SIS soap-free emulsion as well as preparation method and application thereof

Abstract

The invention discloses an SIS soap-free emulsion as well as a preparation method and application thereof, and belongs to the field of preparation of high polymer material latex films. The SIS soap-free emulsion is prepared from an SIS ionomer and water; the SIS ionomer is provided with a lateral carboxylate group or a lateral carboxylic ammonium salt group; the lateral carboxylate group is selected from at least one of sodium carboxylate, potassium carboxylate, lithium carboxylate, calcium carboxylate and magnesium carboxylate; the lateral carboxylic acid ammonium salt group is selected from at least one of triethanolamine maleate, triethylamine maleate, trimethylamine maleate, triethylamine maleate and isopropyl amine maleate. No emulsifier needs to be added in the whole preparation process, the complex cleaning process of emulsifier residues is avoided, and generation of emulsifier wastewater is effectively reduced. Compared with natural rubber gloves and nitrile rubber gloves, the prepared SIS latex gloves are more comfortable to wear, wider in application and higher in adaptability.

Description

Technical Field

[0001] This application relates to a soap-free SIS emulsion, its preparation method, and its application, belonging to the field of polymer material latex film preparation. Background Technology

[0002] Currently, latex gloves on the market are mainly divided into natural latex gloves and nitrile gloves, both of which are widely used in medical, industrial, and other fields. However, they also have some obvious drawbacks. Natural latex gloves may cause latex allergic reactions and may age and crack under the influence of ultraviolet light, air, and temperature changes. Nitrile gloves, on the other hand, are less comfortable. Due to their high strain strength at low deformation, they lack a snug fit around the hand and are prone to discomfort after prolonged wear. Moreover, compared to natural latex gloves, nitrile gloves have higher production costs and are more expensive. In addition, the manufacturing process of latex gloves usually requires emulsifiers to help disperse natural latex or nitrile emulsions into fine particles to form a stable latex system. This not only increases production costs but may also cause the emulsion to yellow, produce odors, and affect the appearance and sensory quality of the product. More importantly, emulsifiers are often difficult to remove, which not only pollutes the environment but may also pose potential health hazards with long-term exposure. Therefore, developing a new type of latex film that offers superior comfort and environmental friendliness, while also addressing issues such as allergies and environmental pollution in existing gloves, has significant market demand and social value.

[0003] Styrene-isoprene-styrene (SIS) block copolymers, as important thermoplastic elastomers, are widely used in various industrial fields due to their excellent elasticity, abrasion resistance, and processability. SIS consists of hard styrene segments and soft isoprene segments; the soft segments have a low glass transition temperature (Tg), giving the material good elasticity and flexibility at room temperature. Unlike traditional vulcanized rubber, SIS does not require crosslinking to achieve excellent tensile strength and resilience, offering the advantage of reprocessability. Therefore, it is widely used in rubber products, adhesives, and asphalt modification. Traditional solid SIS products face problems in bulk applications such as poor compatibility with polar materials, uneven mixing, complex processes, and high energy consumption. In contrast, SIS emulsion products effectively solve these shortcomings, offering significant advantages such as low energy consumption, environmental friendliness, ease of application, and high performance stability. Therefore, converting SIS into emulsion form to enhance its processing performance and application range is an important direction for future research. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a method for preparing an environmentally friendly and comfortable latex film using an ionic SIS emulsion. The method involves preparing an ionic SIS soap-free emulsion by neutralizing maleic acid-modified SIS with alkali or amine, followed by dip-coating to prepare the SIS latex film. The prepared latex film exhibits reduced phase separation due to the self-assembly of polystyrene and polyisoprene segments within the latex particles and the crosslinking sites generated by ionic groups. This results in improved tensile strength, higher elongation at break, and lower tensile strength under low strain, while simultaneously increasing tensile strength and maintaining a relatively high elongation at break. Specifically, using SIS as a starting material, a maleic acid copolymer is first grafted onto a maleic anhydride solution in an organic solvent at high temperature. This copolymer is then neutralized with an alkali metal or alkaline earth metal hydroxide solution or an amine compound to obtain an ionomer organic solution. This solution is mixed with water to obtain the ionomer solution, and finally, the organic solvent is removed by vacuum distillation to obtain the soap-free SIS emulsion. The prepared soap-free SIS emulsion is then coated onto a glove mold, and after drying and curing, a latex glove with soft, environmentally friendly, and durable properties is obtained. This glove can solve the problems of allergies and environmental pollution that exist in existing latex gloves while maintaining excellent comfort and elasticity.

[0005] The purpose of this invention is to provide a method for preparing latex films using ionic SIS emulsions, and to further apply this method to the manufacture of latex gloves. This novel latex glove improves comfort and addresses the environmental shortcomings of existing glove products. The method does not use emulsifiers, reducing environmental pollution, and enhances wearer comfort by optimizing the glove's materials and structure.

[0006] According to a first aspect of this application, a soap-free SIS emulsion is provided. This soap-free SIS emulsion is purely composed of SIS containing only carboxylate or ammonium carboxylate groups and water.

[0007] A soap-free SIS emulsion, said SIS soap-free emulsion being composed of SIS ionomers and water;

[0008] The SIS ionomer has a side carboxyl salt group or a side carboxyl ammonium salt group;

[0009] The side group carboxylate is selected from at least one of sodium carboxylate, potassium carboxylate, lithium carboxylate, calcium carboxylate, and magnesium carboxylate.

[0010] The side group carboxylic acid ammonium salt is selected from at least one of triethanolamine maleate, triethylamine maleate, trimethylamine maleate, triethylamine maleate, and isopropylamine maleate.

[0011] Optionally, the content of side carboxyl salt groups or side carboxylate ammonium salt groups in the SIS ionomer is 1 wt% to 15 wt%; preferably, the content of side carboxyl salt groups or side carboxylate ammonium salt groups is 1 wt% to 10 wt%.

[0012] Optionally, the SIS soap-free emulsion has a solid content of 1wt%-60wt%, an average particle size of 40nm-2000nm, and a particle size distribution index (PDI) of 0.05-0.58; preferably, the SIS soap-free emulsion has a solid content of 5wt%-50wt%, an average particle size of 40nm-500nm, and a particle size distribution index (PDI) of 0.05-0.3.

[0013] According to a second aspect of this application, a method for preparing a soap-free SIS emulsion is provided.

[0014] The method for preparing the SIS soap-free emulsion described above is characterized in that the preparation method includes:

[0015] (A1) Dissolve the SIS with succinic anhydride groups in an organic solvent and stir to dissolve;

[0016] (A2) Then add a metal hydroxide solution or an amine compound and stir to prepare a polymer solution with carboxylate groups or ammonium carboxylate groups;

[0017] (A3) Mix water with the polymer solution to obtain an ionomer solution;

[0018] (A4) The organic solvent and some water are removed by vacuum distillation to obtain the soap-free SIS emulsion.

[0019] As a preferred embodiment, the method for preparing the SIS soap-free emulsion includes:

[0020] (A1) Dissolve the SIS with succinic anhydride group in an organic solvent and stir at a certain temperature until fully dissolved.

[0021] (A2) Subsequently, an alkali metal or alkaline earth metal hydroxide solution or an amine compound is added and stirred at a certain temperature to prepare a polymer solution with carboxylate groups or ammonium carboxylate groups.

[0022] (A3) Next, the deionized water is mixed with the polymer solution to obtain an ionomer solution.

[0023] (A4) Finally, the organic solvent and part of the deionized water are removed by vacuum distillation to obtain the soap-free emulsion.

[0024] Optionally, in step A1, the SIS with succinic anhydride groups is maleic acid-modified SIS, and its preparation method includes:

[0025] SIS and maleic anhydride were mixed, stirred and reacted under an inactive protective atmosphere, cooled, precipitated, and dried to obtain the SIS with succinic anhydride groups.

[0026] Optionally, the SIS has the following structural formula:

[0027]

[0028] The molecular weight of the SIS is 50,000 to 260,000;

[0029] The styrene content in the SIS is 12wt% to 45wt%;

[0030] The isoprene content in the SIS is 8 wt% to 75 wt%.

[0031] Preferably, the molecular weight of the SIS is 60,000 to 130,000, and more preferably 70,000 to 100,000.

[0032] Preferably, the styrene content in the SIS is 12wt% to 35wt%.

[0033] Preferably, the isoprene content in the SIS is 20wt% to 75wt%.

[0034] Optionally, the mass ratio of maleic anhydride to SIS is 1 wt% to 40 wt%; preferably, the mass ratio of maleic anhydride to SIS is 10 wt% to 30 wt%.

[0035] Optionally, the reaction temperature is 160℃~250℃, and the reaction time is 0.5h or more.

[0036] Preferably, the reaction temperature is 170℃~250℃ and the reaction time is 1h~4h.

[0037] As a preferred embodiment, the method for preparing the SIS with succinic anhydride groups is as follows:

[0038] (B1) Add SIS and a certain amount of maleic anhydride and solvent to the reactor, pump out and purge with nitrogen, repeat three times, and replace with a nitrogen protective atmosphere.

[0039] (B2) Stir and react at 170℃~250℃ for several hours.

[0040] (B3) Cool, precipitate with acetone, wash three times and then vacuum dry.

[0041] Optionally, in step B1, the solvent is selected from at least one of toluene and xylene.

[0042] Optionally, in step A1, the mass ratio of the SIS with succinic anhydride groups to the organic solvent is 3:1 to 1:5; preferably, the mass ratio of the SIS with succinic anhydride groups to the organic solvent is 2:1 to 1:2.

[0043] Optionally, in step A1, the organic solvent is selected from at least one of tetrahydrofuran, cyclohexane, acetone, dichloromethane, and toluene.

[0044] Optionally, in step A1, the stirring temperature is 30℃ to 65℃. Preferably, in step A1, the stirring temperature is 40℃ to 60℃.

[0045] Optionally, in step A2, the stirring temperature is 30℃ to 65℃. Preferably, in step A2, the stirring temperature is 40℃ to 60℃.

[0046] Optionally, in step A2, the concentration of the metal hydroxide solution is 0.00005 mol / mL to 0.02 mol / mL.

[0047] Optionally, in step A2, the metal hydroxide is selected from at least one of sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium hydroxide, and magnesium hydroxide;

[0048] The amine compound is selected from at least one of triethanolamine, triethylamine, ethylenediamine, trimethylamine, and diisopropylamine.

[0049] Optionally, in step A2, the molar ratio of the amount of metal hydroxide added to the succinic anhydride group in the SIS containing the succinic anhydride group is 0.5:1 to 3:1;

[0050] The molar ratio of the amount of the amine compound added to the succinic anhydride group in the SIS containing the succinic anhydride group is 1:1 to 4:1.

[0051] Preferably, the molar ratio of the amount of metal hydroxide added to the succinic anhydride group in the SIS containing the succinic anhydride group is 1:1 to 2:1;

[0052] The molar ratio of the amount of the amine compound added to the succinic anhydride group in the SIS containing the succinic anhydride group is 2:1 to 3:1.

[0053] Optionally, in step A2, the reaction temperature is 30℃-65℃.

[0054] Optionally, in step A3, the mass ratio of water to polymer solution is 1:2 to 3:1.

[0055] Preferably, in step A3, the mass ratio of water to polymer solution is 1:1 to 2:1.

[0056] Optionally, in step A3, the mixing method can be by adding water droplets to the polymer solution, adding the polymer solution droplets to water, slowly pouring water into the polymer solution, or slowly pouring the polymer solution into water.

[0057] Optionally, in step A3, the dropping rate is controlled between 0.01 mL / s and 10 mL / s.

[0058] Preferably, in step A3, the dropping rate is controlled between 0.05 mL / s and 5 mL / s.

[0059] Optionally, in step A3, the stabilization time of the polymer mixture solution is 0 h to 24 h.

[0060] Preferably, in step A3, the stabilization time of the polymer mixture solution is 1 h to 8 h.

[0061] Optionally, in step A3, the stirring method can be magnetic stirring, mechanical stirring, or high-speed stirring.

[0062] Preferably, in step A3, mechanical stirring is selected.

[0063] Optionally, in step A3, the dropping and stabilization temperature is selected to be between 30℃ and 70℃.

[0064] Preferably, in step A3, the temperature for adding and stabilizing is selected as 50℃~60℃.

[0065] Optionally, in step A4, the vacuum distillation temperature is controlled between 30°C and 100°C.

[0066] Preferably, in step A4, the vacuum distillation temperature is selected to be between 50°C and 100°C.

[0067] Optionally, in step A4, the stirring method can be magnetic stirring, mechanical stirring, or high-speed stirring.

[0068] Preferably, in step A4, mechanical stirring is selected as the stirring method.

[0069] Optionally, in step A4, the solvent removal rate is 0.001 mL / s to 20 mL / s.

[0070] Preferably, in step A4, the solvent removal rate is 0.01 mL / s to 0.1 mL / s.

[0071] According to a third aspect of this application, a SIS latex film is provided.

[0072] A SIS latex film, characterized in that it is prepared from the SIS soap-free emulsion described above.

[0073] This SIS latex film features high tensile strength, high elongation at break, and low strength under low deformation. The film thickness ranges from 0.05 to 1 mm. The average tensile strength of the 1 mm film is above 16 MPa, the average elongation at break exceeds 1000%, while the 100% tensile strength is below 3.5 MPa. The tensile strength of the 0.07 mm film is above 4.0 MPa, the average elongation at break exceeds 500%, and the 100% tensile strength is below 0.5 MPa. This film is prepared by dip coating and other processes using SIS soap-free emulsion.

[0074] According to a fourth aspect of this application, an application of SIS latex film is provided.

[0075] The above-mentioned application of SIS latex film in the preparation of rubber products.

[0076] Optionally, the rubber products include personal protective equipment.

[0077] Preferably, the personal protective equipment includes latex gloves.

[0078] The beneficial effects that this application can produce include:

[0079] The SIS soap-free emulsion, its preparation method, and its applications provided in this application offer advantages such as high solids content, absence of surfactants, wide control range of particle size, and narrow particle size distribution. More importantly, the entire preparation process eliminates the need for emulsifiers, avoiding the complex cleaning process associated with emulsifier residues and effectively reducing the generation of emulsifier wastewater. SIS latex gloves prepared using this method exhibit low tensile strength, softness, a close fit to the human body, high tensile strength, are not easily torn, are comfortable to wear, and do not cause protein allergies. They are more comfortable, have a wider range of applications, and are more adaptable than natural rubber gloves and nitrile rubber gloves. Detailed Implementation

[0080] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0081] Unless otherwise specified, all raw materials used in the embodiments of this application were purchased through commercial channels.

[0082] Unless otherwise specified, all test methods are standard and all instrument settings are those recommended by the manufacturer.

[0083] Performance evaluation of the emulsion:

[0084] The average particle size, aggregation index, and zeta potential of the emulsion were characterized using a laser nanoparticle size analyzer (DLS), specifically the Malvern NanoZS.

[0085] The grafting rate was tested using Method A of GB / T 2895-2008 (Determination of Partial and Total Acid Values ​​of Polyester Resins in Plastics). The specific method is as follows:

[0086] Take m1g of maleic acidified SIS and dissolve it in a 50ml Erlenmeyer flask containing a mixed solvent (2 parts (volume) of toluene and 1 part (volume) of anhydrous ethanol). Add 5 drops of 1% phenolphthalein ethanol solution and titrate with potassium hydroxide ethanol standard solution, shaking the solution while adding the solution until the color remains pink for about 20 seconds. Record the volume V1 of the KOH solution.

[0087]

[0088] The mechanical properties of the latex film were characterized using a universal testing machine, specifically a CMT4104 microcomputer-controlled electronic universal testing machine.

[0089] The styrene-isoprene-styrene block copolymers used in the examples were labeled as SIS according to the different PS and PI contents. 15％ SIS 20％ and SIS 45％ .

[0090] Example 1

[0091] (1) Add 40g of SIS to a 500ml reactor. 45％ 300 ml of xylene solution and 6 g of maleic anhydride were added, and the mixture was purged three times, then purged with nitrogen and stirred until dissolved. SIS 45 Mn = 76000, ω -PS =38%, ω -1，4PB =58%.

[0092] (2) Heat to 180℃, stir for 5 hours, cool and precipitate with acetone, then wash with cyclohexane and acetone to obtain maleic acidified SIS1. The grafting rate after the reaction was determined to be 4.3%.

[0093] (3) Weigh 0.5g of maleic acidified SIS1 from step (2) and 49.5g of tetrahydrofuran (THF) to prepare a SIS1 solution with a mass concentration of ω = 1%.

[0094] (4) Prepare 1 mL of 0.00095 mol / mL sodium hydroxide aqueous solution. Add the sodium hydroxide solution dropwise to the SIS1 solution in step (3) at 50°C. After stabilizing for 3 h with mechanical stirring (500 rpm) on a regular stirrer, the SIS1 ionomer solution is obtained.

[0095] (5) Under mechanical stirring (500 rpm) with a normal stirrer, water is added dropwise to the SIS1 ionomer solution (water to SIS1 ionomer solution mass ratio is 1:1) in step (4) at a speed of 0.1 mL / s. After stabilizing at 50 °C for 3 h, a mixed solution of SIS1 ionomer is obtained.

[0096] (6) Distill the mixed solution of SIS1 ionomers from step (5) under reduced pressure at 50°C (the distillation rate is 0.1 mL / s), and collect the distilled organic solvent and part of the water through a condenser until the organic solvent content in the solution is less than 0.5 wt%, to obtain SIS1 soap-free emulsion.

[0097] The prepared SIS1 soap-free emulsion was characterized as follows: the average particle size of the latex particles measured by DLS was 175.6 nm, the PDI was 0.043, the Zeta potential was -52.7 mV, and the solid content was 1.53 wt%.

[0098] Example 2

[0099] Steps (1) and (2) are the same as in Example 1.

[0100] (3) Weigh 15g of maleic acidified SIS1 from step (2) and 35g of tetrahydrofuran (THF) to prepare a SIS1 solution with a mass concentration of ω = 20%.

[0101] (4) Prepare 2 mL of 0.0064 mol / mL sodium hydroxide aqueous solution. Add the sodium hydroxide solution dropwise to the SIS1 solution in step (3) at 50°C. After stabilizing for 3 h with mechanical stirring (500 rpm) on a regular stirrer, the SIS1 ionomer solution is obtained.

[0102] Steps (5) and (6) are the same as in Example 1.

[0103] The prepared SIS1 soap-free emulsion was characterized as follows: the average particle size of the latex particles measured by DLS was 315.6 nm, the PDI was 0.239, the Zeta potential was -41.1 mV, and the solid content was 31.5 wt%.

[0104] Example 3

[0105] (1) Add 40g of SIS to a 500ml reactor. 45％ 300 ml of xylene solution and 6 g of maleic anhydride were added, and the mixture was purged three times, then purged with nitrogen and stirred until dissolved. SIS 45 Mn = 76000, ω -PS =38%, ω -1，4PB =58%.

[0106] (2) Heat to 200℃, stir for 5 hours, cool and precipitate with acetone, then wash with cyclohexane and acetone to obtain maleic acidified SIS2. The grafting rate after the reaction was determined to be 6.2%.

[0107] (3) Weigh 5g of maleic acidified SIS2 from step (2) and 45g of tetrahydrofuran (THF) to prepare a SIS1 solution with a mass concentration of ω = 10%.

[0108] (4) Prepare 1 mL of 0.0064 mol / mL sodium hydroxide aqueous solution. Add the sodium hydroxide solution dropwise to the SIS2 solution in step (3) at 50°C. After stabilizing for 3 h with mechanical stirring (500 rpm) on a regular stirrer, the SIS2 ionomer solution is obtained.

[0109] (5) Under mechanical stirring (500 rpm) with a normal stirrer, water is added dropwise to the SIS2 ionomer solution (water to SIS2 ionomer solution mass ratio is 1:1) in step (4) at a speed of 0.1 mL / s. After stabilizing at 50 °C for 3 h, a mixed solution of SIS2 ionomer is obtained.

[0110] (6) Distill the mixed solution of SIS2 ionomers from step (5) under reduced pressure at 50°C (the distillation rate is 0.1 mL / s), and collect the distilled organic solvent and part of the water through a condenser until the organic solvent content in the solution is less than 0.5 wt%, to obtain a soap-free SIS2 emulsion.

[0111] The prepared SIS2 soap-free emulsion was characterized as follows: the average particle size of the latex particles measured by DLS was 182.1 nm, the PDI was 0.112, the Zeta potential was -51.1 mV, and the solid content was 12.53 wt%.

[0112] Example 4

[0113] Steps (1) and (2) are the same as in Example 3.

[0114] (3) Weigh 15g of maleic acidified SIS2 from step (2) and 35g of tetrahydrofuran (THF) to prepare a SIS2 solution with a mass concentration of ω = 30%.

[0115] (4) Prepare 3 mL of 0.0064 mol / mL sodium hydroxide aqueous solution. Add the sodium hydroxide solution dropwise to the SIS1 solution in step (3) at 50 °C. After stabilizing for 3 h with mechanical stirring (500 rpm) on a regular stirrer, the SIS2 ionomer solution is obtained.

[0116] Steps (5) and (6) are the same as in Example 4.

[0117] The prepared SIS2 soap-free emulsion was characterized as follows: the average particle size of the latex particles measured by DLS was 223.2 nm, the PDI was 0.212, the Zeta potential was -49.1 mV, and the solid content was 33.56 wt%.

[0118] Example 5

[0119] (1) Add 40g of SIS to a 500ml reactor. 45％ 300 ml of xylene solution and 6 g of maleic anhydride were added, and the mixture was purged three times, then purged with nitrogen and stirred until dissolved. SIS 45％ Mn = 76000, ω -PS =38%, ω -1，4PB =58%.

[0120] (2) Heat to 210℃, stir for 5 hours, cool and precipitate with acetone, then wash with cyclohexane and acetone to obtain maleic acidified SIS3. The grafting rate after the reaction was determined to be 7.1%.

[0121] (3) Weigh 5g of maleic acidified SIS3 from step (2) and 45g of tetrahydrofuran (THF) to prepare a SIS3 solution with a mass concentration of ω = 10%.

[0122] (4) Prepare 1 mL of 0.0064 mol / mL sodium hydroxide aqueous solution. Add the sodium hydroxide solution dropwise to the SIS3 solution in step (3) at 50°C. After stabilizing for 3 h with mechanical stirring (500 rpm) using a regular stirrer, the SIS3 ionomer solution is obtained.

[0123] (5) Under mechanical stirring (500 rpm) with a normal stirrer, water is added dropwise to the SIS3 ionomer solution (water to SIS3 ionomer solution mass ratio is 1:1) in step (4) at a speed of 0.1 mL / s. After stabilizing at 50 °C for 3 h, a mixed solution of SIS3 ionomer is obtained.

[0124] (6) Distill the mixed solution of SIS3 ionomers from step (5) under reduced pressure at 50°C (the distillation rate is 0.1 mL / s), and collect the distilled organic solvent and part of the water through a condenser until the organic solvent content in the solution is less than 0.5 wt%, to obtain SIS3 soap-free emulsion.

[0125] The prepared SIS3 soap-free emulsion was characterized as follows: the average particle size of the latex particles measured by DLS was 156.2 nm, the PDI was 0.101, the Zeta potential was -61.1 mV, and the solid content was 11.96 wt%.

[0126] Example 6

[0127] Steps (1) and (2) are the same as in Example 5.

[0128] (3) Weigh 15g of maleic acidified SIS3 from step (2) and 35g of tetrahydrofuran (THF) to prepare a SIS3 solution with a mass concentration of ω = 20%.

[0129] (4) Prepare 3.5 mL of 0.0064 mol / mL sodium hydroxide aqueous solution, add the sodium hydroxide solution dropwise to the SIS3 solution in step (3) at 50 °C, and stabilize it for 3 h with mechanical stirring (500 rpm) on a normal stirrer to obtain the SIS3 ionomer solution.

[0130] Steps (5) and (6) are the same as in Example 6.

[0131] The prepared SIS3 soap-free emulsion was characterized as follows: the average particle size of the latex particles measured by DLS was 168.3 nm, the PDI was 0.129, the Zeta potential was -56.1 mV, and the solid content was 31.23 wt%.

[0132] Example 7

[0133] (1) Add 40g of SIS to a 500ml reactor. 45％ 300 ml of xylene solution and 6 g of maleic anhydride were added, and the mixture was purged three times, then purged with nitrogen and stirred until dissolved. SIS 45％ Mn = 76000, ω -PS =38%, ω -1，4PB =58%.

[0134] (2) Heat to 220℃, stir for 5 hours, cool and precipitate with acetone, then wash with cyclohexane and acetone to obtain maleic acidified SIS4. The grafting rate after the reaction was determined to be 8.1%.

[0135] (3) Weigh 5g of maleic acidified SIS4 from step (2) and 45g of tetrahydrofuran (THF) to prepare a SIS4 solution with a mass concentration of ω = 10%.

[0136] (4) Prepare 1.5 mL of 0.0064 mol / mL sodium hydroxide aqueous solution, add the sodium hydroxide solution dropwise to the SIS4 solution in step (3) at 50 °C, and stabilize it for 3 h with mechanical stirring (500 rpm) on a normal stirrer to obtain the SIS4 ionomer solution.

[0137] (5) Under mechanical stirring (500 rpm) with a normal stirrer, water is added dropwise to the SIS4 ionomer solution (water to SIS4 ionomer solution mass ratio is 1:1) in step (4) at a speed of 0.1 mL / s. After stabilizing at 50 °C for 3 h, a mixed solution of SIS4 ionomer is obtained.

[0138] (6) Distill the mixed solution of SIS4 ionomers from step (5) under reduced pressure at 50°C (the distillation rate is 0.1 mL / s), and collect the distilled organic solvent and part of the water through a condenser until the organic solvent content in the solution is less than 0.5 wt%, to obtain SIS4 soap-free emulsion.

[0139] The prepared SIS4 soap-free emulsion was characterized as follows: the average particle size of the latex particles measured by DLS was 112.2 nm, the PDI was 0.086, the Zeta potential was -62.3 mV, and the solid content was 10.86 wt%.

[0140] Example 8

[0141] Steps (1) and (2) are the same as in Example 7.

[0142] (3) Weigh 20g of maleic acidified SIS4 from step (2) and 30g of tetrahydrofuran (THF) to prepare a SIS4 solution with a mass concentration of ω = 40%.

[0143] (4) Prepare 5 mL of 0.0064 mol / mL sodium hydroxide aqueous solution. Add the sodium hydroxide solution dropwise to the SIS4 solution in step (3) at 50 °C. After stabilizing for 3 h with mechanical stirring (500 rpm) using a regular stirrer, the SIS4 ionomer solution is obtained.

[0144] Steps (5) and (6) are the same as in Example 6.

[0145] The prepared SIS4 soap-free emulsion was characterized as follows: the average particle size of the latex particles measured by DLS was 198.8 nm, the PDI was 0.255, the Zeta potential was -43.5 mV, and the solid content was 39.65 wt%.

[0146] Example 9

[0147] (1) Add 40g of SIS to a 500ml reactor. 45％ 300 ml of xylene solution and 6 g of maleic anhydride were added, and the mixture was purged three times, then purged with nitrogen and stirred until dissolved. SIS 45％ Mn = 76000, ω -PS =38%, ω -1，4PB =58%.

[0148] (2) Heat to 230℃, stir for 5 hours, cool and precipitate with acetone, then wash with cyclohexane and acetone to obtain maleic acidified SIS5. The grafting rate after the reaction was determined to be 8.9%.

[0149] (3) Weigh 15g of maleic acidified SIS5 from step (2) and 35g of tetrahydrofuran (THF) to prepare a SIS5 solution with a mass concentration of ω = 30%.

[0150] (4) Prepare 4 mL of 0.0064 mol / mL sodium hydroxide aqueous solution. Add the sodium hydroxide solution dropwise to the SIS5 solution in step (3) at 50 °C. After stabilizing for 3 h with mechanical stirring (500 rpm) using a regular stirrer, the SIS5 ionomer solution is obtained.

[0151] (5) Under mechanical stirring (500 rpm) with a normal stirrer, water is added dropwise to the SIS5 ionomer solution (water to SIS5 ionomer solution mass ratio is 1:1) in step (4) at a speed of 0.1 mL / s. After stabilizing at 50 °C for 3 h, a mixed solution of SIS5 ionomer is obtained.

[0152] (6) Distill the mixed solution of SIS5 ionomers from step (5) under reduced pressure at 50°C (the distillation rate is 0.1 mL / s), and collect the distilled organic solvent and part of the water through a condenser until the organic solvent content in the solution is less than 0.5 wt%, to obtain SIS5 soap-free emulsion.

[0153] The prepared SIS5 soap-free emulsion was characterized as follows: the average particle size of the latex particles measured by DLS was 118.8 nm, the PDI was 0.095, the Zeta potential was -61.5 mV, and the solid content was 30.65 wt%.

[0154] Example 10

[0155] Steps (1) and (2) are the same as in Example 9.

[0156] (3) Weigh 25g of maleic acidified SIS5 from step (2) and 25g of tetrahydrofuran (THF) to prepare a SIS5 solution with a mass concentration of ω = 50%.

[0157] (4) Prepare 7 mL of 0.0064 mol / mL sodium hydroxide aqueous solution. Add the sodium hydroxide solution dropwise to the SIS5 solution in step (3) at 50 °C. After stabilizing for 3 h with mechanical stirring (500 rpm) on a regular stirrer, the SIS5 ionomer solution is obtained.

[0158] Steps (5) and (6) are the same as in Example 9.

[0159] The prepared SIS5 soap-free emulsion was characterized as follows: the average particle size of the latex particles measured by DLS was 415.8 nm, the PDI was 0.215, the Zeta potential was -49.5 mV, and the solid content was 53.15 wt%.

[0160] Example 11

[0161] (1) Add 40g of SIS to a 500ml reactor. 15％300 ml of xylene solution and 6 g of maleic anhydride were added, and the mixture was purged three times, then purged with nitrogen and stirred until dissolved. SIS 15％ :Mn=76000:Mn=83000, ω -PS =15%, ω -1，4PB =77%.

[0162] (2) Heat to 210℃, stir for 1 hour, cool and precipitate with acetone, then wash with cyclohexane and acetone to obtain maleic acidified SIS6, and determine its grafting rate after reaction to be 6.6%.

[0163] (3) Weigh 5g of maleic acidified SIS6 from step (2) and 45g of tetrahydrofuran (THF) to prepare a SIS6 solution with a mass concentration of ω = 10%.

[0164] (4) Prepare 1 mL of 0.0064 mol / mL sodium hydroxide aqueous solution, add the sodium hydroxide solution dropwise to the SIS6 solution in step (3) at 50°C, and stabilize it for 3 h under mechanical stirring (500 rpm) with a normal stirrer to obtain the SIS6 ionomer solution.

[0165] (5) Under mechanical stirring (500 rpm) with a normal stirrer, water is added dropwise to the SIS6 ionomer solution (water to SIS6 ionomer solution mass ratio is 1:1) in step (4) at a speed of 0.1 mL / s. After stabilizing at 50 °C for 3 h, a mixed solution of SIS6 ionomer is obtained.

[0166] (6) Distill the mixed solution of SIS6 ionomers from step (5) under reduced pressure at 50°C (the distillation rate is 0.1 mL / s), and collect the distilled organic solvent and part of the water through a condenser until the organic solvent content in the solution is less than 0.5 wt%, to obtain SIS6 soap-free emulsion.

[0167] The prepared SIS6 soap-free emulsion was characterized as follows: the average particle size of the latex particles measured by DLS was 128.8 nm, the PDI was 0.093, the Zeta potential was -61.5 mV, and the solid content was 10.26 wt%.

[0168] Example 12

[0169] Step (1) is the same as in Example 11.

[0170] (2) Heat to 210℃, stir for 2 hours, cool and precipitate with acetone, then wash with cyclohexane and acetone to obtain maleic acidified SIS7. The grafting rate after the reaction was determined to be 7.8%.

[0171] (3) Weigh 5g of maleic acidified SIS7 from step (2) and 45g of tetrahydrofuran (THF) to prepare a SIS7 solution with a mass concentration of ω = 10%.

[0172] (4) Prepare 1 mL of 0.0064 mol / mL sodium hydroxide aqueous solution. Add the sodium hydroxide solution dropwise to the SIS7 solution in step (3) at 50°C. After stabilizing for 3 h with mechanical stirring (500 rpm) using a regular stirrer, the SIS7 ionomer solution is obtained.

[0173] Steps (5) and (6) are the same as in Example 11.

[0174] The prepared SIS7 soap-free emulsion was characterized as follows: the average particle size of the latex particles measured by DLS was 105.4 nm, the PDI was 0.091, the Zeta potential was -63.4 mV, and the solid content was 10.56 wt%.

[0175] Example 13

[0176] Step (1) is the same as in Example 11.

[0177] (2) Heat to 210℃, stir for 3 hours, cool and precipitate with acetone, then wash with cyclohexane and acetone to obtain maleic acidified SIS8, and determine its grafting rate after reaction to be 9.5%.

[0178] (3) Weigh 5g of maleic acidified SIS8 from step (2) and 45g of tetrahydrofuran (THF) to prepare a SIS8 solution with a mass concentration of ω = 10%.

[0179] (4) Prepare 1.5 mL of 0.0064 mol / mL sodium hydroxide aqueous solution, add the sodium hydroxide solution dropwise to the SIS8 solution in step (3) at 50 °C, and stabilize it for 3 h with mechanical stirring (500 rpm) on a normal stirrer to obtain the SIS8 ionomer solution.

[0180] Steps (5) and (6) are the same as in Example 11.

[0181] The prepared SIS7 soap-free emulsion was characterized as follows: the average particle size of the latex particles measured by DLS was 93.4 nm, the PDI was 0.091, the Zeta potential was -63.4 mV, and the solid content was 11.21 wt%.

[0182] Example 14

[0183] Step (1) is the same as in Example 11.

[0184] (2) Heat to 210℃, stir for 4 hours, cool and precipitate with acetone, then wash with cyclohexane and acetone to obtain maleic acidified SIS9. The grafting rate after the reaction was determined to be 10.3%.

[0185] (3) Weigh 5g of maleic acidified SIS9 from step (2) and 45g of tetrahydrofuran (THF) to prepare a SIS9 solution with a mass concentration of ω = 10%.

[0186] (4) Prepare 2 mL of 0.0064 mol / mL sodium hydroxide aqueous solution. Add the sodium hydroxide solution dropwise to the SIS9 solution in step (3) at 50 °C. After stabilizing for 3 h with mechanical stirring (500 rpm) using a regular stirrer, the SIS9 ionomer solution is obtained.

[0187] Steps (5) and (6) are the same as in Example 11.

[0188] The prepared SIS7 soap-free emulsion was characterized as follows: the average particle size of the latex particles measured by DLS was 90.4 nm, the PDI was 0.081, the Zeta potential was -63.4 mV, and the solid content was 10.13 wt%.

[0189] Example 15

[0190] (1) Add 40g of SIS to a 500ml reactor. 15％ 300 ml of xylene solution and 4 g of maleic anhydride were added, and the mixture was purged three times, then purged with nitrogen and stirred until dissolved. SIS 15％ Mn = 110300, ω -PS =15%, ω -1，4PB =77%.

[0191] (2) Heat to 210℃, stir for 1 hour, cool and precipitate with acetone, then wash with cyclohexane and acetone to obtain maleic acidified SIS. 10 The grafting rate after the reaction was measured to be 5.1%.

[0192] Step (3) is the same as in Example 11.

[0193] (4) Prepare 1 mL of 0.0064 mol / mL sodium hydroxide aqueous solution, and add the sodium hydroxide solution dropwise to the SIS in step (3) at 50 °C. 10 After stabilizing the solution in a conventional stirrer (500 rpm) for 3 hours, SIS was obtained. 10 Ionomer solution.

[0194] Steps (5) and (6) are the same as in Example 11.

[0195] For the prepared SIS 10The soap-free emulsion was characterized as follows: the average particle size of the latex particles was 168.8 nm, the PDI was 0.153, the Zeta potential was -52.5 mV, and the solid content was 10.63 wt%.

[0196] Example 16

[0197] (1) Add 40g of SIS to a 500ml reactor. 15％ 300 ml of xylene solution and 8 g of maleic anhydride were added, and the mixture was purged three times, then purged with nitrogen and stirred until dissolved. SIS 15％ Mn = 110300, ω -PS =15%, ω -1，4PB =77%.

[0198] (2) Heat to 210℃, stir for 1 hour, cool and precipitate with acetone, then wash with cyclohexane and acetone to obtain maleic acidified SIS. 11 The grafting rate after the reaction was measured to be 7.1%.

[0199] Step (3) is the same as in Example 11.

[0200] (4) Prepare 1.5 mL of 0.0064 mol / mL sodium hydroxide aqueous solution, and add the sodium hydroxide solution dropwise to the SIS in step (3) at 50 °C. 11 After stabilizing the solution in a conventional stirrer (500 rpm) for 3 hours, SIS was obtained. 11 Ionomer solution.

[0201] Steps (5) and (6) are the same as in Example 11.

[0202] For the prepared SIS 11 The soap-free emulsion was characterized as follows: the average particle size of the latex particles was 102.8 nm, the PDI was 0.142, the Zeta potential was -58.5 mV, and the solid content was 10.71 wt%.

[0203] Example 17

[0204] (1) Add 40g of SIS to a 500ml reactor. 15％ 300 ml of xylene solution and 12 g of maleic anhydride were added, and the mixture was purged three times, then purged with nitrogen and stirred until dissolved. SIS 15％ Mn = 110300, ω -PS =15%, ω -1，4PB =77%.

[0205] (2) Heat to 210℃, stir for 1 hour, cool and precipitate with acetone, then wash with cyclohexane and acetone to obtain maleic acidified SIS. 13The grafting rate after the reaction was measured to be 9.3%.

[0206] Step (3) is the same as in Example 11.

[0207] (4) Prepare 1.5 mL of 0.0064 mol / mL sodium hydroxide aqueous solution, and add the sodium hydroxide solution dropwise to the SIS in step (3) at 50 °C. 13 After stabilizing the solution in a conventional stirrer (500 rpm) for 3 hours, SIS was obtained. 13 Ionomer solution.

[0208] Steps (5) and (6) are the same as in Example 11.

[0209] For the prepared SIS 13 The soap-free emulsion was characterized as follows: the average particle size of the latex particles measured by DLS was 92.8 nm, the PDI was 0.112, the Zeta potential was -65.5 mV, and the solid content was 10.57 wt%.

[0210] Example 18

[0211] Steps (1), (2), and (3) are the same as in Example 11.

[0212] (4) Prepare 1 mL of 0.0064 mol / mL sodium hydroxide aqueous solution. Add the sodium hydroxide solution dropwise to the SIS6 solution in step (3) at 50°C. After stabilizing for 3 h with mechanical stirring (1500 rpm) on a high-speed stirrer, the SIS6 ionomer solution is obtained.

[0213] (5) Under mechanical stirring of a high-speed stirrer (1500 rpm), water is added dropwise to the SIS6 ionomer solution in step (4) at a speed of 0.2 mL / s (the mass ratio of water to SIS6 ionomer solution is 1:1). After stabilizing at 50°C for 3 h, a mixed solution of SIS6 ionomer is obtained.

[0214] Step (6) is the same as in Example 11.

[0215] The prepared SIS6 soap-free emulsion was characterized as follows: the average particle size of the latex particles measured by DLS was 158.8 nm, the PDI was 0.213, the Zeta potential was -59.5 mV, and the solid content was 12.26 wt%.

[0216] Example 19

[0217] Steps (1), (2), and (3) are the same as in Example 12.

[0218] (4) Prepare 1.3 mL of 0.0064 mol / mL sodium hydroxide aqueous solution. Add the sodium hydroxide solution dropwise to the SIS7 solution in step (3) at 50 °C. After stabilizing for 3 h with mechanical stirring (1500 rpm) on a high-speed stirrer, the SIS7 ionomer solution is obtained.

[0219] Steps (5) and (6) are the same as in Example 12.

[0220] The prepared SIS7 soap-free emulsion was characterized as follows: the average particle size of the latex particles measured by DLS was 143.6 nm, the PDI was 0.192, the Zeta potential was -56.5 mV, and the solid content was 11.52 wt%.

[0221] Example 20

[0222] Steps (1), (2), and (3) are the same as in Example 13.

[0223] (4) Prepare 1.5 mL of 0.0064 mol / mL sodium hydroxide aqueous solution. Add the sodium hydroxide solution dropwise to the SIS8 solution in step (3) at 50 °C. After stabilizing for 3 h with mechanical stirring (1500 rpm) on a high-speed stirrer, the SIS8 ionomer solution is obtained.

[0224] Steps (5) and (6) are the same as in Example 13.

[0225] The prepared SIS8 soap-free emulsion was characterized as follows: the average particle size of the latex particles was 125.9 nm, the PDI was 0.152, the Zeta potential was -63.5 mV, and the solid content was 10.64 wt%.

[0226] Example 21

[0227] Steps (1), (2), and (3) are the same as in Example 14.

[0228] (4) Prepare 1.7 mL of 0.0064 mol / mL sodium hydroxide aqueous solution. Add the sodium hydroxide solution dropwise to the SIS9 solution in step (3) at 50 °C. After stabilizing for 3 h with mechanical stirring (1500 rpm) on a high-speed stirrer, the SIS9 ionomer solution is obtained.

[0229] Steps (5) and (6) are the same as in Act 14.

[0230] The prepared SIS9 soap-free emulsion was characterized as follows: the average particle size of the latex particles was 105.9 nm, the PDI was 0.122, the Zeta potential was -60.5 mV, and the solid content was 11.24 wt%.

[0231] Example 22

[0232] Steps (1), (2), (3), and (4) are the same as in Example 11.

[0233] (5) Under mechanical stirring (500 rpm) with a normal stirrer, the SIS6 ionomer solution from step (4) was added dropwise to water (the mass ratio of water to SIS6 ionomer solution was 1:1) at a speed of 0.2 mL / s. After stabilizing at 50°C for 3 h, a mixed solution of SIS6 ionomer was obtained.

[0234] Step (6) is the same as in Example 11.

[0235] The prepared SIS6 soap-free emulsion was characterized as follows: the average particle size of the latex particles measured by DLS was 218.8 nm, the PDI was 0.153, the Zeta potential was -0.61.5 mV, and the solid content was 11.26 wt%.

[0236] Example 23

[0237] Steps (1), (2), (3), and (4) are the same as in Example 11.

[0238] (5) Under mechanical stirring (500 rpm) with a normal stirrer, the SIS6 ionomer solution from step (4) was added dropwise to water (the mass ratio of water to SIS6 ionomer solution was 2:1) at a speed of 0.2 mL / s. After stabilizing at 50°C for 3 h, a mixed solution of SIS6 ionomer was obtained.

[0239] Step (6) is the same as in Example 11.

[0240] The prepared SIS6 soap-free emulsion was characterized as follows: the average particle size of the latex particles measured by DLS was 163.8 nm, the PDI was 0.113, the Zeta potential was -0.58.5 mV, and the solid content was 5.16 wt%.

[0241] Example 24

[0242] (1) Add 40g of SIS to a 500ml reactor. 15％ 300 ml of xylene solution and 6 g of maleic anhydride were added, and the mixture was purged three times, then purged with nitrogen and stirred until dissolved. SIS 15％ Mn = 110300, ω -PS =15%, ω -1，4PB =77%.

[0243] (2) Heat to 210℃, stir for 1 hour, cool and precipitate with acetone, then wash with cyclohexane and acetone to obtain maleic acidified SIS6, and determine its grafting rate after reaction to be 6.6%.

[0244] (3) Weigh 5g of maleic acidified SIS6 from step (2) and 45g of tetrahydrofuran (THF) to prepare a SIS6 solution with a mass concentration of ω = 10%.

[0245] (4) At 50°C, 0.47 ml of triethylamine was added dropwise to the SIS6 solution in step (3). After stabilizing for 3 h with mechanical stirring (500 rpm) on a regular stirrer, the SIS6 ionomer solution was obtained.

[0246] (5) Under mechanical stirring (500 rpm) with a normal stirrer, water is added dropwise to the SIS6 ionomer solution (water to SIS6 ionomer solution mass ratio is 1:1) in step (4) at a speed of 0.1 mL / s. After stabilizing at 50 °C for 3 h, a mixed solution of SIS6 ionomer is obtained.

[0247] (6) Distill the mixed solution of SIS6 ionomers from step (5) under reduced pressure at 50°C (the distillation rate is 0.1 mL / s), and collect the distilled organic solvent and part of the water through a condenser until the organic solvent content in the solution is less than 0.5 wt%, to obtain SIS6 soap-free emulsion.

[0248] The prepared SIS6 soap-free emulsion was characterized as follows: the average particle size of the latex particles measured by DLS was 78.8 nm, the PDI was 0.093, the Zeta potential was -61.5 mV, and the solid content was 10.26 wt%.

[0249] Example 25

[0250] Steps (1) and (2) are the same as in Example 11.

[0251] (3) Weigh 15g of maleic acidified SIS6 from step (2) and 35g of tetrahydrofuran (THF) to prepare a SIS6 solution with a mass concentration of ω = 30%.

[0252] (4) At 50°C, 1.40 ml of triethylamine was added dropwise to the SIS6 solution in step (3). After stabilizing for 3 h with mechanical stirring (500 rpm) on a regular stirrer, the SIS6 ionomer solution was obtained.

[0253] Steps (5) and (6) are the same as in Example 11.

[0254] The prepared SIS6 soap-free emulsion was characterized as follows: the average particle size of the latex particles measured by DLS was 98.8 nm, the PDI was 0.116, the Zeta potential was -58.5 mV, and the solid content was 31.56 wt%.

[0255] Example 26

[0256] Steps (1) and (2) are the same as in Example 12.

[0257] (3) Weigh 5g of maleic acidified SIS7 from step (2) and 45g of tetrahydrofuran (THF) to prepare a SIS7 solution with a mass concentration of ω = 10%.

[0258] (4) At 50°C, 0.55 ml of triethylamine was added dropwise to the SIS7 solution in step (3). After stabilizing for 3 h with mechanical stirring (500 rpm) using a regular stirrer, the SIS7 ionomer solution was obtained.

[0259] Steps (5) and (6) are the same as in Example 12.

[0260] The prepared SIS7 soap-free emulsion was characterized as follows: the average particle size of the latex particles measured by DLS was 78.8 nm, the PDI was 0.106, the Zeta potential was -61.5 mV, and the solid content was 11.58 wt%.

[0261] Example 27

[0262] Steps (1) and (2) are the same as in Example 12.

[0263] (3) Weigh 15g of maleic acidified SIS7 from step (2) and 35g of tetrahydrofuran (THF) to prepare a SIS7 solution with a mass concentration of ω = 30%.

[0264] (4) At 50°C, 1.64 ml of triethylamine was added dropwise to the SIS7 solution in step (3). After stabilizing for 3 h with mechanical stirring (500 rpm) on a regular stirrer, the SIS7 ionomer solution was obtained.

[0265] Steps (5) and (6) are the same as in Example 12.

[0266] The prepared SIS7 soap-free emulsion was characterized as follows: the average particle size of the latex particles measured by DLS was 73.6 nm, the PDI was 0.126, the Zeta potential was -61.5 mV, and the solid content was 29.63 wt%.

[0267] Example 28

[0268] Steps (1) and (2) are the same as in Example 14.

[0269] (3) Weigh 15g of maleic acidified SIS9 from step (2) and 35g of tetrahydrofuran (THF) to prepare a SIS9 solution with a mass concentration of ω = 30%.

[0270] (4) At 50°C, 2.10 ml of triethylamine was added dropwise to the SIS9 solution in step (3). After stabilizing for 3 h with mechanical stirring (500 rpm) on a regular stirrer, the SIS9 ionomer solution was obtained.

[0271] Steps (5) and (6) are the same as in Example 14.

[0272] The prepared SIS9 soap-free emulsion was characterized as follows: the average particle size of the latex particles measured by DLS was 45.6 nm, the PDI was 0.016, the Zeta potential was -63.5 mV, and the solid content was 32.57 wt%.

[0273] Example 29

[0274] (1) Add 40g of SIS to a 500ml reactor. 15％ 300 ml of xylene solution and 6 g of maleic anhydride were added, and the mixture was purged three times, then purged with nitrogen and stirred until dissolved. SIS 15％ Mn = 110300, ω -PS =15%, ω -1，4PB =77%.

[0275] (2) Heat to 210℃, stir for 1 hour, cool and precipitate with acetone, then wash with cyclohexane and acetone to obtain maleic acidified SIS6, and determine its grafting rate after reaction to be 6.6%.

[0276] (3) Weigh 5g of maleic acidified SIS6 from step (2) and 45g of tetrahydrofuran (THF) to prepare a SIS6 solution with a mass concentration of ω = 10%.

[0277] (4) At room temperature, take 2 ml of deionized water and add it dropwise to the SIS6 solution in step (3). After stabilizing for 3 h with mechanical stirring (500 rpm) on a regular stirrer, the SIS6 ionomer solution is obtained.

[0278] (5) At 50°C, 0.49 ml of triethanolamine was added dropwise to the SIS6 ionomer solution in step (4), and stabilized for 3 h with mechanical stirring (500 rpm) using a regular stirrer.

[0279] (6) Under mechanical stirring (500 rpm) with a normal stirrer, water is added dropwise to the SIS6 ionomer solution (water to SIS6 ionomer solution mass ratio is 1:1) in step (5) at a speed of 0.1 mL / s. After stabilizing at 50 °C for 3 h, a mixed solution of SIS6 ionomer is obtained.

[0280] (7) Distill the mixed solution of SIS6 ionomers from step (5) under reduced pressure at 50°C (the distillation rate is 0.1 mL / s), and collect the distilled organic solvent and part of the water through a condenser until the organic solvent content in the solution is less than 0.5 wt%, to obtain SIS6 soap-free emulsion.

[0281] The prepared SIS6 soap-free emulsion was characterized as follows: the average particle size of the latex particles measured by DLS was 1132.8 nm, the PDI was 0.493, the Zeta potential was -41.5 mV, and the solid content was 10.26 wt%.

[0282] Example 30

[0283] Steps (1), (2), and (3) are the same as in Example 29.

[0284] (4) At room temperature, take 2 ml of deionized water and add it to the SIS6 solution in step (3). After stabilizing for 24 h with mechanical stirring (500 rpm) on a regular stirrer, the SIS6 ionomer solution is obtained.

[0285] Steps (5), (6), and (7) are the same as in Example 29.

[0286] The prepared SIS6 soap-free emulsion was characterized as follows: the average particle size of the latex particles measured by DLS was 92.8 nm, the PDI was 0.283, the Zeta potential was -51.5 mV, and the solid content was 11.23 wt%.

[0287] Example 31

[0288] Steps (1), (2), and (3) are the same as in Example 14.

[0289] (4) At room temperature, take 1 ml of deionized water and add it to the SIS9 solution in step (3). After stabilizing for 24 h with mechanical stirring (500 rpm) on a regular stirrer, the SIS9 ionomer solution is obtained.

[0290] (5) At 50°C, take 0.70 ml of triethanolamine and add it dropwise to the SIS6 ionomer solution in step (4). Sterilize for 3 h with mechanical stirring (500 rpm) using a regular stirrer.

[0291] Steps (6) and (7) are the same as in Example 33=29.

[0292] The prepared SIS9 soap-free emulsion was characterized as follows: the average particle size of the latex particles measured by DLS was 81.6 nm, the PDI was 0.265, the Zeta potential was -53.5 mV, and the solid content was 12.45 wt%.

[0293] Example 32

[0294] Steps (1) and (2) are the same as in Example 14.

[0295] (3) Weigh 25g of maleic acidified SIS9 from step (2) and 25g of tetrahydrofuran (THF) to prepare a SIS9 solution with a mass concentration of ω = 50%.

[0296] (4) At room temperature, take 2 ml of deionized water and add it to the SIS9 solution in step (3). After stabilizing for 24 h with mechanical stirring (500 rpm) on a regular stirrer, the SIS9 ionomer solution is obtained.

[0297] (5) At 50°C, take 3.50 ml of triethanolamine and add it dropwise to the SIS6 ionomer solution in step (4). Sterilize for 3 h with mechanical stirring (500 rpm) using a regular stirrer.

[0298] Steps (6) and (7) are the same as in Example 29.

[0299] The prepared SIS9 soap-free emulsion was characterized as follows: the average particle size of the latex particles measured by DLS was 421.6 nm, the PDI was 0.365, the Zeta potential was -51.5 mV, and the solid content was 48.36 wt%.

[0300] Example 33

[0301] An appropriate amount of the SIS1 soap-free emulsion from Example 1 was poured into a polytetrafluoroethylene mold and dried at room temperature to constant weight. The average film thickness was measured to be 1.01 mm. Its mechanical properties were measured, and its tensile strength was 28.6 MPa, elongation at break was 980%, and 100% tensile strength was 2.31 MPa.

[0302] Example 34

[0303] Take an appropriate amount of SIS from Example 15 10 The soap-free emulsion was poured into a polytetrafluoroethylene mold and dried at room temperature to constant weight. The average film thickness was measured to be 0.99 mm. Its mechanical properties were measured, and its tensile strength was 19.8 MPa, elongation at break was 1110%, and 100% tensile strength was 0.98 MPa.

[0304] Example 35

[0305] An appropriate amount of the SIS6 soap-free emulsion from Example 25 was poured into a polytetrafluoroethylene mold and dried at room temperature to constant weight. The average film thickness was measured to be 0.98 mm. Its mechanical properties were measured, and its tensile strength was 17.2 MPa, elongation at break was 1210%, and 100% tensile strength was 1.01 MPa.

[0306] Example 36

[0307] An appropriate amount of the SIS7 soap-free emulsion from Example 27 was poured into a polytetrafluoroethylene mold and dried at room temperature to constant weight. The average film thickness was measured to be 1.02 mm. Its mechanical properties were measured, and its tensile strength was 17.1 MPa, elongation at break was 1290%, and 100% tensile strength was 0.98 MPa.

[0308] Example 37

[0309] (1) Add 160g SIS to a 1L reactor 20％ 800 ml of xylene solution and 24 g of maleic anhydride were dissolved by purging three times, followed by nitrogen purging and stirring. SIS 20％ Mn = 105000, ω -PS =20%, ω -1，4PB =71%.

[0310] (2) Heat to 210℃, stir for 2 hours, cool and precipitate with acetone, then wash with cyclohexane and acetone to obtain maleic acidified SIS. 14 The grafting rate after the reaction was measured to be 6.7%.

[0311] (3) Weigh 150g of the maleic acidified SIS from step (2). 14 Prepare a SIS5 solution with a mass concentration of ω = 30% by mixing it with 500g of tetrahydrofuran (THF).

[0312] (4) Prepare 32 mL of 0.0064 mol / mL sodium hydroxide aqueous solution, and add the sodium hydroxide solution dropwise to the SIS in step (3) at 50 °C. 14 After stabilizing the solution in a conventional stirrer (500 rpm) for 3 hours, SIS was obtained. 14 Ionomer solution.

[0313] (5) Under mechanical stirring on a regular stirrer (500 rpm), add water droplets at a rate of 0.1 mL / s to the SIS in step (4). 14 Ionomer solutions (water and SIS) 14 After stabilizing at 50°C for 3 hours in an ionomer solution with a mass ratio of 1:1, SIS was obtained. 14 A mixed solution of ionomers.

[0314] (6) The SIS from step (5) 14 The mixed solution of ionomers was distilled under reduced pressure at 50°C (distillation rate of 0.1 mL / s), and the distilled organic solvent and some water were collected through a condenser until the organic solvent content in the solution was less than 0.5 wt%, thus obtaining SIS. 14 Soap-free emulsion.

[0315] For the prepared SIS 14 The soap-free emulsion was characterized as follows: the average particle size of the latex particles measured by DLS was 231.6 nm, the PDI was 0.165, the Zeta potential was -61.5 mV, and the solid content was 30.36 wt%.

[0316] (7) Take a clean ceramic hand and soak it in the acid washing solution for half a minute, then rinse it with deionized water, then soak it in the alkaline washing solution for half a minute, take it out and rinse it with clean water, then scrub it with laundry detergent, and put it into an electric constant temperature drying oven to dry at 80℃ for 10 minutes.

[0317] (8) Immerse the heated hand mold into the coagulant heated to 50°C, slightly above the blue line on the hand mold. The coagulant consists of: 24% calcium nitrate, 4% release agent, 0.3% wetting agent, and an appropriate amount of deionized water.

[0318] (9) Slowly immerse the hand mold, which has been impregnated with the coagulant, into the SIS of step (6). 14 Immerse the hand mold in the soap-free emulsion up to the top blue line and keep it immersed for 5-10 seconds. Slowly lift the hand mold and continuously turn it over to make the latex flow evenly. Place the gloves with the film on the table and let them sit for a few minutes.

[0319] (10) Place the completed uniform coating hand mold into an electric heating constant temperature drying oven for 10 minutes, and control the oven temperature at 40℃.

[0320] (11) The hand mold after shaping is rolled manually, and the rolled gloves are demolded manually to obtain SIS rubber gloves.

[0321] Six slices were randomly cut from the obtained SIS rubber gloves. The film thickness was measured to be between 0.071 and 0.078 mm, the average tensile strength was 16.8 MPa, the average elongation at break was 810%, and the 100% tensile strength was 0.43 MPa.

[0322] Example 38

[0323] The preparation process was the same as in Example 37, but in step (4), 14.1 ml of triethylamine was used to replace the sodium hydroxide aqueous solution. The average particle size of the resulting soap-free emulsion was 56.6 nm, the PDI was 0.065, the Zeta potential was -63.5 mV, and the solid content was 31.04 wt%.

[0324] Six slices were randomly cut from the obtained SIS rubber gloves. The film thickness was measured to be between 0.082 and 0.089 mm, the average tensile strength was 15.3 MPa, the average elongation at break was 790%, and the 100% tensile strength was 0.41 MPa.

[0325] Example 39

[0326] The preparation process was the same as in Example 37, but in step (4), 13.5 ml of triethanolamine was used to replace the sodium hydroxide aqueous solution. The average particle size of the resulting soap-free emulsion was 48.6 nm, the PDI was 0.059, the Zeta potential was -62.6 mV, and the solid content was 30.31 wt%.

[0327] Six slices were randomly cut from the obtained SIS rubber gloves. The film thickness was measured to be between 0.068 and 0.076 mm, the average tensile strength was 15.8 MPa, the average elongation at break was 720%, and the 100% tensile strength was 0.41 MPa.

[0328] Example 40

[0329] The preparation process is the same as in Example 37, but in step (2) SIS with a grafting rate of 4.5% is used. 15 The obtained soap-free emulsion had an average particle size of 235.6 nm, a PDI of 0.172, a Zeta potential of -61.6 mV, and a solid content of 30.41 wt%.

[0330] Six slices were randomly cut from the obtained SIS rubber gloves. The film thickness was measured to be between 0.071 and 0.074 mm, the average tensile strength was 14.3 MPa, the average elongation at break was 810%, and the 100% tensile strength was 0.41 MPa.

[0331] Example 41

[0332] The preparation process is the same as in Example 37, but SIS is used in step (1). 20％ Mn = 99000, ω-PS = 20%, ω-1,4PB = 77% replaces the original SIS 20 The resulting soap-free emulsion had an average particle size of 226.6 nm, a PDI of 0.145, a Zeta potential of -59.6 mV, and a solid content of 30.68 wt%.

[0333] Six slices were randomly cut from the obtained SIS rubber gloves. The film thickness was measured to be between 0.069 and 0.075 mm, the average tensile strength was 15.1 MPa, the average elongation at break was 730%, and the 100% tensile strength was 0.42 MPa.

[0334] In summary, the characterization results of the soap-free emulsions prepared in Examples 1 to 22 show that the maleated SIS can be used to prepare soap-free emulsions through alkali neutralization. The solid content of the prepared soap-free emulsions is 1wt% to 50wt%, the average particle size is 162.9nm to 301.4nm, the PDI is 0.073 to 0.223, and the Zeta potential is -61.6mV to -42.7mV. The characterization results of the soap-free emulsions prepared in Examples 23 to 32 show that the maleated SIS can be used to prepare soap-free emulsions through amine neutralization (triethylamine, triethanolamine). The solid content of the prepared soap-free emulsions is 1wt% to 55wt%, the average particle size is 45.6nm to 1132.8nm, the PDI is 0.016 to 0.493, and the Zeta potential is -63.5mV to -51.5mV. As can be seen from the SIS latex films prepared in Examples 33 to 41, the thickness of the SIS latex films prepared in this invention is between 0.05 and 1.00 mm. The latex films prepared through the self-assembly of polystyrene and polyisoprene segments within the latex particles and the crosslinking sites generated by ionic groups reduce the degree of phase separation, thereby improving tensile strength and achieving a relatively high elongation at break while maintaining low tensile strength under low strain. Specifically, as shown in Examples 33 to 36, the average tensile strength of the films with a thickness of approximately 1 mm is above 16 MPa, the average elongation at break exceeds 800%, while the 100% tensile strength is below 1.0 MPa. As shown in Examples 37 to 41, the thickness of the latex gloves prepared is approximately 0.07 mm, the tensile strength of the films is above 12.0 MPa, the average elongation at break exceeds 600%, and the 100% tensile strength is below 0.5 MPa.

[0335] Comparative Example 1

[0336] Take an appropriate amount of SIS 45％ Dissolved in tetrahydrofuran solution, then poured into a polytetrafluoroethylene mold, and dried at room temperature to constant weight, the average film thickness was measured to be 1.00 mm. Its mechanical properties were measured, with a tensile strength of 31.2 MPa, an elongation at break of 890%, and a 100% constant elongation strength of 2.86 MPa.

[0337] Comparative Example 2

[0338] Take an appropriate amount of SIS 15％ Dissolved in tetrahydrofuran solution, then poured into a polytetrafluoroethylene mold, and dried at room temperature to constant weight, the average film thickness was measured to be 1.03 mm. Its mechanical properties were measured, with a tensile strength of 16.8 MPa, an elongation at break of 1101%, and a 100% constant elongation strength of 0.78 MPa.

[0339] Comparative Example 3

[0340] Take an appropriate amount of SIS 20％ Dissolved in tetrahydrofuran solution, then poured into a polytetrafluoroethylene mold, and dried at room temperature to constant weight, the average film thickness was measured to be 0.07 mm. Its mechanical properties were measured, with a tensile strength of 11.2 MPa, an elongation at break of 640%, and a 100% constant elongation strength of 0.41 MPa.

[0341] Comparative Example 4

[0342] Using the same testing method, a pair of nitrile gloves (product number 100194375304) and a pair of medical natural rubber gloves (product number 100166085958) purchased from JD.com were used as comparison samples:

[0343] The nitrile gloves have a thickness of 0.07 mm, a tensile strength of 3.6 MPa at 100% elongation, an elongation at break of 700%, and a tensile strength of 19.3 MPa. The medical rubber gloves have a thickness of 0.14 mm, a tensile strength of 1.0 MPa at 100% elongation, an elongation at break of 850%, and a tensile strength of 12.3 MPa. In comparison, the SIS latex film prepared by this invention exhibits significantly lower deformation strength at low deformation compared to the nitrile and natural rubber gloves. Therefore, the rubber gloves prepared using this method have high tensile strength at break but low tensile strength at 100% elongation, and contain quaternary ammonium salt groups, providing a certain degree of bactericidal effect. Consequently, they are more comfortable to wear, have a wider range of applications, and are more adaptable.

[0344] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A soap-free SIS emulsion, characterized in that, The soap-free SIS emulsion is composed of SIS ionomers and water; The SIS ionomer has a side carboxyl salt group or a side carboxyl ammonium salt group; The side group carboxylate is selected from at least one of sodium carboxylate, potassium carboxylate, lithium carboxylate, calcium carboxylate, and magnesium carboxylate. The side group carboxylic acid ammonium salt is selected from at least one of triethanolamine maleate, triethylamine maleate, trimethylamine maleate, triethylamine maleate, and isopropylamine maleate.

2. The SIS soap-free emulsion according to claim 1, characterized in that, The content of side group carboxylate salt groups or side group ammonium carboxylate salt groups in the SIS ionomer is 1 wt% to 15 wt%. Preferably, the content of side group carboxylate salt group or side group carboxylate ammonium salt group is 1 wt% to 10 wt%.

3. The SIS soap-free emulsion according to claim 1, characterized in that, The SIS soap-free emulsion has a solid content of 1wt%-60wt%, an average particle size of 40nm-2000nm, and an aggregation index of 0.05-0.

58. Preferably, the SIS soap-free emulsion has a solid content of 5wt%-50wt%, an average particle size of 40nm-500nm, and an aggregation index of 0.05-0.

3.

4. The method for preparing the SIS soap-free emulsion according to any one of claims 1 to 3, characterized in that, The preparation method includes: (A1) Dissolve the SIS with succinic anhydride groups in an organic solvent and stir to dissolve; (A2) Then add a metal hydroxide solution or an amine compound and stir to prepare a polymer solution with carboxylate groups or ammonium carboxylate groups; (A3) Mix water with the polymer solution to obtain an ionomer solution; (A4) The organic solvent and some water are removed by vacuum distillation to obtain the soap-free SIS emulsion.

5. The preparation method according to claim 1, characterized in that, In step A1, the SIS with succinic anhydride groups is maleic acid-modified SIS, and its preparation method includes: SIS and maleic anhydride were mixed, stirred and reacted under an inactive protective atmosphere, cooled, precipitated, and dried to obtain the SIS with succinic anhydride groups. Preferably, the SIS has the following structural formula: The molecular weight of the SIS is 50,000 to 260,000; The styrene content in the SIS is 12wt% to 45wt%; The isoprene content in the SIS is 8 wt% to 75 wt%. Preferably, the mass ratio of maleic anhydride to SIS is 1 wt% to 40 wt%. Preferably, the mass ratio of maleic anhydride to SIS is 10wt% to 30wt%; Preferably, the reaction temperature is 160℃~250℃ and the reaction time is 0.5h or more.

6. The preparation method according to claim 4, characterized in that, In step A1, the mass ratio of the SIS with succinic anhydride groups to the organic solvent is 3:1 to 1:5; Preferably, the mass ratio of the SIS with succinic anhydride groups to the organic solvent is 2:1 to 1:

2.

7. The preparation method according to claim 4, characterized in that, In step A2, the metal hydroxide is selected from at least one of sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium hydroxide, and magnesium hydroxide; The amine compound is selected from at least one of triethanolamine, triethylamine, ethylenediamine, trimethylamine, and diisopropylamine; Preferably, in step A2, the molar ratio of the amount of metal hydroxide added to the succinic anhydride group in the SIS containing the succinic anhydride group is 0.5:1 to 3:1; The molar ratio of the amount of the amine compound added to the succinic anhydride group in the SIS containing the succinic anhydride group is 1:1 to 4:

1. Preferably, the molar ratio of the amount of metal hydroxide added to the succinic anhydride group in the SIS containing the succinic anhydride group is 1:1 to 2:1; The molar ratio of the amount of the amine compound added to the succinic anhydride group in the SIS containing the succinic anhydride group is 2:1 to 3:

1. Preferably, in step A2, the reaction temperature is 30℃-65℃.

8. The preparation method according to claim 4, characterized in that, In step A3, the mass ratio of water to polymer solution is 1:2-3:1; Preferably, in step A3, the mass ratio of water to polymer solution is 1:1 to 2:

1.

9. A SIS latex film, characterized in that, It is prepared from the SIS soap-free emulsion according to any one of claims 1 to 3.

10. The application of the SIS latex film according to claim 9 in the preparation of rubber products; Preferably, the rubber products include personal protective equipment; Preferably, the personal protective equipment includes latex gloves.

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