A polyurethane female sheath containing an inbuilt ring push rod and a method of making the same

Abstract

The application relates to the field of medical polymer material modification, in particular to a medical catheter sleeve body with an extremely low friction coefficient and a preparation method thereof; the core content is as follows: high-performance wet-state lubrication: in a simulated body fluid environment, the wet-state friction coefficient of the sleeve body surface is reduced from the unmodified to the modified, and the reduction amplitude is more than 50%; long-term stability: a hydration lubricating layer is constructed through covalent bond anchoring technology, and after 1000 times of continuous reciprocating friction test, the friction coefficient does not increase significantly, and excellent anti-loss and durability are shown; through excellent self-lubricating performance, the application effectively solves the problem of mucosa damage possibly caused by the catheter in the use process; through chemical modification at the molecular level, efficient wear reduction and long-term stability of the lubricating coating are realized, the interventional damage is reduced, and the safety of the medical equipment is improved.

Description

Technical Field

[0001] This invention relates to the field of medical devices and medical polymer materials technology, specifically to a polyurethane women's sleeve with a built-in ring push rod and its preparation method. Background Technology

[0002] Existing female condoms have two major technical shortcomings in clinical and daily use:

[0003] Instrument structural defects: Traditional female condoms have a simple internal positioning ring structure, which is significantly obstructed when inserted deep into the vagina. They often require additional tools or fingers to apply additional axial load for insertion, which can easily lead to slippage and cause a foreign body sensation under reciprocating friction load. If a hard plastic push rod is used, although it is easy to insert, it cannot conform to the physiological curve and poses a safety hazard of puncturing the vaginal fornix mucosa.

[0004] Material performance defects: Currently, the surface of mainstream natural latex or ordinary polyurethane materials lacks the hydration and lubrication of natural mucous membranes, resulting in a high coefficient of friction. The lack of surface lubrication can easily lead to micro-damage to the mucous membrane, increasing the risk of viral infection. Although this can often be alleviated by applying lubricants such as silicone oil, the physically attached lubricant is easily washed away in the context of intense friction and high humidity. Furthermore, silicone oil residue can easily disrupt the vaginal microecological balance. Summary of the Invention

[0005] The purpose of this invention is to provide a polyurethane female condom with a built-in ring push rod and its preparation method, aiming to improve the problems of existing female condoms, such as difficulty in insertion, rigid push rods that cannot conform to physiological curves and easily damage the mucosa, and lack of hydration lubrication on the condom surface leading to easy lubricant loss, high coefficient of friction, and easy disruption of the vaginal microecology. By integrating the temperature-sensitive shape memory push rod with self-lubricating waterborne polyurethane, convenient insertion, body temperature softening and conformation, and long-lasting stable lubrication are achieved.

[0006] To achieve the above objectives, the core technical solution of this invention is as follows: a women's condom is provided, which is integrally formed from a polyurethane sleeve and a built-in ring push rod; wherein, the sleeve is made of waterborne polyurethane containing a specific sulfonic acid inner salt zwitterionic structure and polydimethylsiloxane segments, and the surface achieves long-term hydration and self-lubrication through covalent bonding; the built-in ring push rod is made of temperature-sensitive shape memory polyurethane with polycaprolactone diol as the soft segment and a specific diisocyanate and chain extender as the hard segment, and has a crystallization phase transition temperature of 35℃-37℃, realizing a dynamic mechanical transformation of high rigidity at room temperature and easy insertion, and softening and fitting at body temperature.

[0007] The present invention has the following beneficial effects: under simulated body fluid wetting, the wet friction coefficient of the sleeve surface is reduced to 0.03; after 1000 continuous reciprocating friction tests, the friction coefficient does not increase significantly, proving that the hydrated lubricating layer is anchored by covalent bonds and has long-term anti-leakage properties; dynamic thermomechanical analysis shows that the bending modulus of the push rod at 25°C is 185MPa; after immersion in a 37°C water bath for 60s, the bending modulus is significantly reduced to 8.5MPa, automatically softening and fitting with body temperature, effectively reducing the feeling of foreign objects, and has good physical barrier and mechanical properties. Attached Figure Description

[0008] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be conventionally introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0009] Figure 1 This is a flowchart illustrating a polyurethane women's sleeve with a built-in ring push rod and its preparation method according to the present invention. Detailed Implementation

[0010] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0011] Example 1:

[0012] Please see Figure 1 This embodiment provides a polyurethane women's sleeve with a built-in ring push rod, specifically including the following steps:

[0013] Synthesis of S1, 3-(di(2-hydroxyethyl)methylammonium)propane-1-sulfonic acid inner salt: 0.10 mol N-methyldiethanolamine was dissolved in 100 mL anhydrous acetone and placed in a three-necked flask equipped with a condenser and a constant-pressure dropping funnel. The mixture was deoxygenated for 30 min under nitrogen protection. 0.11 mol 1,3-propanesulfonic acid lactone was dissolved in 50 mL anhydrous acetone and added dropwise to the above system over 1 h. After the addition was complete, the temperature was raised to 65 °C and refluxed for 24 h. The reaction solution was cooled to room temperature and filtered. The resulting white precipitate was washed three times with anhydrous acetone and dried under vacuum at 50 °C for 24 h to obtain 3-(di(2-hydroxyethyl)methylammonium)propane-1-sulfonic acid inner salt with a yield of 88%. The purity was determined to be greater than 99.0% by high-performance liquid chromatography. Infrared spectroscopy characterization showed that the precipitate was 1040 nm. The characteristic absorption peak of sulfonic acid group appeared at the position, and the 1H NMR spectrum confirmed that its structure was as expected.

[0014] S2. Preparation of Temperature-Sensitive Shape Memory Polyurethane Propeller: 100 parts by weight of polycaprolactone diol with a number average molecular weight of 2500 were vacuum dehydrated at 110℃ for 2 hours; the temperature was lowered to 80℃, and 13.6 parts by weight of hexamethylene diisocyanate and 0.05 parts by weight of bismuth isooctanoate were added, and the reaction was carried out for 2 hours to obtain a prepolymer. This prepolymer provides stable urethane base segments with terminal isocyanate groups for subsequent chain extension reactions; 3.6 parts by weight of 1,4-butanediol were added to the prepolymer, and after high-speed stirring for 3 minutes, it was poured into a polytetrafluoroethylene mold and cured at 100℃ for 12 hours; after the cured material was crushed and granulated, it was molded using an injection molding machine with the barrel temperature controlled at 170℃ to obtain an integrated built-in ring propeller with a ring part and a push rod part; differential scanning calorimetry test showed that the material's crystallization phase transition temperature was 36.2℃;

[0015] S3. Preparation of waterborne polyurethane emulsion: 80 parts by mass of polycarbonate diol with a number average molecular weight of 2000 and 20 parts by mass of hydroxyl-terminated polydimethylsiloxane with a number average molecular weight of 1000 were mixed and vacuum dehydrated at 75°C for 1.5 h; 35 parts by mass of isophorone diisocyanate and 0.05 parts by mass of bismuth isooctanoate were added and reacted at 75°C for 2 h to obtain a prepolymer. This prepolymer imparts lower surface energy and excellent flexibility to the subsequent film-forming material by introducing siloxane segments into the main chain.

[0016] Eight parts by mass of 3-(bis(2-hydroxyethyl)methylammonium)propane-1-sulfonic acid inner salt and three parts by mass of dimethylolpropionic acid obtained in step S1 were added to the prepolymer, and the reaction was continued at 80°C for 3 hours. After cooling to 40°C, 2.2 parts by mass of triethylamine were added for neutralization, and 183 parts by mass of deionized water were slowly added at 3000 rpm to form a phase inversion emulsion. Then, 1.6 parts by mass of ethylenediamine were added for aqueous chain extension, and acetone was removed under reduced pressure to obtain an aqueous polyurethane emulsion with a solid content of 45 wt%.

[0017] S4. Integrated Molding: The built-in ring push rod obtained in step S2 is fitted into the positioning groove at the top of the glass molding mold for the women's sleeve; the surface of the molding mold and the push rod is treated with low-pressure oxygen plasma at a power of 50W for 60s; the treated mold is vertically immersed in the water-based polyurethane emulsion obtained in step S3, pulled up at a speed of 80mm / min, and dried sequentially in gradient ovens at 80℃, 90℃, and 100℃ to form a film; the immersion and drying are repeated 3 times to achieve a sleeve wall thickness of 0.05mm; after curing at 120℃ for 30min, the mold is removed to obtain the target product.

[0018] Example 2:

[0019] This embodiment provides a polyurethane women's sleeve with a built-in ring push rod, specifically including the following steps:

[0020] Synthesis of S1, 3-(di(2-hydroxyethyl)methylammonium)propane-1-sulfonic acid inner salt: The molar ratio of N-methyldiethanolamine to 1,3-propanesulfonic acid lactone was controlled at 1:1.0; the reflux temperature was 60°C, the reflux time was 20 h, the drying temperature was 45°C, the drying time was 20 h, and the remaining operations were the same as in Example 1.

[0021] S2. Preparation of Temperature-Sensitive Shape Memory Polyurethane Propeller: 100 parts by weight of polycaprolactone diol with a number average molecular weight of 2000 were vacuum dehydrated at 105℃ for 1.5h; 14.2 parts by weight of hexamethylene diisocyanate and 0.04 parts by weight of bismuth isooctanoate were added, and the mixture was reacted at 75℃ for 1.5h to obtain a prepolymer. This prepolymer provides stable urethane-based segments with terminal isocyanate groups for subsequent chain extension reactions; 4.0 parts by weight of 1,4-butanediol were added, mixed, and cured at 95℃ for 10h; the cured material was pulverized, granulated, and then injection molded at a barrel temperature of 160℃; the crystallization phase transition temperature of the obtained temperature-sensitive shape memory polyurethane was 35.1℃.

[0022] S3. Preparation of waterborne polyurethane emulsion: 90 parts by weight of polycarbonate diol with a number average molecular weight of 1800 and 10 parts by weight of hydroxyl-terminated polydimethylsiloxane with a number average molecular weight of 800 were mixed and dehydrated. 33 parts by weight of isophorone diisocyanate were added and reacted at 70°C for 1.5 h to obtain a prepolymer. This prepolymer, by introducing siloxane segments into the main chain, endows the subsequent film-forming material with lower surface energy and excellent flexibility. 6 parts by weight of 3-(di(2-hydroxyethyl)methylammonium)propane-1-sulfonic acid inner salt and 2 parts by weight of dimethylolpropionic acid were added to the prepolymer and reacted at 75°C for 2.5 h. Neutralization, phase inversion emulsification, and ethylenediamine aqueous chain extension were carried out according to Example 1, controlling the emulsion solid content to be 40 wt%.

[0023] S4. Integrated molding plasma treatment power 40W, treatment time 50s; impregnation and drying repeated twice, gradient drying temperature 80℃, 88℃, 95℃, film wall thickness controlled at 0.04mm; curing temperature 115℃, time 25min.

[0024] Example 3:

[0025] This embodiment provides a polyurethane women's sleeve with a built-in ring push rod, specifically including the following steps;

[0026] Synthesis of S1, 3-(di(2-hydroxyethyl)methylammonium)propane-1-sulfonic acid inner salt: The molar ratio of N-methyldiethanolamine to 1,3-propanesulfonic acid lactone was controlled at 1:1.2; the reflux temperature was 70°C, the reflux time was 28 h, the drying temperature was 55°C, the drying time was 28 h, and the remaining operations were the same as in Example 1.

[0027] S2. Preparation of Temperature-Sensitive Shape Memory Polyurethane Propeller: 100 parts by weight of polycaprolactone diol with a number average molecular weight of 3000 were vacuum dehydrated at 115℃ for 2.5h; 12.8 parts by weight of hexamethylene diisocyanate and 0.05 parts by weight of bismuth isooctanoate were added, and the mixture was reacted at 85℃ for 2.5h; 3.2 parts by weight of 1,4-butanediol were added, and the mixture was mixed and shaped, and cured at 105℃ for 14h; after pulverization and granulation, it was injection molded at a barrel temperature of 180℃; the crystallization phase transition temperature of the obtained temperature-sensitive shape memory polyurethane was 36.8℃.

[0028] S3. Preparation of waterborne polyurethane emulsion: 70 parts by weight of polycarbonate diol with a number average molecular weight of 2200 and 30 parts by weight of hydroxyl-terminated polydimethylsiloxane with a number average molecular weight of 1200 were mixed and dehydrated; 36 parts by weight of isophorone diisocyanate were added and reacted at 80℃ for 2.5 h; 10 parts by weight of 3-(di(2-hydroxyethyl)methylammonium)propane-1-sulfonic acid inner salt and 3 parts by weight of dimethylolpropionic acid were added and reacted at 85℃ for 3.5 h; after neutralization, reverse emulsification was performed, and ethylenediamine was added for chain extension, controlling the solid content of the emulsion to be 50 wt%.

[0029] S4. Integrated molding plasma treatment power 60W, treatment time 70s; impregnation and drying repeated 3 times, gradient drying temperature 85℃, 93℃, 100℃, film wall thickness controlled at 0.06mm; curing temperature 125℃, time 35min.

[0030] Example 4:

[0031] This embodiment provides a polyurethane women's sleeve with a built-in ring push rod, specifically including the following steps;

[0032] Synthesis of S1,3-(bis(2-hydroxyethyl)methylammonium)propane-1-sulfonic acid inner salt: The molar ratio of N-methyldiethanolamine to 1,3-propanesulfonic acid lactone was 1:1.1, the reflux temperature was 66℃, the reflux time was 24h, the drying temperature was 50℃, and the drying time was 24h.

[0033] S2. Preparation of Temperature-Sensitive Shape Memory Polyurethane Propeller: 100 parts by weight of polycaprolactone diol with a number-average molecular weight of 2800 were vacuum dehydrated at 110℃ for 2 hours; 13.0 parts by weight of hexamethylene diisocyanate and 0.05 parts by weight of bismuth isooctanoate were added, and the mixture was reacted at 80℃ for 2 hours; 3.4 parts by weight of 1,4-butanediol were added, and the mixture was cured at 100℃ for 12 hours; after pulverization and granulation, the mixture was injection molded at a barrel temperature of 170℃; the crystallization phase transition temperature of the obtained temperature-sensitive shape memory polyurethane was 35.9℃.

[0034] S3. Preparation of waterborne polyurethane emulsion: 85 parts by weight of polycarbonate diol with a number average molecular weight of 2000 and 15 parts by weight of hydroxyl-terminated polydimethylsiloxane with a number average molecular weight of 1000 were mixed and dehydrated; 34 parts by weight of isophorone diisocyanate were added and reacted at 75°C for 2 hours; 9 parts by weight of 3-(di(2-hydroxyethyl)methylammonium)propane-1-sulfonic acid inner salt and 3 parts by weight of dimethylolpropionic acid were added and reacted at 80°C for 3 hours; neutralization, phase inversion emulsification and ethylenediamine chain extension were carried out according to Example 1, and the solid content of the emulsion was controlled at 46 wt%.

[0035] S4. Integrated molding plasma treatment power 50W, treatment time 60s; impregnation and drying repeated 3 times, gradient drying temperature 80℃, 90℃, 100℃, film wall thickness controlled at 0.05mm; curing temperature 120℃, time 30min.

[0036] Comparative Example 1:

[0037] The difference between this comparative example and Example 1 is that: in step S3, 3-(di(2-hydroxyethyl)methylammonium)propane-1-sulfonic acid inner salt is not added, but is replaced by an equal mass of 1,4-butanediol; the other operating steps and process parameters are exactly the same as in Example 1.

[0038] Comparative Example 2:

[0039] The difference between this comparative example and Example 1 is that: in step S3, hydroxyl-terminated polydimethylsiloxane is not added, but is replaced by an equal mass of polycarbonate diol; the other operating steps and process parameters are exactly the same as in Example 1.

[0040] Comparative Example 3:

[0041] The difference between this comparative example and Example 1 is that in step S2, polycaprolactone diol with a number average molecular weight of 2500 is replaced with polycaprolactone diol with a number average molecular weight of 1500. Other operating steps and process parameters are exactly the same as in Example 1. The crystallization phase transition temperature of this temperature-sensitive shape memory polyurethane is 31.4℃.

[0042] Comparative Example 4:

[0043] The difference between this comparative example and Example 1 is that the plasma activation treatment of the molding die and the surface of the built-in ring push rod is omitted in step S4, while the other operation steps and process parameters are exactly the same as in Example 1.

[0044] Comparative Example 5:

[0045] The difference between this comparative example and Example 1 is that in step S2, polycaprolactone diol with a number average molecular weight of 2500 is replaced with polycaprolactone diol with a number average molecular weight of 4000. Other operating steps and process parameters are exactly the same as in Example 1. The crystallization phase transition temperature of this temperature-sensitive shape memory polyurethane is 39.8℃.

[0046] Performance Testing and Data Sheet: The wet friction coefficient was measured using a reciprocating tribometer. Samples were equilibrated in phosphate buffer at 37℃ for 30 min before testing. The normal load was 1 N, the reciprocating stroke was 10 mm, and the frequency was 1 Hz. The stable friction coefficient was recorded after 1000 cycles. Protein adsorption was determined using the fluorescein isothiocyanate-labeled bovine serum albumin method, with the adsorption amount on the surface of Comparative Example 1 sample set to 100% for relative calculation. The bending modulus of the push rod was measured using dynamic thermomechanical analysis in a three-point bending mode at 25℃ and 37℃. The interfacial peel strength was tested using the 180° peel method. The tensile strength of the sleeve was tested according to the thin film tensile method in ISO 23409.

[0047] Comparing the test results of Example 1 and Comparative Example 1 in the table, it can be seen that after omitting the 3-(bis(2-hydroxyethyl)methylammonium)propane-1-sulfonic acid inner salt, the initial wet friction coefficient increased from 0.03 to 0.42, the wet friction coefficient after 1000 cycles increased from 0.04 to 0.46, and the relative protein adsorption increased from 4% to 100%.

[0048] The underlying mechanism is that the zwitterionic groups in the inner salt of 3-(bis(2-hydroxyethyl)methylammonium)propane-1-sulfonic acid can form a stable hydration layer on the material surface. This hydration layer relies on the strong binding between the ionic groups and water molecules to maintain boundary lubrication and inhibit the non-specific adsorption of proteins. If this feature is omitted, only ordinary polyurethane segments are retained on the surface of the sleeve, the surface water content decreases, it is difficult to maintain a stable lubrication interface during friction, and proteins are more likely to deposit on the material surface. Therefore, the wet lubricity and anti-biofouling performance are significantly reduced.

[0049] Comparing the test results of Example 1 and Comparative Example 2 in the table, it can be seen that after omitting the polydimethylsiloxane chain segment, the initial wet friction coefficient increased from 0.03 to 0.11, the wet friction coefficient after 1000 cycles increased from 0.04 to 0.15, and the tensile strength of the sleeve decreased from 38 MPa to 32 MPa.

[0050] The underlying mechanism is that the polydimethylsiloxane segments have low surface energy and high segment flexibility, which can reduce the shear resistance of the polyurethane film surface and improve the soft segment movement capability; without this segment, the surface energy of the material increases, the molecular chain flexibility weakens, and the wet contact friction resistance increases.

[0051] Meanwhile, the stress dispersion ability of the sleeve decreases during the stretching process, resulting in a decrease in mechanical properties; the protein adsorption amount in this comparative example remains at a low level, indicating that the anti-protein adsorption is mainly contributed by zwitterionic segments, while the low surface friction coefficient also requires the coordination of polydimethylsiloxane segments.

[0052] Comparing the test results of Example 1 and Comparative Example 3 in the table, it can be seen that after reducing the number-average molecular weight of polycaprolactone diol in the soft segment of the push rod from 2500 to 1500, the flexural modulus at 25°C decreased from 185 MPa to 62 MPa, and the flexural modulus at 37°C decreased to 5.6 MPa. The underlying mechanism is that the lower molecular weight of polycaprolactone diol has lower crystallinity, resulting in a reduction in the number of reversible crystalline regions, which leads to insufficient physical cross-linking points at room temperature, and the material already shows significant softening at 25°C. This change does not directly affect the wet friction and protein adsorption of the sleeve, so the relevant data are similar to those of Example 1. However, the support capacity of the push rod during insertion decreases, which is not conducive to stably delivering the sleeve to the target position.

[0053] A comparison of the test results of Example 1 and Comparative Example 4 in the table shows that, omitting the plasma activation treatment, the interfacial peel strength decreased from 6.8. Dropped to 1.9 The tensile strength of the sleeve decreased from 38 MPa to 28 MPa. The underlying mechanism is that plasma treatment can increase the polar group density and surface roughness of the propeller surface, which is beneficial for the spread of waterborne polyurethane emulsion on its surface during impregnation and film formation, and enhances the hydrogen bonding and molecular chain entanglement at the interface. After omitting this step, the surface activity of the propeller is insufficient, and the interface bonding mainly relies on limited physical contact, which makes the integrated part prone to interface peeling under stress, thus reducing the overall mechanical stability.

[0054] As can be seen from the comparison of the test results of Example 1 and Comparative Example 5 in the table, after increasing the number-average molecular weight of polycaprolactone diol in the soft segment of the push rod from 2500 to 4000, the flexural modulus at 25°C increased from 185MPa to 210MPa, while the flexural modulus at 37°C was still as high as 42MPa.

[0055] The underlying mechanism is that polycaprolactone diol with excessively high molecular weight has a stronger tendency to crystallize, resulting in an increase in the crystallization phase transition temperature to 39.8℃. Under body temperature conditions, the crystalline region in the push rod is not fully melted, and the modulus difference between room temperature and body temperature is reduced. The material still maintains a large flexural modulus after entering the body. This change will not significantly affect the lubrication performance of the sleeve and the interfacial bonding strength, but it will weaken the smooth and conforming ability of the push rod in use.

[0056] The comparison of the test results of Examples 1 and Examples 2 to 4 in the table shows that by adjusting the molecular weight, content and molding parameters of each component within a limited range, the samples all maintain a low wet friction coefficient, a low protein adsorption amount and a significant change in temperature-sensitive modulus. This indicates that the limited material composition and process window can stably achieve the synergistic effect of self-lubrication of the sleeve and temperature-sensitive softening of the push rod.

[0057] A detailed comparison of the effect data between different constant values ​​within each range shows that when the plasma treatment power varies between 40W and 60W, Example 3 uses 60W power, and its interface peel strength is 6.2. Example 2, using 40W power, achieved an interfacial peel strength of 5.9. This indicates that higher power can further increase the density of polar groups on the surface and enhance interfacial bonding; when the amount of 3-(bis(2-hydroxyethyl)methylammonium)propane-1-sulfonic acid inner salt varies from 6 to 10 parts by mass, the relative protein adsorption amount in Example 3 is 6%, while the relative protein adsorption amount in Example 2 is 8%, indicating that increasing the content of zwitterionic groups can further improve the surface hydration layer and reduce non-specific protein adsorption.

[0058] Furthermore, in Example 2, the amount of dimethylolpropionic acid was adjusted to 2 parts by mass and bismuth isooctanoate was adjusted to 0.04 parts by mass. Compared with 3 parts by mass and 0.05 parts by mass in Example 1, the emulsion solid content and film-forming properties remained good, indicating that the hydrophilicity and catalytic efficiency of the waterborne polyurethane could be guaranteed within this dosage range. Example 4 used intermediate parameters, and the overall performance was close to that of Example 1. The above results show that the component ratio and process conditions used in Example 1 have a good overall balance within the scope of protection of this application.

[0059] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments for application in other fields. However, any conventional modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the technical solution of the present invention shall still fall within the protection scope of the technical solution of the present invention.

Claims

1. A polyurethane women's sleeve with a built-in ring push rod, comprising a polyurethane sleeve body and a built-in ring push rod; The polyurethane sleeve has an open end and a closed end; The built-in ring push rod is fixedly disposed inside the polyurethane sleeve near the closed end, and the built-in ring push rod includes an annular part and a push rod part extending from the annular part; Its features are, The polyurethane sleeve is made of waterborne polyurethane material, wherein the polyurethane main chain of the waterborne polyurethane material contains 3-(di(2-hydroxyethyl)methylammonium)propane-1-sulfonic acid inner salt structural unit and polydimethylsiloxane segment. The built-in ring push rod is made of temperature-sensitive shape memory polyurethane material, the soft segment of which is polycaprolactone diol with a number average molecular weight between 2000 and 3000, and the crystallization phase transition temperature of which is 35℃-37℃.

2. The polyurethane women's sleeve with a built-in ring push rod according to claim 1, characterized in that, The 3-(bis(2-hydroxyethyl)methylammonium)propane-1-sulfonic acid inner salt is covalently linked to the polyurethane backbone of the waterborne polyurethane material via urethane bonds.

3. The polyurethane women's sleeve with a built-in ring push rod according to claim 1, characterized in that, The built-in ring push rod has a bending modulus greater than 150 MPa at 25°C and a bending modulus less than 10 MPa at 37°C.

4. The polyurethane women's sleeve with a built-in ring push rod according to claim 1, characterized in that, The rigid segments of the temperature-sensitive shape memory polyurethane material are composed of hexamethylene diisocyanate and 1,4-butanediol.

5. A method for preparing a polyurethane women's sleeve with a built-in ring push rod as described in any one of claims 1-4, characterized in that, The specific steps are as follows: Synthesis of S1, 3-(bis(2-hydroxyethyl)methylammonium)propane-1-sulfonic acid inner salt: N-methyldiethanolamine was dissolved in anhydrous acetone. After deoxygenation by passing an inert gas through the solution, an anhydrous acetone solution of 1,3-propanesulfonic acid lactone was added dropwise. The mixture was heated to reflux to undergo a ring-opening quaternization reaction. After the reaction was completed, the precipitate was collected, washed, and dried under vacuum to obtain 3-(bis(2-hydroxyethyl)methylammonium)propane-1-sulfonic acid inner salt. S2. Preparation of temperature-sensitive shape memory polyurethane push rod: Polycaprolactone diol is dehydrated under vacuum, and then a first diisocyanate is added and reacted with a first catalyst to obtain a prepolymer; then a small molecule diol chain extender is added, and the mixture is stirred and cured; the cured product is crushed, granulated, and injection molded to obtain the built-in ring push rod; S3. Synthesis of waterborne polyurethane emulsion: After dehydration of macromolecular diol and hydroxyl-terminated polydimethylsiloxane, a second diisocyanate and a second catalyst are added to react and obtain a prepolymer; then, the 3-(di(2-hydroxyethyl)methylammonium)propane-1-sulfonic acid inner salt and dimethylolpropionic acid obtained in step S1 are added to continue the reaction; after the reaction is completed, the temperature is lowered, a neutralizing agent is added for neutralization, and then deionized water is added under high-speed shearing to perform reverse emulsification; finally, an amine chain extender is added to perform aqueous chain extension, and the solvent is removed to obtain a waterborne polyurethane emulsion. S4. Integrated molding: The built-in ring push rod obtained in step S2 is fitted into the top positioning groove of the molding die; The surfaces of the molding die and the built-in ring push rod are subjected to plasma activation treatment; then the molding die with the built-in ring push rod is immersed in the aqueous polyurethane emulsion obtained in step S3, and after lifting and gradient drying to form a film, it is demolded after curing to obtain the polyurethane women's sleeve containing the built-in ring push rod.

6. The method according to claim 5, characterized in that, In step S1, the molar ratio of N-methyldiethanolamine to 1,3-propanesulfonic acid lactone is 1:(1 1.2); The reflux temperature is 55-60℃ and the time is 20-28h; The vacuum drying temperature is 45-55℃ and the time is 20-28h.

7. The method according to claim 5, characterized in that, In step S2, the vacuum dehydration temperature is 105-115℃ and the time is 1.5-2.5h; the reaction temperature for preparing the prepolymer is 75-85℃ and the reaction time is 1.5-2.5h. The small molecule diol chain extender is 1,4-butanediol, the first diisocyanate is hexamethylene diisocyanate, and the first catalyst is bismuth isooctanoate. The curing temperature is 95-105℃, and the curing time is 10-14h; the barrel temperature for injection molding is 160-180℃.

8. The method according to claim 5, characterized in that, In step S3, the macromolecular diol is a polycarbonate diol with a number average molecular weight between 1800 and 2200, and the hydroxyl-terminated polydimethylsiloxane has a number average molecular weight between 800 and 1200. The mass ratio of the macromolecular diol to the hydroxyl-terminated polydimethylsiloxane is (7:3). (9:1); The reaction temperature for preparing the prepolymer is 70-80℃, and the reaction time is 1.5-2.5h; the reaction temperature after adding the 3-(di(2-hydroxyethyl)methylammonium)propane-1-sulfonic acid inner salt and the dimethylolpropionic acid is 75-85℃, and the reaction time is 2.5-3.5h; the amount of the 3-(di(2-hydroxyethyl)methylammonium)propane-1-sulfonic acid inner salt added accounts for 6-10 wt% of the total solids mass of the waterborne polyurethane emulsion. The second diisocyanate is isophorone diisocyanate, the second catalyst is bismuth isooctanoate; the neutralizing agent is triethylamine, the amine chain extender is ethylenediamine; and the solid content of the waterborne polyurethane emulsion is 40-50 wt%.

9. The method according to claim 5, characterized in that, In step S4, the conditions for plasma activation treatment are: power 40-60W, treatment time 50-70s; The temperature range for gradient drying is 80℃-100℃; the step of immersing the molding die with the built-in ring push rod into the aqueous polyurethane emulsion and gradient drying to form a film is repeated 2-3 times until the film wall thickness reaches 0.04-0.06mm. The ripening temperature is 115-125℃ and the time is 25-35 minutes.

Images