An ultralow-temperature-resistant and ultraviolet radiation-resistant acrylate pressure-sensitive adhesive as well as a preparation method and application thereof

Abstract

The application relates to an acrylic ester pressure-sensitive adhesive resistant to ultralow temperature and ultraviolet radiation, a preparation method and application thereof, and belongs to the technical field of high polymer materials. In order to solve the problems that the existing acrylic ester pressure-sensitive adhesive is brittle and loses adhesion at ultralow temperature (-80 DEG C), the cohesion strength is insufficient at high temperature (150 DEG C), aging degradation is caused by space ultraviolet radiation, and microcracks cannot be self-repaired in application scenes such as aerospace, the mass fractions of components in the acrylic ester pressure-sensitive adhesive are as follows: 45-65 parts of soft monomers, 2-6 parts of hindered amino acrylic ester, 15-30 parts of hard monomers, 10-20 parts of fluorosilicon monomers, 2.2 parts of a thermal initiator, 2-8 parts of POSS modified acrylic ester and 1-5 parts of dithiodipropionic acid.

Description

Technical Field

[0001] This invention relates to an acrylic pressure-sensitive adhesive, its preparation method, and its application, belonging to the field of polymer materials technology. Background Technology

[0002] Currently, traditional organic adhesives face severe performance challenges in space environments (such as extreme temperature differences, strong ultraviolet radiation, and high-energy particle bombardment). On the one hand, conventional pressure-sensitive adhesives or structural adhesives typically have narrow glass transition temperatures (Tg), making it difficult to balance high-temperature creep resistance with low-temperature chain segment mobility, leading to brittle fracture or a sharp drop in adhesive strength under cryogenic conditions. On the other hand, while existing silicone-containing acrylate adhesives have improved temperature resistance to some extent, their crosslinking networks largely rely on single covalent bond structures. Once exposed to radiation or stress, microcracks develop, making in-situ self-repair impossible, resulting in insufficient long-term reliability. To address radiation damage, some studies have used high-concentration heavy metal compounds or carbon-based fillers to construct radiation shielding layers. However, this often leads to a precipitous drop in initial adhesive strength, and the poor interfacial compatibility between the organic and inorganic phases makes them prone to phase separation during extreme thermal expansion and contraction, forming micro-gaps that further weaken adhesive strength and sealing performance. Meanwhile, the intense ultraviolet radiation in the space environment is generally considered a harmful factor that accelerates material aging, and current technologies have not yet been able to convert it into a driving energy source that is beneficial for material repair. Therefore, developing a novel adhesive system with low-temperature bonding stability, radiation energy dissipation capability, excellent interfacial compatibility, and the ability to trigger self-healing using the space environment has significant engineering application value. Summary of the Invention

[0003] This invention addresses the problems faced by existing acrylic pressure-sensitive adhesives in aerospace and other applications, such as embrittlement and loss of adhesion at ultra-low temperatures (-80°C), insufficient cohesive strength at high temperatures (150°C), aging and degradation caused by space ultraviolet radiation, and the inability of microcracks to repair themselves. It proposes an acrylic pressure-sensitive adhesive that is resistant to ultra-low temperatures and ultraviolet radiation, as well as its preparation method and applications.

[0004] The technical solution adopted by the present invention to solve the above problems is as follows: the mass fractions of each component in the acrylate pressure-sensitive adhesive of the present invention are: 45-65 parts of soft monomer, 2-6 parts of hindered amine acrylate, 15-30 parts of hard monomer, 10-20 parts of fluorosilicone monomer, 2.2 parts of thermal initiator, 2-8 parts of POSS modified acrylate, and 1-5 parts of dithiodipropionic acid.

[0005] Furthermore, the soft monomers and hindered amine acrylates are polymerized under the action of a low concentration of thermal initiator accounting for 0.2% of the total monomer mass, and a physical cross-linked network is formed through effective entanglement.

[0006] Furthermore, the hard monomer, fluorosilicone monomer, and POSS-modified acrylate form a dynamic covalent cross-linked self-healing network. The hard monomer, fluorosilicone monomer, and POSS-modified acrylate are polymerized in situ under the action of a high-concentration thermal initiator accounting for 2% of the total monomer mass. The ring-opening reaction between the epoxy groups of the side chains of POSS-modified acrylate and dithiodipropionic acid forms a covalent cross-linked network containing dynamic disulfide bonds.

[0007] POSS-modified acrylates are acrylate monomers grafted or copolymerized with polyhedral oligomeric silsesquioxanes, and their POSS structural units are cage-like or ladder-like structures. The core has an acrylate or methacrylate group attached to at least one vertex silicon atom.

[0008] Furthermore, the soft monomer is one or more of ethyl acrylate, butyl acrylate, isooctyl acrylate, lauryl acrylate, lauryl methacrylate, lauryl acrylate, and alkyl dodecyl acrylate.

[0009] Furthermore, the hard monomer is one or more of methyl acrylate, methyl methacrylate, isobornyl acrylate, isobornyl methacrylate, styrene, acrylonitrile, methacrylic acid, and methacryloxypropyl glycidyl ether.

[0010] Furthermore, the hindered amine acrylate is one or both of 4-acryloyloxy-2,2,6,6-tetramethylpiperidine and 4-methacryloyloxy-2,2,6,6-tetramethylpiperidine.

[0011] Furthermore, the fluorosilicone monomer is one or more of vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, trifluoroethyl methacrylate, and hexafluorobutyl methacrylate. The thermal initiator is a peroxide initiator or an azo initiator, specifically one of benzoyl peroxide, dicumyl peroxide, azobisisobutyronitrile, or azobisisoheptanenitrile.

[0012] Furthermore, the acrylate pressure-sensitive adhesive also includes KH570 surface-modified radiation-resistant nanofiller, in parts by weight of 1-5 parts.

[0013] The steps of the method for preparing acrylate pressure-sensitive adhesive according to the present invention include: Step 1: Mix 45-65 parts of soft monomer with 2-6 parts of hindered amine acrylate, add 0.2% of thermal initiator by mass of total monomer, and prepolymerize at 40-60°C for 1-5 hours to form prepolymer A containing a physical entanglement network; Step 2: Mix 15-30 parts of hard monomer, 10-20 parts of fluorosilicone monomer, 2-8 parts of POSS modified acrylate, 1-5 parts of dithiodipropionic acid and 2% of thermal initiator by mass of total monomers to obtain mixture B. Step 3: Add mixture B to prepolymer A, stir evenly, and continue the polymerization reaction at 60-90℃ for 1.5-6 hours to allow the dynamic covalent crosslinked self-healing network to polymerize in situ in the physically entangled network structure to form an interpenetrating network structure, thus obtaining the acrylate pressure-sensitive adhesive. Add 1-5 parts of KH570 surface-modified radiation-resistant nanofiller while adding mixture B.

[0014] The acrylic pressure-sensitive adhesive described in this invention is used in aerospace surface protection materials.

[0015] The pressure-sensitive adhesive can be used at temperatures ranging from -80℃ to 150℃. When microcracks occur in the material, the dynamic disulfide bonds in the dynamic covalent crosslinked self-healing network can achieve autonomous healing of the microcracks through a dynamic exchange mechanism.

[0016] The beneficial effects of this invention are: 1. This invention has ultra-wide temperature range adhesive stability: The physical entanglement network (Network I) constructed by the low concentration of initiator provides the chain segment mobility and free volume at extremely low temperatures, ensuring good wettability and peel strength at -80℃; at the same time, the dynamic covalent network with high cross-linking density (Network II) endows the material with creep resistance and cohesive strength at 150℃, realizing stable adhesion in the environment of drastic temperature difference alternation from -80℃ to 150℃.

[0017] 2. This invention possesses dynamic self-healing capabilities: the disulfide bonds in the dynamic covalently cross-linked self-healing network are formed after the ring-opening reaction of the epoxy groups on the side chains of POSS-modified acrylate with dithiodipropionic acid, exhibiting dynamic covalent exchange characteristics. When microcracks occur in the material, the disulfide bonds can undergo reversible exchange under external thermal stimulation or at room temperature, achieving autonomous healing of the microcracks and significantly extending the material's service life during spacecraft operation.

[0018] 3. This invention achieves a multi-dimensional synergistic mechanism of UV and radiation protection: ① The π-electron cloud of the aromatic ring in the monomer can effectively dissipate space radiation energy; ② Hindered amine acrylate (HAA) can capture free radicals generated by photo-oxidation and inhibit chain degradation reactions; ③ The radiation-resistant nanofiller modified with KH570 surface is uniformly dispersed through chemical anchoring, further shielding ultraviolet rays and space radiation. The synergistic effect of these three factors enables the pressure-sensitive adhesive to maintain excellent performance under long-term space irradiation.

[0019] 4. This invention can achieve fluorosilicone synergistic toughening and surface energy regulation: The introduction of fluorosilicone monomers reduces the surface energy of the pressure-sensitive adhesive, giving it excellent antifouling, hydrophobic and weather-resistant properties. At the same time, it synergistically constructs low-temperature flexible segments with POSS modified acrylate, improving the material's elongation at break and impact resistance at low temperatures.

[0020] 5. This invention also features an interpenetrating network structure locking effect: the dynamic covalently cross-linked self-healing network polymerizes in situ within the already formed physically entangled network, creating an interpenetrating topological structure of physical entanglement and chemical cross-linking. This structure avoids the high-temperature flow of a single physical network and overcomes the low-temperature brittleness of a single chemical network, achieving synergistic enhancement of mechanical properties. The preparation process is simple and controllable: a one-pot process with staged initiation and stepwise polymerization is employed, requiring no complex post-processing and facilitating industrial production. By adjusting the initiator concentration and polymerization temperature, the morphology and ratio of the two networks can be precisely controlled, thereby regulating the overall performance of the final material.

[0021] This invention can maintain stable bonding performance in a wide temperature range of -80℃ to 150℃, can withstand space ultraviolet radiation, and microcracks generated during use can be self-healed through the self-repair mechanism of dynamic disulfide bonds, thereby significantly extending the service life of spacecraft surface protective materials and reducing on-orbit maintenance costs.

[0022] Example Example 1 The dosage of each component in this embodiment is within a more preferred range.

[0023] Formulation: The soft monomer is selected from 35 parts butyl acrylate and 20 parts ethyl acrylate. The hindered amine acrylate is selected from 4... Acryloyloxy 2,2,6,6 Tetramethylpiperidine, 4 parts. The hard monomer is isobornyl methacrylate, 18 parts; methacryloyloxypropyl glycidyl ether, 4 parts. The fluorosilicone monomer is vinyltrimethoxysilane, 15 parts. The POSS-modified acrylate is acryloyloxypropyl cage-like polysilsesquioxane, 4.5 parts. Dithiodipropionic acid, 3 parts. The thermal initiator is benzoyl peroxide, used in step one at 0.2% of the total monomer mass, and in step three at 2% of the total monomer mass. This embodiment does not add KH570 surface-modified nano-cerium dioxide radiation-shielding filler. Step one: constant temperature at 80℃ for 4 hours. Step three: constant temperature at 80℃ for 4 hours.

[0024] Example 2 In this embodiment, the amount of soft monomer is too high, and the amount of hindered amine acrylate is too low.

[0025] Formulation: The soft monomer is selected from 20 parts butyl acrylate and 40 parts lauryl acrylate. The hindered amine acrylate is selected from 4... Acryloyloxy 2,2,6,6 Tetramethylpiperidine, used in a dose of 3 parts. The hard monomers are methyl methacrylate (10 parts) and glycidyl acrylate (10 parts). The fluorosilicone monomer is γ-... Methacryloxypropyltrimethoxysilane, used in an amount of 12 parts. POSS-modified acrylate is acryloyloxypropyl cage-like polysilsesquioxane, used in an amount of 5 parts. Dithiodipropionic acid is used in an amount of 2.5 parts. The thermal initiator is benzoyl peroxide, used in the same amount as in Example 1.

[0026] Preparation steps: Same as in Example 1.

[0027] Example 3 In this embodiment, the amount of hard monomer and the amount of fluorosilicone monomer are both relatively high.

[0028] Formula: The soft monomer consists of 10 parts ethyl acrylate, 15 parts lauryl acrylate, and 25 parts isooctyl acrylate. The hindered amine acrylate consists of 4... Acryloyloxy 2,2,6,6 Tetramethylpiperidine, used in a quantity of 5 parts. The hard monomers selected are methyl acrylate (12 parts), acrylonitrile (3 parts), and methacryloxypropyl glycidyl ether (6 parts). The fluorosilicone monomer selected is γ-... Nine parts of methacryloyloxypropyltrimethoxysilane and six parts of trifluoroethyl methacrylate were used. Three parts of acryloyloxypropyl cage-like polysilsesquioxane were used as the POSS-modified acrylate. Four parts of dithiodipropionic acid were used. Azobisisoheptane was used as the thermal initiator, with the same dosage as in Example 1. Preparation steps: 80℃, constant temperature for 5 hours.

[0029] Example 4 In this embodiment, KH570 surface-modified nano-cerium dioxide radiation-shielding filler was added. The formulation consisted of 35 parts lauryl acrylate, 5 parts alkyl icosate, and 10 parts ethyl acrylate as the soft monomers. Hindered amine acrylate was selected from 4... Acryloyloxy 2,2,6,6 Tetramethylpiperidine, used in a quantity of 4 parts. The hard monomers selected are 2 parts methacrylic acid, 5 parts isobornyl methacrylate, 2 parts styrene, and 6 parts methacryloxypropyl glycidyl ether. Five parts of methacryloyloxypropyltrimethoxysilane and ten parts of hexafluorobutyl methacrylate were used. 4.5 parts of acryloyloxypropyl cage-like polysilsesquioxane were used for the POSS-modified acrylate. Three parts of dithiodipropionic acid were used. Three parts of KH570 surface-modified nano-cerium dioxide were used. Benzoyl peroxide was used as the thermal initiator, with the same dosage as in Example 1. Preparation steps: Step 1: Same as Step 1 of Example 1. Step 2: After mixing, ultrasonically disperse for 20 minutes. Step 3: Same as Step 3 of Example 1.

[0030] Example 5 The soft monomers selected are 40 parts isooctyl acrylate, 8 parts lauryl acrylate and alkyl dodecyl acrylate, and 10 parts lauryl methacrylate. The hindered amine acrylates selected are 4... Acryloyloxy 2,2,6,6 Tetramethylpiperidine, 4.5 parts. Styrene 15 parts, isobornyl acrylate 5 parts, methacryloxypropyl glycidyl ether 4 parts. Vinyltrimethoxysilane 10 parts, γ-methacryloyloxypropyltrimethoxysilane 4 parts. Acryloyloxypropyl cage-like polysilsesquioxane 4 parts for the POSS-modified acrylate. Dithiodipropionic acid 3.5 parts. Azobisisobutyronitrile (AIBN) as the thermal initiator, same as in Example 1.

[0031] Preparation steps: Step 1: React at 70℃ for 1.5 h. Step 2: After mixing, ultrasonically disperse for 20 minutes. Step 3: React at 70℃ for 1.5 h.

[0032] Example 6 Formulation: The soft monomers used are 12 parts butyl acrylate, 20 parts isooctyl acrylate, 5 parts lauryl acrylate and alkyl dodecyl acrylate, and 18 parts lauryl acrylate. Hindered amine acrylates are used in the form of 4... Acryloyloxy 2,2,6,6 Tetramethylpiperidine, used in an amount of 3.5 parts. The hard monomers used are methyl methacrylate (14 parts), acrylonitrile (5 parts), and methacryloxypropyl glycidyl ether (5 parts). The fluorosilicone monomer used is γ-... Methacryloxypropyltrimethoxysilane, used in an amount of 6 parts. POSS-modified acrylate is acryloyloxypropyl cage-like polysilsesquioxane, used in an amount of 6 parts. Dithiodipropionic acid, used in an amount of 2 parts. The thermal initiator is dicumyl peroxide, used in the same amount as in Example 1. Preparation steps: 90℃, constant temperature for 6 hours.

[0033] Comparative Example 1 Formulation: The soft monomer consists of 35 parts butyl acrylate and 20 parts ethyl acrylate. The hard monomer consists of 18 parts isobornyl methacrylate and 4 parts methacryloxypropyl glycidyl ether. The fluorosilicone monomer consists of 15 parts vinyltrimethoxysilane. The POSS-modified acrylate consists of 4.5 parts acryloyloxypropyl cage-like polysilsesquioxane. The dithiodipropionic acid consists of 3 parts. The thermal initiator is benzoyl peroxide, used in step one at 0.2% of the total monomer mass and in step three at 2% of the total monomer mass. The steps are exactly the same as in Example 1.

[0034] Comparative Example 2 The soft monomers selected are 40 parts isooctyl acrylate, 8 parts lauryl acrylate and alkyl dodecyl acrylate, and 10 parts lauryl methacrylate. The hindered amine acrylates selected are 4... Acryloyloxy 2,2,6,6 Tetramethylpiperidine, 4.5 parts. Styrene 15 parts, isobornyl acrylate 5 parts, methacrylic acid 4 parts. Vinyltrimethoxysilane 10 parts, γ-methacryloyloxypropyltrimethoxysilane 4 parts. Acryloyloxypropyl cage-like polysilsesquioxane 4 parts for the POSS-modified acrylate. Aluminum acetylacetonate 3.5 parts. Azobisisobutyronitrile (AIBN) thermal initiator, same as in Example 5. The steps are exactly the same as in Example 5.

[0035] Comparative Example 3 The soft monomers selected are 12 parts butyl acrylate, 20 parts isooctyl acrylate, 5 parts lauryl acrylate and alkyl dodecyl acrylate, and 18 parts lauryl acrylate. The hindered amine acrylate is selected as 4... Acryloyloxy 2,2,6,6 Tetramethylpiperidine, used in an amount of 3.5 parts. The hard monomers used are methyl methacrylate (14 parts), acrylonitrile (5 parts), and methacryloxypropyl glycidyl ether (5 parts). The fluorosilicone monomer used is γ-... Methacryloxypropyltrimethoxysilane, used in an amount of 6 parts. POSS-modified acrylate is acryloyloxypropyl cage-like polysilsesquioxane, used in an amount of 6 parts. Dithiodipropionic acid, used in an amount of 2 parts. The thermal initiator is dicumyl peroxide, used in the same amount as in Example 1. The steps are basically the same as in Example 6.

[0036] Comparative Example 4 This comparative example lacks fluorosilicone monomers.

[0037] In this embodiment, KH570 surface-modified nano-cerium dioxide radiation-shielding filler was added. The formulation consisted of 35 parts lauryl acrylate, 5 parts alkyl icosate, and 10 parts ethyl acrylate as the soft monomers. Hindered amine acrylate was selected from 4... Acryloyloxy 2,2,6,6 Tetramethylpiperidine, used in an amount of 4 parts. The hard monomers used are: 2 parts methacrylic acid, 5 parts isobornyl methacrylate, 2 parts styrene, and 6 parts methacryloxypropyl glycidyl ether. Dithiodipropionic acid is used in an amount of 3 parts. KH570 surface-modified nano-cerium dioxide is used in an amount of 3 parts. The thermal initiator is benzoyl peroxide, used in the same amount as in Example 1. Preparation steps: Same as in Example 4.

[0038] V. Performance Testing Methods The acrylic pressure-sensitive adhesives prepared in the above examples and comparative examples were coated onto a 50 μm thick PET film, with the dry adhesive thickness controlled at 30 μm. A release film was then applied to create test rolls. Except for the low-temperature peel strength test, all tests were conducted under standard environmental conditions, i.e., a temperature of 23 ± 2 °C and a relative humidity of 50 ± 5%.

[0039] I. Performance tests were conducted on the acrylic pressure-sensitive adhesives obtained in Examples 1 to 6, and the results are shown in the table below:

[0040] 1. Peel strength test at room temperature The test was conducted according to the national standard GB / T 2792-2014, "Test Method for Peel Strength of Adhesive Tapes". Pressure-sensitive adhesive tape was cut into samples 25mm wide and 200mm long. After removing the release film, the samples were adhered to a clean aluminum plate and tested using a 2kg rubber roller at 300mm·min. -1 The roller is pressed back and forth at a speed of once. After application, the sample is placed under standard environmental conditions for 30 minutes. Then, a universal tensile testing machine is used to measure the peel force at a peel angle of 180 degrees and a peel speed of 300 mm per minute. Three samples are tested for each sample, and the average value is taken. The result is expressed in Newtons per 25 mm width.

[0041] 2. Low-temperature peel strength test The pressure-sensitive adhesive tape sample was attached to an aluminum plate (using the same method as the room temperature peel strength test). After being placed under standard environmental conditions for 30 minutes, the sample was placed in a -80°C freezer for 2 hours. Immediately after removal, the sample was placed in a low-temperature environment chamber and subjected to a peel at -80°C with a peel angle of 180 degrees and a peel strength of 300 mm·min. -1 The peel force was determined by the peel speed. Three samples were tested for each sample, and the average value was taken. The result is expressed in N / 25mm.

[0042] 3. High-temperature holding power test Cut pressure-sensitive adhesive tape into samples 25mm wide and 150mm long, and attach them to a clean stainless steel plate. The sample area should be 25mm x 25mm. Use a 2kg roller at 300 mm / min. -1 The roller is pressed back and forth three times at a certain speed. The steel plate with the sample attached is placed vertically in a constant temperature oven at 150℃, and a 1kg weight is suspended from the end of the sample. The time it takes for the sample to completely detach is recorded, with a maximum test time of 1440 minutes. Three samples are tested for each sample, and the average value is taken. The result is in minutes.

[0043] 4. Self-repair efficiency test Acrylic pressure-sensitive adhesive was coated onto a release film to a thickness of 1 mm and dried at 75°C for 6 hours to obtain a uniformly thick film. The film was then cut into dumbbell-shaped specimens according to the dumbbell dimensions specified in ISO 37-2011. A 50 μm deep cut was made in the middle of each specimen using a blade. The cut specimens were then heat-treated in a 60°C oven for 2 hours. After cooling to room temperature, the specimens were tested using a universal tensile testing machine at 50 mm / min. -1 The tensile strength of the repaired specimen was tested at a high speed. Simultaneously, the tensile strength of the original, undamaged specimen was also tested. The self-healing efficiency was calculated using the following formula: tensile strength after repair divided by the original tensile strength, then multiplied by 100%. Five specimens were tested for each sample, and the average value was taken. The result is expressed as a percentage.

[0044] 5. Peel strength retention rate test after UV aging Accelerated aging tests were conducted using a UV aging chamber. The test conditions were: irradiation wavelength of 340 nm and irradiation intensity of 0.65 W·m⁻¹. -2 The blackboard temperature was 60 ℃, the relative humidity was 50%, and no water was sprayed. Aluminum plate samples with pressure-sensitive adhesive tape were placed in an aging chamber and irradiated for 500 h. After removing the samples, the peel strength after aging was determined according to the low-temperature peel strength test method. Simultaneously, the initial peel strength was determined using unaged samples from the same batch. The peel strength retention rate was calculated using the following formula: peel strength after aging divided by the initial peel strength, then multiplied by 100%. Three samples were tested for each sample, and the average value was taken. The result is expressed as a percentage.

[0045] Analysis of low-temperature peel performance: Example 5 exhibited the highest peel force at -80°C. This is because the soft monomer used in Example 5 was isooctyl acrylate, which has a lower glass transition temperature and can maintain chain segment mobility even at extremely low temperatures. Simultaneously, Example 5 used styrene and isobornyl acrylate as a mixed hard monomer, further optimizing low-temperature toughness. Comparative Example 2 lacked dithiodipropionic acid, and Comparative Example 3 lacked POSS-modified acrylate; both showed significantly lower low-temperature peel forces than all other examples, indicating that the dynamic covalent crosslinking network and POSS structure are crucial for maintaining adhesive strength at low temperatures.

[0046] Analysis of self-healing performance: Example 5 exhibited the highest self-healing efficiency, reaching 90%. The self-healing efficiencies of Examples 1, 2, 3, 4, and 6 were all between 82% and 89%. These results demonstrate that when the formulation contains both dithiodipropionic acid and POSS-modified acrylate, the dynamic disulfide bond network formed through their ring-opening reaction can effectively achieve autonomous healing of microcracks. Comparative Example 2 lacked dithiodipropionic acid, and Comparative Example 3 lacked POSS-modified acrylate; both had self-healing efficiencies below 20%, exhibiting almost no self-healing ability. This fully demonstrates that only the simultaneous presence of dithiodipropionic acid and POSS-modified acrylate can construct an effective dynamic covalent cross-linked network.

[0047] Analysis of UV aging resistance: Example 4 exhibited the highest peel strength retention rate after UV aging, reaching 96%. Examples 1-3, 5, and 6 all showed retention rates between 89% and 93%. These results are attributed to the effective capture of photo-oxidative free radicals by hindered amine acrylate, and the UV shielding effect of the additional KH570 surface-modified nano-cerium dioxide added in Example 4. Comparative Example 1, lacking hindered amine acrylate, showed a retention rate of only 54% after UV aging, indicating severe performance degradation, demonstrating the indispensability of hindered amine acrylate for UV aging resistance.

[0048] Analysis of high-temperature tack performance: The tack performance at 150°C in all embodiments was greater than 1440 min, or 24 h. This indicates that the dual-network interpenetrating structure of the present invention can maintain sufficient cohesive strength under high-temperature conditions. Specifically, the POSS-modified acrylate in Network II provides irreplaceable nano-rigid reinforcing nodes, the piperidine ring rigid side groups of the hindered amine acrylate enhance the high-temperature creep resistance of the physically entangled network, and the siloxane crosslinking nodes of the fluorosilicone monomer further stabilize the network structure. All three are indispensable; the absence of any one will lead to a significant decrease in high-temperature tack performance, failing to meet the stringent requirement of 24 hours at 150°C.

[0049] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent substitutions, and improvements made to the above embodiments without departing from the scope of the present invention, based on the technical essence of the present invention and within the spirit and principles of the present invention, shall still fall within the protection scope of the present invention.

Claims

1. An acrylic pressure-sensitive adhesive resistant to ultra-low temperatures and ultraviolet radiation, characterized in that, The mass fractions of each component in the acrylate pressure-sensitive adhesive are as follows: 45-65 parts of soft monomer, 2-6 parts of hindered amine acrylate, 15-30 parts of hard monomer, 10-20 parts of fluorosilicone monomer, 2.2 parts of thermal initiator, 2-8 parts of POSS-modified acrylate, and 1-5 parts of dithiodipropionic acid.

2. The acrylic pressure-sensitive adhesive resistant to ultra-low temperatures and ultraviolet radiation according to claim 1, characterized in that, The soft monomers and hindered amine acrylates are polymerized under the action of a low concentration of thermal initiator accounting for 0.2% of the total monomer mass, and a physical cross-linked network is formed through effective entanglement.

3. The acrylic pressure-sensitive adhesive resistant to ultra-low temperatures and ultraviolet radiation according to claim 1, characterized in that, Hard monomers, fluorosilicone monomers, and POSS-modified acrylates form a dynamic covalent cross-linked self-healing network. The hard monomers, fluorosilicone monomers, and POSS-modified acrylates are polymerized in situ under the action of a high-concentration thermal initiator accounting for 2% of the total monomer mass. The ring-opening reaction between the epoxy groups of the side chains of POSS-modified acrylates and dithiodipropionic acid forms a covalent cross-linked network containing dynamic disulfide bonds.

4. The acrylic pressure-sensitive adhesive resistant to ultra-low temperatures and ultraviolet radiation according to claim 1, characterized in that, The soft monomer is one or more of ethyl acrylate, butyl acrylate, isooctyl acrylate, lauryl acrylate, lauryl methacrylate, lauryl acrylate, and alkyl dodecyl acrylate.

5. The acrylic pressure-sensitive adhesive resistant to ultra-low temperatures and ultraviolet radiation according to claim 1, characterized in that, The hard monomer is one or more of methyl acrylate, methyl methacrylate, isobornyl acrylate, isobornyl methacrylate, styrene, acrylonitrile, methacrylic acid, and methacryloxypropyl glycidyl ether.

6. The acrylic pressure-sensitive adhesive resistant to ultra-low temperatures and ultraviolet radiation according to claim 1, characterized in that, The hindered amine acrylate is one or both of 4-acryloyloxy-2,2,6,6-tetramethylpiperidine and 4-methacryloyloxy-2,2,6,6-tetramethylpiperidine.

7. The acrylic pressure-sensitive adhesive resistant to ultra-low temperatures and ultraviolet radiation according to claim 1, characterized in that, The fluorosilicone monomer is one or more of vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, trifluoroethyl methacrylate, and hexafluorobutyl methacrylate; The thermal initiator is a peroxide initiator or an azo initiator, specifically one of benzoyl peroxide, dicumyl peroxide, azobisisobutyronitrile, or azobisisoheptanenitrile.

8. The acrylic pressure-sensitive adhesive resistant to ultra-low temperatures and ultraviolet radiation according to claim 1, characterized in that, The acrylic pressure-sensitive adhesive also includes KH570 surface-modified radiation-resistant nanofiller, which is 1-5 parts by weight.

9. A method for preparing the acrylic pressure-sensitive adhesive according to any one of claims 1 to 8, characterized in that, The specific steps include: Step 1: Mix 45-65 parts of soft monomer with 2-6 parts of hindered amine acrylate, add 0.2% of thermal initiator by mass of total monomer, and prepolymerize at 40-60°C for 1-5 hours to form prepolymer A containing a physical entanglement network; Step 2: Mix 15-30 parts of hard monomer, 10-20 parts of fluorosilicone monomer, 2-8 parts of POSS modified acrylate, 1-5 parts of dithiodipropionic acid and 2% of thermal initiator by mass of total monomers to obtain mixture B. Step 3: Add mixture B to prepolymer A, stir evenly, and continue the polymerization reaction at 60-90℃ for 1.5-6 hours to allow the dynamic covalent crosslinked self-healing network to polymerize in situ in the physically entangled network structure to form an interpenetrating network structure, thus obtaining the acrylate pressure-sensitive adhesive. Add 1-5 parts of KH570 surface-modified radiation-resistant nanofiller while adding mixture B.

10. An application of the acrylic pressure-sensitive adhesive according to any one of claims 1 to 8, characterized in that, The acrylate pressure-sensitive adhesive is used in aerospace surface protection materials.

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