Hydrophobic alkyl acrylate copolymer as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of polymers, and particularly discloses a hydrophobic alkyl acrylate copolymer as well as a preparation method and application thereof. The hydrophobic alkyl acrylate copolymer at least comprises a block Z-(Ax-co-By)-b-Cz; wherein Z is an amphiphilic macromolecular RAFT (reversible addition-fragmentation chain transfer) polymer; the block Ax-co-By is formed by polymerizing a first hydrophobic monomer A and a steric hindrance monomer B, and-co-represents that Ax and By exist in a random form; the block Cz is formed by polymerizing a cross-linking monomer C, and-b-represents (Ax-co-By) and Cz exist in a block form; the first hydrophobic monomer is a C12-C26 (methyl) acrylate monomer, the steric hindrance monomer is a C5-C20 (methyl) acrylate monomer with an alicyclic / bicyclic side group, and the crosslinking monomer is a C5-C20 monomer with an epoxy group and / or a blocked isocyanate monomer.

Description

Technical Field

[0001] This application belongs to the field of polymer technology, and more specifically, relates to a hydrophobic alkyl acrylate copolymer, its preparation method and application. Background Technology

[0002] With increasingly stringent environmental regulations and growing consumer demand for green products, the shift from fluorinated to fluorine-free waterproofing agents in the textile chemicals industry is an irreversible trend. In this transition, long-chain alkyl acrylate-based fluorine-free waterproofing agents are a key candidate to replace fluorinated ones. The main component of these agents is a copolymer of long-chain alkyl acrylates and other functional monomers. Compared to fluorinated waterproofing agents, long-chain alkyl acrylate-based fluorine-free agents have lower waterproofing efficiency. To achieve satisfactory waterproofing, the amount of waterproofing agent used is significantly increased, leading to increased costs and problems such as white marks on the fabric, a stiff feel, and insufficient peel strength.

[0003] The hydrophobicity of alkyl acrylate monomers is significantly positively correlated with their alkyl chain length, increasing with increasing carbon chain length. Only when the alkyl chain length exceeds twelve carbon atoms (C12) can the resulting copolymer meet the basic requirements for hydrophobic performance of the main functional components in textile waterproofing agents. However, the extremely strong hydrophobicity of long-side-chain alkyl acrylate monomers at this point results in poor dispersion stability in aqueous / polar solvents, making them difficult to emulsify. To achieve effective emulsification, a large amount of small-molecule emulsifiers is usually introduced. However, during the application of waterproofing agents, these small-molecule emulsifiers migrate to the fabric surface and accumulate there, leading to an increase in fabric surface energy and significantly reducing waterproofing performance.

[0004] Currently, the industrial preparation of long-side-chain alkyl acrylate copolymers mainly adopts the emulsion random copolymerization process (Zhang Pengfei, Ma Ye, Zhang Guixia, et al. Synthesis and performance study of octadecyl acrylate copolymers [J]. Materials Reports, 2016, 30 (6): 4). The process involves: hydrophobic long-side-chain alkyl acrylate monomers and other functional monomers (such as monomers containing reactive groups like hydroxyl and epoxy groups) in an aqueous medium, forming a stable micellar dispersion system through a small-molecule emulsifier, and then using a water-soluble initiator such as persulfate to initiate a free radical copolymerization reaction, ultimately obtaining polymer latex particles. Two or more monomers are randomly arranged in the copolymerization reaction, and the monomer units in the molecular chain are randomly distributed. This results in the polymer's performance largely depending on its composition and structure. Random copolymerization cannot finely control the polymer structure, thus limiting the performance of long-side-chain alkyl acrylate copolymers. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this application is to synthesize a hydrophobic alkyl acrylate copolymer, its preparation method and application, with the aim of improving the waterproof efficiency of the hydrophobic alkyl acrylate copolymer.

[0006] To achieve the above objectives, in a first aspect, this application provides a hydrophobic alkyl acrylate copolymer comprising at least the block Z-(Ax-co-By)-b-Cz; in, Z is an amphiphilic macromolecular RAFT polymer; Block Ax-co-By is polymerized from the first hydrophobic monomer A and the sterically hindered monomer B, and -co- indicates that Ax and By exist in a random form; block Cz is polymerized from the crosslinking monomer C, and -b- indicates that (Ax-co-By) and Cz exist in a block form. The first hydrophobic monomer is a C12-C26 (meth)acrylate monomer, the sterically hindered monomer is a C5-C20 (meth)acrylate monomer with alicyclic / bicyclic side groups, and the crosslinking monomer is a C5-C20 monomer with epoxy groups and / or a terminal isocyanate monomer. x, y, and z represent the average degree of polymerization, where x is 50 to 1000 and x:y:z is 20:(1 to 4):(2 to 10).

[0007] Preferably, the first hydrophobic monomer is a C18-C26 (meth)acrylate monomer.

[0008] Preferably, the sterically hindered monomer is one or more of isobornyl methacrylate, cyclohexyl methacrylate, or 4-tert-butylcyclohexyl (meth)acrylate.

[0009] Preferably, the crosslinking monomer is one or more of glycidyl acrylate, glycidyl methacrylate, 3-isopropyl-α,α-dimethylbenzyl isocyanate, or isophorone diisocyanate.

[0010] Preferably, the chemical formula of the amphiphilic macromolecular RAFT polymer is R-[D]. m -b-[E] n ; Wherein, R is a small molecule RAFT group; Block [D] m It is synthesized by double bond addition polymerization of hydrophilic monomer D, wherein the hydrophilic monomer is a C7-C20 quaternary ammonium salt monomer and / or sulfonate monomer; Block [E] n It is formed by double bond addition polymerization of the second hydrophobic monomer E, wherein the second hydrophobic monomer is a C10-C22 methacrylate or acrylate monomer; -b- indicates [D] m and [E] n It exists in the form of segments, where m and n are each independently 3 to 50.

[0011] As a further preferred embodiment, the number-average molecular weight of the amphiphilic macromolecular RAFT polymer is 2000~7000.

[0012] As a further preferred embodiment, the small molecule RAFT group includes a carboxylic acid group, a dithioester group, and / or a trithioester group.

[0013] As a further preferred embodiment, the quaternary ammonium salt monomer is one or more of (meth)acryloyloxyethyltrimethylammonium chloride, diallyl dimethylammonium chloride, or (meth)acrylate dimethylaminoethyl ester; the sulfonate monomer is 2-acrylamido-2-methylpropanesulfonic acid and / or sodium styrene sulfonate.

[0014] As a further preferred embodiment, the second hydrophobic monomer is a C10, C12, C16 or C18 methacrylate or acrylate monomer.

[0015] Secondly, this application also discloses a method for preparing the above-mentioned hydrophobic alkyl acrylate copolymer, comprising the following steps: S1. In terms of molar parts, 1 part of the amphiphilic macromolecular RAFT polymer Z, x parts of the first hydrophobic monomer A and y parts of the steric hindrance monomer B are uniformly dispersed in an aqueous phase; then, in an inert atmosphere, at a temperature of 50℃~85℃, a first initiator is added to carry out a first polymerization reaction to obtain an emulsion of the first block copolymer Z-Ax-co-By. Wherein, the first hydrophobic monomer is a C12-C26 (meth)acrylate monomer, and the sterically hindered monomer is a C5-C20 (meth)acrylate monomer with alicyclic / bicyclic side groups; x is 50~1000; S2. Add z parts of crosslinking monomer C to the emulsion of the first block copolymer Z-Ax-co-By, and then add a second initiator in an inert atmosphere at a temperature of 50℃~85℃ to carry out a second polymerization reaction to obtain an emulsion of hydrophobic alkyl acrylate copolymer Z-(Ax-co-By)-b-Cz. Wherein, the crosslinking monomer is a C5-C20 monomer with an epoxy group and / or a terminal isocyanate monomer, and x:y:z is 20:(1~4):(2~10).

[0016] Preferably, the first initiator and the second initiator are water-soluble azo initiators, peroxide initiators, or redox system initiators.

[0017] As a further preferred embodiment, the mass of the first initiator is 0.1% to 3% of the sum of the masses of the first hydrophobic monomer and the sterically hindered monomer, and the mass of the second initiator is 0.1% to 3% of the mass of the crosslinking monomer.

[0018] Thirdly, this application also discloses the application of the above-mentioned hydrophobic alkyl acrylate copolymer in waterproofing textiles.

[0019] In summary, compared with the prior art, the technical solutions conceived in this application have the following main technical advantages: 1. Compared with traditional random copolymers, the hydrophobic alkyl acrylate copolymer synthesized in this application has a well-designed block structure. The first block structure is constructed by random copolymerization of a first hydrophobic monomer and a sterically hindered monomer. The introduction of a small amount of sterically hindered monomer not only does not destroy the chain segment regularity, but also achieves a dual effect by utilizing its steric hindrance effect: on the one hand, it promotes the close arrangement of the long alkyl side chains of the acrylate monomer and enhances the crystallinity of the chain segment; on the other hand, it effectively stabilizes the crystalline region, thereby improving the waterproof performance of the copolymer. 2. The second block structure of the hydrophobic alkyl acrylate copolymer of this application uses crosslinking monomers. This structure can promote the enrichment of crosslinking monomers in the microphase region, thereby significantly increasing the local concentration of functional groups in the molecular chain of the hydrophobic alkyl acrylate copolymer. The block structure leads to the local enrichment of crosslinking groups on the molecular chain, promoting intermolecular crosslinking reactions. This not only enhances the stability of the crosslinking structure, but also fixes the crystalline region, which is beneficial to improving the waterproof performance of the copolymer.

[0020] 3. By using an amphiphilic macromolecular RAFT polymer that combines highly efficient chain transfer activity with excellent emulsifying ability for long-chain alkyl acrylate monomers, RAFT emulsion polymerization of long-chain alkyl acrylate monomers without the addition of small-molecule emulsifiers was successfully achieved. This allows the amphiphilic macromolecular RAFT polymer to be part of the hydrophobic alkyl acrylate copolymer structure of this application, which not only avoids the introduction of small-molecule surfactants in traditional emulsion polymerization, but also ensures the stability of the polymerization process and the purity of the product. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0022] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0023] Furthermore, throughout this specification, references to "an embodiment"; "an embodiment," "an example," or similar language indicate that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment of this application. Therefore, the appearance of the phrase "in one embodiment;" throughout this specification, and similar language, may, but not necessarily, refer to the same embodiment.

[0024] To achieve the above objectives, in a first aspect, this application provides a hydrophobic alkyl acrylate copolymer that can be used for waterproofing textiles, comprising at least the block Z-(Ax-co-By)-b-Cz; Wherein, Z is an amphiphilic macromolecular RAFT polymer; Block Ax-co-By is polymerized from the first hydrophobic monomer A and the sterically hindered monomer B, and -co- indicates that Ax and By exist in a random form; Block Cz is polymerized from the crosslinking monomer C, and -b- indicates that (Ax-co-By) and Cz exist in a block form; x, y and z represent the average degree of polymerization, x is 50~1000, and x:y:z is 20:(1~4):(2~10).

[0025] The number-average molecular weight of this amphiphilic macromolecular RAFT polymer is 2000–7000, and its chemical formula is R-[D]. m -b-[E] n Where R is a small molecule RAFT group, such as a carboxylic acid group, a dithioester group, and / or a trithioester group; block [D] m It is synthesized by double bond addition polymerization of hydrophilic monomer D, wherein the hydrophilic monomer is a C7-C20 quaternary ammonium salt monomer and / or sulfonate monomer; the quaternary ammonium salt monomer includes one or more of (meth)acryloyloxyethyltrimethylammonium chloride, diallyl dimethylammonium chloride or (meth)acrylate dimethylaminoethyl ester; the sulfonate monomer is 2-acrylamido-2-methylpropanesulfonic acid and / or sodium styrene sulfonate.

[0026] Block [E] n It is formed by double bond addition polymerization of the second hydrophobic monomer E, wherein the second hydrophobic monomer is a C10-C22 methacrylate or acrylate monomer, such as a C10, C12, C16 or C18 methacrylate or acrylate monomer.

[0027] -b- indicates [D] m and [E] n It exists in the form of segments, where m and n are each independently 3 to 50.

[0028] The first hydrophobic monomer A is a C12-C26 (meth)acrylate monomer (preferably C18 or above); the sterically hindered monomer is a C5-C20 (meth)acrylate monomer with alicyclic / bicyclic side groups, preferably one or more of isobornyl methacrylate, cyclohexyl methacrylate, or 4-tert-butylcyclohexyl (meth)acrylate; the crosslinking monomer is a C5-C20 monomer with epoxy groups and / or a terminal isocyanate monomer, preferably one or more of glycidyl acrylate, glycidyl methacrylate, 3-isopropyl-α,α-dimethylbenzyl isocyanate, or isophorone diisocyanate.

[0029] The preparation method of this hydrophobic alkyl acrylate copolymer includes the following steps: S1. On a molar basis, 1 part of the amphiphilic macromolecular RAFT polymer Z, x parts of the first hydrophobic monomer A and y parts of the steric hindrance monomer B are uniformly dispersed in an aqueous phase; then, in an inert atmosphere, at a temperature of 50℃~85℃, 0.1%~3% of the first initiator equivalent to the sum of the mass of the first hydrophobic monomer and the steric hindrance monomer are added to carry out the first polymerization reaction to obtain an emulsion of the first block copolymer Z-Ax-co-By; S2. Add z parts of crosslinking monomer C to the emulsion of the first block copolymer Z-Ax-co-By, and then, in an inert atmosphere at a temperature of 50℃~85℃, add 0.1%~3% of a second initiator equivalent to the mass of the crosslinking monomer to carry out a second polymerization reaction to obtain an emulsion of hydrophobic alkyl acrylate copolymer Z-(Ax-co-By)-b-Cz; The first initiator and the second initiator are water-soluble azo initiators, peroxide initiators, or redox system initiators.

[0030] The following are examples and comparative examples. The macromolecular RAFT reagents used in the examples and comparative examples of this application are DDMAT-DMC8-b-LA5 (molecular weight approximately 3228) and CPPA-DADMC9-b-HA4 (molecular weight approximately 2739). Specifically, DDMAT is 2-(dodecyltrithiocarbonate)-2-methylpropionic acid (molecular weight 364.63), DMC is methacryloyloxyethyltrimethylammonium chloride (molecular weight 207.698), LA is dodecyl acrylate (molecular weight 240.38), CPPA is 4-cyano-4-(phenylcarbonthioylthio)pentanoic acid (molecular weight 98.176), DADMAC is dimethyl diallyl ammonium chloride (molecular weight 161.67), and HA is hexadecyl acrylate (molecular weight 296.5). Their structures and preparation methods can be found in the prior application CN202511799888.4.

[0031] The preparation method of DDMAT-DMC8-b-LA5 is as follows: S1: Add 1.1 g DDMAT, 5.0 g DMC, and 55 g ethanol to a four-necked flask and stir until completely dissolved. While stirring continuously, purge with nitrogen gas at room temperature for 30 min to remove oxygen, then raise the temperature to 80 °C. Slowly add a solution of 0.2 g V501 initiator dissolved in 5 g ethanol to the reaction system. After reacting for 6 h, cool to room temperature.

[0032] S2: Subsequently, 3.63 g of LA dissolved in 25 g of 1,4-dioxane was added, stirred thoroughly to dissolve, and the mixture was again deoxygenated by purging with nitrogen at room temperature for 30 min, then heated to 80 °C. A solution of 0.04 g of V501 initiator dissolved in 5 g of 1,4-dioxane was slowly added dropwise to the reaction system, and the reaction continued for 10 h. During the reaction, 2 g of ethanol was added to the system every 3 h, for a total of three times. After the reaction was complete, the yellow liquid in the flask was transferred, dried at 110 °C to remove the solvent, yielding a light yellow waxy solid, which is DDMAT-DMC8-b-LA5.

[0033] The preparation method of CPPA-DADMC9-b-HA4 is as follows: S1: Add 0.4 g CPPA, 5.9 g DADMC, and 50 g isopropanol to a four-necked flask and stir until completely dissolved. While stirring continuously, purge with nitrogen gas at room temperature for 30 min to remove oxygen, then raise the temperature to 80 °C. Slowly add a solution of 0.12 g V501 initiator dissolved in 5 g isopropanol to the reaction system. After reacting for 6 h, cool to room temperature.

[0034] S2: Subsequently, 4.8 g of HA dissolved in 30 g of tetrahydrofuran was added, stirred thoroughly to dissolve, and the mixture was again deoxygenated by purging with nitrogen at room temperature for 30 min, then heated to 80 °C. A solution of 0.09 g of V501 initiator dissolved in 5 g of tetrahydrofuran was slowly added dropwise to the reaction system, and the reaction continued for 9 h. During the reaction, 1.5 g of ethanol was added to the system every 2 h, for a total of four times. After the reaction was complete, the yellow liquid in the flask was transferred, dried at 110 °C to remove the solvent, yielding a light yellow waxy solid, which is CPPA-DADMC9-b-HA4.

[0035] Example 1 The hydrophobic monomer is dodecyl acrylate LA (molecular weight 240.4), the sterically hindered monomer is isobornyl methacrylate IBOMA (molecular weight 222.3), the crosslinking monomer is glycidyl methacrylate GMA (molecular weight 142.2), the initiator is KPS (potassium persulfate), and the macromolecular RAFT reagent is DDMAT-DMC8-b-LA5.

[0036] Step S1: Add 0.8g of macromolecular RAFT reagent, 7.5g of hydrophobic monomer, 0.8g of sterically hindered monomer and 45g of deionized water to a four-necked flask, and sonicate to form a homogeneous preemulsion. Step S2: Under continuous stirring, nitrogen gas was introduced at room temperature for 30 min to remove oxygen, and then the temperature was raised to 80 °C. A solution of 1% (by mass of the initiator, consisting of the hydrophobic monomer and the sterically hindered monomer) dissolved in 5 g of deionized water was slowly added dropwise to the system. After reacting for 5 h, the mixture was cooled to room temperature. Then, 0.9 g of crosslinking monomer was added, and the mixture was stirred thoroughly to ensure homogeneous emulsification. Step S3: Nitrogen was purged again at room temperature for 30 min to remove oxygen, and then the temperature was raised to 80 °C. A solution of 1% by weight of the crosslinking monomer initiator dissolved in 1.5 g of deionized water was slowly added dropwise to the reaction system, and the reaction was continued for 3 h. The mixture was then cooled to room temperature to finally obtain a long-chain alkyl acrylate block copolymer emulsion.

[0037] Calculations show x≈126, y≈15, z≈26, and x:y:z≈10:1:2, meaning the molecular formula of the long-chain alkyl acrylate block copolymer is DDMAT-DMC8-b-LA5-(LA 126 -co-IBOMA 15 )-b-GMA 26 The first segment is a random copolymer of LA and IBOMA, which then forms a block with the GMA of the second segment.

[0038] Example 2 The hydrophobic monomer is octadecyl acrylate SA (molecular weight 324.5), the sterically hindered monomer is isobornyl methacrylate IBOMA (molecular weight 222.3), the crosslinking monomer is dimethylpyridine-terminated 3-isopropyl-dimethylbenzyl isocyanate (terminated TMI) (molecular weight 282.4), the initiator is KPS, i.e. potassium persulfate, and the macromolecular RAFT reagent is DDMAT-DMC8-b-LA5.

[0039] Step S1: Add 1.2g of amphiphilic macromolecular RAFT reagent, 7.2g of hydrophobic monomer, 0.8g of sterically hindered monomer and 45g of deionized water to a four-necked flask, and sonicate to form a homogeneous preemulsion. Step S2: Under continuous stirring, nitrogen gas was introduced at room temperature for 30 min to remove oxygen, and then the temperature was raised to 80 °C. A solution of 1% (by mass of the hydrophobic monomer and the sterically hindered monomer) of the initiator dissolved in 5 g of deionized water was slowly added dropwise to the system. After reacting for 5 h, the mixture was cooled to room temperature. Then, 0.8 g of crosslinking monomer was added, and the mixture was stirred thoroughly to ensure homogeneous emulsification. Step S3: Nitrogen was purged again at room temperature for 30 min to remove oxygen, and then the temperature was raised to 80 °C. A solution of 1% by weight of the crosslinking monomer initiator dissolved in 1.5 g of deionized water was slowly added dropwise to the reaction system, and the reaction was continued for 3 h. The mixture was then cooled to room temperature to finally obtain a long-chain alkyl acrylate block copolymer emulsion.

[0040] Calculations show x≈60, y≈9.7, z≈7.6, and x:y:z≈10:1.6:1:3, indicating that the molecular formula of the long-chain alkyl acrylate block copolymer is DDMAT-DMC8-b-LA5-(SA 60 -co-IBOMA 9.7 )-b-TMI 7.6 The first segment is a random copolymer of SA and IBOMA, which then forms a block with the second segment TMI.

[0041] Example 3 The hydrophobic monomer is octadecyl acrylate SA (molecular weight 324.5), the sterically hindered monomer is 4-tert-butylcyclohexyl acrylate TBCHA (molecular weight 210.3), the crosslinking monomer is glycidyl methacrylate GMA (molecular weight 142.2), the initiator is KPS (potassium persulfate), and the macromolecular RAFT reagent is DDMAT-DMC8-b-LA5.

[0042] Step S1: Add 1.1g of amphiphilic macromolecular RAFT reagent, 7.0g of hydrophobic monomer, 0.8g of sterically hindered monomer and 45g of deionized water to a four-necked flask, and sonicate to form a homogeneous preemulsion. Step S2: Under continuous stirring, nitrogen gas was introduced at room temperature for 30 min to remove oxygen, and then the temperature was raised to 80 °C. A solution of 1% by mass of the initiator (the sum of the mass of the hydrophobic monomer and the sterically hindered monomer) dissolved in 5 g of deionized water was slowly added dropwise to the system. After reacting for 5 h, the mixture was cooled to room temperature. Then, 1.1 g of crosslinking monomer was added, and the mixture was stirred thoroughly to ensure homogeneous emulsification. Step S3: Nitrogen was purged again at room temperature for 30 min to remove oxygen, and then the temperature was raised to 80 °C. A solution of 1% by weight of the crosslinking monomer initiator dissolved in 1.5 g of deionized water was slowly added dropwise to the reaction system, and the reaction was continued for 3 h. The mixture was then cooled to room temperature to finally obtain a long-chain alkyl acrylate block copolymer emulsion.

[0043] Calculations show x≈63, y≈11, z≈22.7, and x:y:z≈10:1.8:3.6, indicating that the molecular formula of the long-chain alkyl acrylate block copolymer is DDMAT-DMC8-b-LA5-(SA 63 -co-TBCHA 11 )-b-GMA 22.7 The first segment is a random copolymer of SA and TBCHA, which then forms a block with the GMA in the second segment.

[0044] Example 4 The hydrophobic monomer is octadecyl methacrylate (SMA) (molecular weight 338.6), the sterically hindered monomer is cyclohexyl methacrylate (molecular weight 168.2), the crosslinking monomer is glycidyl acrylate (GA) (molecular weight 128.1), the initiator is KPS (potassium persulfate), and the macromolecular RAFT reagent is CPPA-DADMC9-b-HA4.

[0045] Step S1: Add 1.0 g of amphiphilic macromolecular RAFT reagent, 15.0 g of hydrophobic monomer, 0.6 g of sterically hindered monomer and 45 g of deionized water to a four-necked flask, and sonicate to form a homogeneous preemulsion. Step S2: Under continuous stirring, nitrogen gas was purged at room temperature for 30 min to remove oxygen, and then the temperature was raised to 80 °C. A solution of 1% (by mass of the hydrophobic monomer and the sterically hindered monomer) of the initiator dissolved in 5 g of deionized water was slowly added dropwise to the system. After reacting for 5 h, the mixture was cooled to room temperature. Then, 1.5 g of crosslinking monomer was added, and the mixture was stirred thoroughly to ensure homogeneous emulsification. Step S3: Nitrogen was purged again at room temperature for 30 min to remove oxygen, and then the temperature was raised to 80 °C. A solution of 1% by weight of the crosslinking monomer initiator dissolved in 1.5 g of deionized water was slowly added dropwise to the reaction system, and the reaction was continued for 3 h. The mixture was then cooled to room temperature to finally obtain a long-chain alkyl acrylate block copolymer emulsion.

[0046] Calculations show x≈121, y≈9.8, z≈32.1, and x:y:z≈10:0.8:2.6, indicating that the molecular formula of the long-chain alkyl acrylate block copolymer is CPPA-DADMC9-b-HA4-(SMA) 121 cyclohexyl methacrylate 9.8 )-b-GA 32.1 The first segment is a random copolymer of SMA and cyclohexyl methacrylate, which then forms a block with GA in the second segment.

[0047] Example 5 The hydrophobic monomer is dodecyl methacrylate (LMA) (molecular weight 254.4), the sterically hindered monomer is cyclohexyl methacrylate (molecular weight 168.2), the crosslinking monomer is dimethylpyridine-terminated isophorone diisocyanate-terminated IBDI (molecular weight 412.5), the initiator is KPS (potassium persulfate), and the macromolecular RAFT reagent is CPPA-DADMC9-b-HA4.

[0048] Step S1: Add 1.0 g of amphiphilic macromolecular RAFT reagent, 14.0 g of hydrophobic monomer, 1.0 g of sterically hindered monomer and 45 g of deionized water to a four-necked flask, and sonicate to form a homogeneous preemulsion. Step S2: Under continuous stirring, nitrogen gas was introduced at room temperature for 30 min to remove oxygen, and then the temperature was raised to 80 °C. A solution of 1% (by mass of the hydrophobic monomer and the sterically hindered monomer) of the initiator dissolved in 5 g of deionized water was slowly added dropwise to the system. After reacting for 5 h, the mixture was cooled to room temperature. Then, 3.0 g of crosslinking monomer was added, and the mixture was stirred thoroughly to ensure homogeneous emulsification. Step S3: Nitrogen was purged again at room temperature for 30 min to remove oxygen, and then the temperature was raised to 80 °C. A solution of 1% by weight of the crosslinking monomer initiator dissolved in 1.5 g of deionized water was slowly added dropwise to the reaction system, and the reaction was continued for 3 h. The mixture was then cooled to room temperature to finally obtain a long-chain alkyl acrylate block copolymer emulsion.

[0049] The calculations show that x≈151, y≈16.3, z≈20, and x:y:z≈10:1.1:1.3.

[0050] Example 6 The hydrophobic monomer is octadecyl acrylate SA (molecular weight 324.5), the sterically hindered monomer is cyclohexyl methacrylate (molecular weight 168.2), the crosslinking monomer is glycidyl methacrylate GMA (molecular weight 142.2), the initiator is KPS (potassium persulfate), and the macromolecular RAFT reagent is CPPA-DADMC9-b-HA4.

[0051] Step S1: Add 1.0 g of amphiphilic macromolecular RAFT reagent, 10.1 g of hydrophobic monomer, 0.8 g of sterically hindered monomer and 45 g of deionized water to a four-necked flask, and sonicate to form a homogeneous preemulsion. Step S2: Under continuous stirring, nitrogen gas was introduced at room temperature for 30 min to remove oxygen, and then the temperature was raised to 80 °C. A solution of 1% (by mass of the hydrophobic monomer and the sterically hindered monomer) of the initiator dissolved in 5 g of deionized water was slowly added dropwise to the system. After reacting for 5 h, the mixture was cooled to room temperature. Then, 0.5 g of crosslinking monomer was added, and the mixture was stirred thoroughly to ensure homogeneous emulsification. Step S3: Nitrogen was purged again at room temperature for 30 min to remove oxygen, and then the temperature was raised to 80 °C. A solution of 1% by weight of the crosslinking monomer initiator dissolved in 1.5 g of deionized water was slowly added dropwise to the reaction system, and the reaction was continued for 3 h. The mixture was then cooled to room temperature to finally obtain a long-chain alkyl acrylate block copolymer emulsion.

[0052] The calculations show that x≈85, y≈13, z≈10, and x:y:z≈10:1.5:1.1.

[0053] Example 7 The hydrophobic monomer is dodecyl acrylate LA (molecular weight 240.4), the sterically hindered monomer is cyclohexyl methacrylate (molecular weight 168.2), the crosslinking monomer is glycidyl methacrylate GMA (molecular weight 142.2), the initiator is KPS (potassium persulfate), and the macromolecular RAFT reagent is CPPA-DADMC9-b-HA4.

[0054] Step S1: Add 1.0 g of amphiphilic macromolecular RAFT reagent, 43.7 g of hydrophobic monomer, 1.9 g of sterically hindered monomer and 200 g of deionized water to a four-necked flask, and sonicate to form a homogeneous preemulsion. Step S2: Under continuous stirring, nitrogen gas was introduced at room temperature for 30 min to remove oxygen, and then the temperature was raised to 80 °C. A solution of 2% (by mass of the hydrophobic monomer and the sterically hindered monomer) of the initiator dissolved in 15 g of deionized water was slowly added dropwise to the system. After reacting for 5 h, the mixture was cooled to room temperature. Then, 3.5 g of crosslinking monomer was added, and the mixture was stirred thoroughly to ensure homogeneous emulsification. Step S3: Nitrogen was purged again at room temperature for 30 min to remove oxygen, and then the temperature was raised to 80 °C. A solution of 2% by weight of the crosslinking monomer initiator dissolved in 5g of deionized water was slowly added dropwise to the reaction system, and the reaction was continued for 3 h. The mixture was then cooled to room temperature to finally obtain a long-chain alkyl acrylate block copolymer emulsion.

[0055] The calculations show that x≈500, y≈31, z≈70, and x:y:z≈10:0.6:1.4.

[0056] Comparative Example 1 The macromolecular RAFT reagent, hydrophobic monomer, steric hindrance, and crosslinking monomer are the same as in Example 1.

[0057] Step S1: Add 0.8g of amphiphilic macromolecular RAFT reagent, 7.5g of hydrophobic monomer, 0.8g of sterically hindered monomer, 0.9g of crosslinking monomer and 45g of deionized water to a four-necked flask, and sonicate to form a uniform preemulsion. Step S2: Under continuous stirring, nitrogen gas was introduced at room temperature for 30 min to remove oxygen, followed by heating to 80 °C. A solution of 1% (by mass of the initiator, consisting of the hydrophobic monomer, crosslinking monomer, and sterically hindered monomer) dissolved in 5 g of deionized water was slowly added dropwise to the system. After reacting for 5 h, the mixture was cooled to room temperature. The final product was a random copolymer emulsion of side-long-chain alkyl acrylates.

[0058] Calculations show x≈126, y≈15, and z≈26, meaning the molecular formula of the long-chain alkyl acrylate block copolymer is DDMAT-DMC8-b-LA5-(LA 126 -co-IBOMA 15 -co-GMA 26 LA, IBOMA and GMA all exist in the form of random copolymers.

[0059] Comparative Example 2 The macromolecular RAFT reagent, hydrophobic monomer, steric hindrance, and crosslinking monomer are the same as in Example 2.

[0060] Step S1: Add 1.2g of amphiphilic macromolecular RAFT reagent, 7.2g of hydrophobic monomer, 0.8g of crosslinking monomer and 45g of deionized water to a four-necked flask, and sonicate to form a homogeneous preemulsion. Step S2: Under continuous stirring, nitrogen gas was introduced at room temperature for 30 min to remove oxygen, and then the temperature was raised to 80 °C. A solution of 1% (by mass of the initiator, consisting of the hydrophobic monomer and the crosslinking monomer) dissolved in 5 g of deionized water was slowly added dropwise to the system. After reacting for 5 h, the mixture was cooled to room temperature. Then, 0.8 g of sterically hindered monomer was added, and the mixture was stirred thoroughly to ensure homogeneous emulsification. Step S3: Nitrogen was purged again at room temperature for 30 min to remove oxygen, and then the temperature was raised to 80 °C. A solution of 1% by weight of the sterically hindered monomer initiator dissolved in 1.5 g of deionized water was slowly added dropwise to the reaction system, and the reaction was continued for 3 h. The mixture was then cooled to room temperature to finally obtain a long-chain alkyl acrylate block copolymer emulsion.

[0061] Calculations show x≈60, y≈9.7, and z≈7.6, indicating that the molecular formula of the long-chain alkyl acrylate block is DDMAT-DMC8-b-LA5-(SA 60 -co-TMI 7.6)-b- IBOMA 9.7 The first segment is a random copolymer of SA and TMI, which then forms a block with the second segment IBOMA.

[0062] Comparative Example 3 The macromolecular RAFT reagent, hydrophobic monomer, steric hindrance, and crosslinking monomer are the same as in Example 3.

[0063] Step S1: Add 1.1g of amphiphilic macromolecular RAFT reagent, 7.0g of hydrophobic monomer, 0.8g of crosslinking monomer and 45g of deionized water to a four-necked flask, and sonicate to form a homogeneous preemulsion. Step S2: Under continuous stirring, nitrogen gas was introduced at room temperature for 30 min to remove oxygen, and then the temperature was raised to 80 °C. A solution of 1% (by mass of the initiator, consisting of the hydrophobic monomer and the crosslinking monomer) dissolved in 5 g of deionized water was slowly added dropwise to the system. After reacting for 5 h, the mixture was cooled to room temperature. Then, 11 g of sterically hindered monomer was added, and the mixture was stirred thoroughly to ensure homogeneous emulsification. Step S3: Nitrogen was purged again at room temperature for 30 min to remove oxygen, and then the temperature was raised to 80 °C. A solution of 1% by weight of the sterically hindered monomer initiator dissolved in 1.5 g of deionized water was slowly added dropwise to the reaction system, and the reaction was continued for 3 h. The mixture was then cooled to room temperature to finally obtain a long-chain alkyl acrylate block copolymer emulsion.

[0064] Calculations show x≈63, y≈11, and z≈22.7, indicating that the molecular formula of the long-chain alkyl acrylate block copolymer is DDMAT-DMC8-b-LA5-(SA 63 -co-GMA 22.7 )-b-TBCHA 11 The first segment is a random copolymer of SA and GMA, which then forms a block with the second segment, TBCHA.

[0065] Comparative Example 4 The hydrophobic monomer is octadecyl methacrylate (SMA) (molecular weight 338.6), the sterically hindered monomer is cyclohexyl methacrylate (molecular weight 168.2), the crosslinking monomer is glycidyl acrylate (GA) (molecular weight 128.1), the initiator is KPS (potassium persulfate), the small molecule RAFT reagent is CPPA (4-cyano-4-(phenylcarbothioylthio)valerate), and the small molecule emulsifier is a mixture of octadecyltrimethylammonium chloride (1831) and isomeric tridecyl alcohol polyoxyethylene ether (1310) in a 1:1 mass ratio.

[0066] Step S1: Add 0.04g of small molecule RAFT reagent (replacing the amphiphilic macromolecule RAFT reagent in each example), 15.0g of hydrophobic monomer, 0.6g of sterically hindered monomer, 1.2g of small molecule emulsifier and 45g of deionized water to a four-necked flask, and sonicate to form a uniform pre-emulsion. Step S2: Under continuous stirring, nitrogen gas was purged at room temperature for 30 min to remove oxygen, and then the temperature was raised to 80 °C. A solution of 1% (by mass of the hydrophobic monomer and the sterically hindered monomer) of the initiator dissolved in 5 g of deionized water was slowly added dropwise to the system. After reacting for 5 h, the mixture was cooled to room temperature. Then, 1.5 g of crosslinking monomer was added, and the mixture was stirred thoroughly to ensure homogeneous emulsification. Step S3: Nitrogen was purged again at room temperature for 30 min to remove oxygen, and then the temperature was raised to 80 °C. A solution of 1% by weight of the crosslinking monomer initiator dissolved in 1.5 g of deionized water was slowly added dropwise to the reaction system, and the reaction was continued for 3 h. The mixture was then cooled to room temperature to finally obtain a long-chain alkyl acrylate block copolymer emulsion.

[0067] Calculations show x≈121, y≈9.8, and z≈32.1, indicating that the molecular formula of the long-chain alkyl acrylate block copolymer is CPPA-(SMA). 121 cyclohexyl methacrylate 9.8 )-b-GA 32.1 The first segment is a random copolymer of SMA and cyclohexyl methacrylate, which then forms a block with GA in the second segment.

[0068] Verification Example 1 The appearance of the emulsions in Examples 1-4 and Comparative Examples 1-4 was observed, and the average particle size of the polymer was tested using the dynamic light scattering method. The results are shown in Table 1.

[0069] Table 1. Appearance of emulsions in Examples 1-4 and Comparative Examples 1-4

[0070] Verification Example 2 Test sample preparation: Polymer film sample preparation: The emulsion was drop-coated onto a glass slide, dried slowly at low temperature, and heated at 170℃ for 3 minutes.

[0071] Fabric samples: grey spring spun and green taslon Emulsion dosage: 20 g / L and 45 g / L (based on 17.5% solids content) Finishing process: one dip and one roll, 170℃ setting and drying for 60 seconds The static contact angle (water) test was conducted using the ASTM D7334 method, and the results are shown in Table 2. The spray test was conducted using the AATCC 22-2017 method, and the results are shown in Table 3.

[0072] Table 2 Static contact angle (water) test results

[0073] Table 3 Results of the first spray test

[0074] Verification Example 3 According to AATCC 130 After five washes according to the washing procedure in "2018", a spray test was conducted again using AATCC 22-2017 method. The results are shown in Table 4. Table 4 Results of the second spray test

[0075] As can be seen from the verification examples, under the same monomer composition and molecular weight, compared with random and other block copolymers, the block copolymers synthesized using the technology of this application exhibit significant advantages in the following aspects (e.g., Examples 1 and Comparative Example 1, Examples 2 and Comparative Example 2, Examples 3 and Comparative Example 3): First, the water contact angle of the obtained polymer film and various fabrics treated with emulsions of different concentrations is significantly improved; Second, various fabrics treated with different amounts of emulsion achieve higher scores in the standard spray test; Third, after five washes, the spray score of the examples is still significantly higher than that of the comparative examples, and the gap between the two further widens. Compared with the initial value, the score decay of the examples is much lower than that of the comparative examples, proving that the scheme of this application has superior wash resistance. The comprehensive results show that the block copolymers prepared by this application have superior waterproof performance.

[0076] It has been verified that macromolecular RAFT polymers that meet the protection scope of the prior application CN202511799888.4 can successfully prepare hydrophobic side-long-chain alkyl acrylate copolymers by replacing the amphiphilic macromolecular RAFT reagents in each example, and exhibit the same properties in emulsion appearance, contact angle test and spray test.

[0077] Those skilled in the art will readily understand that the above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A hydrophobic alkyl acrylate copolymer characterized in that, comprises at least a block Z-(Ax-co-By)-b-Cz; wherein, Z is a parent macromolecular RAFT polymer; the block Ax-co-By is polymerized from a first hydrophobic monomer A and a steric-hindered monomer B, -co- indicates that Ax and By exist in a random form; the block Cz is polymerized from a crosslinking monomer C, -b- indicates that (Ax-co-By) and Cz exist in a block form; the first hydrophobic monomer is a (meth)acrylate monomer with C12-C26, the steric-hindered monomer is a (meth)acrylate monomer with aliphatic ring / bicyclic side groups with C5-C20, and the crosslinking monomer is a monomer with an epoxy group with C5-C20 and / or a blocked isocyanate monomer; x, y and z represent average polymerization degrees, x is 50-1000, and x:y:z is 20:(1-4):(2-10).

2. The hydrophobic alkyl acrylate copolymer according to claim 1, wherein the first hydrophobic monomer is a (meth)acrylate monomer with C18-C26.

3. The hydrophobic alkyl acrylate copolymer according to claim 1, wherein the steric-hindered monomer is one or more of isobornyl methacrylate, cyclohexyl methacrylate or 4-tert-butylcyclohexyl (meth)acrylate.

4. The hydrophobic alkyl acrylate copolymer according to claim 1, wherein the crosslinking monomer is one or more of glycidyl acrylate, glycidyl methacrylate, 3-isopropyl-alpha,alpha-dimethylbenzyl isocyanate or isophorone diisocyanate.

5. The hydrophobic alkyl acrylate copolymer according to claim 1, wherein The chemical formula of the amphiphilic macromolecule RAFT polymer is R-[D] m -b-[E] n ; wherein, R is a small molecule RAFT group; Block [D] m formed by the addition polymerization of a hydrophilic monomer D, which is a C7-C20 quaternary ammonium salt monomer and / or a sulfonate monomer, via a double bond; Block [E] n formed by the addition polymerization of a second hydrophobic monomer E, which is a C10-C22 methacrylate or acrylate monomer; - b- represents [D] m and [E] n are present in the form of blocks, m and n are each independently 3 to 50.

6. The hydrophobic alkyl acrylate copolymer according to claim 5, wherein the number average molecular weight of the parent macromolecular RAFT polymer is 2000-7000.

7. The hydrophobic alkyl acrylate copolymer according to claim 5, wherein the alkyl acrylate copolymer is a copolymer of acrylic acid and a C1-C4 alkyl acrylate. the small molecule RAFT group includes a carboxylic acid group, a dithioester group and / or a trithioester group.

8. The hydrophobic alkyl acrylate copolymer according to claim 5, wherein the quaternary ammonium salt monomer is one or more of (meth)acryloyloxyethyl trimethyl ammonium chloride, diallyl dimethyl ammonium chloride or dimethylaminoethyl (meth)acrylate; and the sulfonate monomer is 2-acrylamido-2-methylpropane sulfonic acid and / or sodium styrene sulfonate.

9. Process for the preparation of the hydrophobic alkyl acrylate copolymer according to any one of claims 1 to 8, characterized in that, comprises the following steps: S1. dispersing 1 part of the parent macromolecular RAFT polymer Z, x parts of the first hydrophobic monomer A and y parts of the steric-hindered monomer B in a water phase in terms of mole fraction; then adding a first initiator to carry out a first polymerization reaction at a temperature of 50-85°C in an inert atmosphere to obtain an emulsion of a first block copolymer Z-Ax-co-By; wherein, the first hydrophobic monomer is a (meth)acrylate monomer with C12-C26, the steric-hindered monomer is a (meth)acrylate monomer with aliphatic ring / bicyclic side groups with C5-C20, and x is 50-1000; S2. adding a crosslinking monomer C in a mole fraction of z parts to the emulsion of the first block copolymer Z-Ax-co-By, then adding a second initiator to carry out a second polymerization reaction at a temperature of 50-85°C in an inert atmosphere to obtain an emulsion of a hydrophobic alkyl acrylate copolymer Z-(Ax-co-By)-b-Cz; wherein, the crosslinking monomer is a monomer with an epoxy group with C5-C20 and / or a blocked isocyanate monomer, and x:y:z is 20:(1-4):(2-10).

10. The use of the hydrophobic alkyl acrylate copolymer according to any one of claims 1-8 in waterproofing textiles.

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