Fluoride-free water repellent synthesized based on docosyl acrylate compound

Abstract

The invention discloses a fluoride-free water repellent synthesized based on an acrylic acid docosyl ester compound. The fluoride-free water repellent is prepared by the following steps: step 1, emulsifying the acrylic acid docosyl ester compound, a functional acrylic monomer, a polar olefin compound, a thiol compound, an acetate compound, a surfactant and water; 2, introducing inert gas into the reactant emulsion, heating to a reaction temperature, adding an initiator, and reacting for a preset time to obtain a fluoride-free water repellent emulsion; and the docosyl acrylate compound is docosyl acrylate or docosyl methacrylate. The water repellent is synthesized by adopting the docosyl acrylate compound as a main monomer, the fluorine-free water repellent emulsion synthesized by adopting an emulsion polymerization method has the solid content of more than 30%, and the fluorine-free water repellent emulsion has excellent storage stability and more excellent hydrophobicity and water repellency.

Description

Technical Field

[0001] This invention relates to the field of water repellents, and more specifically to a fluorine-free water repellent synthesized based on docosyl acrylate compounds. Background Technology

[0002] Water repellency is a key performance indicator for medical protective fabrics, military clothing, special work clothing, and civilian outdoor products, playing an irreplaceable role in high-tech fields such as aerospace, construction, and seawater desalination. Traditional fluorinated water repellents have long dominated the market due to their superior water-repellent properties (surface energy as low as 6.7 mJ / m²). However, their core components, perfluorinated compounds (PFCs), pose serious environmental and health risks. PFCs not only exhibit environmental persistence and bioaccumulation but have also been proven to have potential toxicity; long-term exposure may lead to health problems such as thyroid disease, liver damage, and reproductive system disorders. Faced with increasingly stringent environmental regulations, international environmental agreements such as the Stockholm Convention and the EU REACH regulation have implemented strict controls on PFCs. Industry analysis predicts that Europe may be the first to achieve PFC-free water repellents by 2025 and drive a complete ban on fluorinated water repellents globally by 2030. Against this backdrop, the development of fluorinated water repellents has become an important topic in the field of materials science.

[0003] Poly(meth)acrylate-based fluorine-free water repellents, with their designable molecular structures and controllable physicochemical properties, have become one of the most promising research directions in the field of fluorine-free water repellents. These polymers, with stable C-C single bonds forming the main chain backbone, possess excellent heat and light resistance. Their unique comb-like molecular structure, intermediate between branched and linear polymers, allows for precise control of crystallinity through precise adjustment of side chain length, resulting in a low surface tension of 23-26 mN / m. This unique structural characteristic endows poly(meth)acrylate water repellents with multiple technical advantages: firstly, the abundant functional ester groups can form strong interfacial bonds with polar matrices; secondly, large-scale production can be achieved through mature processes such as free radical polymerization and emulsion polymerization; and thirdly, various performance parameters can be flexibly controlled through copolymerization modification. Due to cost and limitations of natural raw materials, the main functional monomer currently used in polyacrylate-based fluorine-free water repellents is octadecyl acrylate, which cannot meet the high hydrophobicity requirements. Lacruz et al. [Progress in Organic Coatings, 2021, 150: 105968] innovatively copolymerized propyl 3-[tris(trimethylsiloxy)silyl]methacrylate (M3T) with octadecyl methacrylate to synthesize a fluorine-free water repellent. The unique umbrella-shaped Si(OSi(CH3)3)3 structure of M3T reduces the surface energy to an extremely low level, resulting in contact angles of 127° and 120° with water and olive oil, respectively, after the copolymer was applied to the fabric. However, the high cost of M3T limits its industrial application. Based on the theoretical basis that polymers with longer carbon chains in comb-like compounds exhibit higher crystallinity and lower surface tension, and driven by the urgent market demand for high-performance hydrophobic fluorine-free water repellents, the use of higher carbon chain acrylates in the synthesis of fluorine-free water repellents has become an inevitable trend in industry research. Docosyl acrylate compounds synthesized from bio-based natural high-carbon alcohol 1-eicosyl alcohol are monomers with great application potential for synthesizing hydrophobic fluorine-free water repellents. However, due to the high melting temperature and extremely low water solubility of docosyl acrylate compounds, it is difficult to achieve large-scale production using the emulsion free radical polymerization method commonly used in industry. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a fluorine-free water repellent based on docosyl acrylate compounds.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A fluorine-free water repellent synthesized based on docosyl acrylate compounds. It is prepared by the following methods: Step 1: Emulsify the docosyl acrylate compound, functional acrylic monomer, polar olefin compound, thiol compound, acetate compound, surfactant and water; Step 2: Inert gas is introduced into the reactant emulsion, heated to the reaction temperature, and then an initiator is added. The reaction is carried out for a predetermined time to obtain a fluorine-free water-repellent emulsion. The docosyl acrylate compound is docosyl acrylate or docosyl methacrylate.

[0006] As a further improvement of the present invention The functional acrylic monomer is a hydroxyl-containing monomer; preferably, the hydroxyl-containing monomer is selected from at least one of 2-hydroxyethyl methacrylate, polyethylene glycol methacrylate, and N-hydroxymethylacrylamide.

[0007] As a further improvement of the present invention The polar olefin compound is a chlorinated olefin; wherein, the chlorinated olefin is preferably vinylidene chloride or dichloroethylene.

[0008] As a further improvement of the present invention The thiol compound is an alkyl thiol; preferably, the alkyl thiol is selected from at least one of decanethiol, dodecanethiol, and tetradecanethiol.

[0009] As a further improvement of the present invention The acetate compound is an alcohol ether acetate; wherein the alcohol ether acetate is selected from at least one of propylene glycol methyl ether acetate and dipropylene glycol methyl ether acetate.

[0010] As a further improvement of the present invention The surfactant is a cationic surfactant and / or a nonionic surfactant.

[0011] As a further improvement of the present invention The inert gas is nitrogen or argon.

[0012] As a further improvement of the present invention The components, by mass parts, are as follows: 20-50 parts of docosyl acrylate compounds 2-5 parts of functional acrylic monomers 0.5-2 parts of polar olefin compounds, Thiols, 0.1-0.5 parts, Acetate compounds 5-10 parts, 5-10 parts surfactant.

[0013] As a further improvement of the present invention The initiator is a water-soluble free radical initiator; The water-soluble free radical initiator is at least one of 2,2'-azobisisobutyramidine hydrochloride, persulfate, and redox initiator.

[0014] The water-repellent agent and its synthesis method described in this invention have the following advantages: (1) The present invention uses docosyl acrylate compounds (such as docosyl acrylate or docosyl methacrylate) as the main monomers to synthesize water repellents. The fluorine-free water repellent emulsion synthesized by emulsion polymerization has a solid content of more than 30% and has excellent storage stability. (2) The water repellent prepared by this invention has superior water repellency compared to water repellents synthesized using octadecyl acrylate (such as octadecyl acrylate or octadecyl methacrylate) as a functional monomer. The contact angle between the treated polyester fabric and water can reach 164°, achieving a superhydrophobic effect, and the rain rating can reach 90-100′, exhibiting excellent hydrophobicity and water repellency. Attached Figure Description

[0015] Figure 1 The NMR spectra of Embodiment 1 and Comparative Example 1 of the present invention; Figure 2 This is the NMR spectrum of Comparative Example Six of the present invention; Figure 3 The graph shows the storage stability test results of Embodiments 1 to 5 and Comparative Examples 1 to 5 of the present invention; Figure 4 This is a graph showing the storage stability test results of Comparative Example Six of the present invention; Figure 5 The graph shows the solid content test results of Examples 1 to 5 and Comparative Examples 1 to 5 of this invention; Figure 6 These are particle size distribution diagrams of Examples 1 to 5 and Comparative Examples 1 to 5 of the present invention; Figure 7 This is a comparison chart of the average particle size of Examples 1 to 5 and Comparative Examples 1 to 5 of the present invention; Figure 8 This is a comparison diagram of the contact angles of polyester spring fabrics after finishing in Examples 1 to 5 and Comparative Examples 1 to 5 of the present invention. Figure 9 This is a comparison chart of the water repellency levels of polyester spring fabrics after finishing in Examples 1 to 5 and Comparative Examples 1 to 5 of the present invention. Figure 10 This is a SEM image showing the results of the polyester film treated with the water-repellent agent of Example 2 of the present invention. Figure 11 The image shows the SEM test results of the polyester film treated with the comparative two water-repellent agents of this invention. Figure 12 The image shows the SEM test results of polyester fabric treated with the water-repellent agent of Example 2 of this invention. Figure 13 The image shows the SEM test results of polyester fabrics treated with the water-repellent agent of Comparative Example 2 of this invention. Detailed Implementation

[0016] The present invention will now be described in further detail with reference to the embodiments shown in the accompanying drawings. Example 1:

[0017] Step 1: Mix 28.06g of docosyl acrylate, 0.48g of hydroxyethyl 2-methacrylate, 0.92g of polyethylene glycol methacrylate, 0.92g of N-hydroxymethylacrylamide, 0.24g of n-dodecyl mercaptan, 6.46g of dipropylene glycol methyl ether acetate, 4.52g of nonionic surfactant (ethoxylated 16-18 alcohol), 2.26g of cationic surfactant (1631-30), and 100g of water. Stir at 200rpm for 20min in a 55℃ water bath. Then, in an ice-water bath, use a cell wall disruptor to ultrasonically emulsify for 15min. The ultrasonic emulsification uses a pulse mode with a 30s working time and a 3s interval, and the ultrasonic power is 30%. Step 2: Add the emulsified reactants to a three-necked flask, purge with nitrogen at 55°C for 30 min, and add 0.97 g of 1,1-dichloroethylene and 0.21 g of initiator (V50). Under nitrogen protection, react at 55°C for 6 h, then cool the reaction solution to room temperature to obtain a fluorine-free water-repellent polyacrylate. Example 2:

[0018] Step 1: Mix 31.56g of docosyl acrylate, 0.48g of hydroxyethyl 2-methacrylate, 0.92g of polyethylene glycol methacrylate, 0.92g of N-hydroxymethylacrylamide, 0.24g of n-dodecyl mercaptan, 6.46g of dipropylene glycol methyl ether acetate, 4.52g of nonionic surfactant (ethoxylated 16-18 alcohol), 2.26g of cationic surfactant (1631-30), and 100g of water. Stir at 200rpm for 20min in a 55℃ water bath. Then, in an ice-water bath, use a cell wall disruptor to ultrasonically emulsify for 15min. The ultrasonic emulsification uses a pulse mode with a 30s working time and a 3s interval, and the ultrasonic power is 30%. Step 2: Add the emulsified reactants to a three-necked flask, purge with nitrogen at 55°C for 30 min, and add 0.97 g of 1,1-dichloroethylene and 0.24 g of initiator (V50). Under nitrogen protection, react at 55°C for 6 h, then cool the reaction solution to room temperature to obtain a fluorine-free water-repellent polyacrylate. Example 3:

[0019] Step 1: Mix 35.07g of docosyl acrylate, 0.48g of hydroxyethyl 2-methacrylate, 0.92g of polyethylene glycol methacrylate, 0.92g of N-hydroxymethylacrylamide, 0.24g of n-dodecyl mercaptan, 6.46g of dipropylene glycol methyl ether acetate, 4.52g of nonionic surfactant (ethoxylated 16-18 alcohol), 2.26g of cationic surfactant (1631-30), and 100g of water. Stir at 200rpm for 20min in a 55℃ water bath. Then, in an ice-water bath, use a cell wall disruptor to ultrasonically emulsify for 15min. The ultrasonic emulsification uses a pulse mode with a 30s working time and a 3s interval, and the ultrasonic power is 30%. Step 2: Add the emulsified reactants to a three-necked flask, purge with nitrogen at 55°C for 30 min, and add 0.97 g of 1,1-dichloroethylene and 0.26 g of initiator (V50). Under nitrogen protection, react at 55°C for 6 h, then cool the reaction solution to room temperature to obtain a fluorine-free water-repellent polyacrylate. Example 4:

[0020] Step 1: Mix 38.58g of docosyl acrylate, 0.48g of hydroxyethyl 2-methacrylate, 0.92g of polyethylene glycol methacrylate, 0.92g of N-hydroxymethylacrylamide, 0.24g of n-dodecyl mercaptan, 6.46g of dipropylene glycol methyl ether acetate, 4.52g of nonionic surfactant (ethoxylated 16-18 alcohol), 2.26g of cationic surfactant (1631-30), and 100g of water. Stir at 200rpm for 20min in a 55℃ water bath. Then, in an ice-water bath, use a cell wall disruptor to ultrasonically emulsify for 15min. The ultrasonic emulsification uses a pulse mode with a 30s working time and a 3s interval, and the ultrasonic power is 30%. Step 2: Add the emulsified reactants to a three-necked flask, purge with nitrogen at 55°C for 30 min, and add 0.97 g of 1,1-dichloroethylene and 0.28 g of initiator (V50). Under nitrogen protection, react at 55°C for 6 h, then cool the reaction solution to room temperature to obtain a fluorine-free water-repellent polyacrylate. Example 5:

[0021] Step 1: Mix 42.08g of docosyl acrylate, 0.48g of hydroxyethyl 2-methacrylate, 0.92g of polyethylene glycol methacrylate, 0.92g of N-hydroxymethylacrylamide, 0.24g of n-dodecyl mercaptan, 6.46g of dipropylene glycol methyl ether acetate, 4.52g of nonionic surfactant (ethoxylated 16-18 alcohol), 2.26g of cationic surfactant (1631-30), and 100g of water. Stir at 200rpm for 20min in a 55℃ water bath. Then, in an ice-water bath, use a cell wall disruptor to ultrasonically emulsify for 15min. The ultrasonic emulsification uses a pulse mode with a 30s working time and a 3s interval, and the ultrasonic power is 30%. Step 2: Add the emulsified reactants to a three-necked flask, purge with nitrogen at 55°C for 30 min, and add 0.97 g of 1,1-dichloroethylene and 0.31 g of initiator (V50). Under nitrogen protection, react at 55°C for 6 h, then cool the reaction solution to room temperature to obtain a fluorine-free water-repellent polyacrylate. Comparative Example 1:

[0022] Step 1: Mix 23.92g of octadecyl acrylate, 0.48g of hydroxyethyl 2-methacrylate, 0.92g of polyethylene glycol methacrylate, 0.92g of N-hydroxymethylacrylamide, 0.24g of n-dodecyl mercaptan, 4.52g of nonionic surfactant (ethoxylated 16-18 alcohol), 2.26g of cationic surfactant (1631-30), and 100g of water. Stir at 200rpm for 20min in a 55℃ water bath. Then, in an ice-water bath, use a cell wall disruptor to ultrasonically emulsify for 15min. The ultrasonic emulsification uses a pulse mode with a 30s working time and a 3s interval, and the ultrasonic power is 30%. Step 2: Add the emulsified reactants to a three-necked flask, purge with nitrogen at 55°C for 30 min, and add 0.97 g of 1,1-dichloroethylene and 0.21 g of initiator (V50). Under nitrogen protection, react at 55°C for 6 h, then cool the reaction solution to room temperature to obtain a fluorine-free water-repellent polyacrylate. Comparative Example 2:

[0023] Step 1: Mix 26.91g of octadecyl acrylate, 0.48g of hydroxyethyl 2-methacrylate, 0.92g of polyethylene glycol methacrylate, 0.92g of N-hydroxymethylacrylamide, 0.24g of n-dodecyl mercaptan, 4.52g of nonionic surfactant (ethoxylated 16-18 alcohol), 2.26g of cationic surfactant (1631-30), and 100g of water. Stir at 200rpm for 20min in a 55℃ water bath. Then, in an ice-water bath, use a cell wall disruptor for ultrasonic emulsification for 15min. The ultrasonic emulsification uses a pulse mode with a 30s working time and a 3s interval, and the ultrasonic power is 30%. Step 2: Add the emulsified reactants to a three-necked flask, purge with nitrogen at 55°C for 30 min, and add 0.97 g of 1,1-dichloroethylene and 0.24 g of initiator (V50). Under nitrogen protection, react at 55°C for 6 h, then cool the reaction solution to room temperature to obtain a fluorine-free water-repellent polyacrylate. Comparative Example 3:

[0024] Step 1: Mix 29.90g of octadecyl acrylate, 0.48g of hydroxyethyl 2-methacrylate, 0.92g of polyethylene glycol methacrylate, 0.92g of N-hydroxymethylacrylamide, 0.24g of n-dodecyl mercaptan, 4.52g of nonionic surfactant (ethoxylated 16-18 alcohol), 2.26g of cationic surfactant (1631-30), and 100g of water. Stir at 200rpm for 20min in a 55℃ water bath. Then, in an ice-water bath, use a cell wall disruptor to ultrasonically emulsify for 15min. The ultrasonic emulsification uses a pulse mode with a 30s working time and a 3s interval, and the ultrasonic power is 30%. Step 2: Add the emulsified reactants to a three-necked flask, purge with nitrogen at 55°C for 30 min, and add 0.97 g of 1,1-dichloroethylene and 0.26 g of initiator (V50). Under nitrogen protection, react at 55°C for 6 h, then cool the reaction solution to room temperature to obtain a fluorine-free water-repellent polyacrylate. Comparative Example 4:

[0025] Step 1: Mix 32.89g of octadecyl acrylate, 0.48g of hydroxyethyl 2-methacrylate, 0.92g of polyethylene glycol methacrylate, 0.92g of N-hydroxymethylacrylamide, 0.24g of n-dodecyl mercaptan, 4.52g of nonionic surfactant (ethoxylated 16-18 alcohol), 2.26g of cationic surfactant (1631-30), and 100g of water. Stir at 200rpm for 20min in a 55℃ water bath. Then, in an ice-water bath, use a cell wall disruptor to ultrasonically emulsify for 15min. The ultrasonic emulsification uses a pulse mode with a 30s working time and a 3s interval, and the ultrasonic power is 30%. Step 2: Add the emulsified reactants to a three-necked flask, purge with nitrogen at 55°C for 30 min, and add 0.97 g of 1,1-dichloroethylene and 0.28 g of initiator (V50). Under nitrogen protection, react at 55°C for 6 h, then cool the reaction solution to room temperature to obtain a fluorine-free water-repellent polyacrylate. Comparative Example 5:

[0026] Step 1: Mix 35.88g of octadecyl acrylate, 0.48g of hydroxyethyl 2-methacrylate, 0.92g of polyethylene glycol methacrylate, 0.92g of N-hydroxymethylacrylamide, 0.24g of n-dodecyl mercaptan, 4.52g of nonionic surfactant (ethoxylated 16-18 alcohol), 2.26g of cationic surfactant (1631-30), and 100g of water. Stir at 200rpm for 20min in a 55℃ water bath. Then, in an ice-water bath, use a cell wall disruptor to ultrasonically emulsify for 15min. The ultrasonic emulsification uses a pulse mode with a 30s working time and a 3s interval, and the ultrasonic power is 30%. Step 2: Add the emulsified reactants to a three-necked flask, purge with nitrogen at 55°C for 30 min, and add 0.97 g of 1,1-dichloroethylene and 0.31 g of initiator (V50). Under nitrogen protection, react at 55°C for 6 h, then cool the reaction solution to room temperature to obtain a fluorine-free water-repellent polyacrylate. Comparative Example 6:

[0027] Step 1: Mix 35.07g of docosyl acrylate, 0.48g of hydroxyethyl 2-methacrylate, 0.92g of polyethylene glycol methacrylate, 0.92g of N-hydroxymethylacrylamide, 0.24g of n-dodecyl mercaptan, 4.52g of nonionic surfactant (ethoxylated 16-18 alcohol), 2.26g of cationic surfactant (1631-30), and 100g of water. Stir at 200rpm for 20min in a 55℃ water bath. Then, in an ice-water bath, use a cell wall disruptor to ultrasonically emulsify for 15min. The ultrasonic emulsification uses a pulse mode with a 30s working time and a 3s interval, and the ultrasonic power is 30%. Step 2: Add the emulsified reactants to a three-necked flask, purge with nitrogen at 55°C for 30 min, and add 0.97 g of 1,1-dichloroethylene and 0.26 g of initiator (V50). Under nitrogen protection, react at 55°C for 6 h, then cool the reaction solution to room temperature to obtain a fluorine-free water-repellent polyacrylate.

[0028] Raw material list: sample factory docosyl acrylate C22 Ron Octadecyl acrylate C18 Shanghai McLean Biochemical Technology Co., Ltd. 2-Hydroxyethyl methacrylate Shanghai Aladdin Biochemical Technology Co., Ltd. Polyethylene glycol methacrylate Ron N-hydroxymethylacrylamide Ron Vinylidene chloride Ron 2,2'-Azobisisobutyramidine hydrochloride (V50) Zhongshan Dixing Chemical Co., Ltd. n-dodecanethiol Aladdin Reagent Co., Ltd. Dipropylene glycol methyl ether acetate Ron Ethoxylated 16-18 alcohol Shanghai McLean Biochemical Technology Co., Ltd. Cationic surfactant 1631-30 Qinxiang New Materials (Guangzhou) Co., Ltd. test: 1. Perform NMR tests on Example 2, Comparative Example 2, and Comparative Example 6; 2. Storage stability test: Examples 1 to 5, Comparative Examples 1 to 5, and Comparative Example 6 were stored in an environment of 25°C for 90 days, and the latex was observed to show signs of demulsification and stratification.

[0029] 3. Solid content test: A certain mass of copolymer emulsion is dried in an electrically heated constant temperature drying oven at 105℃ and normal pressure until the mass no longer changes. The solid content is calculated according to the following formula:

[0030] m1 is the weight of the weighing bottle, m2 is the weight of the weighing bottle and the dried water-repellent agent, and m is the weight of the water-repellent agent emulsion.

[0031] 4. Particle size distribution testing: The Z-mean particle size and polydispersity index (PDI) of the fine emulsion latex particles were determined using a Zetasizer nanoparticle size analyzer at 25℃ and a scattering angle of 90° via dynamic light scattering (DLS) technology. Specifically, the emulsion was prepared to a concentration of 5 / 1000 and added to a polystyrene cuvette for DLS testing. The particle size was calculated as the average of three tests to obtain the average particle size and particle size distribution map of the nanoparticles.

[0032] 5. Contact Angle Testing and Surface Free Energy Calculation: The static water contact angle of the treated polymer film and polyester fabric was tested using a DSA 30 video contact angle tensiometer (Krüss GmbH, Germany) to evaluate wetting performance. A 3.0 μL drop of deionized water was placed on the sample surface and allowed to stand for 30 seconds. The contact angle value was recorded. Five different points were tested on each sample, and the average value was taken as the final contact angle. A larger contact angle value indicates lower surface tension of the emulsion and better hydrophobic effect.

[0033] The static contact angle of the polymer film was measured using water (3 μL) and diiodomethane (1 μL) as test liquids, and a German Krüss DSA 30 optical contact angle meter was used. Five measurements were taken at different locations for each sample, and the average value was recorded. The surface free energy of the film was calculated using the Owens-Wendt equation and the Young equation.

[0034]

[0035]

[0036] Where γ d s and γ p s It refers to the dispersive and polar components of the material surface. γ d and γ p These represent the dispersed and polar components of the tested liquid, respectively, and the gamma ray of water. l It is 72.8 mN·m -1 γ p l and γ d l 51.0 mN·m -1 and 21.8 mN·m -1 γ-diiodomethane l 50.8 mN·m -1 γ p l and γd l 0 mN·m -1 and 50.8 mN·m -1 .

[0037] 6. Water repellency test: Refer to standard AATCC 22-2017 and use rain test to evaluate the water repellency of polyester fabrics treated with emulsion.

[0038] 7. SEM test: The polyester spring spun yarn before and after treatment, as well as the polymer films of Example 2 and Comparative Example 2, were placed on conductive tape, and then subjected to gold sputtering treatment. The changes in the morphology of the fabric surface and the polymer film were observed using a scanning electron microscope (SEM). The working voltage was 3kV.

[0039] Test results: 1. Nuclear magnetic resonance (NMR) test: Refer to Figure 1 and Figure 2 , Figure 1 The NMR spectrum of Sample 1 (C22) is from Example 2, and the NMR spectrum of Comparative Sample 1 (C18) is from Comparative Example 2. It can be seen that both Example 2 and Comparative Example 2 successfully synthesized the target product. Figure 2 The NMR spectrum of Comparative Example 6 shows a large number of peaks between chemical shifts 5.5 and 6.5. These peaks are double bond peaks, indicating that most of the double bonds of the monomers in the starting material did not react, suggesting that Comparative Example 6 was not successfully synthesized.

[0040] Here we can see that the water repellent synthesized using octadecyl acrylate as a monomer can be successfully synthesized without the addition of dipropylene glycol methyl ether acetate, but Comparative Example 6, using docosyl acrylate as a monomer, cannot be synthesized successfully. In the examples with the addition of dipropylene glycol methyl ether acetate, docosyl acrylate as a monomer can be successfully synthesized, indicating that dipropylene glycol methyl ether acetate plays a crucial role. The polymerization reaction is carried out in water, and the addition of dipropylene glycol methyl ether acetate helps to uniformly disperse docosyl acrylate, making it better dispersed in water, thus enabling successful polymerization.

[0041] 2. Storage stability test, refer to Figure 3 ,in Figure 3 The images show Comparative Examples 1-5 and Examples 1-5 after 90 days of storage. All polymers were uniform, milky-white liquids with a bluish tint; the C22 emulsion was yellowish. No stratification occurred after 3 months of storage, indicating stable emulsion performance. Figure 4 As shown in the photograph of Comparative Example 6, stored for 90 days, it can be seen that due to the failure of compositing, obvious layering occurs.

[0042] 3. Solid content test, refer to Figure 5The figures show the solid content test results for Examples 1 to 5 and Comparative Examples 1 to 5. As the monomer dosage increases, the solid content of the polymer emulsion increases progressively, with Examples 1 to 5 showing higher solid content than Comparative Examples 1 to 5. This is mainly due to the larger molecular weight and higher quality of monomers used in Examples 1 to 5 for the same reaction molarity. The solid content of Examples 1 to 5 and Comparative Examples 1 to 5 is generally around 30%, meeting the requirements for solid content in commercially available water repellents. This is primarily because at a solid content of 30%, the viscosity of the water repellent is moderate, resulting in appropriate adsorption on the fabric during finishing impregnation. The water repellent can effectively penetrate into the fabric substrate, forming a uniform water-repellent layer on the substrate surface. Furthermore, an appropriate solid content helps maintain the uniformity and stability of the water repellent, preventing clumping or delamination during storage.

[0043] 4. Particle size distribution test, refer to Figure 6 and Figure 7 The results are the particle size distribution test results for Examples 1 to 5 and Comparative Examples 1 to 5. The particle size of Comparative Examples 1 to 5 is between 121-141 nm. As the amount of octadecyl acrylate monomer increases, the emulsion particle size gradually increases. The particle size of Examples 1 to 5 is 167-194 nm, which is significantly higher than that of Comparative Examples 1 to 5. This indicates that under the same polymerization conditions, the polymer generated by the polymerization of docosyl acrylate has a higher molecular weight and a longer hydrophobic segment. Its solubility in water is lower than that of Comparative Examples 1 to 5, making it easier to form larger aggregates. The larger polymer molecular weight is beneficial for the molecules to form a film on the fabric surface, which is beneficial for improving the water repellency. The PDI of the emulsion particle size of Comparative Examples 1 to 5 and Examples 1 to 5 is less than 0.3, the particle size distribution is narrow, and the particle size is relatively uniform.

[0044] 5. Contact angle test: Examples 1 to 5 and Comparative Examples 1 to 5 were tested. The specific preparation methods are as follows: Polyester spring-sleeved textile → Two dips and two nips with water-repellent finishing agent (pressure 0.2MPa, water repellent 40g / L) → Baking at 170℃ for 1min → Water contact angle test Test results are as follows Figure 8 As shown; The surface free energy was calculated, and tests were conducted on Examples 1 to 5 and Comparative Examples 1 to 5. The specific preparation methods are as follows: The purified water repellent sample was dissolved in toluene to prepare a 4% concentration solution. The solution was drop-coated onto a silicon wafer using a syringe. The solvent was allowed to evaporate at room temperature for 30 minutes until the toluene solvent was completely evaporated. Then, the wafer was dried in an oven at 170°C for 10 minutes to prepare a polymer film.

[0045] The test results are shown in the table below: sample <![CDATA[Surface energy (mN·m -1 )]]> Example 1 22.68 Example 2 22.43 Example 3 22.57 Example 4 22.92 Example 5 22.91 Comparative Example 1 23.50 Comparative Example 2 23.13 Comparative Example 3 23.30 Comparative Example 4 23.19 Comparative Example 5 23.19 6. Water repellency test: Examples 1 to 5 and Comparative Examples 1 to 5 were tested. The specific preparation methods are as follows: Polyester spring fabric → two dips and two nips with water-repellent finishing agent (pressure 0.2MPa, water repellent 40g / L) → baking at 170℃ for 1min → water repellency.

[0046] Test results are as follows Figure 9 As shown.

[0047] The water repellency of Examples 1 to 5 is better than that of Comparative Examples 1 to 5. Furthermore, with the increase in the amount of functional monomer, the water repellency of the emulsion initially increases and then slightly decreases. When the monomer content is 90% (Example 2), the water repellency of Example 2 can reach 90-100′. The contact angle of the treated polyester fabric initially increases and then remains constant. When the monomer content is 90%, the contact angle is relatively high at 164°, indicating superhydrophobicity, higher than Comparative Examples 1 to 5 (148° in Comparative Example 2). After the monomer content exceeds 90%, the contact angle increases slowly. This is mainly because when the monomer content is low, the solid content of the water repellent is low, resulting in a lower effective value of the water repellent at the same concentration, leading to poorer film formation on the fabric surface and thus a lower water repellency and contact angle. When the amount of functional monomer reaches a certain value, the emulsion can form a relatively complete film on the fabric surface. The film formation effect is mainly affected by the setting temperature and the fabric surface structure. Therefore, the water repellency of the fabric remains basically unchanged, and the contact angle of the treated fabric also remains basically unchanged. The water-repellent effect of Examples 1 to 5 is better than that of Comparative Examples 1 to 5. The examples have longer aliphatic chain hydrocarbons, which have higher crystallinity after high temperature setting and form a more regular arrangement on the fabric surface, resulting in better hydrophobicity.

[0048] The surface energy of Examples 1 to 5 is approximately 22-23 mN·m. m -1 The lowest level can reach 22.42 mN. · m -1 ,contrast Examples one through five are basically in the 23s. - 24 mN ·m -1 Under the same polymerization conditions, the surface energy of Examples 1 to 5 is lower than that of Comparative Examples 1 to 5, thus the examples have better water repellency. This is related to the molecular weight and crystallinity of Examples 1 to 5 and Comparative Examples 1 to 5. Examples 1 to 5 have a better molecular weight, and under the same heating conditions, their crystallinity is higher than that of Comparative Examples 1 to 5, and their arrangement is more regular, thus resulting in a lower surface energy.

[0049] 7. SEM test results: Samples from Example 2 (Sample 2) and Comparative Example 2 (Comparative Sample 2) were prepared. The specific preparation process is as follows: The water repellent sample was dissolved in water to prepare a 4% concentration solution. The solution was dripped onto a silicon wafer using a syringe, air-dried at room temperature, and then baked in an oven at 170℃ for 5 minutes to prepare a polymer film. In addition, 40 g / L of water repellent was applied to polyester fabric using a two-dip, two-ply method, followed by baking at 170℃ for 5 minutes. The polymer film and the treated polyester fabric were placed on conductive tape, and after gold sputtering, the morphological changes of the fabric surface and the polymer film were observed using a scanning electron microscope (SEM) at a working voltage of 3 kV. The SEM results of the polymer film are shown below. Figure 10 (Example 2) and Figure 11 (Comparative Example 2) shows the SEM images of the polyester fabric. Figure 12 (Example 2) and Figure 13 (Comparative Example 2).

[0050] The film surface of Example 2 exhibits a more pronounced rough structure and a larger particle size, approximately 190 nm, consistent with the particle size test results. In contrast, the film surface of Comparative Example 2 is relatively smooth. Example 2, on the other hand, has a micro-nano-scale rough structure. According to the "lotus effect" principle, low surface energy and an appropriate rough structure can impart better hydrophobicity to the material. Therefore, the material treated in Example 2 should have better hydrophobicity.

[0051] In summary, the water repellent prepared by this invention and its synthesis method have the following advantages: (1) The present invention uses (meth)acrylate docosyl ester as the main monomer to synthesize water repellent. The fluorine-free water repellent emulsion synthesized by emulsion polymerization has a solid content of more than 30% and has excellent storage stability. (2) The water repellent prepared by this invention has superior water repellency compared to water repellent synthesized with octadecyl methacrylate as the functional monomer. The contact angle between the treated polyester fabric and water can reach 164°, achieving a superhydrophobic effect, and the rain rating can reach 90-100′, exhibiting excellent hydrophobicity and water repellency.

[0052] This study demonstrates that elongating the side chains of poly(meth)acrylate contributes to a more regular polymer molecular arrangement and increased crystallinity, thereby reducing surface tension. This research provides valuable guidance for the development of high-performance, fluorine-free water-repellent polyacrylates.

[0053] 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 fluorine-free water repellent synthesized based on docosyl acrylate compounds, characterized in that, It is prepared by the following method: Step 1: Emulsify the docosyl acrylate compound, functional acrylic monomer, polar olefin compound, thiol compound, acetate compound, surfactant and water; Step 2: Inert gas is introduced into the reactant emulsion, heated to the reaction temperature, and then an initiator is added. The reaction is carried out for a predetermined time to obtain a fluorine-free water-repellent emulsion. The docosyl acrylate compound is docosyl acrylate or docosyl methacrylate.

2. The fluorine-free water repellent synthesized based on docosyl acrylate compounds according to claim 1, characterized in that: The functional acrylic monomers are hydroxyl-containing monomers; Preferably, the hydroxyl-containing monomer is selected from at least one of 2-hydroxyethyl methacrylate, polyethylene glycol methacrylate, and N-hydroxymethylacrylamide.

3. The fluorine-free water repellent synthesized based on docosyl acrylate compounds according to claim 1, characterized in that: The polar olefin compounds are chlorinated olefins; The chlorinated olefin is preferably vinylidene chloride or dichloroethylene.

4. The fluorine-free water repellent synthesized based on docosyl acrylate compounds according to claim 1, characterized in that: The thiols are alkyl thiols; The alkyl thiol is selected from at least one of decanethiol, dodecanethiol, and tetradecanethiol.

5. A fluorine-free water repellent synthesized based on docosyl acrylate compounds according to claim 1, characterized in that: The acetate compounds are alcohol ether acetates; The alcohol ether acetate is selected from at least one of propylene glycol methyl ether acetate and dipropylene glycol methyl ether acetate.

6. The fluorine-free water repellent synthesized based on docosyl acrylate compounds according to claim 1, characterized in that: The surfactant is a cationic surfactant and / or a nonionic surfactant.

7. A fluorine-free water repellent synthesized based on docosyl acrylate compounds according to claim 1, characterized in that: The inert gas is nitrogen or argon.

8. A fluorine-free water repellent synthesized based on docosyl acrylate compounds according to claim 1, characterized in that: Each component, by mass parts, includes: 20-50 parts of docosyl acrylate compounds 2-5 parts of functional acrylic monomers 0.5-2 parts of polar olefin compounds, Thiols, 0.1-0.5 parts, Acetate compounds 5-10 parts, 5-10 parts surfactant.

9. A fluorine-free water repellent synthesized based on docosyl acrylate compounds according to claim 1, characterized in that: The initiator is a water-soluble free radical initiator; The water-soluble free radical initiator is at least one of 2,2'-azobisisobutyramidine hydrochloride, persulfate, and redox initiator.

Images