阅读说明：本技术 一种亲水膜及其制备方法 (Hydrophilic membrane and preparation method thereof ) 是由 江健波 纪照辉 吴苗苗 于 2020-12-25 设计创作，主要内容包括：本发明公开了一种亲水膜,其特征在于：包括有亲水纤维膜以及涂覆在亲水纤维膜上的亲水涂层；其中,按质量份数计,所述的亲水纤维膜包括有以下原料：改性淀粉树脂40～60份、聚羟基乙酸20～30份、氰基胍1～4份；按质量份数计,所述的改性淀粉树脂包括有以下原料：糯米淀粉30～50份、丙烯酸树脂20～30份、引发剂0.5～1份、溶剂30份、NaOH溶液20份；按质量份数计,所述的亲水涂料包括有以下原料：丙烯酸类共聚物100份、去离子水30～50份、聚乙烯醇20～30份。本发明还公开了该亲水膜的制备方法。与现有技术相比,本发明的亲水膜安全健康,吸水和保水效果好,且可降解。(The invention discloses a hydrophilic membrane, which is characterized in that: comprises a hydrophilic fiber membrane and a hydrophilic coating coated on the hydrophilic fiber membrane; the hydrophilic fiber membrane comprises the following raw materials in parts by weight: 40-60 parts of modified starch resin, 20-30 parts of polyglycolic acid and 1-4 parts of cyanoguanidine; the modified starch resin comprises the following raw materials in parts by weight: 30-50 parts of glutinous rice starch, 20-30 parts of acrylic resin, 0.5-1 part of initiator, 30 parts of solvent and 20 parts of NaOH solution; the hydrophilic coating comprises the following raw materials in parts by weight: 100 parts of acrylic copolymer, 30-50 parts of deionized water and 20-30 parts of polyvinyl alcohol. The invention also discloses a preparation method of the hydrophilic membrane. Compared with the prior art, the hydrophilic membrane is safe and healthy, has good water absorption and retention effects, and is degradable.)

1. a hydrophilic membrane, characterized by: comprises a hydrophilic fiber membrane and a hydrophilic coating coated on the hydrophilic fiber membrane;

the hydrophilic fiber membrane comprises the following raw materials in parts by weight:

40-60 parts of modified starch resin

20-30 parts of polyglycolic acid

1-4 parts of cyanoguanidine;

the modified starch resin comprises the following raw materials in parts by weight:

the hydrophilic coating comprises the following raw materials in parts by weight:

acrylic copolymer 100 parts

30-50 parts of deionized water

20-30 parts of polyvinyl alcohol.

2. A hydrophilic membrane according to claim 1, wherein: the amylopectin content in the glutinous rice starch is more than or equal to 85 percent.

3. A hydrophilic membrane according to claim 1, wherein: the acrylic resin is at least one of butyl acrylate, methyl methacrylate, n-butyl methacrylate and 2-hydroxyethyl acrylate.

4. A hydrophilic membrane according to claim 1, wherein: the initiator is at least one of 2, 2-dimethoxy-phenyl ketone, 2, 4-dihydroxy benzophenone, azobisisobutyronitrile and benzoyl peroxide.

5. A hydrophilic membrane according to claim 1, wherein: the solvent is at least one of toluene, chloroform, isopropanol and ethyl acetate.

6. A hydrophilic membrane according to claim 1, wherein: the concentration of the NaOH solution is 7%.

7. A hydrophilic membrane according to claim 1, wherein: the acrylic copolymer is SK-1170.

8. A hydrophilic membrane according to claim 1, wherein: the alcoholysis degree of the polyvinyl alcohol is 88%, and the polymerization degree is 17.

9. A hydrophilic membrane according to any one of claims 1 to 8, wherein: the thickness of the hydrophilic coating is 1-10 mu m.

10. A method of preparing a hydrophilic membrane according to any one of claims 1 to 9, comprising the steps of:

(1) adding water into sticky rice starch according to the mass part ratio for gelatinization to obtain gelatinized starch, then adding acrylic resin, a solvent, an initiator and a NaOH solution, uniformly mixing, placing under an ultraviolet lamp for polymerization, controlling the temperature at 20-30 ℃, filtering, drying, and crushing the obtained substance to obtain the required modified starch resin;

(2) uniformly mixing the modified starch resin obtained in the step (1), polyglycolic acid and cyanoguanidine according to the mass part ratio, and then performing melt extrusion, film blowing, curing and molding to obtain the required hydrophilic fiber film;

(3) adding polyvinyl alcohol into deionized water according to the mass ratio, heating, stirring and dissolving completely, cooling to room temperature, adding the solution into acrylic copolymer for emulsification to obtain the required hydrophilic coating;

(4) and (3) uniformly coating the hydrophilic coating prepared in the step (3) on the hydrophilic fiber membrane prepared in the step (2), and drying to obtain the required hydrophilic membrane.

Technical Field

The invention relates to the technical field of hydrophilic materials, in particular to a hydrophilic membrane and a preparation method thereof.

Background

It is well known that current diapers, sanitary napkins and other sanitary products use super absorbent resins (SAP) as the absorbent. These substances are widely used because they can absorb several times their own mass of liquid, and on average 30 times their own mass of liquid per diaper.

For example, the invention patent of CN201710648872.2 (publication No. CN109320660A) discloses a process for producing SAP (super absorbent polymer) by using aqueous solution adiabatic polymerization, using deionized water as a solvent, using alkali to partially neutralize acrylic acid, adding cured starch, a cross-linking agent and a composite initiator, performing cross-linking polymerization at low temperature to obtain SAP with a three-dimensional space network structure, and performing fluidized drying, secondary surface treatment and crushing to obtain the super absorbent polymer.

However, for SAP, firstly, the water retention rate of the materials is not ideal, and the materials are quickly dried after absorbing water and are not suitable for facial mask products; secondly, the materials are synthesized by using high molecular resin through a chemical method, so that anaphylactic reaction is easily caused to skin, and the SAP can cause health problems such as toxic shock syndrome; third, these materials are not biodegradable, and under ideal conditions, one mask takes 100 years to degrade, and a diaper takes 500 years to degrade. Therefore, the development of a safe and healthy high-water-absorption and water-retention degradable material for the mask is necessary.

Disclosure of Invention

The first technical problem to be solved by the invention is to provide a degradable hydrophilic membrane which is safe and healthy, and has good water absorption and retention effects aiming at the current situation of the prior art.

The second technical problem to be solved by the present invention is to provide a method for preparing the above hydrophilic membrane.

The technical scheme adopted by the invention for solving the first technical problem is as follows: a hydrophilic membrane, characterized by: comprises a hydrophilic fiber membrane and a hydrophilic coating coated on the hydrophilic fiber membrane;

the hydrophilic fiber membrane comprises the following raw materials in parts by weight:

40-60 parts of modified starch resin

20-30 parts of polyglycolic acid

1-4 parts of cyanoguanidine;

the modified starch resin comprises the following raw materials in parts by weight:

the hydrophilic coating comprises the following raw materials in parts by weight:

acrylic copolymer 100 parts

30-50 parts of deionized water

20-30 parts of polyvinyl alcohol (PVA for short).

Preferably, the amylopectin content in the glutinous rice starch is more than or equal to 85 percent.

Preferably, the acrylic resin is at least one of butyl acrylate, methyl methacrylate, n-butyl methacrylate and 2-hydroxyethyl acrylate.

Preferably, the initiator is at least one of 2, 2-dimethoxy-phenyl ketone, 2, 4-dihydroxy benzophenone, azobisisobutyronitrile and benzoyl peroxide.

Preferably, the solvent is at least one of toluene, chloroform, isopropanol and ethyl acetate.

Preferably, the concentration of the NaOH solution is 7%.

Preferably, the acrylic copolymer is SK-1170 (available from Soken chemical Co., Ltd.).

Preferably, the degree of alcoholysis of the polyvinyl alcohol is 88% and the degree of polymerization is 17.

Preferably, the thickness of the hydrophilic coating is 1-10 μm.

The technical scheme adopted by the invention for solving the second technical problem is as follows: the preparation method of the hydrophilic membrane is characterized by comprising the following steps:

(1) adding water into sticky rice starch according to the mass part ratio for gelatinization to obtain gelatinized starch, then adding acrylic resin, a solvent, an initiator and a NaOH solution, uniformly mixing, placing under an ultraviolet lamp for polymerization, controlling the temperature at 20-30 ℃, filtering, drying, and crushing the obtained substance to obtain the required modified starch resin;

(2) uniformly mixing the modified starch resin obtained in the step (1), polyglycolic acid and cyanoguanidine according to the mass part ratio, and then performing melt extrusion, film blowing, curing and molding to obtain the required hydrophilic fiber film;

(3) adding polyvinyl alcohol into deionized water according to the mass ratio, heating, stirring and dissolving completely, cooling to room temperature, adding the solution into acrylic copolymer for emulsification to obtain the required hydrophilic coating;

(4) and (3) uniformly coating the hydrophilic coating prepared in the step (3) on the hydrophilic fiber membrane prepared in the step (2), and drying to obtain the required hydrophilic membrane.

Compared with the prior art, the invention has the advantages that: the hydrophilic material for preparing the high-grade facial mask is prepared by modifying starch by utilizing the hydrophilic property of the starch to obtain modified starch resin, then toughening the starch resin by polyglycolic acid, repeatedly and uniformly combining under the action of an interface binding agent cyanoguanidine to prepare a material with higher water absorption property, and further coating a hydrophilic coating to obtain the hydrophilic material for preparing the high-grade facial mask.

Detailed Description

The present invention will be described in further detail with reference to examples.

Example 1:

(1) the preparation method of the modified starch resin comprises the following steps: adding 30 parts of glutinous rice starch into a three-neck flask with a stirrer, adding distilled water, and stirring at 60 ℃ for gelatinization; cooling to room temperature, adding 20 parts of acrylic resin, 30 parts of isopropanol, 0.5 part of 2, 4-dihydroxy benzophenone and 20 parts of 7% NaOH solution into gelatinized starch, uniformly mixing, placing under a 1200W ultraviolet lamp for polymerization, controlling the temperature to be 20-30 ℃, filtering, drying in an oven at 85 ℃ for 12 hours, and crushing the obtained substance to obtain the required modified starch resin;

(2) the preparation method of the hydrophilic fiber membrane comprises the following steps: uniformly mixing 40 parts of modified starch resin, 20 parts of polyglycolic acid and 1 part of cyanoguanidine, and then performing melt extrusion, film blowing, curing and molding at 240 ℃ to obtain the required hydrophilic fiber film;

(3) the preparation method of the hydrophilic coating comprises the following steps: adding 20 parts of PVA into 30 parts of deionized water, stirring at 70 ℃ until the PVA is completely dissolved, cooling to room temperature, adding the solution into SK-1170, and emulsifying for half an hour to obtain the required hydrophilic coating;

(4) the preparation method of the hydrophilic membrane comprises the following steps: and uniformly coating the prepared hydrophilic coating on a hydrophilic fiber membrane, wherein the thickness of the coating is 1-10 mu m, and drying for 3 minutes by using a drying oven at 60 ℃ to obtain the required hydrophilic membrane.

Example 2:

(1) the preparation method of the modified starch resin comprises the following steps: adding 50 parts of glutinous rice starch into a three-neck flask with a stirrer, adding distilled water, and stirring at 60 ℃ for gelatinization; cooling to room temperature, adding 30 parts of acrylic resin, 30 parts of isopropanol, 1 part of 2, 4-dihydroxy benzophenone and 20 parts of 7% NaOH solution into gelatinized starch, uniformly mixing, placing under a 1200W ultraviolet lamp for polymerization, controlling the temperature to be 20-30 ℃, filtering, drying in an oven at 85 ℃ for 12 hours, and crushing the obtained substance to obtain the required modified starch resin;

(2) the preparation method of the hydrophilic fiber membrane comprises the following steps: uniformly mixing 50 parts of modified starch resin, 30 parts of polyglycolic acid and 4 parts of cyanoguanidine, and then performing melt extrusion, film blowing, curing and molding at 240 ℃ to obtain the required hydrophilic fiber film;

(3) the preparation method of the hydrophilic coating comprises the following steps: adding 30 parts of PVA into 30 parts of deionized water, stirring at 70 ℃ until the PVA is completely dissolved, cooling to room temperature, adding the solution into SK-1170, and emulsifying for half an hour to obtain the required hydrophilic coating;

(4) the preparation method of the hydrophilic membrane comprises the following steps: and uniformly coating the prepared hydrophilic coating on a hydrophilic fiber membrane, wherein the thickness of the coating is 1-10 mu m, and drying for 3 minutes by using a drying oven at 60 ℃ to obtain the required hydrophilic membrane.

Example 3:

(1) the preparation method of the modified starch resin comprises the following steps: adding 40 parts of glutinous rice starch into a three-neck flask with a stirrer, adding distilled water, and stirring at 60 ℃ for gelatinization; cooling to room temperature, adding 25 parts of acrylic resin, 30 parts of isopropanol, 0.8 part of 2, 4-dihydroxy benzophenone and 20 parts of 7% NaOH solution into gelatinized starch, uniformly mixing, placing under a 1200W ultraviolet lamp for polymerization, controlling the temperature to be 20-30 ℃, filtering, drying in an oven at 85 ℃ for 12 hours, and crushing the obtained substance to obtain the required modified starch resin;

(2) the preparation method of the hydrophilic fiber membrane comprises the following steps: uniformly mixing 60 parts of modified starch resin, 25 parts of polyglycolic acid and 2 parts of cyanoguanidine, and then performing melt extrusion, film blowing, curing and molding at 240 ℃ to obtain the required hydrophilic fiber film;

(3) the preparation method of the hydrophilic coating comprises the following steps: adding 25 parts of PVA into 30 parts of deionized water, stirring at 70 ℃ until the PVA is completely dissolved, cooling to room temperature, adding the solution into SK-1170, and emulsifying for half an hour to obtain the required hydrophilic coating;

(4) the preparation method of the hydrophilic membrane comprises the following steps: and uniformly coating the prepared hydrophilic coating on a hydrophilic fiber membrane, wherein the thickness of the coating is 1-10 mu m, and drying for 3 minutes by using a drying oven at 60 ℃ to obtain the required hydrophilic membrane.

Comparative example 1:

(1) the preparation method of the modified starch resin comprises the following steps: adding 20 parts of glutinous rice starch into a three-neck flask with a stirrer, adding distilled water, and stirring at 60 ℃ for gelatinization; cooling to room temperature, adding 20 parts of acrylic resin, 30 parts of isopropanol, 0.5 part of 2, 4-dihydroxy benzophenone and 20 parts of 7% NaOH solution into gelatinized starch, uniformly mixing, placing under a 1200W ultraviolet lamp for polymerization, controlling the temperature to be 20-30 ℃, filtering, drying in an oven at 85 ℃ for 12 hours, and crushing the obtained substance to obtain the required modified starch resin;

(2) the preparation method of the hydrophilic fiber membrane comprises the following steps: uniformly mixing 40 parts of modified starch resin, 20 parts of polyglycolic acid and 2 parts of cyanoguanidine, and then performing melt extrusion, film blowing, curing and molding at 240 ℃ to obtain the required hydrophilic fiber film;

(3) the preparation method of the hydrophilic coating comprises the following steps: adding 20 parts of PVA into 30 parts of deionized water, stirring at 70 ℃ until the PVA is completely dissolved, cooling to room temperature, adding the solution into SK-1170, and emulsifying for half an hour to obtain the required hydrophilic coating;

(4) the preparation method of the hydrophilic membrane comprises the following steps: and uniformly coating the prepared hydrophilic coating on a hydrophilic fiber membrane, wherein the thickness of the coating is 1-10 mu m, and drying for 3 minutes by using a drying oven at 60 ℃ to obtain the required hydrophilic membrane.

Comparative example 2:

(1) the preparation method of the modified starch resin comprises the following steps: adding 60 parts of glutinous rice starch into a three-neck flask with a stirrer, adding distilled water, and stirring at 60 ℃ for gelatinization; cooling to room temperature, adding 30 parts of acrylic resin, 30 parts of isopropanol, 1 part of 2, 4-dihydroxy benzophenone and 20 parts of 7% NaOH solution into gelatinized starch, uniformly mixing, placing under a 1200W ultraviolet lamp for polymerization, controlling the temperature to be 20-30 ℃, filtering, drying in an oven at 85 ℃ for 12 hours, and crushing the obtained substance to obtain the required modified starch resin;

(2) the preparation method of the hydrophilic fiber membrane comprises the following steps: uniformly mixing 40 parts of modified starch resin, 30 parts of polyglycolic acid and 2 parts of cyanoguanidine, and then performing melt extrusion, film blowing, curing and molding at 240 ℃ to obtain the required hydrophilic fiber film;

(3) the preparation method of the hydrophilic coating comprises the following steps: adding 25 parts of PVA into 30 parts of deionized water, stirring at 70 ℃ until the PVA is completely dissolved, cooling to room temperature, adding the solution into SK-1170, and emulsifying for half an hour to obtain the required hydrophilic coating;

(4) the preparation method of the hydrophilic membrane comprises the following steps: and uniformly coating the prepared hydrophilic coating on a hydrophilic fiber membrane, wherein the thickness of the coating is 1-10 mu m, and drying for 3 minutes by using a drying oven at 60 ℃ to obtain the required hydrophilic membrane.

Comparative example 3:

(1) the preparation method of the modified starch resin comprises the following steps: adding 40 parts of glutinous rice starch into a three-neck flask with a stirrer, adding distilled water, and stirring at 60 ℃ for gelatinization; cooling to room temperature, adding 25 parts of acrylic resin, 30 parts of isopropanol, 1 part of 2, 4-dihydroxy benzophenone and 20 parts of 7% NaOH solution into gelatinized starch, uniformly mixing, placing under a 1200W ultraviolet lamp for polymerization, controlling the temperature to be 20-30 ℃, filtering, drying in an oven at 85 ℃ for 12 hours, and crushing the obtained substance to obtain the required modified starch resin;

(2) the preparation method of the hydrophilic fiber membrane comprises the following steps: uniformly mixing 40 parts of modified starch resin, 10 parts of polyglycolic acid and 2 parts of cyanoguanidine, and then performing melt extrusion, film blowing, curing and molding at 240 ℃ to obtain the required hydrophilic fiber film;

(3) the preparation method of the hydrophilic coating comprises the following steps: adding 20 parts of PVA into 30 parts of deionized water, stirring at 70 ℃ until the PVA is completely dissolved, cooling to room temperature, adding the solution into SK-1170, and emulsifying for half an hour to obtain the required hydrophilic coating;

(4) the preparation method of the hydrophilic membrane comprises the following steps: and uniformly coating the prepared hydrophilic coating on a hydrophilic fiber membrane, wherein the thickness of the coating is 1-10 mu m, and drying for 3 minutes by using a drying oven at 60 ℃ to obtain the required hydrophilic membrane.

Comparative example 4:

(1) the preparation method of the modified starch resin comprises the following steps: adding 40 parts of glutinous rice starch into a three-neck flask with a stirrer, adding distilled water, and stirring at 60 ℃ for gelatinization; cooling to room temperature, adding 25 parts of acrylic resin, 30 parts of isopropanol, 1 part of 2, 4-dihydroxy benzophenone and 20 parts of 7% NaOH solution into gelatinized starch, uniformly mixing, placing under a 1200W ultraviolet lamp for polymerization, controlling the temperature to be 20-30 ℃, filtering, drying in an oven at 85 ℃ for 12 hours, and crushing the obtained substance to obtain the required modified starch resin;

(2) the preparation method of the hydrophilic fiber membrane comprises the following steps: uniformly mixing 40 parts of modified starch resin, 50 parts of polyglycolic acid and 3 parts of cyanoguanidine, and then performing melt extrusion, film blowing, curing and molding at 240 ℃ to obtain the required hydrophilic fiber film;

(3) the preparation method of the hydrophilic coating comprises the following steps: adding 20 parts of PVA into 30 parts of deionized water, stirring at 70 ℃ until the PVA is completely dissolved, cooling to room temperature, adding the solution into SK-1170, and emulsifying for half an hour to obtain the required hydrophilic coating;

(4) the preparation method of the hydrophilic membrane comprises the following steps: and uniformly coating the prepared hydrophilic coating on a hydrophilic fiber membrane, wherein the thickness of the coating is 1-10 mu m, and drying for 3 minutes by using a drying oven at 60 ℃ to obtain the required hydrophilic membrane.

Comparative example 5:

(1) the preparation method of the modified starch resin comprises the following steps: adding 50 parts of glutinous rice starch into a three-neck flask with a stirrer, adding distilled water, and stirring at 60 ℃ for gelatinization; cooling to room temperature, adding 30 parts of acrylic resin, 1 part of 2, 4-dihydroxy benzophenone and 20 parts of 7% NaOH solution into gelatinized starch, uniformly mixing, placing under a 1200W ultraviolet lamp for polymerization, controlling the temperature to be 20-30 ℃, filtering, drying in an oven at 85 ℃ for 12 hours, and crushing the obtained substance to obtain the required modified starch resin;

(2) the preparation method of the hydrophilic fiber membrane comprises the following steps: uniformly mixing 40 parts of modified starch resin, 30 parts of polyglycolic acid and 0.1 part of cyanoguanidine, and then performing melt extrusion, film blowing, curing and molding at 240 ℃ to obtain the required hydrophilic fiber film;

(3) the preparation method of the hydrophilic coating comprises the following steps: adding 20 parts of PVA into 30 parts of deionized water, stirring at 70 ℃ until the PVA is completely dissolved, cooling to room temperature, adding the solution into SK-1170, and emulsifying for half an hour to obtain the required hydrophilic coating;

(4) the preparation method of the hydrophilic membrane comprises the following steps: and uniformly coating the prepared hydrophilic coating on a hydrophilic fiber membrane, wherein the thickness of the coating is 1-10 mu m, and drying for 3 minutes by using a drying oven at 60 ℃ to obtain the required hydrophilic membrane.

Comparative example 6:

(1) the preparation method of the modified starch resin comprises the following steps: adding 50 parts of glutinous rice starch into a three-neck flask with a stirrer, adding distilled water, and stirring at 60 ℃ for gelatinization; cooling to room temperature, adding 30 parts of acrylic resin, 1 part of 2, 4-dihydroxy benzophenone and 20 parts of 7% NaOH solution into gelatinized starch, uniformly mixing, placing under a 1200W ultraviolet lamp for polymerization, controlling the temperature to be 20-30 ℃, filtering, drying in an oven at 85 ℃ for 12 hours, and crushing the obtained substance to obtain the required modified starch resin;

(2) the preparation method of the hydrophilic fiber membrane comprises the following steps: uniformly mixing 40 parts of modified starch resin, 30 parts of polyglycolic acid and 4 parts of cyanoguanidine, and then performing melt extrusion, film blowing, curing and molding at 240 ℃ to obtain the required hydrophilic fiber film;

(3) the preparation method of the hydrophilic coating comprises the following steps: adding 10 parts of PVA into 30 parts of deionized water, stirring at 70 ℃ until the PVA is completely dissolved, cooling to room temperature, adding the solution into SK-1170, and emulsifying for half an hour to obtain the required hydrophilic coating;

(4) the preparation method of the hydrophilic membrane comprises the following steps: and uniformly coating the prepared hydrophilic coating on a hydrophilic fiber membrane, wherein the thickness of the coating is 1-10 mu m, and drying for 3 minutes by using a drying oven at 60 ℃ to obtain the required hydrophilic membrane.

Comparative example 7:

(1) the preparation method of the modified starch resin comprises the following steps: adding 40 parts of glutinous rice starch into a three-neck flask with a stirrer, adding distilled water, and stirring at 60 ℃ for gelatinization; cooling to room temperature, adding 25 parts of acrylic resin, 0.8 part of 2, 4-dihydroxy benzophenone and 20 parts of 7% NaOH solution into gelatinized starch, uniformly mixing, placing under a 1200W ultraviolet lamp for polymerization, controlling the temperature to be 20-30 ℃, filtering, drying in an oven at 85 ℃ for 12 hours, and crushing the obtained substance to obtain the required modified starch resin;

(2) the preparation method of the hydrophilic fiber membrane comprises the following steps: uniformly mixing 40 parts of modified starch resin, 25 parts of polyglycolic acid and 4 parts of cyanoguanidine, and then performing melt extrusion, film blowing, curing and molding at 240 ℃ to obtain the required hydrophilic fiber film;

(3) the preparation method of the hydrophilic coating comprises the following steps: adding 50 parts of PVA into 30 parts of deionized water, stirring at 70 ℃ until the PVA is completely dissolved, cooling to room temperature, adding the solution into SK-1170, and emulsifying for half an hour to obtain the required hydrophilic coating;

(4) the preparation method of the hydrophilic membrane comprises the following steps: and uniformly coating the prepared hydrophilic coating on a hydrophilic fiber membrane, wherein the thickness of the coating is 1-10 mu m, and drying for 3 minutes by using a drying oven at 60 ℃ to obtain the required hydrophilic membrane.

The reaction conditions and the results of the performance test for all examples and comparative examples are shown in Table 1.

Note: in table 1, the hydrophilic membrane is tested for various properties as follows:

(1) water retention: preparing a test material into a wafer with the diameter of 150mm, coating 10ml of purified water, weighing M1 after water is completely absorbed, placing a sample at 23 ℃ in a 40% RH environment for 4h, and weighing M2; the water retention rate calculation formula is as follows: (M2 ÷ M1) × 100%;

(2) modulus of elasticity: cutting the test material into a sample with the width of 25mm and the length of 200mm, standing for 20 minutes at the temperature of 23 ℃ under the environment of 50% humidity, vertically pulling up by using an RTG-1210 universal tensile machine, and testing the elastic modulus;

(3) water absorption: cutting a test material into a sample with the length of 30mm and the width of 30mm, weighing a mass M1, soaking in purified water at 23 ℃ for 10 minutes, taking out, wiping off surface moisture, and weighing a mass M2; the water absorption calculation formula is as follows: (M2-M1) ÷ M1X 100%.

As can be seen from table 1: the hydrophilic membrane in the embodiment of the invention has good hydrophilic performance.

The working principle of the invention is as follows: the hydrophilic material for preparing the high-grade facial mask is prepared by modifying starch by utilizing the hydrophilic property of the starch to obtain modified starch resin, then toughening the starch resin by polyglycolic acid, repeatedly and uniformly combining under the action of an interface binding agent cyanoguanidine to prepare a material with higher water absorption property, and further coating a hydrophilic coating to obtain the hydrophilic material for preparing the high-grade facial mask.

Table 1: