Method for regulating and controlling latex coating morphology through electrostatic force and glass transition temperature

Abstract

The invention discloses a method for regulating and controlling the morphology of a latex coating film through electrostatic force and glass transition temperature, and belongs to the technical field of textile assistants. The method comprises the following steps: (a) preparing PMMA emulsion by taking an ionic emulsifier, a nonionic emulsifier, a pH regulator, methyl methacrylate, 2-ethylhexyl acrylate and an initiator as raw materials; (b) carrying out alkali treatment on the glass slide or carrying out silane coupling agent modification after alkali treatment; (c) diluting the PMMA emulsion to obtain a film coating liquid, or adjusting the pH value of the diluted emulsion particles or adding an ionic emulsifier with the same electrical property as the emulsion particles into the diluted emulsion particles to obtain the film coating liquid; and (d) spin-coating a base material with the film coating liquid, or carrying out after-finishing on a polyester fabric through a twice-dipping twice-rolling process by taking the film coating liquid as an impregnation liquid, so as to obtain the latex film with the required morphology. According to the method, the morphology of the film from the nanometer scale to the micrometer scale can be accurately and flexibly regulated and controlled, the process is simple, and industrialization is easy.

Description

Technical Field

[0001] This invention relates to the field of textile auxiliaries technology, and more specifically, to a method for controlling the morphology of latex coatings by electrostatic force and glass transition temperature. Background Technology

[0002] The film-forming process of polymer latex is a key step in coatings, coatings, and functional finishing of textiles, and is widely used in industrial fields such as coating, lamination, and fabric finishing. In this process, the surface topology (such as roughness) and bulk continuity (such as density and porosity) of the thin film formed by latex particles on the substrate surface jointly determine the final functional performance of the coating, such as its water resistance, optical properties, feel, and durability.

[0003] The film formation of latex particles is essentially a complex kinetic process, which classical theory typically describes as three consecutive stages:

[0004] Stage I (Moisture Evaporation and Particle Migration): Moisture evaporation drives latex particles to migrate towards the substrate-air interface via Brownian motion and pack them tightly. In this stage, the electrostatic repulsion and steric hindrance between particles are key to maintaining their dispersed state and affecting their initial packing order.

[0005] Stage II (Particle Deformation and Fusion): Driven by capillary forces and subsequent drying stress, particles overcome energy barriers and deform, coming into contact with and compressing each other. In this stage, the mobility of polymer chain segments (determined by the glass transition temperature of latex particles) is crucial for the successful deformation and fusion of particles.

[0006] Stage III (Molecular Chain Interface Diffusion): Polymer molecular chain segments between adjacent particles diffuse and entangle with each other, eventually forming a continuous and tough thin film bound by molecular chain forces.

[0007] Although this three-stage model has been widely accepted, existing technologies still have limitations in actively controlling the film-forming process. For example, by designing the glass transition temperature (Tg) of latex particles to dominate particle deformation in stage II and chain diffusion in stage III, low-Tg latex particles are easy to spread and fuse to form a dense film, but the particles rearrange with moisture, making it difficult to control the appearance morphology of the film; high-Tg latex particles can maintain the particle shape and construct a rough surface of the film, but it is difficult to form a complete and continuous coating (such as patent CN201510532139.5). Alternatively, adjusting pH and ionic strength can alter electrostatic forces to influence particle migration and initial distribution in stage I. However, such studies primarily serve emulsion stability or adsorption control (e.g., Liu, Y., Zhang, W., Wang, X., & Li, J. (2023). Directed stratification in polymer–latex film blends via pH and drying control. Journal of Colloid and Interface Science, 645(1), 215-224.), and do not systematically link electrostatic interactions with particle behavior in subsequent film-forming stages.

[0008] Therefore, the shortcomings of existing technologies lie in their failure to synergistically design and coordinate the key factors affecting different stages of film formation—electrostatic interactions (the migration and distribution that dominates stage I) and Tg (the deformation and fusion that dominate stages II and III). This fragmented approach to regulation makes it impossible to guide latex particles to complete the entire process from adsorption and migration to final fusion as needed, thus making it difficult to accurately prepare functional films that combine ideal surface structure with bulk continuity. Summary of the Invention

[0009] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for controlling the morphology of latex coatings through electrostatic force and glass transition temperature. This invention, through systematic design, combines latex particles with specific surface charges and glass transition temperature (Tg) with a substrate having specific surface charges, and supplements this with dynamic control of the emulsion environment (pH, ionic emulsifiers), actively guiding the latex particles through a preset "adsorption-migration-fusion" path, ultimately achieving controllable preparation of target films with various morphologies, from continuous layered (FM) to discrete islanded (VW). This method overcomes the limitations of single control methods and can prepare films with various morphologies, from FM to VW, on substrates according to application requirements.

[0010] To achieve the above objectives, the present invention adopts the following technical solution:

[0011] A method for controlling the morphology of latex coatings by electrostatic force and glass transition temperature includes the following steps:

[0012] (a) Control of latex particle electrical properties and glass transition temperature: PMMA emulsion is prepared by emulsification and initiation reaction using ionic emulsifier, nonionic emulsifier, pH adjuster, methyl methacrylate, isooctyl acrylate and initiator as raw materials;

[0013] (b) The glass slide is treated with alkali or treated with alkali and then modified with silane coupling agent to complete the electrical regulation of the substrate;

[0014] (c) Dilute the PMMA emulsion obtained in step (a) and use the diluted latex particle emulsion as a coating liquid, or adjust the pH value of the diluted latex particle emulsion or add an ionic emulsifier with the same charge as the latex particles to the diluted latex particle emulsion as a coating liquid.

[0015] (d) Spin-coating the coating liquid onto the substrate obtained in step (b) to obtain a polymer film with the desired morphology; or using the coating liquid as an impregnation liquid, performing a two-dip and two-paste process on the polyester fabric to obtain a finished fabric with a polymer film of the desired morphology.

[0016] The present invention is further configured such that the ionic emulsifier is a cationic emulsifier or an anionic emulsifier; when the ionic emulsifier is a cationic emulsifier, the pH adjuster is acidic water; when the ionic emulsifier is anionic emulsifier, the pH adjuster is alkaline water.

[0017] The present invention is further configured such that the nonionic emulsifier is an alkyl glycoside; and the ionic emulsifier is hexadecyltrimethylammonium chloride or sodium dodecyl sulfate.

[0018] The present invention is further configured such that, in step (a), the mass ratio of ionic emulsifier, nonionic emulsifier, methyl methacrylate, isooctyl acrylate, and initiator is (0.25-0.48):(0.3-0.7):(8.6-24.5):(1-15):(1.47-1.6).

[0019] The present invention is further configured such that, in step (a), the PMMA emulsion has a solid content of 18-25%.

[0020] The present invention is further configured such that step (a) specifically comprises:

[0021] (1) Mix the ionic emulsifier, nonionic emulsifier, and pH adjuster to form an aqueous phase;

[0022] (2) Mix the ionic emulsifier, nonionic emulsifier, pH adjuster, methyl methacrylate and isooctyl acrylate to prepare a pre-emulsion;

[0023] (3) After mixing the aqueous phase with part of the pre-emulsion, an initiator is added to carry out a pre-reaction;

[0024] (4) After the pre-reaction, a mixture of the remaining pre-emulsion and the initiator aqueous solution is added dropwise to the system to react and obtain PMMA emulsion.

[0025] The present invention is further configured such that, in step (1), the mass ratio of ionic emulsifier to nonionic emulsifier is (0.15-0.28):(0.2-0.4); and in step (2), the mass ratio of ionic emulsifier, nonionic emulsifier, methyl methacrylate, and isooctyl acrylate is (0.1-0.2):(0.1-0.3):(8.6-24.5):(1-15).

[0026] When preparing cationic latex particles, all ionic emulsifiers are cationic emulsifiers, and the pH of the aqueous phase in step (1) and the pre-emulsion in step (2) is 6. When preparing anionic latex particles, all ionic emulsifiers are anionic emulsifiers, and the pH of the aqueous phase in step (1) and the pre-emulsion in step (2) is 8.

[0027] The present invention is further configured such that, in step (3), the mass ratio of ionic emulsifier in the aqueous phase to methyl methacrylate and initiator in part of the pre-emulsion is (0.15-0.28):(0.6-1.5):(0.07-0.1); and in step (4), the mass ratio of methyl methacrylate to initiator in the remaining pre-emulsion is (8-23):(1.4-1.5).

[0028] The present invention is further configured such that, in step (c), the solid content of the diluted latex particle emulsion is 2-3%; the pH value of the coating solution prepared after pH adjustment is 7-3; and the amount of newly added ionic emulsifier in the coating solution prepared by adding ionic emulsifier accounts for 1% of the mass of the final coating solution.

[0029] The present invention is further configured such that, in step (d), the liquid yield in each dip-and-roll process is 60%-80%.

[0030] In summary, the present invention has the following beneficial effects:

[0031] 1. Strong morphology controllability: By matching the combination of "latex particle electrical properties - substrate electrical properties - latex particle Tg", multiple growth modes such as layered (FM), island (VW) or mixed (SK) can be actively realized (for example, high Tg cationic latex particles and negatively charged substrates easily form continuous heterogeneous films; low Tg anionic latex particles and negatively charged substrates easily form continuous homogeneous films). Through precise control of film morphology, functional materials (such as PMMA) can be selectively located on the fiber surface (particulate adsorption) or in the fiber gaps (continuous bridging film), thereby specifically endowing the fabric with different functional properties.

[0032] 2. Dynamic, flexible and low-cost control methods: There is no need to synthesize latex particles with complex structures. The film formation process can be dynamically controlled by adjusting pH and adding common emulsifiers and other post-treatment methods to achieve switching between different morphologies. The process is simple and easy to industrialize. Attached Figure Description

[0033] Figure 1 The Zeta potential distribution diagrams are for the latex particles prepared in Examples 4 and 2.

[0034] Figure 2 The following are DSC scan curves of the latex particles prepared in Examples 4 and 2;

[0035] Figure 3 These are atomic force microscope images of the coatings from Application Examples 1 and 2.

[0036] Figure 4 These are atomic force microscope images of the coatings from Application Examples 3-6;

[0037] Figure 5 These are atomic force microscope images of the coatings from Application Examples 9-11;

[0038] Figure 6 These are atomic force microscope images of the coatings from Application Examples 12-13;

[0039] Figure 7 These are scanning electron microscope images of the surface of the fabrics after finishing in Application Examples 7 and 8 (the two images have the same magnification).

[0040] Among them, the AFM test multiples were consistent for all application examples. Detailed Implementation

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] Examples 1-4

[0043] This invention covers the preparation of four key latex particles: cationic / anionic and high-Tg / low-Tg combinations, and includes the following steps:

[0044] (1) Dissolve the ionic emulsifier and nonionic emulsifier in the pH adjuster to prepare an aqueous phase, and transfer it to a four-necked flask; purge with nitrogen for protection, and heat to 80°C in a water bath while stirring. The mass ratio of ionic emulsifier to nonionic emulsifier is (0.15-0.28):(0.2-0.4).

[0045] (2) Dissolve 0.1-0.2g of ionic emulsifier and 0.1-0.3g of nonionic emulsifier in a pH adjuster, then add 9-25g of methyl methacrylate (MMA) and 1-15g of isooctyl acrylate (EHA) monomer, and emulsify by magnetic stirring to obtain a pre-emulsion. The mass ratio of ionic emulsifier to nonionic emulsifier, methyl methacrylate, and isooctyl acrylate is (0.1-0.2):(0.1-0.3):(8.6-24.5):(1-15).

[0046] In steps (1) and (2): the ionic emulsifiers are all cationic emulsifiers (preferably hexadecyltrimethylammonium chloride (CTAC)) or all anionic emulsifiers (preferably sodium dodecyl sulfate (SDS)). The former is used to prepare cationic latex particles, and the latter is used to prepare anionic latex particles; the nonionic emulsifiers are all preferably alkyl glycosides (OG); the pH adjusters are all acidic water or all alkaline water. Acidic water is used to prepare cationic latex particles, and alkaline water is used to prepare anionic latex particles.

[0047] When preparing cationic latex particles, the pH of the aqueous phase in step (1) and the pre-emulsion in step (2) is 6 (preferably 0.06 g / L HCl solution is used as pH adjuster); when preparing anionic latex particles, the pH of the aqueous phase in step (1) and the pre-emulsion in step (2) is 8 (preferably 0.08 g / L Na2CO3 solution is used as pH adjuster).

[0048] (3) Add a portion of the pre-emulsion to the aqueous phase, and after the system temperature stabilizes at 80°C, add an initiator aqueous solution to carry out the pre-reaction;

[0049] (4) After the pre-reaction is completed for 0.5 hours, the mixture of the remaining pre-emulsion and the initiator aqueous solution is added dropwise. The addition is completed within 2.5 hours, during which the temperature is maintained at 80-85℃. After the addition is completed, the reaction is kept at the temperature for 2 hours. After the reaction is completed, the heating is stopped, and the mixture is cooled to room temperature and then filtered to obtain a PMMA emulsion with a solid content of 18-25%.

[0050] The initiator aqueous solution used in steps (3) and (4) is an aqueous solution of at least one of azobisisobutylammonium hydrochloride or ammonium persulfate; in step (3), the mass ratio of ionic emulsifier in the aqueous phase to methyl methacrylate and initiator in part of the pre-emulsion is (0.15-0.28):(0.6-1.5):(0.07-0.1); in step (4), the mass ratio of methyl methacrylate and initiator in the remaining pre-emulsion is (8-23):(1.4-1.5).

[0051] Four types of latex particles were prepared according to the above method and the formulation in Table 1, and are referred to as Examples 1-4 (Examples 1 and 3 both used 0.06 g / L HCl solution as pH adjuster, and Examples 2 and 4 both used 0.08 g / L Na2CO3 solution as pH adjuster).

[0052] Table 1. Preparation of latex particles with different Tg and electrical properties

[0053]

[0054] The latex particles obtained in Examples 1-4 were cationic, anionic, cationic, and anionic, respectively, and their glass transition temperatures were 86.2℃, 87.4℃, -18.2℃, and -16.1℃, respectively.

[0055] Figure 1 The figures show the Zeta potential distribution of the latex particles prepared in Examples 4 and 2. As can be seen from the figures, the absolute potential of the synthesized PMMA latex particles is around 40 mV, ensuring that the conclusions obtained in this invention are due to the positive or negative electrical properties of the latex particles, rather than errors caused by the amount of charge.

[0056] Figure 2 The figures show the DSC scan curves of the latex particles from Examples 4 and 2. As can be seen from the figures, by adjusting the ratio of MMA monomer to EHA monomer, two types of latex particles with glass transition temperatures of approximately -20°C and 80°C, respectively, were obtained. When coated at room temperature, these two types of latex particles exhibited significant differences in coating morphology due to the difference in molecular chain mobility.

[0057] Application Examples 1-13

[0058] (1) Substrate pretreatment:

[0059] 1.1) Cleaning the glass (ζ=-20mv): Immerse the glass slide in anhydrous ethanol and sonicate for 10 min, then sonicate with deionized water (5 min / time, repeated 3 times), dry with N2 and store in a dry container for later use.

[0060] 1.2) Alkali-treated glass (ζ=-40mv): Prepare a 0.1mol / L NaOH solution, immerse the cleaned glass in it and sonicate for 10min, then sonicate with deionized water (5min / time, repeated 3 times), blow dry with N2 and store in a dry container for later use.

[0061] 1.3) γ-aminopropyltriethoxysilane (KH-550) modified glass (ζ+20mv): Add KH-550 to a mixed solution of anhydrous ethanol and deionized water (ethanol to water volume ratio = 9:1), and control the concentration of silane coupling agent to 5wt%; take a portion of the above-mentioned alkali-treated glass and immerse it in the solution for sonication for 30 min (T=45℃). After sonication, rinse it three times with anhydrous ethanol and then dry it with N2; place it in a 110℃ oven for curing for 45 min. After the reaction is completed, wait for it to cool to room temperature to obtain silanized glass, and store it in a dry container for later use.

[0062] (2) Preparation of coating solution:

[0063] The latex particle emulsion obtained in the examples is diluted with deionized water to a solid content of 2-3%. This diluted latex particle emulsion is used as a coating solution. Alternatively, the pH value of the diluted latex particle emulsion is adjusted to 7-3 (using acetic acid or sodium bicarbonate). Or, an ionic emulsifier with the same electrical properties as the latex particles (preferably, the amount of the newly added ionic emulsifier accounts for 1% of the final coating solution mass) is added to the diluted latex particle emulsion as a coating solution.

[0064] (3) Spin coating of substrate and finishing of polyester fabric:

[0065] Take 10µL of coating liquid and drop it onto the center of the treated substrate; spin coat it using a spin coater (two-stage program: Stage I: 300 rpm / s, 9s; Stage II: 500 rpm / s, 20s), and bake it at the set temperature (25℃) to form a film or place it at room temperature to cure it, thereby obtaining a polymer film with the desired morphology.

[0066] The polyester fabric is immersed in the coating solution and treated with a two-dip and two-pick process. Each immersion time is 60s and the pick-up rate is 60%-80%. Then, it is set at 180℃ for 90s to obtain the latex granule finishing fabric.

[0067] According to the above method and Table 2, the latex particle emulsions obtained in Examples 1-4 were diluted and spin-coated onto substrates with different electrical properties. After being placed at room temperature for 1 day, coating films with different surface morphologies were obtained, which were recorded as Application Examples 1-6, and the appearance morphology of the coating films was characterized. Latex particles with different electrical properties and high Tg (i.e., prepared in Examples 1-2) were treated on polyester fabrics, which were recorded as Application Examples 7-8, and the appearance morphology of the treated fabrics was characterized.

[0068] Table 2. Methods for preparing coatings

[0069]

[0070] Following the above method and as shown in Table 3, the latex particle emulsion obtained in the examples was diluted to a solid content of 2%, and the pH value was adjusted or an ionic emulsifier was added to it (the amount of the added ionic emulsifier accounted for 1% of the mass of the final coating liquid), and then a coating was applied. These were recorded as Application Examples 9-13, and their appearance morphology was tested.

[0071] Table 3. Environmental control schemes for coating solutions and corresponding coating preparation methods

[0072]

[0073] Note: "Unadjusted" in the table means that the coating solution was obtained by diluting the original emulsion without adding acid or alkali substances.

[0074] Figure 3 These are atomic force microscopy (AFM) images obtained after coating anionic latex particles with a Tg of 87.4℃ and cationic latex particles with a Tg of 86.2℃ onto alkali-treated glass (i.e., Application Example 2 and Application Example 1). The images show that in Application Example 2, the cationic latex particles form a continuous but poorly fused layered (FM) film on the alkali-treated substrate, indicating that electrostatic attraction can achieve uniform spreading, but high Tg inhibits particle fusion. In Application Example 1, the anionic latex particles form a discontinuous, island-like VW film on the alkali-treated substrate. This indicates that electrostatic repulsion leads to particle self-aggregation, and high Tg also inhibits particle fusion within the islands.

[0075] Figure 4 These are atomic force microscopy (AFM) images obtained after coating anionic latex particles with a Tg of -16.1℃ and cationic latex particles with a Tg of -18.2℃ onto alkali-treated and silanized substrates, respectively (Application Examples 3-6). The images show that in Application Examples 4 and 5, when the latex particles and the substrate have the same electrical charge, the particles self-aggregate and, due to the low Tg, fully fuse to form a continuous, homogeneous VW film (i.e., islands also fuse into a single sheet). In Application Examples 3 and 6, when the latex particles and the substrate have opposite electrical charges, the particles are anchored and spread out, and, due to the low Tg, further fuse to form an FM film with larger aggregate sizes.

[0076] Figure 5These are atomic force microscopy (AFM) images of latex particles coated on silanized glass after adjusting the pH of the cationic coating solution by adding acid or alkali (i.e., Application Examples 9-11). The images show that as the pH decreases (Application Examples 9 to 10), the latex particle growth pattern changes from layered to island-like. Further decreasing the pH to 3 (Application Example 11), the surface potential of the positively charged substrate significantly increases, while the electrical double layer of the latex particles is compressed. At this point, the latex particles tend to self-aggregate, forming a multi-layered, clustered island structure (VW mode).

[0077] Figure 6 These are atomic force microscopy (AFM) images of coatings (Application Examples 12 and 13) after adding an ionic emulsifier with the opposite charge to the substrate to the coating solution. The images show that the ionic emulsifier introduces the opposite charge and preferentially binds to the substrate, thus reducing the influence of electrostatic forces on subsequent particle film formation. The localized depressions and uneven thickness observed in the samples with added ionic emulsifiers may be due to the hydrophobic end of the emulsifier hindering subsequent particle adsorption.

[0078] Figure 7 These are scanning electron microscope (SEM) images of the surfaces of polyester fabrics treated with anionic latex particles at Tg=87.4℃ and cationic latex particles at Tg=86.2℃ (i.e., Application Example 8 and Application Example 7), respectively. The polyester fabric is negatively charged, with a zeta potential of -65mV. As can be seen from the images, the cationic latex particles are uniformly adsorbed onto the surface of individual fibers in a discrete particle form, with clearly defined pores between fibers. Conversely, the anionic latex particles form a continuous, thick shell-like coating layer on the fiber surface and a large number of continuous thin films at the pores between fibers.

[0079] Characterization methods and descriptions involved in the embodiments and application examples:

[0080] (1) Test of the electrical properties of latex particles: Take 0.1 mL of the emulsion to be tested, dilute it 100 times with deionized water, and sonicate it in a water bath for 30 min to ensure uniform dispersion; use a Nanos90 dynamic light scattering nanoparticle size analyzer (Malvin Instruments Ltd., UK) to measure the zeta potential of the diluted emulsion under constant temperature of 25°C. Perform three parallel measurements and take the arithmetic mean as the final result.

[0081] (2) Test of glass transition temperature (Tg) of latex particles: DSC test: A DSC 214 Polyma differential scanning calorimeter (NETZS Scientific Instruments GmbH, Germany) was used. An appropriate amount of dry latex film was placed in a crucible, and the temperature program was set (Ⅰ: 25℃→(Tg)). target -60)℃;Ⅱ:(Tg target -60)℃ for 10 min; Ⅲ: (Tg target -60)℃→(Tg target+60); Ⅳ:(Tg target +60)℃→(Tg target -60); V: (Tg target -60)℃→(Tg target +60). Heating rate: 10℃ / min) After that, the crucible was placed in the instrument to measure the DSC scan curve. The second segment of the heating curve (stage V) was selected, the glass transition range was determined by the tangent method, and the Tg value was calculated by the midpoint method and the inflection point method.

[0082] (3) Testing of the surface morphology of the coating: The topography of the latex film was tested using the non-contact mode of a Park XE-7 atomic force microscope (Parksystems, Korea). The spin-coated substrate was fixed to the sample stage with conductive adhesive. After optical positioning, the scanning range (5μm × 5μm) was set, and morphology data were acquired at a scanning rate of 0.5 Hz and a resolution of 256×256 pixels. Three independent regions of each sample were scanned continuously. Plane fitting and background subtraction were performed using XEI software, and the image contour was further enhanced using ImageJ image processing software.

[0083] (4) Surface morphology test of the fabric: The polyester fabric was cut into 5mm×5mm sizes, sputtered with gold for 10 minutes, and then imaged using a Sigma 500 field emission scanning electron microscope (Shanghai Baihe Instrument Technology Co., Ltd.) under the conditions of accelerating voltage of 2 kV and working distance of 8 mm. Three representative areas of each sample were selected to collect secondary electron images.

[0084] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A method for controlling the morphology of a latex coating by electrostatic force and glass transition temperature, characterized in that, Includes the following steps: (a) Control of latex particle electrical properties and glass transition temperature: PMMA emulsion is prepared by emulsification and initiation reaction using ionic emulsifier, nonionic emulsifier, pH adjuster, methyl methacrylate, isooctyl acrylate and initiator as raw materials; (b) The glass slide is treated with alkali or treated with alkali and then modified with silane coupling agent to complete the electrical regulation of the substrate; (c) Dilute the PMMA emulsion obtained in step (a) and use the diluted latex particle emulsion as a coating liquid, or adjust the pH value of the diluted latex particle emulsion or add an ionic emulsifier with the same charge as the latex particles to the diluted latex particle emulsion as a coating liquid. (d) Spin-coating the coating liquid onto the substrate obtained in step (b) to obtain a polymer film with the desired morphology; or using the coating liquid as an impregnation liquid, performing a two-dip and two-paste process on the polyester fabric to obtain a finished fabric with a polymer film of the desired morphology.

2. The method for controlling the morphology of a latex coating by electrostatic force and glass transition temperature according to claim 1, characterized in that, The ionic emulsifier can be either a cationic or anionic emulsifier; when the ionic emulsifier is a cationic emulsifier, the pH adjuster is acidic water; when the ionic emulsifier is anionic emulsifier, the pH adjuster is alkaline water.

3. The method for controlling the morphology of a latex coating by electrostatic force and glass transition temperature according to claim 1, characterized in that, The nonionic emulsifier is an alkyl glycoside; the ionic emulsifier is hexadecyltrimethylammonium chloride or sodium dodecyl sulfate.

4. The method for controlling the morphology of a latex coating by electrostatic force and glass transition temperature according to claim 1, characterized in that, In step (a), the mass ratio of ionic emulsifier, nonionic emulsifier, methyl methacrylate, isooctyl acrylate, and initiator is (0.25-0.48): (0.3-0.7): (8.6-24.5): (1-15): (1.47-1.6).

5. The method for controlling the morphology of a latex coating by electrostatic force and glass transition temperature according to claim 1, characterized in that, In step (a), the PMMA emulsion has a solid content of 18-25%.

6. A method for controlling the morphology of a latex coating by means of electrostatic force and glass transition temperature according to any one of claims 1-5, characterized in that, Step (a) specifically involves: (1) Mix the ionic emulsifier, nonionic emulsifier, and pH adjuster to form an aqueous phase; (2) Mix the ionic emulsifier, nonionic emulsifier, pH adjuster, methyl methacrylate and isooctyl acrylate to prepare a pre-emulsion; (3) After mixing the aqueous phase with part of the pre-emulsion, an initiator is added to carry out a pre-reaction; (4) After the pre-reaction, a mixture of the remaining pre-emulsion and the initiator aqueous solution is added dropwise to the system to react and obtain PMMA emulsion.

7. The method for controlling the morphology of a latex coating by electrostatic force and glass transition temperature according to claim 5, characterized in that, In step (1), the mass ratio of ionic emulsifier to nonionic emulsifier is (0.15-0.28):(0.2-0.4); in step (2), the mass ratio of ionic emulsifier, nonionic emulsifier, methyl methacrylate, and isooctyl acrylate is (0.1-0.2):(0.1-0.3):(8.6-24.5):(1-15). When preparing cationic latex particles, all ionic emulsifiers are cationic emulsifiers, and the pH of the aqueous phase in step (1) and the pre-emulsion in step (2) is 6. When preparing anionic latex particles, all ionic emulsifiers are anionic emulsifiers, and the pH of the aqueous phase in step (1) and the pre-emulsion in step (2) is 8.

8. The method for controlling the morphology of a latex coating by electrostatic force and glass transition temperature according to claim 7, characterized in that, In step (3), the mass ratio of ionic emulsifier in the aqueous phase to methyl methacrylate and initiator in part of the pre-emulsion is (0.15-0.28):(0.6-1.5):(0.07-0.1); in step (4), the mass ratio of methyl methacrylate to initiator in the remaining pre-emulsion is (8-23):(1.4-1.5).

9. The method for controlling the morphology of a latex coating by electrostatic force and glass transition temperature according to claim 1, characterized in that, In step (c), the solid content of the diluted latex particle emulsion is 2-3%; the pH value of the coating solution prepared after pH adjustment is 7-3; The amount of newly added ionic emulsifier in the coating solution prepared by adding ionic emulsifier accounts for 1% of the final coating solution mass.

10. The method for controlling the morphology of a latex coating by electrostatic force and glass transition temperature according to claim 1, characterized in that, In step (d), the slurry rate is 60%-80% each time in the two-dip and two-roll process.

Images