Preparation method and application of a dual-temperature response polyethylene glycol-siloxane copolymer pressure-sensitive adhesive film

Abstract

The application discloses a preparation method and application of a double-temperature response type polyethylene glycol-siloxane copolymer pressure-sensitive adhesive film, and the pressure-sensitive adhesive film is formed by crosslinking and curing of a thermal response type polyethylene glycol-siloxane copolymer prepolymer, a trimethylolpropane triacrylate crosslinking agent and a chitosan tackifier.The application has the advantages of simple process and easy operation, and the prepared adhesive film can be firmly adhered to the skin at normal human body temperature (37 DEG C) to meet the medical fixing requirement; the adhesion force can be obviously reduced at high temperature (60 DEG C) or low temperature (0 DEG C), quick and painless peeling is realized, and the adhesive film can be adapted to various substrates.The prepared adhesive film can be used for wound closure, medical dressing fixing or biological sensing patch sticking.

Description

Technical Field

[0001] This invention relates to a method for preparing and applying a temperature-responsive polyethylene glycol-siloxane copolymer pressure-sensitive adhesive film. It belongs to the field of polymer composite materials technology. Background Technology

[0002] Medical pressure-sensitive adhesives (PSAs) are a class of medical materials that adhere firmly to the skin with only slight finger pressure and leave no residue after removal. They are indispensable in epidermal medical applications and are widely used in wound dressings, medical tapes, catheter fixation devices, and wearable biosensor devices. An ideal medical pressure-sensitive adhesive needs to achieve a balance of multiple properties in the complex physiological environment of the human body: First, it must provide durable and reliable adhesion to both dry and moist skin at body temperature (approximately 37°C); second, removal should minimize patient pain and avoid secondary physical damage to newly formed tissue; third, the material itself must possess excellent biocompatibility and be non-irritating to the skin; and fourth, it must withstand high-humidity environments created by wound exudate and sweat to prevent adhesion failure due to water absorption.

[0003] Although existing medical pressure-sensitive adhesives are superior to traditional medical adhesive materials in terms of convenience, safety, and aesthetics, there are still core technical bottlenecks that need to be overcome: on the one hand, mainstream products are prone to adhesion failure in moist wound environments due to the formation of an interfacial water film, making them difficult to adapt to the care needs of exudative wounds or open wounds; on the other hand, removal often causes severe pain or even tissue damage to patients due to excessive adhesive force or adhesion to newly formed tissue, seriously affecting the clinical user experience.

[0004] To address the critical pain point of "painless removal," stimulus-responsive smart pressure-sensitive adhesives have become a cutting-edge research direction in this field. Among them, thermo-induced release pressure-sensitive adhesives have shown significant application potential due to their advantages such as convenient control and manageable response. The core characteristic of this type of stimulus-responsive material is that it can maintain stable interfacial adhesion at physiological temperatures, while when a specific external thermal stimulus (heating or cooling) is applied, its internal polymer network undergoes a reversible phase transition, resulting in a programmed and rapid decrease in adhesion force, ultimately achieving gentle peeling. In the development of such materials, precise control of the release temperature is a key technical challenge: if the release temperature is too high (e.g., >45℃), it can easily cause skin burns and poor patient compliance; if the release temperature is too low (close to room temperature), it will severely weaken the adhesion stability during daily use and fail to meet clinical fixation requirements.

[0005] In the selection of substrates for medical pressure-sensitive adhesives, polysiloxanes, due to the excellent chemical inertness, thermal stability, and flexibility imparted by the Si-O bonds in their main chain, exhibit superior biocompatibility and skin-friendly adhesion properties, making them the preferred substrate for high-end wound care pressure-sensitive adhesives. However, traditional silicone-based pressure-sensitive adhesives still suffer from two long-standing inherent defects:

[0006] (1) Its strong hydrophobicity makes it easy to form an isolating water film at the interface of a moist wound, resulting in a significant decrease or even failure of adhesion [Arellano IH, Silicone perturbation of the polyamide-polyacrylate adhesive interface [J]. Mater. Lett. 2019, 244, 1–5];

[0007] (2) The initial adhesion strength is insufficient, making it difficult to meet the high-strength fixation requirements of high-exudation wounds or moving parts such as joints.

[0008] The development of existing thermo-induced debonding pressure-sensitive adhesives still faces technical limitations. For example, Hwang et al. [Hwang J., Lim D., Lee G., etc., Ambient air-operated thermo-switchable adhesion of N-isopropylacrylamide-incorporated pressure-sensitive adhesives [J]. Mater.Horiz. 2023, 10, 2013–2023] prepared a low critical solution temperature (LCST) pressure-sensitive adhesive using poly(N-isopropylacrylamide) as a substrate, but the debonding temperature reached as high as 80°C, posing a significant risk of skin burns. Conversely, Zeng et al. [Zeng Q., Wang F., Hu R., etc., Debonding-On-Demand Polymeric Wound Patches for Minimal Adhesion and Clinical Communication [J]. Adv. Sci. 2022, 9] (29),2202635] The low-temperature detackable pressure-sensitive adhesive developed using the phase change properties of stearic acid ester has a detack temperature of 26°C, which is close to room temperature. However, the adhesive stability is easily reduced due to fluctuations in ambient temperature during daily use. Summary of the Invention

[0009] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for preparing and applying a dual-temperature responsive polyethylene glycol-siloxane copolymer pressure-sensitive adhesive film, so as to solve the problems of traditional medical adhesives failing to adhere in humid environments and easily causing tissue damage when removed.

[0010] To achieve the above objectives, the present invention adopts the following technical solution:

[0011] A method for preparing a temperature-responsive polyethylene glycol-siloxane copolymer pressure-sensitive adhesive film (SiPSA pressure-sensitive adhesive film) includes the following specific steps:

[0012] S1. First, heat-responsive polyethylene glycol-siloxane copolymer (PEG-Si) prepolymer, trimethylolpropane triacrylate (TMPTA) crosslinking agent and tackifier are stirred and mixed at room temperature to obtain a homogeneous and stable mixed solution;

[0013] S2. Then, the mixed solution is uniformly coated onto the release film, heated for crosslinking, and cooled to room temperature to obtain the dual-temperature responsive polyethylene glycol-siloxane copolymer pressure-sensitive adhesive film.

[0014] The thermoresponsive polyethylene glycol-siloxane copolymer (PEG-Si) prepolymer is prepared by aza-Michael addition reaction of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane (APDS) and polyethylene glycol diacrylate (PEGDA), as shown in the following reaction formula:

[0015]

[0016] Where m and n are both integers ≥ 1.

[0017] The preparation method of the thermoresponsive polyethylene glycol-siloxane copolymer (PEG-Si) prepolymer is as follows: 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane and polyethylene glycol diacrylate (PEGDA) are stirred and dissolved in dichloromethane. The mixture is stirred and reacted at 25°C for 24 hours. The mixture is then concentrated by rotary evaporation to remove the solvent dichloromethane, resulting in a colorless, hygroscopic, viscous liquid.

[0018] More preferably, the ratio of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, polyethylene glycol diacrylate, and dichloromethane is 1 mmol:1 mmol:5 mL.

[0019] Preferably, in step S1, the amounts of trimethylolpropane triacrylate crosslinking agent and thickener are 0.5-1.5% and 0-0.6% of the total mass of the reactants, respectively, and more preferably 0.75% and 0.5%.

[0020] Preferably, in step S1, the thickener is a chitosan thickener, which is prepared by the following method: first, dispersing chitosan powder in deionized water, wherein the mass ratio of chitosan to deionized water is 1:10; then adding glacial acetic acid and stirring, adjusting the pH value of the system to 5.0-5.5, and continuing to stir until the chitosan is completely dissolved to obtain a light yellow viscous solution, which is the final product.

[0021] Preferably, in step S1, the stirring conditions at room temperature are: stirring at 20-30°C for 30 minutes.

[0022] Preferably, in step S2, the release film material is polyethylene terephthalate (PET) with a thickness of 50 μm.

[0023] Preferably, in step S2, a four-sided coater is used to uniformly coat the mixed solution onto the substrate surface, and the wet film thickness is controlled to be 100 μm.

[0024] Preferably, in step S2, the heating crosslinking conditions are: heating at 70-80°C for 1-1.5 hours.

[0025] A temperature-responsive polyethylene glycol-siloxane copolymer pressure-sensitive adhesive film is obtained by the aforementioned preparation method.

[0026] Preferably, the dual-temperature responsive type refers to the pressure-sensitive adhesive film having dual-temperature triggered de-adhesion characteristics: it has excellent adhesion to the skin at 37°C, and the adhesion decreases by 72.3% when heated to 60°C; when cooled to 0°C, the adhesion decreases by 87.1%, which can achieve rapid peeling.

[0027] The aforementioned application of a dual-temperature responsive polyethylene glycol-siloxane copolymer pressure-sensitive adhesive film in the preparation of medical dressings or biosensor patches.

[0028] Preferably, the medical dressing is a wound dressing, and the biosensor patch is a physiological signal monitoring patch.

[0029] The beneficial effects of this invention are:

[0030] This invention provides a method for preparing and applying a thermo-responsive polyethylene glycol-siloxane copolymer pressure-sensitive adhesive film. The film is formed by cross-linking and curing a thermo-responsive polyethylene glycol-siloxane copolymer prepolymer, trimethylolpropane triacrylate crosslinking agent, and chitosan tackifier. The process is simple and easy to operate. The resulting film adheres firmly to the skin at normal human body temperature (37°C), meeting medical fixation requirements. At higher temperatures (60°C) or lower temperatures (0°C), the adhesion significantly decreases, allowing for rapid and painless peeling. It is also compatible with various substrates. The film prepared by this invention can be used for wound closure, medical dressing fixation, or biosensor patch application.

[0031] This invention has the following advantages:

[0032] 1. The SiPSA adhesive film prepared by the method disclosed in this invention achieves dual-temperature sensitive and controllable debonding. The SiPSA adhesive film has a strong adhesion with a peel strength of 208 N / m at 180° when the physiological temperature is 37°C. When heated to 60°C, its adhesion decreases by 72.3%; and when cooled to 0°C, its adhesion decreases by 87.1%. It can be debonded quickly and painlessly, solving the problem of secondary damage caused by the removal of traditional medical adhesives.

[0033] 2. The SiPSA film prepared by this method has excellent wet surface adhesion stability: the film can be directly adhered to exudate wounds and moist skin, and still maintains high peel strength (>160 N / m) after absorbing 20% ​​of its own volume of water, overcoming the adhesion failure defects of traditional silicone adhesives caused by hydrophobicity in wet environments.

[0034] 3. High biocompatibility and safety: The product has no skin irritation, low cytotoxicity, and peptide reactivity that meets medical standards. It can be safely applied to human epidermis and wounds and is suitable for long-term medical use.

[0035] 4. Simple and controllable preparation process: The cross-linking and coating process is initiated by heating at 70-80℃ for 1-1.5 h. The performance can be optimized by adjusting the ratio of raw materials. No complicated equipment is required, and it is easy to carry out large-scale production. Attached Figure Description

[0036] Figure 1 The effect of the amount of TMPTA crosslinking agent (a) and chitosan tackifier (b) in the SiPSA film formulation on its adhesive properties (brown bars represent 180° peel strength, green bars represent adhesive work, and purple bars represent holding time).

[0037] Figure 2 The FTIR spectra of SiPSA film and three raw materials are compared. (a) is PEG-Si, (b) is TMPTA, (c) is Chitosan, and (d) is SiPSA.

[0038] Figure 3 The effects of SiPSA adhesive film on different substrates (a) and temperature on the adhesion strength of the adhesive film to the skin (b).

[0039] Figure 4 The effect of water absorption on the skin peel strength of SiPSA film.

[0040] Figure 5 The cell viability corresponding to different concentrations of SiPSA membranes.

[0041] Figure 6 A comparison of the 180° peel strength of SiPSA adhesive film and commercial patches.

[0042] Figure 7 The effect of crosslinking agent type on the 180° peel adhesion of SiPSA is shown in the figure. X represents the type of crosslinking agent, where HDDA is 1,6-hexanediol diacrylate, DPGDA is dipropylene glycol diacrylate, TMPTA is trimethylolpropane triacrylate, EO-TMPTA is ethoxylated trimethylolpropane triacrylate, and PETTA is pentaerythritol tetraacrylate.

[0043] Figure 8 The effect of tackifier type on the 180° peel adhesion of SiPSA is shown in the figure. Y represents the type of tackifier, None indicates no tackifier, CS is chitosan, GER is rosin glycerol ester, and TPR is terpene phenolic tackifying resin. Detailed Implementation

[0044] The present invention will be further described below with reference to the accompanying drawings and embodiments. It should be noted that the following description is only for explaining the present invention and does not limit its content.

[0045] Example 1: A method for preparing a thermally responsive PEG-Si prepolymer

[0046] The thermally responsive PEG-Si prepolymer is prepared by a non-catalyzed aza-Michael addition reaction of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane (APDS) and polyethylene glycol diacrylate (PEGDA), as shown in the following reaction formula:

[0047]

[0048] The specific steps are as follows:

[0049] 10 mmol of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane (APDS, purchased from Maclean's) and 10 mmol of polyethylene glycol diacrylate (PEGDA, MW=600, purchased from Aladdin) were dissolved together in 50 mL of dichloromethane and reacted at 25 °C for 24 hours with stirring. The reaction progress was monitored by Fourier transform infrared spectroscopy (FTIR) until the characteristic peaks of the acrylate groups completely disappeared. The reaction mixture was concentrated by rotary evaporation to remove the solvent dichloromethane, yielding a colorless, hygroscopic viscous liquid, which was the PEG-Si prepolymer, with a yield of 96%.

[0050] Example 2: A method for preparing a chitosan thickener

[0051] Chitosan powder (degree of deacetylation ≥95%, MW=50000-60000, purchased from Aladdin) was dispersed in deionized water at a mass ratio of 1:10 between chitosan and deionized water. Then, glacial acetic acid was added dropwise and stirred to adjust the pH of the system to 5.0-5.5. Stirring was continued until the chitosan was completely dissolved, resulting in a pale yellow viscous solution, which is the chitosan thickener.

[0052] Example 3: A method for preparing a temperature-responsive polyethylene glycol-siloxane copolymer film.

[0053] A homogeneous and stable mixed solution was prepared by stirring a thermoresponsive polyethylene glycol-siloxane copolymer (PEG-Si) prepolymer, a trimethylolpropane triacrylate (TMPTA) crosslinking agent, and a chitosan tackifier at room temperature (25.0±5.0℃) for 30 min. The mixed solution was then coated onto the surface of a PET release film using a four-sided coater, with the wet film thickness controlled at 100 μm. The coated PET release film was then heated at 75℃ for 1.25 h to initiate a crosslinking reaction. After the reaction was completed, the film was cooled to room temperature to obtain a polyethylene glycol-siloxane copolymer film with dual-temperature responsive characteristics, i.e., a SiPSA film.

[0054] In the mixed solution, the total mass (g) ratio of PEG-Si prepolymer, TMPTA crosslinking agent and chitosan thickener is 100:0.75:0.50.

[0055] The applicant also conducted further screening experiments on crosslinking agents and thickeners.

[0056] Figure 7 The effect of crosslinking agent type on the 180° peel adhesion of SiPSA is shown, where X represents the type of crosslinking agent: HDDA is 1,6-hexanediol diacrylate, DPGDA is dipropylene glycol diacrylate, TMPTA is trimethylolpropane triacrylate, EO-TMPTA is ethoxylated trimethylolpropane triacrylate, and PETTA is pentaerythritol tetraacrylate. Figure 7 It can be seen that the adhesive film prepared by using TMPTA in this invention has significant advantages in bonding performance.

[0057] Figure 8 The effect of tackifier type on the 180° peel adhesion of SiPSA is shown, where Y represents the type of tackifier, None indicates no tackifier, CS is chitosan, GER is rosin glycerol ester, and TPR is terpene phenolic tackifying resin. Figure 8 It can be seen that the adhesive film prepared by using chitosan in this invention has significant advantages in bonding performance.

[0058] Example 4: Performance Testing and Structural Characterization of SiPSA Film

[0059] All the following tests were conducted using the SiPSA film prepared in Example 3.

[0060] 4.1 Adhesion performance testing and formulation optimization

[0061] (1) Test method for adhesion performance

[0062] 180° Peel Strength Test Method: The test is conducted according to ASTM D3330 standard. A 25 mm × 100 mm SiPSA film sample is prepared and bonded to various substrates including PET, PP, PE, PVC, SUS303 stainless steel, and skin. A 2.5 kg manual roller is used to press the film back and forth three times at a speed of 10 mm / s to ensure full adhesion between the film and the substrate. A universal tensile testing machine is used at a peel speed of 300 mm / min at a 180° peel angle. The steady-state peel force during the peeling process is recorded, and the calculation formula is as follows:

[0063]

[0064] In the formula: σ is the peel strength at 180°, in N / m; F is the average force during the peeling process, in N; B is the film width, in 25 mm.

[0065] Test method for holding time: Cut a SiPSA film sample with a specification of 25 mm × 75 mm × 0.1 mm; paste the sample between two 25 mm × 25 mm stainless steel plates to ensure that the bonding overlap area is consistent; suspend a 1 kg weight on the bonded component and record the time from the start of the weight suspension to the complete detachment of the sample. This time is the holding time.

[0066] Test method for adhesive work: Prepare a SiPSA adhesive film sample with dimensions of 10 mm × 10 mm × 0.1 mm; use a probe adhesion meter to contact and separate the probe from the adhesive film sample at a rate of 1 mm / min, and record the force-displacement curve during the separation process; record the peak peel force (P max) when the probe separates from the adhesive film, and the initial displacement (x) during the peeling process. o The bonding work is calculated as follows: (x1) and the final displacement.

[0067]

[0068] Where: Bonding work W adh The unit is J / m 2 ; A Contact area between the probe and the adhesive film, in mm. 2 ;F (x): Force that varies with displacement during the peeling process; x o x1 and x2 are the initial and final displacements of the stripping process.

[0069] (2) Formula optimization

[0070] To optimize the formulation, the amount of chitosan thickener was fixed at 0.5 wt% of the total mass of the three raw materials, and the effect of the amount of TMPTA crosslinking agent was investigated. The results are as follows: Figure 1 As shown in (a), when the amount of TMPTA is 0.75 wt%, the 180° peel strength of the film to the skin reaches a peak of 208 N / m, the adhesive work reaches the maximum, and the holding time exceeds 200 hours.

[0071] The effect of chitosan thickener dosage on the amount of TMPTA crosslinking agent was investigated by fixing the dosage at 0.75 wt%; the results are as follows. Figure 1 As shown in (b), when the amount of chitosan is 0.5 wt%, the peel strength, adhesive work and holding time of the film are all optimal.

[0072] 4.2 Structural Characterization (FTIR Analysis)

[0073] The structure of the product was characterized by Fourier transform infrared spectroscopy (FTIR). Figure 2 ).Depend on Figure 2 As can be seen in (a), the characteristic functional group peaks of PEG-Si, the raw material for SiPSA film synthesis (such as NH at 3320 cm⁻¹, CH at 2952 / 2920 cm⁻¹, C=O at 1734 cm⁻¹, etc.) are completely preserved in SiPSA, indicating that its main structure has not been destroyed. Figure 2 In (b), TMPTA represents the characteristic peak at 1627 cm⁻¹ of the C=C double bond in the final product SiPSA. Figure 2 The disappearance of TMPTA in (d) proves that TMPTA, as a crosslinking agent, underwent an addition reaction, and new chemical bonds were formed in the system; Figure 2 In (c), the characteristic absorption peak of chitosan is 3446 cm⁻¹ (-OH stretching vibration), which is similar to that of pure PEG-Si. Figure 2 (a) and pure TMPTA ( Figure 2 The spectra in (b) show a clear difference in wavenumber. The hydroxyl / amino peak of PEG-Si is 3320 cm⁻¹, while the peak of 3446 cm⁻¹ is clearly observed in the spectrum of SiPSA, indicating that the functional groups of chitosan have entered the molecular structure of the product. Thus, FTIR analysis proves that SiPSA was successfully synthesized by the reaction of PEG-Si, TMPTA and chitosan.

[0074] 4.3 Substrate universality

[0075] SiPSA films exhibit good adhesion to a variety of common medical substrates. Figure 3 (a) At 37°C, its 180° peel strength to stainless steel (SUS303) and polyvinyl chloride (PVC) exceeds 200 N / m, and even to low surface energy polyethylene (PE) substrates, the peel strength reaches 98 N / m. This result demonstrates that the film has excellent substrate versatility.

[0076] 4.4 Temperature-sensitive de-adhesive properties

[0077] SiPSA film exhibits optimal skin adhesion at physiological temperature (37℃), with a 180° peel strength of 208 N / m. Figure 3 (b) Meanwhile, its adhesion exhibits significant dual-temperature response characteristics: it remains stable in the 20-40℃ range (>145 N / m); it decreases sharply when the temperature is below 10℃ or above 40℃; at trigger temperatures of 60℃ or 0℃, the peel strength decreases by 72.3% and 87.1% respectively, enabling rapid and clean peeling.

[0078] 4.5 Moisture Adhesion Resistance

[0079] Immerse the film sample in deionized water until it absorbs 20% of its own volume. Remove the sample and remove the surface moisture. Immediately test its 180° peel strength to the skin according to ASTM D3330 standard.

[0080] like Figure 4 As shown, the peel strength of the adhesive film after water absorption remains above 160 N / m, indicating that the adhesive film can still maintain effective adhesion in a humid environment and is suitable for clinical scenarios with exudate.

[0081] 4.6 In vitro degradability

[0082] The SiPSA film samples (10 mm × 10 mm) were immersed in media with pH values ​​of 3.0 (hydrochloric acid solution), 7.4 (PBS buffer), and 10.0 (sodium hydroxide solution), respectively, and placed in a constant temperature shaking oven at 37°C. The samples were periodically removed, rinsed with deionized water, vacuum dried, and weighed to calculate the mass loss rate. The experimental results showed that the degradation rate was pH-dependent; the 7-day mass loss rate was: alkaline (28%) > acidic (12%) > neutral (5%). In the alkaline environment, only 45% of the tensile strength was retained; the neutral environment showed relatively stable performance (90% strength retention). Conclusion: The hydrolysis rate of the SiPSA film can be controlled by pH to adapt to the "on-demand degradation" requirements of different scenarios.

[0083] 4.7 Cell compatibility

[0084] The cytotoxicity of the SiPSA membrane was assessed using the MTT assay. The procedure was as follows: SiPSA membranes were extracted in DMEM cell culture medium (Thermo Fisher Scientific) to prepare extracts of different concentrations (100-1000 μg / mL). HeLa cells were seeded in 96-well plates, exposed to the extracts for 24 hours, incubated with MTT reagent, and then the generated formazan crystals were dissolved in DMSO (100 μL DMSO per well). The absorbance was measured at 570 nm, and the relative cell viability was calculated. The results are as follows: Figure 5 As shown, the cell survival rate was higher than 92% at each test concentration, indicating that the material has no significant cytotoxicity.

[0085] 4.8 Performance Comparison with Commercial Products

[0086] Under the same test conditions (37°C, ASTM D3330), the 180° peel strength of the SiPSA adhesive film of this invention was compared with that of three commercially available medical pressure-sensitive adhesive patches (A, B, C). The results are as follows: Figure 6 As shown, the peel strength of the adhesive film of the present invention is significantly higher than that of all comparative samples.

[0087] 4.9 Thermal stability

[0088] Thermogravimetric analysis (TGA) of this SiPSA film shows that the material's 5% mass loss temperature (T5%) reaches 170°C, far exceeding the temperature of conventional medical environments, thus avoiding material degradation and deterioration in high-temperature sterilization or clinical hyperthermia scenarios; the glass transition temperature (Tg) is as low as -58°C, ensuring good flexibility in low-temperature environments and preventing adhesion failure due to low-temperature embrittlement.

[0089] Example 5: Application of SiPSA film

[0090] 5.1 Used for wound dressing fixation

[0091] Cut the SiPSA film to a size slightly larger than the wound. After cleaning the wound area, remove the release liner from the film and apply it smoothly to the healthy skin around the wound. Then cover with a sterile dressing and gently press to secure it.

[0092] When removing the film, you can use a cold compress (about 0°C, 3-5 minutes) or a hot compress (about 60°C, 2-3 minutes) to reduce the adhesion of the film, and then gently peel it off from the edge.

[0093] 5.2 Used for bonding biosensor patches

[0094] The bioelectric sensing electrode is pre-fixed to the adhesive side of the SiPSA film. In use, align it with the skin detection area, smooth it out, and connect the device for monitoring; removal is done in the same way.

[0095] 5.3 Application Validation

[0096] Test results simulating real-world usage environments demonstrate that the SiPSA adhesive film exhibits excellent overall application performance: In tests simulating joint flexion and extension movements, the film showed no delamination or detachment after 30 cycles, showcasing its superior flexibility and dynamic adhesion stability; the film maintained effective adhesion even after absorbing 20% ​​of its own volume in water, indicating its suitability for wound environments with minimal exudate; long-term adhesion tests showed that the film maintained reliable adhesion for over 168 hours without requiring replacement. Furthermore, the film maintained its adhesive properties even after short-term exposure to humid environments. When removal is required, debonding can be easily triggered by the aforementioned low-temperature (0°C) or high-temperature (60°C) stimulation, achieving rapid and complete peeling.

[0097] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Based on the technical solutions of the present invention, various modifications or variations that can be made by those skilled in the art without creative effort are still within the scope of protection of the present invention.

Claims

1. A method for preparing a dual-temperature responsive polyethylene glycol-siloxane copolymer pressure-sensitive adhesive film, characterized in that, The specific steps are as follows: S1. First, the thermoresponsive polyethylene glycol-siloxane copolymer prepolymer, trimethylolpropane triacrylate crosslinking agent and tackifier are stirred and mixed at room temperature to obtain a homogeneous and stable mixed solution; S2. Then, the mixed solution is uniformly coated onto the release film, heated for crosslinking, and cooled to room temperature to obtain the dual-temperature responsive polyethylene glycol-siloxane copolymer pressure-sensitive adhesive film. The thermoresponsive polyethylene glycol-siloxane copolymer prepolymer is prepared by aza-Michael addition reaction of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane and polyethylene glycol diacrylate, as shown in the following reaction formula: Where m and n are both integers ≥ 1.

2. The preparation method according to claim 1, characterized in that, The preparation method of the thermoresponsive polyethylene glycol-siloxane copolymer prepolymer is as follows: 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane and polyethylene glycol diacrylate are stirred and dissolved in dichloromethane. The mixture is stirred and reacted at 25°C for 24 hours. The mixture is then concentrated by rotary evaporation to remove the solvent dichloromethane, resulting in a colorless, hygroscopic viscous liquid, which is the final product.

3. The preparation method according to claim 1, characterized in that, In step S1, the amounts of trimethylolpropane triacrylate crosslinking agent and thickener are 0.5-1.5% and 0-0.6% of the total mass of the reactants, respectively.

4. The preparation method according to claim 1, characterized in that, In step S1, the thickener is a chitosan thickener, which is prepared by the following method: first, chitosan powder is dispersed in deionized water, wherein the mass ratio of chitosan to deionized water is 1:10; then glacial acetic acid is added dropwise and stirred, the pH value of the system is adjusted to 5.0-5.5, and stirring is continued until the chitosan is completely dissolved, resulting in a light yellow viscous solution.

5. The preparation method according to claim 1, characterized in that, In step S1, the stirring conditions at room temperature are: stirring at 20-30℃ for 30 minutes.

6. The preparation method according to claim 1, characterized in that, In step S2, the release film is made of polyethylene terephthalate and has a thickness of 50 μm.

7. The preparation method according to claim 1, characterized in that, In step S2, a four-sided coater is used to uniformly coat the mixed solution onto the substrate surface, and the wet film thickness is controlled to be 100 μm.

8. The preparation method according to claim 1, characterized in that, In step S2, the heating crosslinking conditions are: heating at 70-80℃ for 1-1.5 hours.

9. A temperature-responsive polyethylene glycol-siloxane copolymer pressure-sensitive adhesive film, characterized in that, It is obtained by the preparation method described in any one of claims 1 to 8.

10. The application of the dual-temperature responsive polyethylene glycol-siloxane copolymer pressure-sensitive adhesive film of claim 9 in the preparation of medical dressings or biosensor patches.

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