CN109160990B

CN109160990B - Alkyl side chain modified polyurethane aqueous emulsion, preparation method thereof and application thereof in polyurethane condom

Info

Publication number: CN109160990B
Application number: CN201810988289.0A
Authority: CN
Inventors: 谢兴益; 袁帅; 张青
Original assignee: Sichuan University
Current assignee: Sichuan University
Priority date: 2018-08-22
Filing date: 2018-08-28
Publication date: 2020-09-18
Anticipated expiration: 2038-08-28
Also published as: CN109160990A

Abstract

An aqueous emulsion of polyurethane containing hydrocarbon-base side chain, its preparing process and its application in preparing condom are disclosed. The preparation method of the polyurethane aqueous emulsion comprises the following steps: according to parts by mass, firstly, dehydrating a mixture of 50-65 parts of polyether glycol and 3-20 parts of hydrophobic polymer glycol or diamine at high temperature in vacuum, and then carrying out prepolymerization reaction with 15-30 parts of diisocyanate; then reacting with 0-2 parts of micromolecular diol chain extender, 3-6 parts of chain extender with carboxyl and 1.5-6 parts of chain extender with alkyl side chain, and adding an organic solvent for dilution; then adding the diluted reaction mixture into deionized water containing 0.5-3 parts of amine chain extender and 0-0.5 part of graphene oxide for stirring and emulsifying; finally, removing the organic solvent in vacuum to obtain the polyurethane aqueous emulsion. And the polyurethane condom is obtained by the procedures of dip-coating a mould, heating and drying, curling, vacuum drying, packaging and the like. The condom has a thickness less than 0.025mm, 100% modulus of elongation less than 1.3MPa, tensile strength greater than 25MPa, and elongation at break greater than 1000%.

Description

Alkyl side chain modified polyurethane aqueous emulsion, preparation method thereof and application thereof in polyurethane condom

Technical Field

The invention belongs to the field of polymer materials, and particularly relates to a water emulsion of polyurethane containing a hydrocarbon-based side chain and application thereof in polyurethane condoms.

Background

Condom is a commonly used contraceptive device, and has the function of preventing sexually transmitted diseases. The condom which is most widely used at present is still a natural latex condom. The condom is produced with natural latex as base material and through hot vulcanization and forming with rubber assistant, such as antiager, promoter, vulcanizing agent, etc. Its advantages are high elasticity and flexibility, and high effect on contraception and preventing sexually transmitted diseases. However, there are also significant disadvantages, mainly: (1) the material strength is not high enough, so that the condom is thick (generally 0.06-0.07 mm), the heat-conducting property is low, and the use comfort degree still needs to be improved; (2) the natural latex contains water-soluble protein, which cannot be removed in the manufacturing process, and is easy to cause allergy and contact dermatitis. About 10% of caucasians are statistically allergic to proteins in latex, and 2% of caucasians are also allergic; (3) recent studies have shown that natural latex condoms contain nitrosamines, which are strong carcinogens (mainly generated during vulcanization molding), and are therefore frequently used for a long time, with the risk of inducing tumors.

Aiming at the defects of the existing natural latex condoms, Polyurethane (PU) condoms have been developed in the last 90 years, Meiying and other countries. PU itself is a widely used medical material, and is a copolymer of soft and hard segments, and micro-phase separation exists between the soft and hard segments. The soft segment makes PU have good elasticity, and the hard segment increases the strength of PU. The condom adopts a solution film forming process, has compact condom film, overcomes the micron-sized macropores of natural latex, and has good virus-blocking capability. Meanwhile, the PU film has better strength, and can be used for manufacturing thinner condoms (0.045 mm); the PU material has better thermal conductivity than natural latex, thereby increasing sensitivity and comfort of use. However, the PU sleeve also has the obvious defects: (1) although the strength of the material is high, the rigidity is also high, the elongation is small (generally 500% -650%), and the flexibility is different from the natural latex (the elongation of the natural latex is 1300% -1500%). Therefore, the user generally thinks that the PU sleeve has stronger plastic feeling, reduces the comfort level and is easy to slip off in the using process; (2) a large amount of organic solvent is used in the production process, which causes environmental pollution.

Aiming at the defect of large pollution of solvent type polyurethane, in recent years, waterborne polyurethane condoms are developed at home and abroad. Patent CN 106750079A discloses a water-based polyurethane resin for condoms and a preparation method thereof, which is characterized in that a sulfonate-containing chain extender is adopted, so that the condoms have high solid content and good sag resistance, but the performance of the prepared condoms is not disclosed. Patent CN 107266645A discloses a siloxane modified aqueous polyurethane emulsion and a preparation method of an aqueous polyurethane condom, which is characterized in that 7.5-15% of hydroxyl-terminated polydimethylsiloxane is adopted as a soft segment of polyurethane in the formula, and the thickness of the prepared polyurethane condom is as low as below 0.03mm, the elongation at break is more than 1000%, the breaking strength is more than 30MPa, and the 100% modulus is less than 2 MPa.

Although great progress has been made in the above polyurethane condoms, there is still a large difference in flexibility compared to natural latex, such as: the majority of 100 percent modulus of the existing polyurethane condom is 1.5-2 MPa, and the 100 percent modulus of the natural latex is about 0.7 MPa. This indicates that the polyurethane condom is still far less flexible than a natural latex condom. Accordingly, there remains a need for improved polyurethane condoms to improve overall performance.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and firstly provides a water emulsion of polyurethane containing hydrocarbon-based side chains and a preparation method thereof.

Another object of the present invention is to provide the use of aqueous emulsions of polyurethanes containing hydrocarbon side chains for the preparation of condoms.

The inventor carefully inspects the preparation method of the existing waterborne polyurethane condom and finds that the existing preparation method mainly improves the flexibility of the polyurethane condom by the following modes: firstly, mixed macromolecular polyol is adopted as a soft segment, and comprises polytetrahydrofuran polyol, polypropylene glycol polyol and polysiloxane polyol, wherein the polysiloxane polyol is also favorable for improving water resistance; secondly, a plurality of chain extenders are adopted, including hydrophilic dihydric alcohol (such as dimethylolpropionic acid), aliphatic diol (such as butanediol, cyclohexanedimethanol, neopentyl glycol and the like), amine chain extenders and the like. Wherein the chain extender with carboxyl groups mainly provides anions to stabilize the aqueous emulsion; the amine chain extender is mainly used for further improving the molecular weight in the emulsification stage so as to obtain the polyurethane with excellent mechanical strength. The purpose of adopting the mixed soft segment and the mixed chain extender is to disturb the ordered arrangement of polyurethane molecular chains so as to improve the flexibility. As mentioned above, the polyurethane condoms obtained by the prior art methods are still far less flexible than natural latex condoms and the comfort of use is still to be improved.

Aiming at the defects of the prior art, the inventor provides that alkyl side chains are introduced into the hard polyurethane segment according to the principle of high molecular structure and performance, and the arrangement of the hard segment is further disturbed, so that the flexibility of the polyurethane condom is greatly improved, and the foundation of the invention is laid. Based on the above, the invention provides a water emulsion of polyurethane containing hydrocarbon-based side chain and a preparation method of the water-based polyurethane. The method is characterized by comprising the following steps in parts by mass:

1) preparing a prepolymer: firstly, uniformly mixing 50-65 parts of polyether glycol and 3-20 parts of hydrophobic polymer glycol or diamine in a reaction kettle, stirring and heating to 100-120 ℃, dehydrating under the vacuum condition of less than-0.09 MPa for 1-4 hours, cooling to 60-80 ℃, then adding 15-30 parts of diisocyanate, and stirring at 100-110 ℃ for 1-3 hours to obtain a polyurethane prepolymer;

2) chain extension reaction: adding 0-2 parts of a small-molecular-weight diol chain extender, 3-6 parts of a chain extender with carboxyl and 1.5-6 parts of a chain extender with a hydrocarbyl side chain into the polyurethane prepolymer, stirring for 1-3 hours at 80-110 ℃, cooling to 40-60 ℃, adding 50-120 parts of an organic solvent for dilution, and adding a tertiary amine to completely neutralize the carboxyl group in the chain extender to obtain a polyurethane prepolymer with carboxylate;

3) and (3) an emulsification process: ultrasonically dispersing 0-0.5 part of graphene oxide in 150-400 parts of deionized water, adding 0.5-3 parts of amine chain extender into the deionized water, slowly pouring the polyurethane prepolymer with carboxylate obtained in the step 2) into the deionized water, and stirring at a high speed (such as 1000-1500 rpm) for 2-4 hours to obtain a polyurethane emulsion;

4) and (3) desolventizing process: heating the polyurethane emulsion obtained in the step 3) to 40-60 ℃, and removing the organic solvent under a vacuum condition to obtain a polyurethane aqueous emulsion;

5) the preparation method of the water-based polyurethane condom comprises the following steps:

(1) firstly, diluting or not diluting the polyurethane aqueous emulsion to ensure that the solid content of the polyurethane aqueous emulsion is 10-30%, if the polyurethane aqueous emulsion needs to be diluted and does not contain graphene oxide, adding 0-0.5 part of graphene oxide into deionized water required for dilution, and carrying out ultrasonic dispersion on the obtained product to dilute the polyurethane aqueous emulsion;

(2) ultrasonically cleaning a glass mold in ethanol for 10 minutes and drying;

(3) immersing a glass mold into the polyurethane aqueous emulsion obtained in the step (1) for 10-30 s, taking out, and carrying out staged heating and drying, wherein drying is carried out at 60 ℃ for 2-4 minutes, at 80 ℃ for 3-5 minutes, and at 100-120 ℃ for 10-20 minutes; if necessary, after drying at 80 ℃, soaking the polyurethane aqueous emulsion obtained in the step (1) once again, taking out, and performing staged heating and drying again, wherein drying is performed at 60 ℃ for 2-4 minutes, at 80 ℃ for 3-5 minutes, and at 100-120 ℃ for 10-20 minutes;

(4) curling the coated polyurethane film to a proper position, cooling to room temperature, soaking an anti-sticking agent or anti-sticking powder, completely curling and demolding, drying at 80-120 ℃ for 10-20 minutes under the vacuum condition of less than-0.09 MPa, cooling to room temperature, adding medical silicone oil, and packaging to obtain a condom finished product;

wherein the hydrophobic polymeric diamine is a polysiloxane diamine; the hydrophobic polymer diol is at least one of polysiloxane diol, polybutadiene diol and poly (butadiene acrylonitrile) diol, wherein the mass percentage of acrylonitrile chain units is 1-40%; the tertiary amine is at least one of triethylamine, methyl diethylamine, diethanolamine and triethanolamine; the organic solvent is at least one of acetone, methyl ethyl ketone, tetrahydrofuran and acetonitrile; the micromolecular diol chain extender is aliphatic dihydric alcohol with carbon atoms of 2-6, and can contain methyl and/or ethyl side chains; the chain extender with carboxyl is at least one of dimethylolpropionic acid and dimethylolbutyric acid; the chain extender having a hydrocarbon side chain contains at least one hydrocarbon chain having 3 or more carbon atoms.

In the preparation method of the polyurethane aqueous emulsion and the condom, the polyether diol is a mixture of polyoxypropylene diol and polytetrahydrofuran ether diol, wherein the mass percentage of the polyoxypropylene diol is 20-80%; preferably 30 to 40%.

In the preparation method of the polyurethane aqueous emulsion and the condom, the diisocyanate is at least one of isophorone diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, lysine ethyl ester diisocyanate, toluene diisocyanate and diphenylmethane diisocyanate.

In the preparation method of the polyurethane aqueous emulsion and the condom, the amine chain extender is aliphatic diamine with 2 to 6 carbon atoms, or lysine, or gamma-aminoethyl aminopropyl trialkoxy silane, wherein the alkoxy is methoxy or ethoxy.

In the preparation method of the polyurethane aqueous emulsion and the condom, the chain extender with the alkyl side chain is trimethylolpropane monofatty acid ester, wherein the number of carbon atoms of the fatty acid chain is 4-20; or N-alkyl diethanol amine, wherein the carbon atom number of an alkyl chain is 3-20; or 2-alkyl-1, 3-propanediol or 2, 2-dialkyl-1, 3-propanediol, wherein the carbon number of the alkyl chain is 3-20.

In the preparation method of the polyurethane aqueous emulsion and the condom, the sheet diameter of the graphene oxide is less than 1 micron. The graphene oxide sheets can be stacked in parallel along the surface of the condom film, so that the defects of the film are reduced, and the virus blocking capacity is improved; meanwhile, the thermal conductivity coefficient of the graphene oxide is greatly higher than that of the polyurethane film, so that the thermal conductivity of the condom can be improved, and the use comfort is improved.

In the above-mentioned preparation method of aqueous emulsion of polyurethane, the molecular weight of polyether diol, hydrophobic polymer diol and hydrophobic polymer diamine is 500-4000.

The invention also provides the aqueous emulsion of polyurethane prepared by the preparation method.

The invention also provides a polyurethane condom prepared by the preparation method, wherein the thickness of the condom is less than 0.025mm, the 100% modulus of elongation is less than 1.3MPa, the tensile strength is greater than 25MPa, and the elongation at break is greater than 1000%.

Compared with the prior art, the invention has the following advantages:

1. the preparation method of the polyurethane aqueous emulsion provided by the invention does not contain a catalyst, and can avoid the stimulation of catalyst residues to human bodies.

2. The polyurethane aqueous emulsion provided by the invention contains the hydrophobic alkyl side chain, so that the ordered arrangement of the hard segments of polyurethane molecular chains is disturbed, the prepared condom not only maintains the excellent mechanical strength of polyurethane, but also has the flexibility close to natural latex, and the comfort level of the polyurethane condom can be greatly improved.

3. The polyurethane condom provided by the invention can contain graphene oxide, and the graphene oxide can be uniformly dispersed in water, so that the graphene oxide can be uniformly mixed with polyurethane aqueous emulsion, and graphene oxide sheets in the obtained condom are uniformly dispersed. The addition of the graphene oxide can improve the barrier property, improve the thermal conductivity of the condom and improve the safety and comfort of the condom.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be noted that all of these examples are intended to further illustrate the present invention and should not be construed as limiting the present invention. The invention is not limited to the above embodiments, but may be modified and modified within the scope of the invention.

Examples 1-6 preparation of aqueous emulsions of graphene oxide free polyacids

The formulations of examples 1-6 are shown in tables 1 and 2, wherein the designations are as follows: PPG represents polyoxypropylene diol, PTMG represents polytetrahydrofuran ether diol, PDMS represents polysiloxane diol (with polysiloxane diamine), PB represents polybutadiene diol, and all the values after these symbols represent molecular weight (e.g., PTMG-2000); PNB is a poly (butadiene acrylonitrile) diol such as PNB18-1000, where 18 represents 18% by mass of acrylonitrile units and 1000 represents a molecular weight of 1000. The other symbols represent corresponding small molecules, wherein DMPA is dimethylolpropionic acid, DMBA is dimethylolbutyric acid, IPDI is isophorone diisocyanate, HDI is hexamethylene diisocyanate, H₁₂MDI is dicyclohexylmethane diisocyanate, LDI is lysine ethyl ester diisocyanate, TDI is toluene diisocyanate, and MDI is diphenylmethane diisocyanate.

TABLE 1

Note: the two hydroxyl groups of the PDMS diols used in examples 1 and 4 were at one end of the polysiloxane chain, i.e. the polysiloxane chain was a side chain; the PDMS diol used in example 3 was a linear polysiloxane diol.

TABLE 2

The process parameters for examples 1-6 are shown in Table 3. The preparation process of each example is as follows: [1] vacuum dehydration and prepolymerization reaction: uniformly mixing polyether diol and hydrophobic polymer diol or diamine in a formula amount in a reaction kettle, heating to a specified temperature, dehydrating for a certain time under a vacuum condition, cooling to the specified temperature, adding diisocyanate in the formula amount, and reacting for a certain time at the specified temperature to obtain a polyurethane prepolymer; [2] chain extension reaction: adding a micromolecule diol chain extender, a chain extender with carboxyl and a chain extender with a hydrocarbon side chain in a formula amount into the polyurethane prepolymer, keeping stirring for a certain time at a specified temperature, cooling to the specified temperature, adding an organic solvent in the formula amount for diluting, and adding tertiary amine to completely neutralize the carboxyl group in the chain extender to obtain the polyurethane prepolymer with carboxylate; [3] and (3) an emulsification process: dissolving the amine chain extender with the formula amount into water with the formula amount, slowly adding the carboxylate prepolymer into the deionized water, and stirring at a high speed of 1000 rpm for a certain time to obtain polyurethane emulsion; [4] and (3) desolventizing process: and heating the obtained polyurethane emulsion to a specified temperature, and removing the organic solvent under a vacuum condition to prepare the aqueous emulsion for preparing the polyurethane condom. The measured solids contents of the aqueous emulsions obtained are shown in tables 1 and 2.

TABLE 3

Note: the unit of temperature is; the unit of time is hours.

Examples 7 to 9 preparation of aqueous emulsion of graphene oxide-containing Polyamic acid

Graphene Oxide (GO) is added in the preparation of the aqueous emulsion of polyurethane in the embodiment, wherein 0.1 kg of GO with the sheet diameter of 0.5-0.8 mu m is added in the embodiment 7, 0.2 kg of GO with the sheet diameter of 0.1-0.4 mu m is added in the embodiment 8, and 0.5 kg of GO with the sheet diameter of 20-100 nm is added in the embodiment 9. Formulations other than GO: example 7 is the same as example 1, example 8 is the same as example 2, and example 9 is the same as example 3. The preparation processes of the embodiments 7 to 9 are the same as those of the embodiments 1 to 6, except that the emulsification process of the third step is changed as follows: [3] and (3) an emulsification process: adding the required GO into deionized water with a corresponding formula amount, performing ultrasonic dispersion to obtain a suspension, adding an amine chain extender with a formula amount into the suspension, slowly adding a prepolymer with carboxylate into the suspension, and stirring at a high speed of 1400 rpm for a certain time to obtain the polyurethane emulsion. The solid content of the prepared polyurethane aqueous emulsion is equivalent to that of the corresponding aqueous emulsion without the graphene oxide.

Examples 10-21 preparation of polyurethane condoms

In this group of examples, the aqueous emulsions of polyurethane prepared in examples 1 to 9 were used to prepare polyurethane condoms, and the required formulation amounts and preparation process parameters of graphene oxide are shown in table 4. For the embodiments 10-15, the prepared condom does not contain graphene oxide, and the preparation process comprises the following steps: in examples 11 and 12, no dilution is needed, and in examples 10 and 13 to 16, deionized water is used for firstly diluting the original polyurethane aqueous emulsion to the required concentration; ultrasonically cleaning a glass mold in ethanol for 10 minutes and drying; secondly, immersing the glass mold into polyurethane aqueous emulsion for a specified time, taking out, and then carrying out stage heating and drying, wherein the process parameters are shown in a table 4; for examples 13 and 15, the stage was heated to 80 ℃ and dried, then dipped again in the aqueous polyurethane emulsion and heated again to dry. And finally, curling the coated polyurethane film to a proper position, cooling to room temperature, soaking anti-sticking white carbon black, completely curling and demolding, drying under the vacuum condition of-0.09 MPa, cooling to room temperature, adding medical silicone oil, and packaging to obtain a finished condom product. For examples 16-18, the aqueous polyurethane emulsion used itself contained the required graphene oxide, wherein in example 16, the raw water emulsion was diluted with deionized water; the condom was prepared in the same manner as in examples 10 to 12 (see Table 4). In examples 19 to 21, the preparation method was to ultrasonically disperse the amount of graphene oxide in the required diluted deionized water, and then to dilute the corresponding emulsion with the deionized water containing graphene oxide; the resulting emulsion was used to prepare condoms by the same method as in examples 13 to 15 (see Table 4)

TABLE 4

Note: band is the solid content of the original emulsion after dilution.

The properties of the resulting condom are shown in Table 5. As can be seen from Table 5, the strength of the prepared condom is more than twice that of the latex condom (the latex is generally 10-15 MPa), and the 100% modulus (flexibility) is close to that of the latex condom (about 0.7 MPa). Therefore, the condom obtained by the invention maintains the characteristics of ultrathin and high strength of the polyurethane condom and has the flexibility close to that of a latex condom. Further, it can be seen that when the sheet diameter of graphene oxide is less than 100nm and the amount of the formula is 0.01 to 0.1 parts by weight (examples 19 to 21), the strength of the condom is hardly reduced or even increased by the added graphene oxide, the elongation of the film is increased, and the constant modulus at 100% is not significantly changed.

TABLE 5

Claims

1. A preparation method of a water emulsion of polyurethane modified by a hydrocarbon side chain is characterized by comprising the following steps in parts by weight:

1) firstly, uniformly mixing 50-65 parts of polyether glycol and 3-20 parts of hydrophobic polymer glycol or diamine in a reaction kettle, stirring and heating to 100-120 ℃, dehydrating under the vacuum condition of less than-0.09 MPa for 1-4 hours, cooling to 60-80 ℃, then adding 15-30 parts of diisocyanate, and stirring at 100-110 ℃ for 1-3 hours to obtain a polyurethane prepolymer; wherein the hydrophobic polymeric diamine is a polysiloxane diamine; the hydrophobic polymer diol is at least one of polysiloxane diol, polybutadiene diol and polybutadiene acrylonitrile diol, wherein the mass percentage of acrylonitrile chain units is 1-40%; the polyether diol is a mixture of polyoxypropylene diol and polytetrahydrofuran ether diol, wherein the mass percentage of the polyoxypropylene diol is 20-80%;

2) adding 0-2 parts of a small-molecular-weight diol chain extender, 3-6 parts of a chain extender with carboxyl and 1.5-6 parts of a chain extender with a hydrocarbyl side chain into the polyurethane prepolymer, stirring for 1-3 hours at 80-110 ℃, cooling to 40-60 ℃, adding 50-120 parts of an organic solvent for dilution, and adding a tertiary amine to completely neutralize the carboxyl group in the chain extender to obtain a polyurethane prepolymer with carboxylate; the tertiary amine is at least one of triethylamine, methyl diethylamine and triethanolamine; the organic solvent is at least one of acetone, methyl ethyl ketone, tetrahydrofuran and acetonitrile; the micromolecular diol chain extender is aliphatic dihydric alcohol with carbon atoms of 2-6, and can contain methyl and/or ethyl side chains; the chain extender with carboxyl is at least one of dimethylolpropionic acid and dimethylolbutyric acid; the chain extender with a hydrocarbyl side chain contains at least one hydrocarbyl chain with 3 or more carbon atoms;

3) ultrasonically dispersing 0-0.5 part of graphene oxide in 150-400 parts of deionized water, adding 0.5-3 parts of amine chain extender into the deionized water, slowly pouring the polyurethane prepolymer with carboxylate obtained in the step 2) into the deionized water, and stirring for 2-4 hours to obtain a polyurethane emulsion; the sheet diameter of the graphene oxide is lower than 1 micron;

4) heating the polyurethane emulsion obtained in the step 3) to 40-60 ℃, and removing the organic solvent under a vacuum condition to obtain the alkyl side chain modified polyurethane aqueous emulsion.

2. The production method according to claim 1, wherein the polyoxypropylene diol is contained in an amount of 30 to 40% by mass.

3. The method according to claim 1, wherein the diisocyanate is at least one selected from isophorone diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, lysine ethyl ester diisocyanate, toluene diisocyanate, and diphenylmethane diisocyanate.

4. The preparation method according to claim 1, wherein the amine chain extender is aliphatic diamine with 2 to 6 carbon atoms, or lysine, or gamma-aminoethylaminopropyl trialkoxysilane, and the alkoxy is methoxy or ethoxy.

5. The preparation method according to claim 1, wherein the chain extender having a hydrocarbon-based side chain is trimethylolpropane monofatty acid ester, wherein the number of carbon atoms in the fatty acid chain is 4 to 20; or N-alkyl diethanol amine, wherein the carbon atom number of an alkyl chain is 3-20; or 2-alkyl-1, 3-propanediol or 2, 2-dialkyl-1, 3-propanediol, wherein the carbon number of the alkyl chain is 3-20.

6. The aqueous emulsion of polyurethane prepared by the method according to any one of claims 1 to 5.

7. A preparation method of a water-based polyurethane condom is characterized by comprising the following steps:

(1) firstly, diluting or not diluting the aqueous emulsion of polyurethane as claimed in claim 6 to ensure that the solid content is 10-30%;

(2) ultrasonically cleaning a glass mold in ethanol for 10 minutes and drying;

(4) curling the coated polyurethane film to a proper position, cooling to room temperature, soaking an anti-sticking agent or anti-sticking powder, completely curling and demolding, drying at 80-120 ℃ for 10-20 minutes under the vacuum condition of less than-0.09 MPa, cooling to room temperature, adding medical silicone oil, and packaging to obtain a condom finished product.

8. The method according to claim 7, further comprising diluting the aqueous polyurethane emulsion by: adding 0-0.5 part of graphene oxide into deionized water, and carrying out ultrasonic dispersion to dilute the polyurethane aqueous emulsion; wherein the graphene oxide has a platelet size of less than 1 micron.

9. The method according to claim 8, wherein the graphene oxide has a sheet diameter of less than 100 nm.

10. A condom prepared by the method according to any one of claims 7 to 9.