An acrylic rubber and a method for producing the same

Abstract

The application belongs to the technical field of elastomer materials, and relates to high-strength and high-toughness acrylic rubber and a preparation method thereof. The high-strength and high-toughness acrylic rubber is formed by cross-linking of ortho-nitroalkyl benzene modified acrylic ester polymer, polymerizable monomer with single functionality or multi-functionality and a photoinitiator. The ortho-nitroalkyl benzene modified acrylic ester polymer is formed by copolymerization of ortho-nitroalkyl benzene monomer and alkyl acrylate monomer under thermal initiation. The ortho-nitroalkyl benzene monomer comprises two covalently connected parts: one part is an ortho-nitroalkyl benzene group with photosensitive activity; and the other part is a polymerizable active group. The application can quickly obtain acrylic ester rubber with high strength and high toughness, and the preparation method of the acrylic ester rubber provided by the application has the advantages of simple steps, no need for high temperature and pressure, easy preparation conditions, short preparation time and significant advantages in the preparation process.

Description

Technical Field

[0001] This invention belongs to the field of elastomer materials technology, and in particular relates to a high-strength and tough acrylic rubber and its preparation method. Background Technology

[0002] Acrylic rubber is a material obtained by copolymerizing alkyl acrylates as the main monomer, along with functional monomers and a small amount of vulcanizate monomers with crosslinking active groups. Because the main chain of acrylic rubber is a saturated carbon chain and the side groups contain highly polar ester groups, acrylic rubber possesses many excellent properties, such as heat resistance, oil resistance, aging resistance, ozone resistance, and UV resistance. Various products made from acrylic rubber are widely used in the automotive, aerospace, chemical, pharmaceutical, and transportation industries. In recent years, with the rapid development of soft robots, intelligent actuators, electronic sensors, and other related fields, the demand for high-performance acrylic rubber as a raw material for manufacturing electrically driven deformable components—dielectric elastomers—is increasing daily.

[0003] Current acrylic rubber technology still has many shortcomings in terms of mechanical properties and processing. In terms of mechanical properties, acrylic rubber often faces a dilemma of balancing strength and toughness. On the one hand, to ensure the elastic properties of the material, the crosslinking density of acrylic rubber is usually low, with the content of the vulcanizing point monomer generally not exceeding 5 wt%. Low crosslinking density gives acrylic rubber excellent deformation capacity and toughness, but also results in the strength of acrylic rubber generally being below 10 MPa or even lower. For example, the TangoBlack and Agilus30 Clear series of acrylic rubbers developed by Stratasys have a maximum strain of 240%, but a tensile strength of only 3.1 MPa. On the other hand, many applications (such as dielectric elastomers) often require acrylic rubber to have a Young's modulus as low as several megapascals or even kilopascals to match the high deformation requirements of these applications. To ensure a low modulus, it is often necessary to further reduce the crosslinking density. In this case, the strength of the acrylic rubber is even more difficult to guarantee, and may even fail to reach the megapascal level. For example, the widely used VHB acrylic rubber developed by 3M... TM 4910 has a modulus of 0.23 MPa and a toughness of 4.88 MJ / m. 3 Its strength is only 0.99 MPa. It can be seen that in order to ensure high toughness or low modulus, the strength of the elastomer is often sacrificed.

[0004] In terms of processing and preparation, acrylic rubber is usually produced from raw rubber through a high-temperature vulcanization process, which involves harsh conditions such as high temperature and high pressure, and the preparation process is lengthy and complex. The contradiction between strength and toughness, as well as the processing and preparation problems mentioned above, limit the further development and application of acrylic rubber, especially in high-value-added and cutting-edge fields such as soft robots and electronic sensors. Summary of the Invention

[0005] In view of the current situation where strength and toughness of acrylate rubber cannot be simultaneously achieved, this invention proposes a high-strength and high-toughness acrylate rubber and its preparation method. Based on the solution provided by this invention, acrylate rubber with both high strength and high toughness can be obtained quickly. Furthermore, the preparation method of the acrylate rubber provided by this invention has simple steps, does not require high temperature or pressure, the preparation conditions are readily available, and the preparation time is short, which has significant advantages in the preparation process.

[0006] This invention first prepares an acrylate polymer containing photosensitive active groups by copolymerization, and then crosslinks it based on photopolymerization to form a high-strength and tough acrylate rubber.

[0007] The objective of this invention can be achieved through the following technical solutions:

[0008] The first objective of this invention is to provide an o-nitroalkylbenzene monomer that simultaneously possesses both photosensitive active groups and polymerizable active groups.

[0009] The o-nitroalkylbenzene monomer comprises two covalently linked structural parts: one part is a photosensitive o-nitroalkylphenyl group; the other part is a polymerizable active group. The structure is shown in Formula I:

[0010]

[0011] Wherein, R1 is an alkyl group containing 1 to 10 carbon atoms; R2 and R3 are independently selected from hydrogen, hydroxyl, mercapto, halogen, alkoxy, alkyl or modified alkyl, wherein the modified alkyl is a group obtained by replacing any carbon atom of an alkyl group with other heteroatoms or groups; P is a polymerizable active group containing a double bond and covalently connected to R2 or R3.

[0012] Preferably, R1 is selected from methyl or ethyl; R2 and R3 are independently selected from hydrogen, hydroxyl, halogen atom, alkyl or alkoxy; and P is an active group containing polymerizable double bonds.

[0013] Further preferably, R1 is selected from methyl or ethyl; R2 and R3 are independently selected from hydrogen, hydroxyl, halogen atom, alkyl or alkoxy; and P is an active group containing an acrylate, methacrylate, acrylamide, methacrylamide or styrene structure.

[0014] More preferably, the o-nitroalkylbenzene monomer is selected from any one of the monomers with the structures shown in a1 to a21 below:

[0015]

[0016] A second objective of the present invention is to provide an acrylate polymer modified with o-nitroalkylbenzene.

[0017] The acrylate polymer is formed by copolymerization of the o-nitroalkylbenzene monomer and the alkyl acrylate monomer provided in the first object of the present invention under thermal initiation conditions.

[0018] In one embodiment of the invention, the acrylate polymer is formed by copolymerization of the o-nitroalkylbenzene monomer, the alkyl acrylate monomer, and the functional monomer provided in the first object of the invention under thermal initiation conditions.

[0019] In one embodiment of the present invention, the alkyl acrylate monomer is an alkyl-containing acrylate monomer or an alkyl-containing methacrylate monomer, wherein the alkyl length of the alkyl acrylate monomer is 1 to 20 carbon atoms.

[0020] Preferably, the alkyl acrylate monomer is selected from ethyl acrylate monomer, n-butyl acrylate monomer, lauryl acrylate monomer, 2-ethylhexyl acrylate monomer, lauryl methacrylate monomer, or n-octyl methacrylate monomer.

[0021] In one embodiment of the present invention, the functional monomer refers to a monomer that, after copolymerization with alkyl acrylate monomers, can improve one or more of the following properties of acrylate rubber: high temperature resistance, aging resistance, modulus, adhesion, stain resistance, water resistance, solvent resistance, refractive index, weather resistance, flexibility, or glass transition temperature.

[0022] In one embodiment of the present invention, the content of the functional monomer is adjusted according to the performance requirements of the desired polymer, preferably 0%-50%, and when the content of the functional monomer is 0, it means that no functional monomer is added.

[0023] In one embodiment of the present invention, the functional monomer is selected from one or more of maleic acid, fumaric acid, monomethyl fumarate, methyl methacrylate, ethyl methacrylate, styrene, acrylonitrile, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, acrylamide, acrylic acid, methacrylic acid, or styrene sulfonic acid.

[0024] In one embodiment of the present invention, the copolymerization method of o-nitroalkylbenzene monomer and alkyl acrylate monomer under thermal initiation conditions is selected from one of bulk polymerization, solution polymerization, precipitation polymerization or emulsion polymerization.

[0025] In one embodiment of the present invention, the copolymerization method of the o-nitroalkylbenzene monomer, the alkyl acrylate monomer, and the functional monomer under thermal initiation conditions is selected from one of bulk polymerization, solution polymerization, precipitation polymerization, or emulsion polymerization.

[0026] Preferably, the copolymerization method is selected from emulsion polymerization.

[0027] A third objective of this invention is to provide a high-strength, high-toughness acrylate rubber.

[0028] The high-strength and tough acrylate rubber is formed by crosslinking an acrylate polymer modified with o-nitroalkylbenzene, as provided in the second objective of this invention, a monofunctional or polyfunctional polymerizable monomer, and a photoinitiator.

[0029] In one embodiment of the present invention, the monofunctional or polyfunctional polymerizable monomer is a substance containing one or more polymerizable double bonds in its molecular structure, wherein the polymerizable double bonds are selected from acryloyl, methacryl, styrene, acrylonitrile, and alkenyl.

[0030] In one embodiment of the present invention, the monofunctional or polyfunctional polymerizable monomer is selected from 2-phenoxyethyl acrylate, isobornyl methacrylate, isobornyl acrylate, trimethylolpropane formal acrylate, cyclohexanediol diacrylate, bisphenol A dimethacrylate, bisphenol A diacrylate, triethylene glycol diacrylate, tripropylene glycol diacrylate, ethylene glycol dimethacrylate, tetraethylene glycol triacrylate, 1,6-hexanediol diacrylate, 1,3-butanediol diacrylate, tricyclodecanediol diacrylate, trimethylolpropane triacrylate, tri(2-hydroxyethyl)isocyanurate triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, tripentaerythritol triacrylate, N-acryloylmorpholine, tetrahydrofuran acrylate, acrylic acid, and oligomers containing acrylate or methacrylate groups.

[0031] In one embodiment of the invention, the oligomer refers to a polymer composed of a relatively small number of repeating units, wherein the relatively small number of repeating units refers to 10-100 repeating units.

[0032] In one embodiment of the present invention, the oligomer containing acrylate or methacrylate groups is selected from epoxy acrylate, polyester acrylate, polyether acrylate or polyurethane acrylate.

[0033] In one embodiment of the present invention, the photoinitiator is a compound that can absorb energy of a certain wavelength in the ultraviolet or visible light region, generate free radicals, and thereby initiate polymerization or cross-linking.

[0034] In one embodiment of the present invention, the photoinitiator is preferably one or more of the following: hydroxy-methylphenylpropane-1-one, methyl-2-(4-morpholino)-1-[4-(methylthio)phenyl]-1-propanone, phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, ethyl 2,4,6-trimethylbenzoylphenylphosphonate, hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone, or lithium phenyl(2,4,6-trimethylbenzoyl)phosphate.

[0035] In one embodiment of the present invention, the mass contents of the o-nitroalkylbenzene modified acrylate polymer, the monofunctional or polyfunctional polymerizable monomer, and the photoinitiator in the high-strength and tough acrylate rubber are preferably 30% to 99%, 1% to 70%, and 0.05% to 10%, respectively.

[0036] A fourth objective of this invention is to provide a method for preparing high-strength and high-toughness acrylate rubber, wherein one of the following methods is selected:

[0037] An acrylate polymer modified with o-nitroalkylbenzene, a monofunctional or polyfunctional polymerizable monomer, and a photoinitiator are directly mixed uniformly and then photocrosslinked; or,

[0038] An acrylate polymer modified with o-nitroalkylbenzene, a monofunctional or polyfunctional polymerizable monomer, and a photoinitiator are mixed uniformly in a suitable solvent, and after removing the solvent, they are photocrosslinked; or,

[0039] An acrylate polymer modified with o-nitroalkylbenzene, a monofunctional or polyfunctional polymerizable monomer, and a photoinitiator are mixed uniformly in a suitable solvent, and then the solvent is removed after photocrosslinking.

[0040] In some embodiments of the present invention, the solvent may be selected as needed, for example, it may be dichloromethane, etc.

[0041] In some embodiments of the present invention, the conditions for photocrosslinking can be selected as needed, for example, a light intensity of 100 mW / cm². 2 Irradiate it with a light source with a wavelength of 395nm to completely cure it, and the curing time is 30-300s.

[0042] Traditional acrylate rubbers rely on free radical polymerization reactions that polymerize double bonds or chemical reactions between sulfur and double bonds, or chlorine and metal oxides, to achieve crosslinking. These crosslinking reactions are highly inefficient; for example, when sulfur is used to vulcanize olefins, only 40-50% of the sulfur effectively achieves crosslinking.

[0043] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0044] The crosslinking of o-nitroalkylbenzene with polymerizable double bonds provided by this invention is based on the reaction principle of nitrosyl intermediate (photolysis product of o-nitroalkylbenzene) and carbon free radicals. This is achieved thanks to the extremely high reaction rate (rate constant 10) between nitrosyl and carbon free radicals. 8 -10 9 L·mol -1 s -1 The o-nitroalkylbenzene exhibits high crosslinking efficiency with polymerizable double bonds, resulting in a more complete crosslinking network in the obtained rubber material. This effectively promotes force transmission between internal structures under stress, thereby synergistically enhancing the material's strength and toughness. Therefore, based on the introduction of o-nitroalkylbenzene crosslinking groups, the acrylate rubber provided by this invention achieves excellent strength and toughness.

[0045] Furthermore, unlike the high temperature, pressure, and long vulcanization conditions required for the preparation of traditional acrylate rubber, the acrylate rubber provided by this invention has a simple preparation process, does not require high temperature or pressure, has readily available preparation conditions, and requires a short preparation time, thus having significant advantages in the preparation process. Attached Figure Description

[0046] Figure 1 The results are the dynamic mechanical properties test results of formulation 12 acrylate rubber.

[0047] Figure 2 These are photos of the acrylic rubber of Formula 5 before and during stretching.

[0048] Figure 3 The tensile stress-strain curve of the acrylic rubber in formulation 2 is shown.

[0049] Figure 4 The stress-strain curve of the acrylic rubber of formulation 2 after 10 cycles of tensile stress is shown.

[0050] Figure 5 The tensile stress-strain curve of formulation 6 acrylate rubber is shown.

[0051] Figure 6 The stress-strain curve of formulation 6 acrylate rubber after 10 cycles of tensile stretching.

[0052] Figure 7 The tensile stress-strain curve of formulation 12 acrylate rubber is shown.

[0053] Figure 8 The stress-strain curve of formulation 12 acrylate rubber after 10 cycles of tensile stretching.

[0054] Figure 9 A photograph of a 2kg weight being lifted from a 17-acrylate rubber sample. Detailed Implementation

[0055] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0056] Examples 1 to 21: Synthesis of o-nitroalkylbenzene monomers

[0057] Example 1: Synthesis of monomer a1

[0058]

[0059] Synthesis of compound a1-1: 2-Methoxy-4-methylphenol (13.8 g, 0.1 mol), 2-bromoethyl acetate (33.4 g, 0.2 mol), and anhydrous potassium carbonate (41.5 g, 0.3 mol) were dissolved in anhydrous N,N-dimethylformamide (DMF, 200 mL) and stirred overnight at room temperature. After the reaction was complete, the solvent was evaporated, the system was dissolved in dichloromethane, and extracted three times with water and saturated brine, respectively. The organic phase was dried over anhydrous sodium sulfate, and the crude product was purified by column chromatography. The pure product was a colorless liquid (20 g, 90%). 1 H NMR (400MHz, Chloroform-d): δ = 7.00 (d, 1H), 6.89 (ddd, 2H), 4.54 (t, 2H), 4.46 (t, 2H), 3.90 (s, 3H), 2.35 (t, 3H), 2.02 (s, 3H). MS (ESI): [M+H] 225.1122.

[0060] Synthesis of compound a1-2: The synthesis was carried out according to the method disclosed in Yunlong Yang, Jieyuan Zhang, Zhenzhen Liu, Qiuning Lin, Xiaolin Liu, Chunyan Bao, Yang Wang, Linyong Zhu. Adv. Mater., 2016, 28, 2724-2730. 1 H NMR (400MHz, Chloroform-d): δ = 6.85 (s, 1H), 6.76 (s, 1H), 4.54 (t, 2H), 4.46 ( t,2H),3.90(s,3H),2.29-2.23(m,6H),2.02(s,3H).MS(ESI):[M+H]270.097.

[0061] Synthesis of compound a1-3: Compound a1-2 (5.38 g, 0.02 mol) was dissolved in methanol (100 mL), and sodium hydroxide (NaOH, 10% by mass) aqueous solution was added dropwise. The reaction was monitored by thin-layer chromatography until completion. After the reaction was complete, the solvent was evaporated, the system was dissolved in dichloromethane, and extracted three times with water and saturated brine, respectively. The organic phase was dried over anhydrous sodium sulfate, and the organic phase was evaporated. The crude product was purified by column chromatography, and the pure product was a yellow solid (4.2 g, 92%). 1 H NMR (400MHz, Chloroform-d): δ = 7.69 (s, 1H), 7.24 -7.19(m,1H),4.45(t,2H),3.90(s,3H),3.74(td,2H),2.38(d,3H),1.93(t,1H).MS(ESI):[M+H]228.0867.

[0062] Synthesis of monomer a1: Compound a1-3 (4.54 g, 0.02 mol) was dissolved in anhydrous dichloromethane (100 mL), followed by the addition of anhydrous triethylamine (20.2 g, 0.2 mol). Acryloyl chloride (14.48 g, 0.16 mol) was then added dropwise under ice bath conditions, and the mixture was stirred overnight at room temperature. After the reaction was complete, the solvent was evaporated, and the system was dissolved in dichloromethane. The mixture was extracted three times with water and saturated brine, respectively. The organic phase was dried over anhydrous sodium sulfate, and the crude product was purified by column chromatography. The pure product was a colorless liquid (4.83 g, 86%). 1 H NMR (400MHz, Chloroform-d): δ = 7.64 (s, 1H), 7.13 (s, 1H), 6.42 (dd, 1H), 6.17 (dd, 1H) ,5.86(dd,1H),4.58–4.49(m,4H),3.90(s,3H),2.36(d,3H).MS(ESI):[M+H]282.0970.

[0063] Example 2: Synthesis of monomer a2

[0064]

[0065] Synthesis of compound a2-1: Imidazole (4.68 g, 0.068 mol) and triphenylphosphine (18 g, 0.068 mol) were added to a tetrahydrofuran solution (THF, 150 mL). Iodine (17.46 g, 0.068 mol) was added at 0 °C. After stirring for 5 minutes, diethylene glycol (3.71 g, 0.035 mol) was added. The mixture was reacted at room temperature for another 2 hours, then evaporated under reduced pressure to remove THF, and purified by column chromatography to obtain compound a2-1 (4.5 g, 60%).1 H NMR (400MHz, Chloroform-d): δ = 4.09 (dt, 2H), 3.94 (t, 2H), 3.60 (t, 2H), 3.10 (t, 2H), 2.24 (t, 1H). MS (ESI): [M+H] 216.9722.

[0066] Synthesis of compound a2-2: The synthesis was carried out by referring to the synthesis method of compound a1-1. 1 H NMR (400MHz, Chloroform-d): δ=7.07–6.96(m,2H),6.98–6.90(m,1H),4.17(t,2H),4.09(dt,2 H),3.90(s,3H),3.81(t,2H),3.60(t,2H),2.35(t,3H),2.16(t,1H).MS(ESI):[M+H]227.1280.

[0067] Synthesis of compound a2-3: Compound a2-2 (4.54 g, 0.02 mol) was dissolved in anhydrous dichloromethane (100 mL), and anhydrous triethylamine (20.2 g, 0.2 mol) was added. Acetyl chloride (12.56 g, 0.16 mol) was added dropwise under ice bath conditions, and the mixture was stirred overnight at room temperature. After the reaction was complete, the solvent was evaporated, and the system was dissolved in dichloromethane. The mixture was extracted three times with water and saturated brine, respectively. The organic phase was dried over anhydrous sodium sulfate, and the crude product was purified by column chromatography. The pure product was a colorless liquid (4.83 g, 86%). 1H NMR (400MHz, Chloroform-d): δ = 6.95-6.83 (m, 2H), 6.87 (s, 1H), 4.19 (dt, 2H), 3.90 ( s,3H),3.81(t,2H),3.69(t,2H),2.35(d,3H),2.02(s,3H).MS(ESI):[M+H]269.1382.

[0068] Synthesis of compound a2-4: The synthesis was carried out according to the method disclosed in Yunlong Yang, Jieyuan Zhang, Zhenzhen Liu, Qiuning Lin, Xiaolin Liu, Chunyan Bao, Yang Wang, Linyong Zhu. Adv. Mater., 2016, 28, 2724-2730. 1H NMR (400MHz, Chloroform-d): δ = 7.63 (s, 1H), 7.14 (s, 1H), 4.19 (dt, 4H), 3.90 (s, 3 H),3.81(t,2H),3.69(t,2H),2.37(d,3H),2.02(s,3H).MS(ESI):[M+H]314.1230.

[0069] Synthesis of compound a2-5: The synthesis was carried out by referring to the synthesis method of compound a1-3. 1 H NMR (400MHz, Chloroform-d): δ = 7.64 (s, 1H), 7.21 (s, 1H), 4.17 (t, 2H), 4.09 (dt, 2H), 3. 90(s,3H),3.81(t,2H),3.60(t,2H),2.37(d,3H),2.25(t,1H).MS(ESI):[M+H]272.1131.

[0070] Synthesis of monomer a2: Synthesized using the same method as monomer a1. 1 H NMR (400MHz, Chloroform-d): δ = 7.61 (s, 1H), 7.03 (s, 1H), 6.43 (dd, 1H), 6.16 (dd, 1H), 5.85 (dd, 1H), 4 .28(t,2H),4.17(t,2H),3.90(s,3H),3.81(t,2H),3.69(t,2H),2.38(d,3H).MS(ESI):[M+H]312.1077.

[0071] Example 3: Synthesis of monomer a3

[0072]

[0073] Synthesis of compound a3-1: The synthesis was carried out by referring to the synthesis method of compound a2-1. 1 H NMR (400MHz, Chloroform-d): δ = 4.09 (dt, 2H), 3.94 (t, 2H), 3.60 (d, 6H), 3.10 (t, 2H), 2.16 (t, 1H). MS (ESI): [M+H] 260.9980.

[0074] Synthesis of compound a3-2: The synthesis was carried out by referring to the synthesis method of compound a1-1. 1H NMR (400MHz, Chloroform-d): δ = 7.06-6.88 (m, 3H), 4.21-4.04 (m, 4H), 3.90 (s, 3H), 3.8 1(t,2H),3.61(s,4H),3.60(t,2H),2.35(t,3H),1.88(t,1H).MS(ESI):[M+H]256.1305.

[0075] Synthesis of compound a3-3: The synthesis was carried out by referring to the synthesis method of compound a2-3. 1 H NMR (400MHz, Chloroform-d): δ = 7.06–6.88 (m, 3H), 4.19 (dt, 4H), 3.90 (s, 3H), 3.81 ( t,2H),3.69(t,2H),3.61(s,4H),2.35(s,2H),2.02(s,3H).MS(ESI):[M+H]313.1644.

[0076] Synthesis of compound a3-4: The synthesis was carried out according to the method disclosed in Yunlong Yang, Jieyuan Zhang, Zhenzhen Liu, Qiuning Lin, Xiaolin Liu, Chunyan Bao, Yang Wang, Linyong Zhu. Adv. Mater., 2016, 28, 2724-2730. 1 H NMR (400MHz, Chloroform-d): δ = 6.91–6.83 (m, 2H), 4.19 (dt, 4H), 3.90 (s, 3H), 3.81 (t, 2 H),3.69(t,2H),3.61(s,4H),2.29–2.23(m,6H),2.02(s,3H).MS(ESI):[M+H]358.1496.

[0077] Synthesis of compound a3-5: The synthesis was carried out by referring to the synthesis method of compound a1-3. 1 H NMR (400MHz, Chloroform-d): δ = 7.68 (s, 1H), 7.22 (s, 1H), 4.17 (t, 2H), 4.09 (dt, 2H), 3. 90(s,3H),3.81(t,2H),3.60(d,6H),2.37(d,3H),2.24(t,1H).MS(ESI):[M+H]316.1390.

[0078] Synthesis of monomer a3: The synthesis was carried out by referring to the synthesis method of monomer a1. 1H NMR (400MHz, Chloroform-d): δ = 7.68 (s, 1H), 7.23 (s, 1H), 6.43 (dd, 1H), 6.15 (dd, 1H), 5.85 (dd, 1H), 4.28 (t, 2H),4.17(t,2H),3.90(s,3H),3.81(t,2H),3.69(t,2H),3.61(s,4H),2.37(d,3H).MS(ESI):[M+H]370.1495.

[0079] Example 4: Synthesis of monomer a4

[0080]

[0081] Synthesis of compound a4-1: The synthesis was carried out by referring to the synthesis method of compound a1-1. 1 H NMR (400MHz, Chloroform-d): δ = 7.05–6.89 (m, 3H), 4.13 (dt, 4H), 3.90 (s, 3H), 2.35(t,3H),2.02(s,3H),1.77(dq,4H),1.32(p,2H).MS(ESI):[M+H]267.1597.

[0082] Synthesis of compound a4-2: The synthesis was carried out according to the method disclosed in Yunlong Yang, Jieyuan Zhang, Zhenzhen Liu, Qiuning Lin, Xiaolin Liu, Chunyan Bao, Yang Wang, Linyong Zhu. Adv. Mater., 2016, 28, 2724-2730. 1 H NMR (400MHz, Chloroform-d): δ = 7.57 (s, 1H), 7.00 (q, 1H), 4.13 (dt, 4H), 3.90 (s, 3 H),2.37(d,3H),2.02(s,3H),1.78(dp,4H),1.32(p,2H).MS(ESI):[M+H]312.1440.

[0083] Synthesis of compound a4-3: The synthesis was carried out by referring to the synthesis method of compound a1-3. 1H NMR (400MHz, Chloroform-d): δ = 7.58 (s, 1H), 7.01 (s, 1H), 4.11 (t, 2H), 3.90 (s, 3H), 3.62 (t d,2H),2.26(d,7H),1.82(p,2H),1.58(p,2H),1.36–1.23(m,3H).MS(ESI):[M+H]270.1336.

[0084] Synthesis of monomer a4: The synthesis was carried out by referring to the synthesis method of monomer a1. 1 H NMR (400MHz, Chloroform-d): δ = 7.58 (s, 1H), 7.01 (s, 1H), 6.43 (dd, 1H), 6.16 (dd, 1H), 5.85 (dd, 1 H),4.14(dt,4H),3.90(s,3H),2.37(d,3H),1.78(dp,4H),1.32(p,2H).MS(ESI):[M+H]324.1440.

[0085] Example 5: Synthesis of monomer a5

[0086]

[0087] Synthesis of monomer a5: Synthesized using the same method as monomer a1. 1 H NMR (400MHz, Chloroform-d): δ = 61 (s, 1H), 7.16 (s, 1H), 6.22 (dq, 1H), 5.84 (dq, 1H), 4.5 4(s,3H),4.53(d,1H),3.90(s,3H),2.37(d,3H),2.06(t,3H).MS(ESI):[M+H]296.1130.

[0088] Example 6: Synthesis of monomer a6

[0089]

[0090] Synthesis of compound a6-1: The synthesis was performed following the same method as compound a2-1. 1 H NMR (400MHz, Chloroform-d): δ = 3.99–3.79 (m, 2H), 3.32 (ddd, 2H), 3.17 (dd, 1H) ,3.08(dd,1H),2.57(d,1H),1.21(d,3H),1.12(d,3H).MS(ESI):[M+H]245.0033.

[0091] Synthesis of compound a6-2: The synthesis was carried out by referring to the synthesis method of compound a1-1. 1 H NMR (400MHz, Chloroform-d): δ = 6.95–6.83 (m, 3H), 4.17 (dd, 1H), 3.98–3.89 (m, 1H), 3.90 (s, 3H), 3.91–3. 81(m,1H),3.33(dd,1H),3.09(dd,1H),2.57(d,1H),2.35(t,3H),1.15(dd,6H).MS(ESI):[M+H]255.1590.

[0092] Synthesis of compound a6-3: The synthesis was performed following the method used for compound a2-3. ¹H NMR (400 MHz, Chloroform-d): δ = 7.02–6.87 (m, 3H), 4.82 (h, 1H), 4.22–4.10 (m, 1H), 3.90 (s, 3H), 3.95–3.84 (m, 2H), 3.64 (dd, 1H), 3.14 (dd, 1H), 2.35 (t, 3H), 2.11 (s, 3H), 1.27 (d, 3H), 1.22–1.11 (m, 3H). MS (ESI): [M+H] 297.1697.

[0093] Synthesis of compound a6-4: The synthesis was carried out according to the method disclosed in Yunlong Yang, Jieyuan Zhang, Zhenzhen Liu, Qiuning Lin, Xiaolin Liu, Chunyan Bao, Yang Wang, Linyong Zhu. Adv. Mater., 2016, 28, 2724-2730. 1 H NMR (400MHz, Chloroform-d): δ = 7.67 (s, 1H), 7.23 (q, J = 1.1Hz, 1H), 4.85 (h, 1H), 4.35 (dd, 1H), 3.93 (dt, 1H), 3.90 (s, 3H) ,3.82(dd,1H),3.60(dd,1H),3.21(dd,1H),2.38(d,3H),2.11(s,3H),1.24(d,3H),1.15(d,3H).MS(ESI):[M+H]342.1547.

[0094] Synthesis of compound a6-5: The synthesis was carried out by referring to the synthesis method of compound a1-3. 1H NMR (400MHz, Chloroform-d): δ = 7.48 (s, 1H), 7.13 (q, 1H), 4.18–4.06 (m, 1H), 4.01–3.85 (m, 3H), 3.90 ( s,4H),3.34(dd,1H),3.08(dd,1H),2.57(d,1H),2.36(d,3H),1.15(dd,6H).MS(ESI):[M+H]300.1442.

[0095] Synthesis of monomer a6: The synthesis was carried out by referring to the synthesis method of monomer a1. 1 H NMR (400MHz, Chloroform-d): δ = 7.66 (s, 1H), 7.16 (q, 1H), 6.21 (dd, 1H), 5.84 (dq, 1H), 4.89 (h, 1H), 4.31 (dd, 1H), 3.99–3.86 (m, 1H), 3.90(s,3H),3.83(dd,1H),3.50(dd,1H),3.29(dd,1H),2.37(d,3H),2.06(d,3H),1.27(d,3H),1.17(d,3H).MS(ESI):[M+H]368.1704.

[0096] Example 7: Synthesis of monomer a7

[0097]

[0098] Synthesis of monomer a7: Synthesized using the same method as monomer a1. 1 H NMR (400MHz, Chloroform-d): δ = 7.61 (s, 1H), 7.02 (s, 1H), 6.21 (dt, 1H), 5.83 (dq, 1H), 4.28 (t, 2H),4.17(t,2H),3.90(s,3H),3.81(t,2H),3.69(t,2H),3.61(s,4H),2.37(d,3H),2.05(t,4H).

[0099] Example 8: Synthesis of monomer a8

[0100]

[0101] Synthesis of monomer a8: The synthesis was carried out by referring to the synthesis method of monomer a1. 1H NMR (400MHz, Chloroform-d): δ = 7.62 (s, 1H), 7.11 (s, 1H), 6.20 (dq, 1H), 5.84 (dq, 1H), 4.14 (dt, 4H),3.90(s,3H),2.37(d,3H),2.04(d,3H),1.78(dp,4H),1.32(p,2H).MS(ESI):[M+H]338.1660.

[0102] Example 9: Synthesis of monomer a9

[0103]

[0104] Synthesis of compound a9-1: Potassium o-phenylenediamine (16.5 g, 0.089 mol) was added to a DMF solution (40 mL) of 2-[2-(2-chloroethoxy)ethoxy]ethanol (10 g, 0.059 mol). The mixture was stirred at 90 °C for 8 hours under nitrogen protection, and the DMF was removed by evaporation under reduced pressure. The mixture was then redissolved in dichloromethane and extracted three times with water and saturated brine, respectively. The organic phase was dried over anhydrous sodium sulfate, and the crude product was purified by column chromatography to obtain a white solid (13.8 g, 84%). 1 H NMR (400MHz, CDCl3): δ=7.84(dd,2H),7.71(dd,2H),3.90(t,2H),3.75(t,2H),3. 67-3.63(t,4H),3.62-3.58(m,2H),3.56-3.50(m,2H).MS(ESI):[M+H]236.0918.

[0105] Synthesis of compound a9-2: The synthesis was carried out by referring to the synthesis method of compound a2-1. 1 H NMR (400MHz, Chloroform-d): δ = 7.80 (dd, 2H), 7.70 (dd, 2H), 3.94 (t, 2H), 3.81 (d, 1H), 3.80 (s, 3H), 3.10 (t, 2H). MS (ESI): [M+H] 345.9935.

[0106] Synthesis of compound a9-3: The synthesis was carried out by referring to the synthesis method of compound a1-1. 1H NMR (400MHz, Chloroform-d): δ = 7.80 (dd, 2H), 7.70 (dd, 2H), 6.97 (d, 1H), 6.82 (s, 2H) ,4.17(t,2H),3.90(s,3H),3.81(q,6H),2.38–2.32(m,3H).MS(ESI):[M+H]356.1494.

[0107] Synthesis of compound a9-4: The synthesis was carried out according to the method disclosed in Yunlong Yang, Jieyuan Zhang, Zhenzhen Liu, Qiuning Lin, Xiaolin Liu, Chunyan Bao, Yang Wang, Linyong Zhu. Adv. Mater., 2016, 28, 2724-2730. 1 H NMR (400MHz, Chloroform-d): δ = 7.80 (dd, 2H), 7.70 (dd, 2H), 7.59 (s, 1H), 7.13 (q, 1H),4.17(t,2H),3.90(s,3H),3.81(q,6H),2.38(d,3H).MS(ESI):[M+H]401.1341.

[0108] Synthesis of compound a9-5: Hydrazine hydrate (2.23 g, 0.01 mol) was added to an ethanol solution (250 mL) of compound a9-4 (4 g, 0.01 mol), and the system was stirred at 80 °C for about 1 hour. After filtration under reduced pressure, the filtrate was collected, evaporated under vacuum, and purified by column chromatography to obtain the product (1.89 g, 70%). 1 H NMR (400MHz, Chloroform-d): δ = 7.67 (s, 1H), 7.23 (s, 1H), 4.17 (t, 2H), 3.90 (s, 3H), 3.8 1(t,2H),3.74(t,2H),2.82(t,2H),2.37(d,3H),1.10(s,2H).MS(ESI):[M+H]271.1290.

[0109] Synthesis of monomer a9: The synthesis was carried out by referring to the synthesis method of monomer a1. 1H NMR (400MHz, Chloroform-d): δ = 7.66 (s, 1H), 7.15 (s, 1H), 6.48 (dd, 1H), 6.44 (s, 1H), 6.13 (dd, 1H), 5.69 (dd, 1H),4.17(t,2H),3.90(s,3H),3.81(t,2H),3.74(t,2H),3.13(t,2H),2.38(d,3H).MS(ESI):[M+H]325.1394.

[0110] Example 10: Synthesis of monomer a10

[0111]

[0112] Synthesis of compound a10-1: The synthesis was carried out following the method for the synthesis of compound a1-1. 1 H NMR (400MHz, Chloroform-d): δ = 7.80 (dd, 2H), 7.70 (dd, 2H), 7.06–6.89 (m, 3H), 4.11 (t, 2H), 3.90(s,3H),3.61(t,2H),2.35(t,3H),1.74(dp,4H),1.32(q,2H).MS(ESI):[M+H]354.1698.

[0113] Synthesis of compound a10-2: The synthesis was carried out according to the method disclosed in Yunlong Yang, Jieyuan Zhang, Zhenzhen Liu, Qiuning Lin, Xiaolin Liu, Chunyan Bao, Yang Wang, Linyong Zhu. Adv. Mater., 2016, 28, 2724-2730. 1 H NMR (400MHz, Chloroform-d): δ = 7.80 (dd, 2H), 7.74–7.65 (m, 3H), 7.16 (q, 1H), 4.11 (t, 2H), 3.90 ( s,3H),3.61(t,2H),2.38(d,3H),1.86–1.62(m,4H),1.37–1.24(m,2H).MS(ESI):[M+H]399.1550.

[0114] Synthesis of compound a10-3: The synthesis was carried out by referring to the synthesis method of compound a9-5. 1H NMR (400MHz, Chloroform-d): δ = 7.58 (s, 1H), 7.00 (s, 1H), 4.11 (t, 2H), 3.90 (s, 3H), 2.6 1(t,2H),2.37(d,3H),1.76(dp,4H),1.32(q,2H),1.10(s,2H).MS(ESI):[M+H]369.1498.

[0115] Synthesis of monomer a10: The synthesis was carried out by referring to the synthesis method of monomer a1. 1 H NMR (400MHz, Chloroform-d): δ = 7.64 (s, 1H), 7.17 (s, 1H), 6.48 (dd, 1H), 6.30 (s, 1H), 6.23 (dd, 1H), 5.72 (dd, 1H), 4 .11(t,2H),3.90(s,3H),3.21(t,2H),2.37(d,3H),1.80(p,2H),1.61(p,2H),1.32(q,2H).MS(ESI):[M+H]323.1600.

[0116] Example 11: Synthesis of monomer a11

[0117]

[0118] Synthesis of monomer a11: Synthesized according to the method for synthesizing monomer a1. 1 H NMR (400MHz, Chloroform-d): δ = 7.67 (s, 1H), 6.98 (q, 1H), 6.46 (s, 1H), 5.58 (dq, 1H), 5.37 (dq, 1H), 4.17 (t, 2H),3.90(s,3H),3.81(t,2H),3.74(t,2H),3.13(t,2H),2.39(d,3H),1.96(d,3H).MS(ESI):[M+H]339.1550.

[0119] Example 12: Synthesis of monomer a12

[0120]

[0121] Synthesis of monomer a12: Synthesized using the same method as monomer a1. 1H NMR (400MHz, Chloroform-d): δ = 7.58 (s, 1H), 7.01 (s, 1H), 6.19 (s, 1H), 5.54 (dq, 1H), 5.37–5.31 (m, 1H), 4.11 (t, 2H), 3.90(s,3H),3.21(t,2H),2.37(d,3H),1.98(t,3H),1.80(tt,2H),1.61(p,2H),1.32(q,2H).MS(ESI):[M+H]337.1760.

[0122] Example 13: Synthesis of monomer a13

[0123]

[0124] Synthesis of compound a13-1: The synthesis was carried out by referring to the synthesis method of compound a2-2. 1 H NMR (400MHz, Chloroform-d): δ = 6.99–6.84 (m, 3H), 4.17 (t, J = 3.4Hz, 2H), 4.09 (dt, J = 5.0, 3.8Hz, 2H), 3.88(s,3H),3.81(t,J=3.4Hz,2H),3.60(t,J=3.8Hz,2H),2.38–2.29(m,4H).MS(ESI):[M+H]227.1280.

[0125] Synthesis of compound a13-2: The synthesis was carried out by referring to the synthesis method of compound a2-3. 1 H NMR (400MHz, Chloroform-d): δ = 7.04–6.90 (m, 3H), 4.19 (dt, 4H), 3.88 (s, 3H), 3.81(t,2H),3.69(t,2H),2.35(t,3H),2.02(s,3H).MS(ESI):[M+H]269.1382.

[0126] Synthesis of compound a13-3: The synthesis was carried out according to the method disclosed in Yunlong Yang, Jieyuan Zhang, Zhenzhen Liu, Qiuning Lin, Xiaolin Liu, Chunyan Bao, Yang Wang, Linyong Zhu. Adv. Mater., 2016, 28, 2724-2730. 1H NMR (400MHz, Chloroform-d): δ = 7.57 (s, 1H), 7.02 (s, 1H), 4.19 (dt, 4H), 3.90 (s, 3H) ,3.81(t,2H),3.69(t,2H),2.28–2.23(m,6H),2.02(s,3H).MS(ESI):[M+H]314.1230.

[0127] Synthesis of compound a13-4: The synthesis was carried out by referring to the synthesis method of compound a1-3. 1 H NMR (400MHz, Chloroform-d): δ = 7.57 (s, 1H), 7.02 (s, 1H), 4.17 (t, 2H), 4.09 (td, 2H), 3.9 2(s,3H),3.81(t,2H),3.60(t,2H),2.37(d,3H),1.91(t,1H).).MS(ESI):[M+H]272.1131.

[0128] Synthesis of monomer a13: Synthesized using the same method as monomer a1. 1 H NMR (400MHz, Chloroform-d): δ = 7.61 (s, 1H), 7.03 (q, 1H), 6.43 (dd, 1H), 6.16 (dd, 1H), 5.85 (dd, 1H), 4 .28(t,2H),4.17(t,2H),3.90(s,3H),3.81(t,2H),3.69(t,2H),2.38(d,3H).MS(ESI):[M+H]312.1077.

[0129] Example 14: Synthesis of monomer a14

[0130]

[0131] Synthesis of compound a14-1: The synthesis was carried out by referring to the synthesis method of compound a9-3. 1 H NMR (400MHz, Chloroform-d): δ = 7.80 (dd, 2H), 7.70 (dd, 2H), 7.11–7.03 (m, 2H), 6.84 –6.76(m,2H),4.17(t,2H),3.87–3.74(m,6H),2.31(d,3H).MS(ESI):[M+H]326.1387.

[0132] Synthesis of compound a14-2: The synthesis was carried out according to the method disclosed in Yunlong Yang, Jieyuan Zhang, Zhenzhen Liu, Qiuning Lin, Xiaolin Liu, Chunyan Bao, Yang Wang, Linyong Zhu. Adv. Mater., 2016, 28, 2724-2730. 1 H NMR (400MHz, Chloroform-d): δ = 7.80 (dd, 2H), 7.70 (dd, 2H), 7.30 (dq, H), 7.13 (d, 1 H),7.05(dd,1H),4.17(t,2H),3.81(q,6H),2.43(d,3H).MS(ESI):[M+H]371.1240.

[0133] Synthesis of compound a14-3: The synthesis was carried out by referring to the synthesis method of compound a9-5. 1 H NMR (400MHz, Chloroform-d): δ=7.02–6.94(m,1H),6.66(m,2H),4.17(t,2H),3.81(t,2 H),3.74(t,2H),2.82(t,2H),2.29–2.18(m,6H),1.39(s,2H).MS(ESI):[M+H]241.1185.

[0134] Synthesis of monomer a14: The synthesis was carried out by referring to the synthesis method of monomer a1. 1 H NMR (400MHz, Chloroform-d): δ = 7.08 (dd, 1H), 6.48 (dd, 1H), 6.40 (s, 1H), 6.28 (dd, 1H), 5.75 (dd ,1H),4.17(t,2H),3.81(t,2H),3.74(t,2H),3.13(t,2H),2.45(d,3H).MS(ESI):[M+H]295.1230.

[0135] Example 15: Synthesis of monomer a15

[0136]

[0137] Synthesis of compound a15-1: The synthesis was carried out by referring to the synthesis method of compound a2-2. 1H NMR (400MHz, Chloroform-d): δ = 7.06 (dt, 2H), 6.82–6.75 (m, 2H), 4.17 (t, 2H), 4.09 (t d,2H),3.81(t,2H),3.60(t,2H),2.31(t,3H),1.95(t,1H).MS(ESI):[M+H]197.1170.

[0138] Synthesis of compound a15-2: The synthesis was carried out by referring to the synthesis method of compound a2-3. 1 H NMR (400MHz, Chloroform-d): δ = 7.06 (dq, 2H), 6.83–6.76 (m, 2H), 4.19 (dt, 4H) ,3.81(t,2H),3.69(t,2H),2.31(t,3H),2.02(s,3H).MS(ESI):[M+H]239.1278.

[0139] Synthesis of compound a15-3: The synthesis was carried out according to the method disclosed in Yunlong Yang, Jieyuan Zhang, Zhenzhen Liu, Qiuning Lin, Xiaolin Liu, Chunyan Bao, Yang Wang, Linyong Zhu. Adv. Mater., 2016, 28, 2724-2730. 1 H NMR (400MHz, Chloroform-d): δ = 7.14–6.88 (m, 1H), 6.69–6.61 (m, 2H), 4.19 (dt, 4H), 3.81(t,2H),3.69(t,2H),2.29–2.18(m,6H),2.02(s,3H).MS(ESI):[M+H]284.1130.

[0140] Synthesis of compound a15-4: The synthesis was carried out by referring to the synthesis method of compound a1-3. 1 H NMR (400MHz, Chloroform-d): δ = 7.42 (s, 1H), 7.32 (dq, 1H), 7.14 (dd, 1H), 4.17 (t, 2H), 4. 09(td,2H),3.81(t,2H),3.60(t,2H),2.46(d,3H),1.91(t,1H).MS(ESI):[M+H]242.1020.

[0141] Synthesis of monomer a15: Synthesized using the same method as monomer a1. 1H NMR (400MHz, Chloroform-d): δ = 7.45 (s, 1H), 7.37–7.29 (d, 1H), 7.11 (dd, 1H), 6.44 (dd, 1H), 6.16 (dd, 1H) ,5.85(dd,1H),4.28(t,2H),4.17(t,2H),3.81(t,2H),3.69(t,2H),2.46(d,3H).MS(ESI):[M+H]296.1130.

[0142] Example 16: Synthesis of monomer a16

[0143]

[0144] Synthesis of compound a16-1: The synthesis was carried out by referring to the synthesis method of compound a2-2. 1 H NMR (400MHz, Chloroform-d): δ = 7.22 (s, 1H), 7.08–7.00 (m, 1H), 6.90 (d, 1H), 4.17 (t, 2H) ),4.09(dt,2H),3.81(t,2H),3.60(t,2H),2.30–2.23(m,4H).MS(ESI):[M+H]275.0279.

[0145] Synthesis of compound a16-2: The synthesis was carried out by referring to the synthesis method of compound a2-3. 1 H NMR (400MHz, Chloroform-d): δ = 7.22 (s, 1H), 7.08–7.00 (m, 1H), 6.91 (d, 1H), 4.19 (d t,4H),3.81(t,2H),3.69(t,2H),2.27(t,3H),2.02(s,3H).MS(ESI):[M+H]317.0385.

[0146] Synthesis of compound a16-3: The synthesis was carried out according to the method disclosed in Yunlong Yang, Jieyuan Zhang, Zhenzhen Liu, Qiuning Lin, Xiaolin Liu, Chunyan Bao, Yang Wang, Linyong Zhu. Adv. Mater., 2016, 28, 2724-2730. 1H NMR (400MHz, Chloroform-d): δ = 7.10 (s, 1H), 6.65 (s, 1H), 4.19 (dt, 4H), 3.81 ( t,2H),3.69(t,2H),2.29–2.22(m,6H),2.02(s,3H).MS(ESI):[M+H]362.0234.

[0147] Synthesis of compound a16-4: The synthesis was carried out by referring to the synthesis method of compound a1-3. 1 H NMR (400MHz, Chloroform-d): δ = 7.45 (s, 1H), 7.10 (s, 1H), 4.17 (t, 2H), 4.09 (td, 2 H),3.81(t,2H),3.60(t,2H),2.35(d,3H),1.91(t,1H).MS(ESI):[M+H]320.0130.

[0148] Synthesis of monomer a16: The synthesis was carried out by referring to the synthesis method of monomer a1. 1 H NMR (400MHz, Chloroform-d): δ = 7.48–7.43 (m, 2H), 6.44 (dd, 1H), 6.16 (dd, 1H), 5.85 (dd, 1H) ,4.28(t,2H),4.17(t,2H),3.81(t,2H),3.69(t,2H),2.36(d,3H).MS(ESI):[M+H]374.0234.

[0149] Example 17: Synthesis of monomer a17

[0150]

[0151] Synthesis of monomer a17: 2-(2-(2-methoxy-4-methyl-5-nitrophenoxy)ethoxy)ethane-1-ol (2.71 g, 0.01 mol) and trans-fumarate monomethyl ester (2.60 g, 0.02 mol) were dissolved in anhydrous dichloromethane. 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (5.751 g, 0.03 mol) and 4-dimethylaminopyridine (61 mg, 0.0005 mol) were added. After stirring overnight, the system was extracted three times with water and saturated brine, respectively. The organic phase was dried over anhydrous sodium sulfate, and the crude product was purified by column chromatography to obtain a white solid (3 g, 80%). 1H NMR (400MHz, CDCl3): δ = 7.59 (s, 1H), 7.04–6.98 (m, 1H), 6.98 (s, 2H), 4.28 (t, 2H), 4.17 (t, 2H),3.90(s,3H),3.85–3.75(m,5H),3.69(t,J2H),2.37(d,3H).MS(ESI):[M+H]384.1288.

[0152] Example 18: Synthesis of monomer a18

[0153]

[0154] Synthesis of compound a18-1: The synthesis was carried out according to the methods disclosed in Song, B., Guo, X., Yang, L., Yu, H., Zong, X., Liu, X., Wang, H., Xu, Z., Lin, Z., Yang, W., Angew. Chem. Int. Ed. 2023, 62, e202218886; Angew. Chem. 2023, 135, e202218886. 1 H NMR (400MHz, Chloroform-d): δ = 8.15–8.06 (m, 2H), 7.51–7.42 (m, 2H), 6.72 (ddt, 1H), 5.76 (dd, 1H), 5.25 (dd, 1H). MS (ESI): [M+H] 167.0260.

[0155] Synthesis of monomer a18: The synthesis was carried out by referring to the synthesis method of compound a1. 1 H NMR (400MHz, Chloroform-d): δ=7.87–7.79(m,2H),7.60(s,1H),7.41–7.33(m,2H),7.05(q,1H),6.72(ddt,1H), 5.76(dd,1H),5.25(dd,1H),4.38(t,2H),4.17(t,2H),3.93–3.77(m,7H),2.37(d,3H).MS(ESI):[M+H]402.1550.

[0156] Example 19: Synthesis of monomer a19

[0157]

[0158] Synthesis of compound a19-1: The synthesis was carried out by referring to the synthesis method of compound a2-2. 1H NMR (400MHz, Chloroform-d): δ = 7.06–6.94 (m, 3H), 4.17 (t, 2H), 4.09 (td, 2H), 3.90 (s, 3H), 3.81(t,2H),3.60(t,2H),2.58(qt,2H),1.96(t,1H),1.22(t,3H).MS(ESI):[M+H]241.1436.

[0159] Synthesis of compound a19-2: The synthesis was carried out by referring to the synthesis method of compound a2-3. 1 H NMR (400MHz, Chloroform-d): δ = 7.07–6.96 (m, 3H), 4.19 (dt, 4H), 3.90 (s, 3H), 3.81 (t ,2H),3.69(t,2H),2.58(qt,2H),2.02(s,3H),1.22(t,3H).MS(ESI):[M+H]283.1540.

[0160] Synthesis of compound a19-3: The synthesis was carried out according to the method disclosed in Yunlong Yang, Jieyuan Zhang, Zhenzhen Liu, Qiuning Lin, Xiaolin Liu, Chunyan Bao, Yang Wang, Linyong Zhu. Adv. Mater., 2016, 28, 2724-2730. 1 H NMR (400MHz, Chloroform-d): δ = 7.52 (s, 1H), 7.06–7.01 (m, 1H), 4.19 (dt, 4H), 3.90 (s, 3H), 3.81 (t,2H),3.69(t,J=7.2Hz,2H),2.66(qd,2H),2.02(s,3H),1.21(t,3H).MS(ESI):[M+H]328.1390.

[0161] Synthesis of compound a19-4: The synthesis was carried out by referring to the synthesis method of compound a1-3. 1 H NMR (400MHz, Chloroform-d): δ = 6.84 (t, 1H), 6.78 (s, 1H), 4.17 (t, 2H), 4.09 (dt, 2H), 3.90 (s, 3H), 3.8 1(t,2H),3.60(t,2H),2.45(qd,2H),2.25(s,3H),2.10(t,1H),1.17(t,3H).MS(ESI):[M+H]286.1286.

[0162] Synthesis of monomer a19: The synthesis was carried out by referring to the synthesis method of compound a1. 1 H NMR (400MHz, Chloroform-d): δ = 7.51 (s, 1H), 7.03 (d, 1H), 6.43 (dd, 1H), 6.15 (dd, 1H), 5.85 (dd, 1H), 4.28 (t, 2H),4.17(t,2H),3.90(s,3H),3.81(t,2H),3.69(t,2H),2.66(qd,2H),1.18(t,3H).MS(ESI):[M+H]340.1390.

[0163] Example 20: Synthesis of monomer a20

[0164]

[0165] Synthesis of compound a20-1: The synthesis was carried out by referring to the synthesis method of compound a9-3. 1 H NMR (400MHz, Chloroform-d): δ = 7.80 (dd, 2H), 7.70 (dd, 2H), 7.02–6.94 (m, 3H), 4.17 (t, 2 H),3.90(s,3H),3.87–3.74(m,6H),2.58(qt,2H),1.22(t,3H).MS(ESI):[M+H]370.1650.

[0166] Synthesis of compound a20-2: The synthesis was carried out according to the method disclosed in Yunlong Yang, Jieyuan Zhang, Zhenzhen Liu, Qiuning Lin, Xiaolin Liu, Chunyan Bao, Yang Wang, Linyong Zhu. Adv. Mater., 2016, 28, 2724-2730. 1 H NMR (400MHz, Chloroform-d): δ = 7.80 (dd, 2H), 7.70 (dd, 2H), 6.87 (s, 1H), 6.79 (d, 1H), 4.17 (t, 2H) ,3.90(s,3H),3.87–3.74(m,6H),2.45(qd,2H),2.25(s,3H),1.17(t,3H).MS(ESI):[M+H]415.1500.

[0167] Synthesis of compound a20-3: The synthesis was carried out by referring to the synthesis method of compound a9-5. 1H NMR (400MHz, Chloroform-d): δ = 6.82 (t, 1H), 6.75 (s, 1H), 4.17 (t, 2H), 3.90 (s, 3H), 3.81 (t, 2H), 3.7 4(t,2H),2.82(t,2H),2.45(qd,2H),2.25(s,3H),1.31(s,2H),1.16(t,3H).MS(ESI):[M+H]285.1450.

[0168] Synthesis of monomer a20: The synthesis was carried out by referring to the synthesis method of compound a1. 1 H NMR (400MHz, Chloroform-d): δ = 9.07 (s, 1H), 7.52 (s, 1H), 7.07 (t, 1H), 6.48 (dd, 1H), 6.28 (dd, 1H), 5.75 (dd, 1H), 4. 17(t,2H),3.90(s,3H),3.81(t,2H),3.74(t,2H),3.13(t,2H),2.66(qd,2H),1.32(t,3H).MS(ESI):[M+H]339.1500.

[0169] Example 21: Synthesis of monomer a21

[0170]

[0171] Synthesis of monomer a21: The synthesis was carried out by referring to the synthesis method of compound a17. 1 H NMR (400MHz, Chloroform-d): δ=7.57(s,1H),7.16(t,1H),7.00(d,2H),4.28(t,2H),4.17(t,J=7.2H z,2H),3.90(s,3H),3.81(t,2H),3.69(t,2H),2.66(qd,2H),1.16(t,3H).MS(ESI):[M+H]384.1290.

[0172] Examples 22-30: Synthesis of o-nitroalkylbenzene modified acrylate polymers and their control polymers

[0173] Example 22: Synthesis of o-nitroalkylbenzene modified ethyl acrylate polymer A1

[0174] 0.1 g of o-nitroalkylbenzene monomer a1 was dissolved in 10 g of ethyl acrylate monomer. Fumaric acid (0.1 g), sodium dodecyl sulfate (0.3 g), and deionized water (30 mL) were added, and the mixture was homogenized to obtain an emulsion. The emulsion was transferred to a 100 mL three-necked flask, and potassium persulfate (0.1 g) and sodium sulfite (0.03 g) were added to the reaction system. After deoxygenation for 30 min, the mixture was heated to 70 °C. The reaction temperature was controlled between 70-75 °C and maintained for 5 hours. After the reaction was complete, calcium chloride solution was added to the reaction system for flocculation. The product was washed with hot water and dried to obtain a pale yellow transparent solid product A1 (8.9 g), with a yield of 89%. The modification rate of a1 in the ethyl acrylate polymer A1 was determined by… 1 H NMR confirmed the value to be 0.6%.

[0175] Example 23: Synthesis of o-nitroalkylbenzene modified ethyl acrylate polymer A2

[0176] 0.1 g of o-nitroalkylbenzene monomer a2 was dissolved in 10 g of ethyl acrylate monomer. Sodium dodecyl sulfate (0.3 g) and deionized water (30 mL) were added, and the mixture was homogenized to obtain an emulsion. The emulsion was transferred to a 100 mL three-necked flask, and potassium persulfate (0.1 g) and sodium sulfite (0.03 g) were added to the reaction system. After deoxygenation for 30 min, the mixture was heated to 70 °C. The reaction temperature was controlled between 70-75 °C and maintained for 5 hours. After the reaction was complete, calcium chloride solution was added to the reaction system for flocculation. The product was washed with hot water and dried to obtain a pale yellow transparent solid product A2 (9.0 g), with a yield of 90%. The modification rate of a2 in the ethyl acrylate polymer A2 was determined by… 1 H NMR confirmed the value to be 0.6%.

[0177] Example 24: Synthesis of o-nitroalkylbenzene modified ethyl acrylate-butyl acrylate copolymer A3

[0178] 0.1 g of o-nitroalkylbenzene monomer a3 was dissolved in a mixture of 7 g of ethyl acrylate monomer and 3 g of butyl acrylate monomer. Sodium dodecyl sulfate (0.3 g) and deionized water (30 mL) were added, and the mixture was homogenized to obtain an emulsion. The emulsion was transferred to a three-necked flask (100 mL), and potassium persulfate (0.1 g) and sodium sulfite (0.03 g) were added to the reaction system. After deoxygenation for 30 min, the mixture was heated to 70 °C. The reaction temperature was controlled between 70-75 °C and maintained for 5 hours. After the reaction was completed, calcium chloride solution was added to the reaction system for flocculation. The product was washed with hot water and dried to obtain a pale yellow transparent solid product A3 (8.9 g), with a yield of 88%. The modification rate of a3 in the ethyl acrylate-butyl acrylate copolymer A3 was... 1 H NMR confirmed the value to be 0.7%.

[0179] Example 25: Synthesis of o-nitroalkylbenzene modified butyl acrylate polymer A4

[0180] 0.1 g of o-nitroalkylbenzene monomer a4 was dissolved in 10 g of butyl acrylate monomer. Sodium dodecyl sulfate (0.3 g) and deionized water (30 mL) were added, and the mixture was homogenized to obtain an emulsion. The emulsion was transferred to a 100 mL three-necked flask, and potassium persulfate (0.1 g) and sodium sulfite (0.03 g) were added to the reaction system. After deoxygenation for 30 min, the mixture was heated to 70 °C. The reaction temperature was controlled between 70-75 °C and maintained for 5 hours. After the reaction was complete, calcium chloride solution was added to the reaction system for flocculation. The product was washed with hot water and dried to obtain a pale yellow transparent solid product A4 (9.1 g), with a yield of 91%. The modification rate of a4 in the butyl acrylate polymer A4 was... 1 H NMR confirmed the value to be 0.7%.

[0181] Example 26: Synthesis of o-nitroalkylbenzene modified butyl acrylate polymer A5

[0182] 0.1 g of o-nitroalkylbenzene monomer a5 was dissolved in 10 g of butyl acrylate monomer. Monomethyl fumarate (0.1 g), sodium dodecyl sulfate (0.3 g), and deionized water (30 mL) were added, and the mixture was homogenized to obtain an emulsion. The emulsion was transferred to a three-necked flask (100 mL), and potassium persulfate (0.1 g) and sodium sulfite (0.03 g) were added to the reaction system. After deoxygenation for 30 min, the mixture was heated to 70 °C. The reaction temperature was controlled between 70-75 °C and maintained for 5 hours. After the reaction was complete, calcium chloride solution was added to the reaction system for flocculation. The product was washed with hot water and dried to obtain a pale yellow transparent solid product A5 (9.1 g), with a yield of 91%. The modification rate of a5 in the butyl acrylate polymer A5 was determined by… 1 H NMR confirmed the value to be 0.7%.

[0183] Example 27: Synthesis of o-nitroalkylbenzene modified lauryl acrylate polymer A6

[0184] 0.1 g of o-nitroalkylbenzene monomer a6 was dissolved in 10 g of lauryl acrylate monomer. Acrylonitrile (0.15 g), sodium dodecyl sulfate (0.3 g), and deionized water (30 mL) were added, and the mixture was homogenized to obtain an emulsion. The emulsion was transferred to a 100 mL three-necked flask, and potassium persulfate (0.1 g) and sodium sulfite (0.03 g) were added to the reaction system. After deoxygenation for 30 min, the mixture was heated to 70 °C. The reaction temperature was controlled between 70-75 °C and maintained for 5 hours. After the reaction was complete, calcium chloride solution was added to the reaction system for flocculation. The product was washed with hot water and dried to obtain a pale yellow solid product A6 (9.0 g), with a yield of 90%. The modification rate of a6 in the lauryl acrylate polymer A6 was determined by… 1 H NMR confirmed the value to be 0.6%.

[0185] Example 28: Synthesis of o-nitroalkylbenzene modified 2-ethylhexyl acrylate polymer A7

[0186] 0.1 g of o-nitroalkylbenzene monomer a7, 10 g of 2-ethylhexyl acrylate monomer, 0.15 g of hydroxyethyl acrylate monomer, and 60 mg of azobisisobutyronitrile (AIB) were dissolved in 50 mL of N,N-dimethylformamide, and nitrogen gas was continuously purged into the solution for 30 minutes to remove oxygen. The mixture was then polymerized at 70 °C under mechanical stirring for 2 hours, with nitrogen continuously purging to maintain an oxygen-free environment. After polymerization, the reaction solution was poured into 200 mL of acetone to precipitate the polymer, and residual monomers and initiators were removed. The product was dried to obtain a pale yellow solid (8.8 g, 88%). The modification rate of a7 in the 2-ethylhexyl acrylate polymer A7 was determined by… 1 H NMR confirmed the value to be 0.6%.

[0187] Example 29: Synthesis of o-nitroalkylbenzene modified ethyl acrylate polymers A8-A21

[0188] The o-nitroalkylbenzene monomers a8-a21 (0.1 g) were dissolved in ethyl acrylate monomer (10 g), and sodium dodecyl sulfate (0.3 g) and deionized water (30 mL) were added. The mixture was homogenized to obtain an emulsion. The emulsion was transferred to a three-necked flask (100 mL), and potassium persulfate (0.1 g) and sodium sulfite (0.03 g) were added to the reaction system. After deoxygenation for 30 min, the mixture was heated to 70 °C. The reaction temperature was controlled between 70-75 °C and maintained for 5 hours. After the reaction was completed, calcium chloride solution was added to the reaction system for flocculation. The product was washed with hot water and dried to obtain the solid product A8-A21. The modification rate of a8-a21 in the product was […]. 1 H NMR is used for determination, typically between 0.5% and 1%.

[0189] Comparative Example 30: Synthesis of Ethyl Acrylate Polymer PEA (Unmodified o-nitroalkylbenzene)

[0190] Sodium dodecyl sulfate (0.3 g) and deionized water (30 mL) were added to 10 g of ethyl acrylate monomer and homogenized to obtain an emulsion. The emulsion was transferred to a three-necked flask (100 mL), and potassium persulfate (0.1 g) and sodium sulfite (0.03 g) were added to the reaction system. After deoxygenation for 30 min, the mixture was heated to 70 °C. The reaction temperature was controlled between 70-75 °C and maintained for 5 hours. After the reaction was complete, calcium chloride solution was added to the reaction system for flocculation. The product was washed with hot water and dried to obtain a pale yellow transparent solid product, PEA (9.1 g), with a yield of 91%.

[0191] Example 31: Synthesis of High-Strength and Tough Acrylic Rubber and its Control Rubber

[0192] A series of high-strength and high-toughness acrylic rubbers were synthesized according to the formulations in Table 1.

[0193] Table 1. Formulations for high-strength and tough acrylic rubbers

[0194]

[0195]

[0196] The preparation methods for formulas 1-12 (acrylate rubber) and contrast rubber 1 are as follows:

[0197] Weigh out 5g of each of the following acrylate polymers: A1, A3, A5, A7, A9, A11, A13, A15, A17, A19, A21, or PEA, and place them in centrifuge tubes (50mL). Add 1g of each monofunctional or polyfunctional polymerizable monomer and 0.12g of the photoinitiator ethyl 2,4,6-trimethylbenzoylphenylphosphonate (TPO-L) according to the formulations in Table 1. Add 25mL of dichloromethane to the centrifuge tubes to dissolve and mix the raw materials thoroughly, then remove air bubbles by centrifugation. Pour the solution into a tetrafluoroethylene mold and let it stand at room temperature for 1 hour. After the solvent has completely evaporated, use a light source with an intensity of 100mW / cm². 2 The sample is irradiated with a light source with a wavelength of 395nm to completely cure it (curing time is 30-300s), thereby obtaining acrylic rubber.

[0198] The preparation methods for formulas 13-21 (acrylate rubber and contrast rubber 2) are as follows:

[0199] Weigh out 5g of each of the following acrylate polymers: A2, A4, A6, A8, A10, A12, A14, A16, A18, A20, or PEA, and place them in centrifuge tubes (50mL). Add 1.5g of each monofunctional or polyfunctional polymerizable monomer and 0.13g of the photoinitiator ethyl 2,4,6-trimethylbenzoylphenylphosphonate (TPO-L). Add 25mL of dichloromethane to the centrifuge tubes to dissolve and mix the raw materials thoroughly, then remove air bubbles by centrifugation. Pour the solution into a tetrafluoroethylene mold and let it stand at room temperature for 1 hour. After the solvent has completely evaporated, use a light source with an intensity of 100mW / cm². 2 The sample is irradiated with a light source with a wavelength of 395nm to completely cure it (curing time is 30-300s), thereby obtaining acrylic rubber.

[0200] As can be seen from the above preparation process, the preparation steps of the acrylate rubber provided by the present invention are simple, do not require high temperature or pressure, the preparation conditions are mild and readily available, and the preparation time is short.

[0201] Example 32: Elastic Property Analysis of High-Strength and Tough Acrylic Rubber

[0202] Dynamic mechanical property analysis of formulation 12 acrylate rubber in Example 31

[0203] An acrylic rubber sample (formulation 12) with dimensions of 35.0 mm × 12.8 mm × 3.2 mm was prepared using a mold. The dynamic mechanical analyzer used for testing was a TA Q800; the measurement mode was single cantilever; the test conditions were a frequency of 1 Hz, an amplitude of 15 μm, and a temperature ramp-up scan at a rate of 3 °C / min within the range of -50 °C to 100 °C. The test results are as follows... Figure 1 As shown, from Figure 1 It can be seen that the storage modulus E' of the acrylate rubber gradually decreases with increasing temperature. This is because as the temperature approaches the glass transition temperature (Tg), the acrylate rubber gradually transitions from the glassy state to the rubbery state. The Tg point of the acrylate rubber is below 0℃, indicating that under normal operating temperatures, the acrylate rubber remains in the rubbery state and exhibits the elastic properties of rubber.

[0204] Examples 33-34: Mechanical property testing of high-strength and tough acrylic rubber and its control rubber

[0205] Example 33: Mechanical Properties of Acrylic Rubber

[0206] Tensile tests were performed on the different acrylic rubbers synthesized in Example 31 to obtain their fracture strength and fracture toughness. In addition to comparative rubbers 1 and 2, the commercially available acrylic rubber VHB was also selected.TM 4910 was used as a control rubber 3 for performance comparison. Tensile tests were conducted at room temperature using a universal tensile testing machine (Instron 6800) with a 100N compressive element, at a testing speed of 40 mm / min. The test sample was a rectangular strip measuring 10 mm (length) × 2 mm (width) × 0.5 mm (thickness). Tensile strength was calculated by dividing the stress by the initial cross-sectional area of ​​the elastomer sample. Fracture toughness was obtained by integrating the area covered by the stress-strain curve. The test results are shown in Table 2.

[0207] Table 2. Comparison of strength and toughness of different acrylic rubbers

[0208]

[0209]

[0210] Table 2 summarizes the strength and toughness of acrylate rubbers prepared by the o-nitroalkylbenzene-modified acrylate polymer and monofunctional or polyfunctional polymerizable monomers in different combinations and mass ratios according to this invention. It can be seen that the acrylate rubbers prepared by the method described in this invention all exhibit excellent strength and toughness. Unlike traditional acrylate rubbers, which present a trade-off between strength and toughness, the acrylate rubbers prepared by this method can achieve a balance between strength and toughness, and their strength and toughness are significantly higher than those of the commercially available acrylate rubber VHB. TM 4910. Meanwhile, by comparing with acrylate rubbers that do not contain o-nitroalkylbenzene (comparative rubbers 1 and 2), it can be found that o-nitroalkylbenzene plays a key role in improving the strength and toughness of acrylate rubbers.

[0211] Figure 2 The photographs shown are of the acrylic rubber of Formulation 5 before and during stretching, which demonstrate that the acrylic rubber of the present invention has excellent stretchability, indicating that the acrylic rubber of the present invention has excellent toughness.

[0212] Figures 3-8 The tensile strength and cyclic load properties of acrylate rubbers prepared with different formulations demonstrate the excellent strength and resilience of the acrylate rubbers of this invention.

[0213] Example 34: Weight hang test of formula 17 acrylate rubber

[0214] To visually demonstrate the strength and toughness properties of acrylic rubber, an acrylic rubber sample (formulation 17) with dimensions of 35.0 mm × 2.0 mm × 1.0 mm was prepared and subjected to a weight-lift test. Figure 9 As shown, the acrylic rubber strip can successfully lift a 2kg weight. (The sentence is incomplete and requires further context.) Figure 9It can be seen that even when folded under high load, the acrylic rubber did not crack or break, indicating that the acrylic rubber has excellent strength and toughness.

[0215] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. An acrylate rubber, characterized by, It is formed by crosslinking an acrylate polymer modified with o-nitroalkylbenzene, a monofunctional or polyfunctional polymerizable monomer, and a photoinitiator; The o-nitroalkylbenzene-modified acrylate polymer is formed by copolymerization of o-nitroalkylbenzene monomer and alkyl acrylate monomer under thermal initiation conditions, and contains photosensitive active groups. The o-nitroalkylbenzene monomer is selected from any one of the monomers with the structures shown in a1 to a21 below: ； The alkyl acrylate monomer is selected from ethyl acrylate monomer, n-butyl acrylate monomer, lauryl acrylate monomer, 2-ethylhexyl acrylate monomer, lauryl methacrylate monomer, or n-octyl methacrylate monomer; the monofunctional or polyfunctional polymerizable monomer is selected from isobornyl acrylate, cyclohexanediol diacrylate, bisphenol A dimethacrylate, bisphenol A diacrylate, tripropylene glycol diacrylate, 1,6-hexanediol diacrylate, tricyclodecanediol diacrylate, trimethylolpropane triacrylate, tri(2-hydroxyethyl)isocyanurate triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, tripentaerythritol triacrylate, N-acryloylmorpholine, tetrahydrofuran acrylate, or acrylic acid. In the acrylate rubber, the mass contents of the o-nitroalkylbenzene-modified acrylate polymer, the monofunctional or polyfunctional polymerizable monomer, and the photoinitiator are 30%~99%, 1%~70%, and 0.05%~10%, respectively, and the total mass content of the o-nitroalkylbenzene-modified acrylate polymer, the monofunctional or polyfunctional polymerizable monomer, and the photoinitiator is 100%. The crosslinking of o-nitroalkylbenzene with polymerizable double bonds is achieved by the reaction of nitrosyl intermediates with carbon radicals, wherein the nitrosyl intermediates are photolysis products of o-nitroalkylbenzene.

2. The acrylate rubber according to claim 1, characterized in that, The copolymerization method under thermal initiation conditions can be selected from one of bulk polymerization, solution polymerization, precipitation polymerization or emulsion polymerization.

3. An acrylic rubber according to claim 1, characterized in that, The photoinitiator is selected from one or more of the following: hydroxy-methylphenylpropane-1-one, methyl-2-(4-morpholino)-1-[4-(methylthio)phenyl]-1-propanone, phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, ethyl 2,4,6-trimethylbenzoylphenylphosphonate, hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone, or lithium phenyl(2,4,6-trimethylbenzoyl)phosphate.

4. A method for preparing the acrylate rubber according to any one of claims 1-3, characterized in that, Choose one of the following methods: An acrylate polymer modified with o-nitroalkylbenzene, a monofunctional or polyfunctional polymerizable monomer, and a photoinitiator are directly mixed uniformly and then photocrosslinked; or, An acrylate polymer modified with o-nitroalkylbenzene, a monofunctional or polyfunctional polymerizable monomer, and a photoinitiator are mixed uniformly in a solvent, and after removing the solvent, they are photocrosslinked; or, An acrylate polymer modified with o-nitroalkylbenzene, a monofunctional or polyfunctional polymerizable monomer, and a photoinitiator are mixed uniformly in a solvent, and then the solvent is removed after photocrosslinking.

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