Low-swelling-rate hydrophilic polyurethane sponge composite material as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of polyurethane, and particularly relates to a low-swelling-rate hydrophilic polyurethane sponge composite material as well as a preparation method and application thereof. The low-swelling-rate hydrophilic polyurethane sponge composite material is prepared from a component A and a component B according to the mass ratio of 100: (50-55), and the component A comprises the following raw materials: a foaming agent, wollastonite powder, an antibacterial agent, emulsifying wax and a polyether type cross-linking agent; the component B comprises polyether ester polyol and toluene diisocynate; the polyether type cross-linking agent is prepared by taking triethanolamine as an initiator and carrying out ring-opening polymerization reaction with EO; the polyether ester polyol is prepared by taking polyethylene glycol, diethylene glycol, trimethylolpropane and adipic acid as raw materials through esterification reaction. The hydrophilic polyurethane sponge prepared from the composite material is good in hydrophilicity, high in aperture ratio, fine and smooth in foam hole, low in swelling ratio and excellent in mechanical property.

Description

Technical Field

[0001] The invention belongs to the technical field of polyurethane, and in particular relates to a low swelling rate hydrophilic polyurethane sponge composite material and a preparation method and application thereof. Background Art

[0002] Hydrophilic polyurethane foam is a widely used cotton pad material because of its excellent absorption performance, biocompatibility, no allergic reaction and teratogenic effect; at the same time, it also has good elasticity and toughness, and excellent processing performance.

[0003] At present, the preparation of hydrophilic polyurethane foam materials mainly introduces hydrophilic structures into the molecular chain, such as ethylene oxide (EO) segments, to improve the hydrophilicity of the material. Its production methods are divided into one-step and two-step methods. Among them, the one-step method refers to a method of mixing, pouring, and reacting raw materials such as polyols, surfactants, catalysts, foaming agents, and polyisocyanates at one time; the two-step method is to first react isocyanate with polyether polyol to generate a prepolymer, and then react the prepolymer with other components to obtain foam. However, the hydrophilic foam materials prepared by these two methods have the problems of poor strength, poor open porosity, and high swelling rate, which can no longer meet people's new requirements for cosmetic cotton.

[0004] Chinese patent CN113861370A discloses a polyurethane composite material for cosmetic cotton, which is composed of component A and component B, wherein component A is made of wollastonite powder, foaming agent, chain extender, emulsifying wax, pore opening agent, and color paste; component B is made of hydrophilic polyether polyol A, hydrophilic polyether polyol B, crosslinking agent polyether, and T 80. The cosmetic cotton made of this composite material not only has good resilience in water and good hydrophilicity, but also has fine pores and excellent mechanical properties. However, the application did not study the product's pore opening and swelling rate.

[0005] Therefore, it is necessary to develop a hydrophilic polyurethane sponge composite material with low swelling rate and good porosity to meet the higher requirements for material performance in the fields of cosmetic cotton and the like. Summary of the invention

[0006] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a low swelling rate hydrophilic polyurethane sponge composite material, which can be used in the preparation of cosmetic cotton. The prepared cosmetic cotton not only has good hydrophilicity, high open porosity, fine pores, but also has low swelling rate and excellent mechanical properties.

[0007] Another object of the present invention is to provide a preparation method and application of a low swelling rate hydrophilic polyurethane sponge composite material.

[0008] The technical solution adopted by the present invention is as follows: The low swelling rate hydrophilic polyurethane sponge composite material is made of component A and component B in a mass ratio of 100: (50-55), wherein component A includes the following raw materials in parts by mass: Foaming agent: 50~55 parts; Wollastonite powder: 40-45 parts; Antibacterial agent: 0.5~1 part; Emulsified wax: 1~3 parts; Polyether cross-linking agent: 1~3 parts; Component B includes the following raw materials in parts by weight: Polyether ester polyol: 100 parts; Toluene diisocyanate: 35-40 parts; The polyether crosslinking agent is prepared by a ring-opening polymerization reaction between triethanolamine and EO as an initiator; The polyether ester polyol is prepared by esterification reaction using polyethylene glycol, diethylene glycol, trimethylolpropane and adipic acid as raw materials; The toluene diisocyanate is a mixture of T65 and T100.

[0009] The foaming agent is water.

[0010] The fineness of the wollastonite powder is 400-800 meshes.

[0011] The antibacterial agent is chitosan quaternary ammonium salt.

[0012] The emulsifying wax is a non-ionic emulsifying matrix, preferably 1000NI from BASF of Germany.

[0013] The functionality of the polyether crosslinking agent is 3 and the number average molecular weight is 300-400; the preparation method thereof comprises the following steps: 1) Add triethanolamine and KOH to the autoclave, replace the air with nitrogen three times, and then evacuate the air to a pressure of -0.095~-0.1MPa. Heat the air to 170~180℃ under vacuum conditions, keep the temperature for 2~3h, then cool the air to 120~125℃, continuously introduce EO, and control the pressure in the autoclave to be less than 0.5MPa. After the introduction, keep the temperature at 120℃, continue the reaction until negative pressure appears in the system, cool the air and discharge the material to obtain a crude cross-linking agent; 2) Add the crude cross-linking agent into a container with a stirrer and a thermometer, add distilled water, heat to 70-80°C, and stir for 1-1.5 hours; then add phosphoric acid and continue stirring for 1-1.5 hours; then add refined magnesium silicate and stir for 1-1.5 hours, then vacuum dehydrate at 110-120°C until the moisture content is ≤0.03wt.%, then filter to obtain the polyether cross-linking agent.

[0014] The hydroxyl value of the polyether ester polyol is 56-112 mgKOH / g; the preparation method thereof comprises the following steps: Add polyethylene glycol, diethylene glycol, trimethylolpropane and adipic acid into a four-necked flask equipped with a stirrer, a temperature controller and a condenser, stir evenly, heat to 220-240°C under nitrogen protection to carry out esterification reaction, maintain the temperature of the reaction system at 220-240°C, and vacuum dehydrate the system. During the reaction, monitor the acid value and hydroxyl value of the system. When the acid value (≤0.5 mgKOH / g) and the hydroxyl value reach the theoretical value, terminate the reaction, cool to 100°C and discharge the material to obtain polyether ester polyol. Wherein, the polyethylene glycol has a hydroxyl value of 278-282 mgKOH / g and a functionality of 2.

[0015] The toluene diisocyanate is a mixture of T65 and T100, and the mass ratio thereof is (1-2): (2-1).

[0016] The method for preparing the low swelling rate hydrophilic polyurethane sponge composite material comprises the following steps: (1) Preparation of component A: Add a foaming agent, wollastonite powder, antibacterial agent, emulsifying wax and polyether crosslinking agent into a reaction kettle, and stir for 20 to 30 minutes at room temperature and a rotation speed of 40 to 50 r / min to obtain component A; (2) Preparation of component B: put polyether ester polyol into a reaction kettle, heat it to 110-120°C, dehydrate it under vacuum for 2-3 hours, then cool it to 30-40°C, add toluene diisocyanate, heat it to 75-80°C, keep it warm for 2-3 hours, take samples for testing, and when the -NCO content is 6.0-10.5wt.%, cool it down, discharge it, and seal it for storage to obtain component B; (3) Component A and component B are mixed evenly according to the mass ratio, injected into the mold, and opened and matured after 3 to 5 minutes to obtain a low swelling rate hydrophilic polyurethane sponge composite material.

[0017] The low swelling rate hydrophilic polyurethane sponge composite material is used for preparing cosmetic cotton.

[0018] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention uses oligomer polyethylene glycol, triethanolamine and adipic acid as raw materials, and successfully prepares a new polyether ester polyol through esterification-polycondensation reaction. The molecular chain of the polyether ester polyol contains both ester bond segments and ethylene oxide (EO) segments. The polyurethane sponge composite material prepared by using the polyether ester polyol not only exhibits excellent hydrophilicity, high open porosity and delicate pore structure, but also has a low swelling rate and excellent mechanical properties due to the high strength of the ester bond and the good hydrophilicity of the ethylene oxide (EO) segment. (2) The molecular chain of the polyether crosslinking agent of the present invention contains an ethylene oxide (EO) segment, and the polyurethane sponge composite material prepared by using the polyether crosslinking agent has not only good hydrophilicity but also excellent mechanical properties; (3) The present invention uses a mixture of T65 and T100 toluene diisocyanate to effectively improve the resilience of the polyurethane sponge composite product while ensuring that the performance of the polyurethane sponge composite product meets the standards; (3) The preparation method of the present invention requires fewer types of raw materials, has a simple process flow and high production efficiency. DETAILED DESCRIPTION

[0019] The present invention is further described below with reference to the embodiments, but they do not limit the implementation of the present invention.

[0020] Unless otherwise specified, the raw materials used in the examples and comparative examples are conventional commercially available raw materials, and the process methods used in the examples and comparative examples are conventional methods in the art unless otherwise specified.

[0021] Some of the raw materials used in the examples and comparative examples are described as follows: The fineness of the wollastonite powder is 600±200 mesh.

[0022] Example 1 The low swelling rate hydrophilic polyurethane sponge composite material is made of component A and component B in a mass ratio of 100:55, wherein component A includes the following raw materials in parts by mass: Water: 50 parts; Wollastonite powder: 45 parts; Chitosan quaternary ammonium salt: 1 part; 1000NI: 3 portions; Polyether crosslinking agent: 1 part; Component B includes the following raw materials in parts by weight: Polyether ester polyol: 100 parts; Toluene diisocyanate: 40 parts.

[0023] The toluene diisocyanate is a mixture of T65 and T100, with a mass ratio of 1:2.

[0024] The functionality of the polyether crosslinking agent is 3 and the number average molecular weight is 300; the preparation method thereof comprises the following steps: 1) Add 1 mol of triethanolamine and 0.2 g of KOH to a high-pressure reactor, replace with nitrogen three times, and then evacuate to a pressure of -0.095 MPa. Heat to 170°C under vacuum conditions, keep warm for 2 hours, then cool to 120°C, continuously introduce 3.4 mol of EO, and control the pressure in the reactor to be less than 0.5 MPa. After the introduction is completed, keep warm at 120°C, continue to react until negative pressure appears in the system, cool and discharge, and obtain a crude cross-linking agent; 2) Add the crude cross-linking agent into a container with a stirrer and a thermometer, add distilled water, heat to 70°C, and stir for 1 hour; then add 0.1g of phosphoric acid and continue stirring for 1 hour; then add 0.2g of refined magnesium silicate, stir for 1 hour, and vacuum dehydrate at 110°C until the moisture content is ≤0.03wt.%, then filter to obtain a polyether cross-linking agent.

[0025] The hydroxyl value of the polyether ester polyol is 56 mgKOH / g; the preparation method thereof comprises the following steps: Add 1302g of polyethylene glycol (hydroxyl value is 278mgKOH / g, functionality is 2), 345g of diethylene glycol, 66g of trimethylolpropane and 750g of adipic acid into a four-necked flask equipped with stirring, temperature control and condenser, stir evenly, heat to 220°C for esterification reaction under nitrogen protection, maintain the temperature of the reaction system at 240°C, and vacuum dehydrate the system. Monitor the acid value and hydroxyl value of the system during the reaction. When the acid value is ≤0.5 mgKOH / g and the hydroxyl value is 56mgKOH / g, terminate the reaction, cool to 100°C and discharge to obtain polyether ester polyol; The method for preparing the low swelling rate hydrophilic polyurethane sponge composite material comprises the following steps: (1) Preparation of component A: water, wollastonite powder, chitosan quaternary ammonium salt, 1000NI and polyether crosslinking agent were added to a reaction kettle and stirred at room temperature and a rotation speed of 40 r / min for 20 min to obtain component A; (2) Preparation of component B: put polyether ester polyol into a reaction kettle, heat it to 110°C, dehydrate it under vacuum for 2 hours, then cool it to 30°C, add toluene diisocyanate, heat it to 75°C, keep it warm for 2 hours, take samples for testing, and when the -NCO content is 6.0wt.%, cool it down, discharge it, and seal it for storage to obtain component B; (3) Component A and component B are mixed evenly according to the mass ratio, injected into the mold, and opened and matured after 3 minutes to obtain a low swelling rate hydrophilic polyurethane sponge composite material.

[0026] Example 2 The low swelling rate hydrophilic polyurethane sponge composite material is made of component A and component B in a mass ratio of 100:53, wherein component A includes the following raw materials in parts by mass: Water: 55 parts; Wollastonite powder: 40 parts; Chitosan quaternary ammonium salt: 0.5 part; 1000NI: 1.5 parts; Polyether cross-linking agent: 3 parts; Component B includes the following raw materials in parts by weight: Polyether ester polyol: 100 parts; Toluene diisocyanate: 37 parts.

[0027] The toluene diisocyanate is a mixture of T65 and T100, with a mass ratio of 2:1.

[0028] The functionality of the polyether crosslinking agent is 3 and the number average molecular weight is 350; the preparation method thereof comprises the following steps: 1) Add 1 mol of triethanolamine and 0.15 g of KOH to a high-pressure reactor, replace the atmosphere with nitrogen three times, and then evacuate the reactor to a pressure of -0.098 MPa. Heat the reactor to 180°C under vacuum conditions, keep the temperature for 2.5 hours, then cool the reactor to 122°C, continuously introduce 4.5 mol of EO, and control the pressure in the reactor to be less than 0.5 MPa. After the introduction is completed, keep the temperature at 120°C, continue the reaction until negative pressure appears in the system, cool the reactor and discharge the material to obtain a crude cross-linking agent. 2) Add the crude cross-linking agent into a container with a stirrer and a thermometer, add distilled water, heat to 75°C, and stir for 1.2 hours; then add 0.15g of phosphoric acid and continue stirring for 1.2 hours; then add 0.25g of refined magnesium silicate, stir for 1.2 hours, and vacuum dehydrate at 115°C until the moisture content is ≤0.03wt.%, then filter to obtain a polyether cross-linking agent.

[0029] The hydroxyl value of the polyether ester polyol is 80 mgKOH / g; the preparation method thereof comprises the following steps: Add 1419g of polyethylene glycol (hydroxyl value is 280mgKOH / g, functionality is 2), 376g of diethylene glycol, 72g of trimethylolpropane and 750g of adipic acid into a four-necked flask equipped with stirring, temperature control and condenser, stir evenly, heat to 230°C under nitrogen protection to carry out esterification reaction, maintain the temperature of the reaction system at 230°C, and evacuate the system for dehydration, monitor the acid value and hydroxyl value of the system during the reaction, terminate the reaction when the acid value is ≤0.5 mgKOH / g and the hydroxyl value is 80mgKOH / g, cool to 100°C and discharge to obtain polyether ester polyol; The method for preparing the low swelling rate hydrophilic polyurethane sponge composite material comprises the following steps: (1) Preparation of component A: water, wollastonite powder, chitosan quaternary ammonium salt, 1000NI and polyether crosslinking agent were added to a reaction kettle and stirred at room temperature and a rotation speed of 45 r / min for 25 min to obtain component A; (2) Preparation of component B: put polyether ester polyol into a reaction kettle, heat it to 115°C, dehydrate it under vacuum for 2.5 hours, then cool it to 35°C, add toluene diisocyanate, heat it to 78°C, keep it warm for 2.5 hours, take samples for testing, and when the -NCO content is 8.6wt.%, cool it down, discharge it, and seal it for storage to obtain component B; (3) Component A and component B are mixed evenly according to the mass ratio, injected into the mold, and opened and matured after 4 minutes to obtain a low swelling rate hydrophilic polyurethane sponge composite material.

[0030] Example 3 The low swelling rate hydrophilic polyurethane sponge composite material is made of component A and component B in a mass ratio of 100:50, wherein component A includes the following raw materials in parts by mass: Water: 53.7 parts; Wollastonite powder: 42.6 parts; Chitosan quaternary ammonium salt: 0.7 parts; 1000NI: 1 piece; Polyether crosslinking agent: 2 parts; Component B includes the following raw materials in parts by weight: Polyether ester polyol: 100 parts; Toluene diisocyanate: 35 parts.

[0031] The toluene diisocyanate is a mixture of T65 and T100, with a mass ratio of 1:1.

[0032] The functionality of the polyether crosslinking agent is 3 and the number average molecular weight is 400; the preparation method thereof comprises the following steps: 1) Add 1 mol of triethanolamine and 0.3 g of KOH to a high-pressure reactor, replace the atmosphere with nitrogen three times, and then evacuate the reactor to a pressure of -0.1 MPa. Heat the reactor to 175°C under vacuum conditions, keep the temperature for 3 hours, then cool the reactor to 125°C, continuously introduce 5.7 mol of EO, and control the pressure in the reactor to be less than 0.5 MPa. After the introduction is completed, keep the temperature at 120°C, continue the reaction until negative pressure appears in the system, cool the reactor and discharge the material to obtain a crude cross-linking agent. 2) Add the crude cross-linking agent into a container with a stirrer and a thermometer, add distilled water, heat to 80°C, and stir for 1.5 hours; then add 0.2g of phosphoric acid and continue stirring for 1.5 hours; then add 0.3g of refined magnesium silicate, stir for 1.5 hours, and vacuum dehydrate at 120°C until the moisture content is ≤0.03wt.%, then filter to obtain a polyether cross-linking agent.

[0033] The hydroxyl value of the polyether ester polyol is 112 mgKOH / g; the preparation method thereof comprises the following steps: Add 1602g of polyethylene glycol (hydroxyl value is 282mgKOH / g, functionality is 2), 425g of diethylene glycol, 81g of trimethylolpropane and 750g of adipic acid into a four-necked flask equipped with stirring, temperature control and condenser, stir evenly, heat to 240°C for esterification reaction under nitrogen protection, maintain the temperature of the reaction system at 220°C, and vacuum dehydrate the system. Monitor the acid value and hydroxyl value of the system during the reaction. When the acid value is ≤0.5 mgKOH / g and the hydroxyl value is 112mgKOH / g, terminate the reaction, cool to 100°C and discharge to obtain polyether ester polyol; The method for preparing the low swelling rate hydrophilic polyurethane sponge composite material comprises the following steps: (1) Preparation of component A: water, wollastonite powder, chitosan quaternary ammonium salt, 1000NI and polyether crosslinking agent were added to a reaction kettle and stirred at room temperature and a rotation speed of 50 r / min for 30 min to obtain component A; (2) Preparation of component B: put polyether ester polyol into a reaction kettle, heat it to 80°C, dehydrate it under vacuum for 3 hours, then cool it to 40°C, add toluene diisocyanate, heat it to 80°C, keep it warm for 3 hours, take samples for testing, and when the -NCO content is 10.5wt.%, cool it down, discharge it, and seal it for storage to obtain component B; (3) Component A and component B are mixed evenly according to the mass ratio, injected into the mold, and opened and matured after 5 minutes to obtain a low swelling rate hydrophilic polyurethane sponge composite material.

[0034] Comparative Example 1 The difference from Example 3 is that the polyether crosslinking agent in component A is replaced by the same mass portion of triethanolamine, and the rest is the same as Example 3.

[0035] Comparative Example 2 The difference from Example 3 is that the polyether ester polyol in component B is replaced by the same mass fraction of PEG2000 (hydroxyl value of 112 mgKOH / g), and the rest is the same as Example 3.

[0036] Comparative Example 3 The difference from Example 3 is that the polyether ester polyol in component B is replaced by the same mass fraction of polyether ester polyol 2 (the difference in its preparation method from the polyether ester polyol in Example 3 is that during the preparation process, trimethylolpropane is replaced by an equal molar amount of 1,4-butanediol), and the rest is the same as Example 3.

[0037] Comparative Example 4 The difference from Example 3 is that the toluene diisocyanate in component B is replaced by T100 in the same mass fraction, and the rest is the same as Example 3.

[0038] Comparative Example 5 The difference from Example 3 is that the toluene diisocyanate in component B is replaced by the same mass portion of T65, and the rest is the same as Example 3.

[0039] The polyurethane sponge composite materials prepared in Examples 1 to 3 and Comparative Examples 1 to 5 were subjected to performance tests, and the test methods were as follows: Core density: Tested in accordance with GB / T 6343-2009; Tensile strength: Tested in accordance with GB / T 6344-2008; Elongation at break: Tested in accordance with GB / T 6344-2008; Tear strength: Tested in accordance with GB / T 10808-2006; The test method for water rebound is: immerse a polyurethane sponge composite material with a size of 20mm×20mm×20mm in deionized water, take it out after 10 minutes, squeeze out the water forcefully, and record the time required for the sample to return to its original state.

[0040] The test method for water absorption is as follows: take a polyurethane sponge composite material sample with a size of 20mm×20mm×10mm, weigh it, immerse the sample in deionized water, take it out after 24 hours, hang it in the air for 1 minute and weigh it, and calculate the water absorption rate (W0) of the sample according to the following formula: ; Where: m0 is the weight of the sample after water absorption, g; m is the weight of the sample before water absorption, g.

[0041] The test method for swelling rate is as follows: take a polyurethane sponge composite material sample with a size of 20mm×20mm×10mm, calculate the volume, and then immerse the sample in deionized water. After 24 hours, take it out and measure the volume after suspending it for 1 minute. The water absorption rate of the sample (W) is calculated according to the following formula: v ): ; Where: V1 is the volume of the sample after water absorption, mm 3 ; V0 is the sample volume before water absorption, mm3 .

[0042] The test results are shown in Table 1.

[0043] Table 1 Performance test results

[0044] It can be seen from the data in Table 1 that the polyurethane sponge composite materials prepared in Examples 1 to 3 not only have good resilience in water and excellent mechanical properties, but also have high water absorption and low swelling rate.

[0045] It can be seen from the comparison between Comparative Example 1 and Example 3 that the use of the polyether crosslinking agent of the present invention can improve the mechanical properties and water absorption rate of the product.

[0046] It can be seen from the comparison of Comparative Examples 2 to 3 with Example 3 that by utilizing the polyether ester polyol of the present invention, ester bond segments and ethylene oxide (EO) segments can be simultaneously introduced into the molecular chain, and the polyurethane sponge composite material prepared therefrom not only has good hydrophilicity and high open porosity, but also has low swelling rate and excellent mechanical properties.

[0047] It can be seen from the comparison of Comparative Examples 4-5 with Example 3 that when all T100 is used, although the foaming rate is high and the mechanical properties are good, the rebound in water is relatively poor; when all T65 is used, although the rebound in water is relatively good, the foam state and mechanical properties are relatively poor. In summary, when the toluene diisocyanate in the formula components adopts the isomer ratio of the present invention, the comprehensive performance of the hydrophilic polyurethane sponge is the best.

Claims

1. A low swelling rate hydrophilic polyurethane sponge composite material, characterized in that: It is made of component A and component B in a mass ratio of 100: (50-55), wherein component A includes the following raw materials in mass parts: Foaming agent: 50~55 parts; Wollastonite powder: 40-45 parts; Antibacterial agent: 0.5~1 part; Emulsified wax: 1~3 parts; Polyether cross-linking agent: 1~3 parts; Component B includes the following raw materials in parts by weight: Polyether ester polyol: 100 parts; Toluene diisocyanate: 35-40 parts; The polyether crosslinking agent is prepared by a ring-opening polymerization reaction between triethanolamine and EO as an initiator; The polyether ester polyol is prepared by esterification reaction using polyethylene glycol, diethylene glycol, trimethylolpropane and adipic acid as raw materials; The toluene diisocyanate is a mixture of T65 and T100.

2. The low swelling rate hydrophilic polyurethane sponge composition according to claim 1, characterized in that: The foaming agent is water.

3. The low swelling rate hydrophilic polyurethane sponge composition according to claim 1, characterized in that: The fineness of the wollastonite powder is 400-800 meshes.

4. The low swelling rate hydrophilic polyurethane sponge composition according to claim 1, characterized in that: The antibacterial agent is chitosan quaternary ammonium salt.

5. The low swelling rate hydrophilic polyurethane sponge composition according to claim 1, characterized in that: The emulsifying wax is a non-ionic emulsifying matrix.

6. The low swelling rate hydrophilic polyurethane sponge composition according to claim 1, characterized in that: The functionality of the polyether crosslinking agent is 3, and the number average molecular weight is 300-400; its preparation method, The following steps are involved: Add triethanolamine and KOH into the reaction kettle, raise the temperature to 170-180°C under vacuum conditions, keep warm for 2-3 hours, then cool down to 120-125°C, introduce EO, and control the pressure in the kettle to be less than 0.5MPa. React until negative pressure appears in the system to obtain a crude cross-linking agent, which can be refined to obtain a polyether cross-linking agent.

7. The low swelling rate hydrophilic polyurethane sponge composition according to claim 1, characterized in that: The hydroxyl value of the polyether ester polyol is 56-112 mgKOH / g; the preparation method thereof comprises the following steps: Polyethylene glycol, diethylene glycol, trimethylolpropane and adipic acid are added into a reactor, and the temperature is raised to 220-240° C. for esterification reaction. The temperature of the reaction system is maintained at 220-240° C., and the system is vacuumed and dehydrated. The acid value and hydroxyl value of the system are monitored during the reaction. When the acid value is ≤0.5 mgKOH / g and the hydroxyl value reaches the theoretical value, the reaction is terminated to obtain a polyether ester polyol; wherein the hydroxyl value of the polyethylene glycol is 278-282 mgKOH / g, and the functionality is 2.

8. The low swelling rate hydrophilic polyurethane sponge composition according to claim 1, characterized in that: The toluene diisocyanate is a mixture of T65 and T100, and the mass ratio thereof is (1-2): (2-1).

9. A method for preparing the low swelling rate hydrophilic polyurethane sponge composition according to any one of claims 1 to 8, characterized in that: The following steps are involved: (1) Preparation of component A: Add a foaming agent, wollastonite powder, antibacterial agent, emulsifying wax and polyether crosslinking agent into a reaction kettle, and stir for 20 to 30 minutes at room temperature and a rotation speed of 40 to 50 r / min to obtain component A; (2) Preparation of component B: Add toluene diisocyanate to the dehydrated polyether ester polyol, raise the temperature to 75-80°C, and keep the temperature to react for 2-3 hours. The -NCO content is measured to be 6.0-10.5 wt.%, thus obtaining component B; (3) Component A and component B are mixed evenly according to the mass ratio, injected into the mold, and opened and matured after 3 to 5 minutes to obtain a low swelling rate hydrophilic polyurethane sponge composite material.

10. An application of the low swelling rate hydrophilic polyurethane sponge composition according to any one of claims 1 to 8, characterized in that: Used to prepare cosmetic cotton pads.

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