polyelectrolyte aqueous solution A and the polyelectrolyte aqueous solution B onto the surface of the polypropylene polymer particles 4 times in turn. Then, the hydrophobic polymer particles modified with polyelectrolyte polymers having a polyelectrolyte multilayer film with n=8 layers can be obtained, and the contact angle of the surface is reduced from 95° to 20°, and the maximum solid content of the dispersion in the aqueous phase is 50%.

[0077] Example 9

[0078] Step 1: Use deionized water to prepare aqueous solution A of polyanion electrolyte sodium styrene sulfonate-maleic acid copolymer (PSS-MA) and aqueous solution B of polycation polyethyleneimine (PEI). The concentration of polyanion sodium styrene sulfonate-maleic acid copolymer (PSS-MA) aqueous solution A is 10g / L, the molecular weight is 10,000, and the inorganic salt concentration is 1mol / . The concentration of polyanion electrolyte PSS-MA aqueous solution is 0.1, the molecular weight is 500,000, and the inorganic salt concentration is 1mol / .

[0079] Step 2: Pour 500g of acrylonitrile-butadiene-styrene (ABS) polymer particles with a particle size of 10μm and 500g of polyaniline (PAN) polymer particles with a particle size of 5μm into the coating pot of the coating machine. At a rotation speed of 15rpm, spray 100mL of polycationic electrolyte polyethyleneimine (PEI) solution onto the surface of the polymer particles. Rinse with clean water and then dry with hot air at 40°C. That is, hydrophilic polyelectrolyte multilayer membrane modified hydrophobic polymer particles with a polyelectrolyte multilayer membrane layer number n=1 can be obtained.

[0080] Step 3: Spray 150 mL of polyanion electrolyte hyaluronic acid solution onto the surface of the polymer particles, rinse with clean water, and then dry with hot air at 50°C, and record the number of times n of polyelectrolyte multilayer film surface modification as 2. That is, hydrophilic polyelectrolyte multilayer film-modified hydrophobic polymer particles with polyelectrolyte multilayer film number n=2 can be obtained.

[0081] Step 4: Repeat the process of step 3 and step 4, spray the polycation electrolyte chitosan aqueous solution and the polyanion electrolyte hyaluronic acid aqueous solution onto the surface of the polymer particles 14 times in sequence, and then obtain hydrophilic polyelectrolyte multilayer film modified hydrophobic polymer particles with polyelectrolyte multilayer film number n=14. The contact angle of the surface is reduced from 105° to 20°, and the maximum solid content of the dispersion in the aqueous phase is 80%.

[0082] Example 10

[0083] Step 1: Use deionized water to prepare a mixed aqueous solution A of polycationic polyethyleneimine (PEI) and polydiallyldimethylammonium chloride (PDADMAC) and an aqueous solution of polyanionic electrolyte cellulose sodium (CMC-Na). Polyelectrolyte aqueous solution A is a mixed aqueous solution of PEI and PDADMAC, wherein the concentration of PEI is 0.5 / L, the molecular weight is 200,000, the concentration of PDADMAC is 0.5g / L, the molecular weight is 100,000, and the inorganic salt concentration is 1mol / L; polyelectrolyte aqueous solution B is an aqueous solution of CMC-Na, the concentration is 0.5g / L, the molecular weight is 200,000, and the inorganic salt concentration is 1mol / L.

[0084] Step 2: Pour 500 g of polylactic acid polymer particles with a particle size of 10 μm and 500 g of polymethyl methacrylate polymer particles with a particle size of 5 μm into the water chestnut pot of the coating machine. At a rotation speed of 15 rpm, spray 150 mL of polyelectrolyte aqueous solution A onto the surface of the polymer particles, rinse with clean water, and then dry with hot air at 40°C. The number of times n of surface modification of the polyelectrolyte multilayer film is recorded as 1.

[0085] Step 3: Spray 150 mL of polyelectrolyte aqueous solution B onto the surface of the polymer particles, rinse with clean water, and then dry with hot air at 40°C, and record the number of polyelectrolyte multilayer film surface modifications n as 2. That is, polypropylene polymer particles with a surface containing a hydrophilic polyelectrolyte multilayer film accounting for 5% can be obtained.

[0086] Step 4: Repeat the process of steps 2 and 3, spray the polycation electrolyte chitosan aqueous solution and the polyanion electrolyte hyaluronic acid aqueous solution onto the surface of the polymer particles 14 times in sequence, and the contact angle of the surface decreases from 105° to 12°. The maximum solid content of the dispersion in the aqueous phase is 80%.

[0087] Embodiment 11

[0088] Step 1: Use deionized water to prepare aqueous solution A of sodium polyvinyl sulfonate (PVS) and aqueous solution B of polyelectrolyte polyethyleneimine (PEI). Polyelectrolyte aqueous solution A is an aqueous solution of sodium polyvinyl sulfonate (PVS) with a concentration of 10 g / L, a molecular weight of PVS of 6000, and a NaCl concentration of 0.5 mol / L. Polyelectrolyte aqueous solution B is an aqueous solution of polyethyleneimine (PEI) with a concentration of 1 g / L, a molecular weight of PEI of 50,000, and a NaCl concentration of 0.2 mol / L.

[0089] Step 2: Pour 500 g of styrene-butadiene-styrene block copolymer (SBS) polymer particles with a particle size of 10 μm and 500 g of polyethylene-olefin copolymer (POE) polymer particles with a particle size of 5 μm into the coating pan of a coating machine, spray 150 mL of polyelectrolyte aqueous solution A onto the surface of the polymer particles at a rotation speed of 15 rpm, wash with deionized water, and dry with hot air at 40°C to obtain hydrophobic polymer particles modified with a hydrophilic polyelectrolyte multilayer film with a polyelectrolyte multilayer film layer number n=1.

[0090] Step 3: Spray 150 mL of polyelectrolyte aqueous solution B onto the surface of the polymer particles, wash with deionized water, and dry with hot air at 40° C. to obtain polymer particles with n=2 layers of polyelectrolyte multilayer films modified on the surface.

[0091] Step 4: Repeat the process of steps 3 and 4, and spray the polyelectrolyte aqueous solution A and the polyelectrolyte aqueous solution B onto the surface of the polymer particles 25 times in sequence, so as to obtain hydrophobic polymer particles modified with hydrophilic polyelectrolyte multilayer films with a polyelectrolyte multilayer film layer number n=50. The contact angle of the surface decreases from 105.3° to 8°, and the maximum solid content of the dispersion in the aqueous phase is 80%.

[0092] In summary, the results of the above embodiments and test examples show that the present invention has achieved the following technical effects:

[0093] 1. Modify the surface of hydrophobic polymer particles with a hydrophilic polyelectrolyte multilayer film;

[0094] 2. The coverage area of ​​the polyelectrolyte multilayer film on the surface of the polymer particles and the type of the outermost polar functional groups are regulated by the number of times the polyelectrolyte solution is sprayed.

[0095] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the disclosure disclosed herein. This application is intended to cover any modification, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the claims of the present application.

Claims

1. A method for modifying a polyelectrolyte multilayer film on the surface of polymer particles using a coating machine, characterized in that: With the help of a coating machine, a hydrophilic polyelectrolyte multilayer film with n layers is modified on the surface of the hydrophobic polymer particles through a layer-by-layer self-assembly method. The n is 1-100.

2. The method according to claim 1, characterized in that The steps include: Step 1: preparing polyelectrolytes with opposite charges into polyelectrolyte polymer aqueous solution A and polyelectrolyte polymer aqueous solution B respectively, wherein the polyelectrolytes with opposite charges include polycation electrolytes and polyanion electrolytes; Step 2: After loading the polymer particles with hydrophobic surfaces to be modified into the pot of the coating machine, spray the polyelectrolyte polymer aqueous solution A onto the surface of the polymer particles, wash with clean water, and wait for it to dry. This layer of polyelectrolyte polymer is recorded as a polyelectrolyte multilayer film with a modification number of 1 on the surface of the hydrophobic polymer particles, n=1; Step 3: spray the polyelectrolyte polymer aqueous solution B onto the surface of the polymer particles, wash with clean water, and after drying, this layer of polyelectrolyte polymer is recorded as a polyelectrolyte multilayer film with 2 layers modified on the surface of the hydrophobic polymer particles n=2; Step 4: Repeat steps 2 and 3, and obtain a hydrophilic polyelectrolyte multilayer film with n modified layers on the surface of the hydrophobic polymer particles by adjusting the spraying times and conditions of the polyelectrolyte solutions A and B.

3. The method according to claim 1 or 2, characterized in that: After modifying the hydrophilic polyelectrolyte multilayer membrane with n layers, the contact angle of water on its surface is reduced to below 60 degrees, and the solid content of the saturated solution of the polymer particles modified with the hydrophilic polyelectrolyte multilayer membrane in the water phase is 1% to 80%.

4. The method according to claim 2, characterized in that: In step 1, the polycationic electrolyte comprises one or a mixture of polydiallyldimethylamine halide, polyethyleneimine, polyacrylic acid hydrochloride or chitosan; the molecular weight of the polycationic electrolyte is 5000-1 million, the concentration of the polycationic electrolyte polymer aqueous solution is 0.1g / L-20g / L, and the content of inorganic salt is 0-5mol / L.

5. The method according to claim 2, characterized in that: In step 1, the polyanion electrolyte includes one or more of sodium polystyrene sulfonate, sodium polyethylene sulfonate, polyacrylic acid, polymethacrylic acid, sodium carboxymethyl cellulose, polymethacrylic acid, poly(2-vinyl pyridine), polypeptide, protein, DNA, hyaluronic acid, and sodium styrene sulfonate-maleic acid copolymer; the molecular weight of the polyanion electrolyte is 2000-1 million, the concentration of the polyanion electrolyte polymer aqueous solution is 0.01-20 g / L, and the concentration of the inorganic salt contained is 0-5 mol / L.

6. The method according to claim 2, characterized in that In step 2, the surface hydrophobic polymer particles to be modified include the following polymers or copolymers thereof and derivatives thereof: (a) General-purpose plastics: polyethylene, polypropylene, polyvinyl chloride, polystyrene or acrylonitrile-butadiene-styrene copolymer; (ii) Engineering plastics: polycarbonate, polyamides: nylon 6, nylon 66 or nylon 610, polyoxymethylene, saturated polyesters: polyethylene terephthalate, polybutylene terephthalate or polyphenylene ether; (III) Special plastics: high-temperature nylon: polybutylene adipamide, polyphenylene sulfide; polysulfones: polysulfone, polyethersulfone, polyarylsulfone or polyphenylsulfone; polyimides: homophenylene polyimide, polyetherimide or polyamideimide; polyaryletherketone, polyetheretherketone, polyetherketone or liquid crystal polymer; (iv) Barrier plastics: polyvinyl alcohol, polyvinylidene chloride or polyethylene naphthalate; (V) Corrosion-resistant plastics: polyvinylidene fluoride, polytetrafluoroethylene, polyperfluoroethylene propylene or chlorinated polyether; (6) Photoelectric resin: polyaniline, polythiophene or polypyrrole; (VII) Degradable plastics: polylactic acid: polylactic acid or polyglycolic acid; polyalkyl alkanoate: poly-3-hydroxybutyrate; polyaliphatic ester: polybutylene succinate, polycaprolactone, poly-ε-caprolactone; carbon dioxide copolymer: carbon dioxide-ethylene oxide copolymer; (VIII) Thermoplastic elastomers: Styrene: styrene-butadiene-styrene block copolymer or polyethylene-olefin copolymer; (IX) Other plastics: Thermosetting plastics: phenolic resin, epoxy resin or polymethyl methacrylate; Cellulosic plastics: cellulose acetate; Polyolefins: polybutene; (10) Rubber: natural rubber, synthetic rubber: silicone or styrene-butadiene rubber; The contact angle of water droplets on the surface of polymer particles is 60°~120°.

7. The method according to claim 2, characterized in that In step 2 and / or step 3, the rotation speed of the coating machine is 0-100 rad / min, and the temperature of the hot air used for drying is 20-100°C.

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