High-toughness acrylic rubber and preparation method thereof

Abstract

The invention belongs to the technical field of elastomer materials, and relates to high-toughness acrylic rubber and a preparation method thereof. Wherein the high-toughness acrylate rubber is formed by crosslinking an o-nitroalkylbenzene modified acrylate polymer, a monofunctional or polyfunctional polymerizable monomer and a photoinitiator. The o-nitroalkylbenzene modified acrylate polymer is formed by copolymerization of an o-nitroalkylbenzene monomer and an alkyl acrylate monomer under a thermal initiation condition. The o-nitroalkylbenzene monomer comprises two parts of structures which are covalently connected, wherein one part is an o-nitroalkylphenyl group with photosensitive activity; and the other part is a polymerizable active group. The acrylate rubber with high strength and high toughness can be rapidly obtained, and the preparation method of the acrylate rubber provided by the invention has the advantages of simple steps, no need of high temperature and pressurization, easily available preparation conditions, short preparation time and remarkable advantages in the preparation process.

Description

Technical Field

[0001] The invention belongs to the technical field of elastomer materials, and in particular relates to a high-toughness acrylic rubber and a preparation method thereof. Background Art

[0002] Acrylic rubber is a material obtained by copolymerizing alkyl acrylate as the main monomer with functional monomers and a small amount of vulcanization point monomers with cross-linking active groups. Since the main chain of acrylic rubber is a saturated carbon chain and the side group contains a highly polar ester group, acrylic rubber has many excellent characteristics, such as heat resistance, oil resistance, aging resistance, ozone resistance, and UV resistance. Various products made of acrylic rubber have been widely used in the automotive, aerospace, chemical, pharmaceutical and transportation industries. In recent years, with the rapid development of related fields such as soft robots, intelligent actuators, and electronic sensors, the demand for high-performance acrylic rubber as a raw material for manufacturing electrically driven deformation components-dielectric elastomers has been increasing.

[0003] Existing acrylic rubber technology still has many deficiencies in mechanical properties and processing and preparation. In terms of mechanical properties, acrylic rubber usually faces the contradiction of strength and toughness that are difficult to balance. On the one hand, in order to ensure the elastic properties of the material, the crosslinking density of acrylic rubber is usually low, and the content of the vulcanization point monomer generally does not exceed 5wt%. The low crosslinking density gives acrylic rubber excellent deformation ability and toughness, but it also makes the strength of acrylic rubber generally below 10MPa or even lower. For example, the TangoBlack and Agilus30 Clear series of acrylic rubbers developed by Stratasys have a maximum strain of 240%, but the tensile strength is only 3.1MPa. On the other hand, many application scenarios (such as dielectric elastomers, etc.) often require acrylic rubber to have a Young's modulus as low as several megapascals or even kilopascals to match the application requirements of high deformation. In order to ensure a low modulus, it is often necessary to further reduce the crosslinking density. In this case, the strength of acrylic rubber is even more difficult to guarantee, and may not even reach the megapascal level. For example, the widely used acrylic rubber VHB developed by 3M TM 4910, its modulus is 0.23MPa and toughness is 4.88MJ / m 3 , the strength is only 0.99MPa. 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 by high-temperature vulcanization of raw rubber, which not only involves harsh conditions such as high temperature and high pressure, but also has a lengthy and complicated preparation process. The above contradiction between strength and toughness and processing and preparation problems have limited 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 that acrylic rubber cannot have both strength and toughness, the present invention proposes a high-strength and tough acrylic rubber and a preparation method thereof. Based on the scheme provided by the present invention, acrylic rubber with both high strength and high toughness can be quickly obtained, and the preparation method of the acrylic rubber provided by the present invention has simple steps, does not require high temperature and pressure, the preparation conditions are easy to obtain, and the time required for preparation is short, which has significant advantages in the preparation process.

[0006] The present invention firstly prepares an acrylate polymer containing a photosensitive active group by copolymerization, and then forms a high-toughness acrylate rubber by cross-linking based on a photopolymerization reaction.

[0007] The purpose of the present invention can be achieved by the following technical solutions:

[0008] The first object of the present invention is to provide an o-nitroalkylbenzene monomer having both a photosensitive active group and a polymerizable active group.

[0009] The o-nitroalkylbenzene monomer comprises two covalently linked structures: one is an o-nitroalkylbenzene group with photosensitivity; the other is a polymerizable active group. The structure is shown in Formula I:

[0010]

[0011] Among them, 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, and the modified alkyl is a group obtained by replacing any carbon atom of the alkyl with other heteroatoms or groups; P is a polymerizable active group containing a double bond and is 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 a polymerizable double bond.

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

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

[0015]

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

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

[0018] In one embodiment of the present invention, the acrylic ester polymer is formed by copolymerizing the o-nitroalkylbenzene monomer provided by the first object of the present invention, the alkyl acrylate monomer and the functional monomer 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, and the length of the alkyl group in 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 an alkyl acrylate monomer, can improve one or more of the properties of the acrylic rubber, such as 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%. 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 method for copolymerizing the o-nitroalkylbenzene monomer and the alkyl acrylate monomer under thermal initiation conditions is selected from bulk polymerization, solution polymerization, precipitation polymerization or emulsion polymerization.

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

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

[0027] The third object of the present invention is to provide a high-toughness acrylic rubber.

[0028] The high-toughness acrylic rubber is formed by cross-linking the o-nitroalkylbenzene-modified acrylic polymer provided by the second object of the present invention, a monofunctional or multifunctional 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, and the polymerizable double bonds are selected from acryloyl, methacryloyl, styryl, acrylcyano, and alkenyl.

[0030] In one embodiment of the present invention, the monofunctional or multifunctional polymerizable monomer is selected from 2-phenoxyethyl acrylate, isobornyl methacrylate, isobornyl acrylate, trimethylolpropane formal acrylate, cyclohexanedimethanol diacrylate, ethoxylated bisphenol A dimethacrylate, ethoxylated bisphenol A diacrylate, triethylene glycol diacrylate, tripropylene glycol diacrylate, ethylene glycol dimethacrylate, tetraethylene glycol acrylate, 1,6-hexanediol diacrylate, 1,3-butanediol diacrylate, tricyclodecane dimethanol diacrylate, trimethylolpropane triacrylate, tris(2-hydroxyethyl)isocyanuric acid 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 present invention, the oligomer refers to a polymer composed of fewer repeating units, and the fewer repeating units refers to a repeating unit of 10-100.

[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 type of compound that can absorb energy of a certain wavelength in the ultraviolet or visible light region to generate free radicals, thereby initiating polymerization or cross-linking.

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

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

[0036] The fourth object of the present invention is to provide a method for preparing high-toughness acrylic rubber, which comprises selecting one of the following methods:

[0037] The o-nitroalkylbenzene modified acrylate polymer, the monofunctional or multifunctional polymerizable monomer and the photoinitiator are directly mixed evenly and then cross-linked under light; or,

[0038] The o-nitroalkylbenzene modified acrylate polymer, the monofunctional or multifunctional polymerizable monomer and the photoinitiator are uniformly mixed in a suitable solvent, and after removing the solvent, the cross-linking is formed by light irradiation; or,

[0039] The acrylate polymer modified by o-nitroalkylbenzene, a monofunctional or multifunctional polymerizable monomer and a photoinitiator are uniformly mixed in a suitable solvent, and the solvent is removed after photo-crosslinking.

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

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

[0042] Traditional acrylic rubber relies on free radical polymerization of polymerizable double bonds or chemical reactions between sulfur and double bonds, chlorine and metal oxides to achieve crosslinking. The efficiency of these crosslinking reactions is very limited. For example, when sulfur is used to vulcanize olefins, only 40-50% of the sulfur can effectively achieve the purpose of crosslinking.

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

[0044] The cross-linking of o-nitroalkylbenzene and polymerizable double bonds provided by the present invention is based on the reaction principle of nitroso intermediate (o-nitroalkylbenzene photolysis product) and carbon free radical. Thanks to the extremely high reaction rate of nitroso and carbon free radical (rate constant 10 8 -10 9 L·mol -1 s -1 ), the o-nitroalkylbenzene has a high cross-linking efficiency with the polymerizable double bond, making the cross-linking network of the obtained rubber material more perfect, effectively promoting the force conduction between the internal structures when subjected to force, thereby synergistically improving the strength and toughness of the material. Therefore, based on the introduction of the o-nitroalkylbenzene cross-linking group, the acrylate rubber provided by the present invention can achieve excellent strength and toughness.

[0045] In addition, unlike the high temperature, pressurization, long-term vulcanization and other conditions required for the preparation of traditional acrylic rubber, the preparation steps of the acrylic rubber provided by the present invention are simple, do not require high temperature and pressurization, the preparation conditions are easy to obtain, and the time required for preparation is short, which has significant advantages in the preparation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 The dynamic mechanical properties test results of the acrylic rubber of formula 12 are shown in FIG.

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

[0048] Figure 3 This is the tensile stress-strain curve of the acrylic rubber of formula 2.

[0049] Figure 4 This is the stress-strain curve of the acrylic rubber of formula 2 after 10 cycles of stretching.

[0050] Figure 5 This is the tensile stress-strain curve of the acrylic rubber of formula 6.

[0051] Figure 6 This is the stress-strain curve of the acrylic rubber of formula 6 after 10 cycles of stretching.

[0052] Figure 7 This is the tensile stress-strain curve of the acrylic rubber with formula 12.

[0053] Figure 8 This is the stress-strain curve of the acrylic rubber with formula 12 after 10 cycles of stretching.

[0054] Fig. 9 Photo of a Formulation 17 acrylic rubber specimen lifting a 2 kg weight. DETAILED DESCRIPTION

[0055] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0056] Example 1 to Example 21: Synthesis of o-nitroalkylbenzene monomer

[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 completed, the solvent was dried, the system was dissolved with dichloromethane, extracted three times with water and saturated brine respectively, the organic phase was dried with anhydrous sodium sulfate, the organic phase was dried, and the crude product was purified by column chromatography to obtain a pure product as 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, Zhen 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 an aqueous solution of sodium hydroxide (NaOH, 10% by mass) was added dropwise, and the reaction was detected by thin layer chromatography until the reaction was completed. After the reaction was completed, the solvent was dried, the system was dissolved with dichloromethane, extracted three times with water and saturated brine, respectively, the organic phase was dried with anhydrous sodium sulfate, the organic phase was dried, and the crude product was purified by column chromatography to obtain a pure product as 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), anhydrous triethylamine (20.2 g, 0.2 mol) was added, and then acryloyl chloride (14.48 g, 0.16 mol) was added dropwise under ice bath conditions, and stirred at room temperature overnight. After the reaction was completed, the solvent was dried, the system was dissolved in dichloromethane, extracted three times with water and saturated brine respectively, the organic phase was dried with anhydrous sodium sulfate, the organic phase was dried, and the obtained crude product was purified by column chromatography, and the obtained 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 tetrahydrofuran solution (THF, 150 mL), iodine (17.46, 0.068 mol) was added at 0°C, the system was stirred for 5 minutes, and 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), 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 stirred overnight at room temperature. After the reaction was completed, the solvent was dried, the system was dissolved in dichloromethane, extracted three times with water and saturated brine respectively, the organic phase was dried over anhydrous sodium sulfate, the organic phase was dried, and the crude product was purified by column chromatography to obtain a pure product as 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, Zhen 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: Synthesize according to the synthesis method of 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, Zhen 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: Synthesize 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, Zhen 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: Synthesize 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: Synthesize by referring to the synthesis method of 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: Synthesize by referring to the synthesis method of 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: Synthesis was carried out according to the synthesis method of compound a2-3. 1H NMR (400MHz, 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, Zhen 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: Synthesize 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: Synthesize by referring to the synthesis method of 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: Synthesize 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). Stir at 90°C for 8 hours under nitrogen protection, and remove DMF by evaporation under reduced pressure. The mixture was then redissolved in dichloromethane, extracted three times with water and saturated brine, respectively, and the organic phase was dried over anhydrous sodium sulfate, and the organic phase was spin-dried. The crude product was purified by column chromatography, and the pure product was obtained as 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, Zhen 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: Add hydrazine hydrate (2.23 g, 0.01 mol) to an ethanol solution (250 mL) of compound a9-4 (4 g, 0.01 mol), and stir the system at 80°C for about 1 hour. After filtration under reduced pressure, collect the filtrate, evaporate in vacuo, and purify 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: Synthesize 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 by referring to the synthesis method 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, Zhen 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: Synthesize 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: Synthesize by referring to the synthesis method of 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: Synthesize according to the synthesis method of 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, Zhen 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: Synthesize according to the synthesis method of 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, Zhen 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: 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, Zhen 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: Synthesize according to the synthesis method of 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, Zhen 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: Synthesize according 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-methyl fumarate (2.60 g, 0.02 mol) were dissolved in anhydrous dichloromethane, and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (5.751 g, 0.03 mol) and 4-dimethylaminopyridine (61 mg, 0.0005 mol) were added. After the reaction was stirred overnight, the system was extracted three times with water and saturated brine respectively, the organic phase was dried over anhydrous sodium sulfate, the organic phase was spin-dried, and the crude product was purified by column chromatography to obtain a pure product as 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 method 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, Zhen 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: 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, Zhen 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: Synthesize 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] Example 22-Example 30: Synthesis of o-Nitroalkylbenzene Modified Acrylate Polymer and Control Polymer

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

[0174] The o-nitroalkylbenzene monomer a1 (0.1g) was dissolved in the ethyl acrylate monomer (10g), and fumaric acid (0.1g), sodium dodecyl sulfate (0.3g) and deionized water (30mL) were added, and the emulsion was obtained after homogenization with a homogenizer. The emulsion was transferred to a three-necked flask (100mL), and potassium persulfate (0.1g) and sodium sulfite (0.03g) were added to the reaction system. After deoxygenation for 30 minutes, it was heated to 70°C. The reaction temperature was controlled between 70-75°C and kept warm for 5 hours. After the reaction was completed, calcium chloride solution was added to the reaction system for flocculation, and the product was washed with hot water. After drying, a light yellow transparent solid product A1 (8.9g) was obtained with a yield of 89%. The modification rate of a1 in the ethyl acrylate polymer A1 is 1 H NMR determined 0.6%.

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

[0176] Dissolve the o-nitroalkylbenzene monomer a2 (0.1 g) in the ethyl acrylate monomer (10 g), add sodium dodecyl sulfate (0.3 g) and deionized water (30 mL), and homogenize with a homogenizer to obtain an emulsion. Transfer the emulsion to a three-necked flask (100 mL), add potassium persulfate (0.1 g) and sodium sulfite (0.03 g) to the reaction system, and heat to 70°C after deoxygenation for 30 minutes. Control the reaction temperature between 70-75°C and keep warm for 5 hours. After the reaction is completed, add calcium chloride solution to the reaction system for flocculation, wash the product with hot water, and dry it to obtain a light yellow transparent solid product A2 (9.0 g) with a yield of 90%. The modification rate of a2 in the ethyl acrylate polymer A2 is 1 H NMR determined 0.6%.

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

[0178] Dissolve the o-nitroalkylbenzene monomer a3 (0.1 g) in a mixture of ethyl acrylate monomer (7 g) and butyl acrylate monomer (3 g), add sodium dodecyl sulfate (0.3 g) and deionized water (30 mL), and homogenize with a homogenizer to obtain an emulsion. Transfer the emulsion to a three-necked flask (100 mL), add potassium persulfate (0.1 g) and sodium sulfite (0.03 g) to the reaction system, and heat to 70°C after deoxygenation for 30 minutes. Control the reaction temperature between 70-75°C and keep warm for 5 hours. After the reaction is completed, add calcium chloride solution to the reaction system for flocculation, wash the product with hot water, and dry it to obtain a light 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 is 1 H NMR determined it to be 0.7%.

[0179] Example 25: Synthesis of o-Nitroalkylbenzene Modified Butyl Acrylate Polymer A4

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

[0181] Example 26: Synthesis of o-Nitroalkylbenzene Modified Butyl Acrylate Polymer A5

[0182] The o-nitroalkylbenzene monomer a5 (0.1g) was dissolved in the butyl acrylate monomer (10g), and monomethyl fumarate (0.1g), sodium dodecyl sulfate (0.3g) and deionized water (30mL) were added, and the emulsion was obtained after homogenization by a homogenizer. The emulsion was transferred to a three-necked flask (100mL), and potassium persulfate (0.1g) and sodium sulfite (0.03g) were added to the reaction system. After deoxygenation for 30 minutes, it was heated to 70°C. The reaction temperature was controlled between 70-75°C and kept warm for 5 hours. After the reaction was completed, calcium chloride solution was added to the reaction system for flocculation, and the product was washed with hot water. After drying, a light yellow transparent solid product A5 (9.1g) was obtained with a yield of 91%. The modification rate of a5 in the butyl acrylate polymer A5 is 1 H NMR determined it to be 0.7%.

[0183] Example 27: Synthesis of o-Nitroalkylbenzene Modified Lauryl Acrylate Polymer A6

[0184] The o-nitroalkylbenzene monomer a6 (0.1g) was dissolved in the lauryl acrylate monomer (10g), and acrylonitrile (0.15g), sodium dodecyl sulfate (0.3g) and deionized water (30mL) were added, and an emulsion was obtained after homogenization with a homogenizer. The emulsion was transferred to a three-necked flask (100mL), and potassium persulfate (0.1g) and sodium sulfite (0.03g) were added to the reaction system. After deoxygenation for 30 minutes, the reaction temperature was heated to 70°C. The reaction temperature was controlled between 70-75°C and kept warm for 5 hours. After the reaction was completed, calcium chloride solution was added to the reaction system for flocculation, and the product was washed with hot water and dried to obtain a light yellow solid product A6 (9.0g) with a yield of 90%. The modification rate of a6 in the lauryl acrylate polymer A6 is 1 H NMR determined 0.6%.

[0185] Example 28: Synthesis of o-Nitroalkylbenzene Modified 2-Ethylhexyl Acrylate Polymer A7

[0186] The o-nitroalkylbenzene monomer a7 (0.1g), 2-ethylhexyl acrylate monomer (10g), hydroxyethyl acrylate monomer (0.15g), and azobisisobutyronitrile (60mg) were dissolved in N,N-dimethylformamide (50mL), and nitrogen was continuously passed through the solution for 30 minutes to remove oxygen. The mixed solution was polymerized under mechanical stirring at 70°C for 2 hours, during which nitrogen was continuously passed to maintain an oxygen-free environment in the system. After the polymerization was completed, the reaction solution was poured into acetone (200mL), the polymer was precipitated, and the residual monomer and initiator were removed. After drying, a light yellow solid product (8.8g, 88%) was obtained. The modification rate of a7 in the 2-ethylhexyl acrylate polymer A7 is 1 H NMR determined 0.6%.

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

[0188] Dissolve o-nitroalkylbenzene monomer a8-a21 (0.1g) in ethyl acrylate monomer (10g) respectively, add sodium dodecyl sulfate (0.3g) and deionized water (30mL), and homogenize with a homogenizer to obtain an emulsion. Transfer the emulsion to a three-necked flask (100mL), add potassium persulfate (0.1g) and sodium sulfite (0.03g) to the reaction system, and heat to 70°C after deoxygenation for 30 minutes. Control the reaction temperature between 70-75°C and keep warm for 5 hours. After the reaction is completed, add calcium chloride solution to the reaction system for flocculation, wash the product with hot water, and dry it to obtain solid products A8-A21. The modification rate of a8-a21 in the product is 1 H NMR determination, generally between 0.5% and 1%.

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

[0190] Add sodium dodecyl sulfate (0.3g) and deionized water (30mL) to ethyl acrylate monomer (10g), and homogenize with a homogenizer to obtain an emulsion. Transfer the emulsion to a three-necked flask (100mL), add potassium persulfate (0.1g) and sodium sulfite (0.03g) to the reaction system, and heat to 70°C after deoxygenation for 30min. Control the reaction temperature between 70-75°C and keep warm for 5 hours. After the reaction is completed, add calcium chloride solution to the reaction system for flocculation, wash the product with hot water, and dry it to obtain a light yellow transparent solid product PEA (9.1g) with a yield of 91%.

[0191] Example 31: Synthesis of high-toughness acrylic rubber and its control rubber

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

[0193] Table 1, high-toughness acrylic rubber formula

[0194]

[0195]

[0196] The preparation methods of the acrylic rubber of formula 1-12 and the comparative rubber 1 are as follows:

[0197] Weigh acrylate polymers A1, A3, A5, A7, A9, A11, A13, A15, A17, A19, A21 or PEA (5 g) respectively and place them in a centrifuge tube (50 mL). Add different monofunctional or multifunctional polymerizable monomers (1 g) and photoinitiator 2,4,6-trimethylbenzoylphenylphosphonic acid ethyl ester (TPO-L; 0.12 g) according to the formula in Table 1. Add dichloromethane (25 mL) to the centrifuge tube to dissolve the raw materials and mix them evenly, and then remove the bubbles by centrifugation. Inject the solution into a tetrafluoroethylene mold and let it stand at room temperature for 1 hour. After the solvent is completely evaporated, use a light intensity of 100 mW / cm 2 , irradiate the sample 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 of the acrylic rubbers of formulas 13-21 and comparative rubber 2 are as follows:

[0199] Weigh acrylate polymers A2, A4, A6, A8, A10, A12, A14, A16, A18, A20 or PEA (5 g) respectively and place them in a centrifuge tube (50 mL). Add different monofunctional or multifunctional polymerizable monomers (1.5 g) and photoinitiator 2,4,6-trimethylbenzoylphenylphosphonic acid ethyl ester (TPO-L; 0.13 g) according to the formula in the table. Add dichloromethane (25 mL) to the centrifuge tube to dissolve the raw materials and mix them evenly, and then remove the bubbles by centrifugation. Inject the solution into a tetrafluoroethylene mold and let it stand at room temperature for 1 hour. After the solvent is completely evaporated, use a light intensity of 100 mW / cm 2 , irradiate the sample with a light source with a wavelength of 395nm to completely cure it (curing time is 30-300s), thereby obtaining acrylic rubber.

[0200] It can be seen from the above preparation process that the preparation steps of the acrylic rubber provided by the present invention are simple, no high temperature and pressure are required, the preparation conditions are mild and easy to obtain, and the preparation time is short.

[0201] Example 32: Analysis of elastic properties of high-toughness acrylic rubber

[0202] Dynamic Mechanical Properties Analysis of Acrylic Rubber of Formulation 12 in Example 31

[0203] The test sample size of 35.0 mm × 12.8 mm × 3.2 mm acrylic rubber (formula 12) was prepared by the mold. The dynamic mechanical analyzer model for the test was TA Q800; the measurement mode was single cantilever; the test conditions were frequency 1 Hz, amplitude 15 μm, and temperature scanning in the range of -50°C-100°C at a rate of 3°C / min. The test results are shown in Figure 1 As shown, from Figure 1 It can be seen that the storage modulus E' of the acrylic rubber will gradually decrease with the increase of temperature. This is because the temperature gradually approaches the glass transition temperature (Tg), and the acrylic rubber will gradually change from the glass state to the rubber state. It can be seen that the Tg point of the acrylic rubber is lower than 0°C, indicating that at normal use temperature, the acrylic rubber is in the rubber state and has the elastic properties of rubber.

[0204] Example 33-Example 34: Mechanical Properties Test of High-Toughness Acrylic Rubber and Control Rubber

[0205] Example 33: Mechanical properties of acrylic rubber

[0206] The different acrylic rubbers synthesized in Example 31 were tested by tensile test to obtain their fracture strength and fracture toughness. In addition to the comparative rubbers 1 and 2, a commercial acrylic rubber VHB was also selected.TM 4910 was used as the comparative rubber 3 for performance comparison. The tensile test was conducted at room temperature using a universal tensile tester (Instron 6800) with a 100N load cell at a test speed of 40mm / min. The test sample was a rectangular spline of 10mm (length) × 2mm (width) × 0.5mm (thickness). The tensile strength was calculated by dividing the stress by the initial cross-sectional area of ​​the elastomer sample. The 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 the acrylic rubber prepared by different types of combinations and different mass ratios of the o-nitroalkylbenzene-modified acrylic polymer and monofunctional or multifunctional polymerizable monomers in the present invention. It can be seen that the acrylic rubber prepared by the preparation method of the present invention has excellent strength and toughness. Unlike traditional acrylic rubbers that have a contradiction between strength and toughness, the acrylic rubber prepared by the preparation method can take into account both strength and toughness, and its strength and toughness are significantly higher than those of commercial acrylic rubber VHB. TM 4910. At the same time, by comparing with the acrylic rubber without o-nitroalkylbenzene (comparison rubber 1 and 2), it can be found that o-nitroalkylbenzene plays a key role in improving the strength and toughness of acrylic rubber.

[0211] Figure 2 The photographs of the acrylic rubber of Formula 5 before and during stretching are shown, and it can be seen that the acrylic rubber of the present invention has excellent stretchability, indicating that the acrylic rubber of the present invention has excellent toughness.

[0212] Figure 3 to Figure 8 The tensile strength and cyclic load performance of acrylic rubber prepared with different formulations demonstrate the excellent strength and resilience of the acrylic rubber of the present invention.

[0213] Example 34: Heavy object hanging test of acrylic rubber of formula 17

[0214] In order to intuitively demonstrate the strength and toughness properties of acrylic rubber, a test sample of acrylic rubber (formula 17) with a size of 35.0 mm × 2.0 mm × 1.0 mm was prepared and a heavy object hanging test was performed. Fig. 9 As shown in the figure, the acrylic rubber strip can successfully lift a weight of 2 kg. Fig. 9It can be seen that even when folded in half under high load, the acrylic rubber does not crack or break, indicating that the acrylic rubber has excellent strength and toughness.

[0215] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and 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 present invention should be within the scope of protection of the present invention.

Claims

1. An o-nitroalkylbenzene monomer having both a photosensitive active group and a polymerizable active group, characterized in that: The o-nitroalkylbenzene monomer structure is shown in Formula I: Among them, 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, and the modified alkyl is a group obtained by replacing any carbon atom of the alkyl with other heteroatoms or groups; P is a polymerizable active group containing a double bond and is covalently connected to R2 or R3.

2. The o-nitroalkylbenzene monomer having both a photosensitive active group and a polymerizable active group according to claim 1, characterized in that: The 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 a polymerizable double bond.

3. The o-nitroalkylbenzene monomer having both a photosensitive active group and a polymerizable active group according to claim 1, characterized in that: The R1 is selected from methyl or ethyl; R2 and R3 are independently selected from hydrogen, hydroxyl, halogen atom, alkyl or alkoxy; P is an active group containing acrylate, methacrylate, acrylamide, methacrylamide or styrene structure.

4. The o-nitroalkylbenzene monomer having both a photosensitive active group and a polymerizable active group according to claim 1, characterized in that: The o-nitroalkylbenzene monomer is selected from any one of the monomers having structures shown in a1 to a21 below:

5. An o-nitroalkylbenzene-modified acrylate polymer, characterized in that: The invention is formed by copolymerizing the o-nitroalkylbenzene monomer described in any one of claims 1 to 4 and an alkyl acrylate monomer under thermal initiation conditions.

6. The o-nitroalkylbenzene-modified acrylate polymer according to claim 5, characterized in that: The invention is formed by copolymerizing the o-nitroalkylbenzene monomer described in any one of claims 1 to 4, the alkyl acrylate monomer and the functional monomer under thermal initiation conditions.

7. The o-nitroalkylbenzene-modified acrylate polymer according to claim 5 or 6, characterized in that: The alkyl acrylate monomer is an alkyl-containing acrylate monomer or an alkyl-containing methacrylate monomer, and the length of the alkyl group in the alkyl acrylate monomer is 1 to 20 carbon atoms.

8. The o-nitroalkylbenzene-modified acrylate polymer according to claim 7, characterized in that: 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.

9. The o-nitroalkylbenzene-modified acrylate polymer according to claim 6, characterized in that: The functional monomer refers to a monomer that, after copolymerization with an alkyl acrylate monomer, can improve one or more of the properties of the acrylic rubber, such as high temperature resistance, aging resistance, modulus, adhesion, stain resistance, water resistance, solvent resistance, refractive index, weather resistance, flexibility, or glass transition temperature.

10. The o-nitroalkylbenzene-modified acrylate polymer according to claim 9, characterized in that: 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.

11. The o-nitroalkylbenzene-modified acrylate polymer according to claim 5 or 6, characterized in that: The method of copolymerization under thermal initiation conditions is selected from bulk polymerization, solution polymerization, precipitation polymerization or emulsion polymerization.

12. A high-toughness acrylic rubber, characterized in that: It is formed by cross-linking the acrylate polymer modified with o-nitroalkylbenzene as claimed in claim 5 or 6, a monofunctional or multifunctional polymerizable monomer and a photoinitiator.

13. The high-toughness acrylic rubber according to claim 12, characterized in that: The monofunctional or multifunctional polymerizable monomer is a substance containing one or more polymerizable double bonds in its molecular structure, and the polymerizable double bonds are selected from acryloyl, methacryloyl, styryl, acrylcyano, and alkenyl.

14. The high-toughness acrylic rubber according to claim 13, characterized in that: The monofunctional or multifunctional polymerizable monomer is selected from 2-phenoxyethyl acrylate, isobornyl methacrylate, isobornyl acrylate, trimethylolpropane formal acrylate, cyclohexanedimethanol diacrylate, ethoxylated bisphenol A dimethacrylate, ethoxylated bisphenol A diacrylate, triethylene glycol diacrylate, tripropylene glycol diacrylate, ethylene glycol dimethacrylate, tetraethylene glycol acrylate, 1,6-hexanediol diacrylate, 1,3-butanediol diacrylate, tricyclodecane dimethanol diacrylate, trimethylolpropane triacrylate, tris(2-hydroxyethyl)isocyanuric acid triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, tripentaerythritol triacrylate, N-acryloylmorpholine, tetrahydrofuran acrylate, acrylic acid, and oligomers containing acrylate or methacrylate groups.

15. The high-toughness acrylic rubber according to claim 12, characterized in that: The photoinitiator is selected from one or more of hydroxy-methylphenylpropane-1-one, methyl-2-(4-morpholinyl)-1-[4-(methylthio)phenyl]-1-propanone, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, ethyl 2,4,6-trimethylbenzoylphenylphosphonate, hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylpropiotone or phenyl(2,4,6-trimethylbenzoyl)phosphate lithium salt.

16. The high-toughness acrylic rubber according to claim 12, characterized in that: In the high-toughness acrylic rubber, the mass contents of the ortho-nitroalkylbenzene-modified acrylic polymer, the monofunctional or multifunctional polymerizable monomer and the photoinitiator are 30% to 99%, 1% to 70% and 0.05% to 10% respectively.

17. The method for preparing the high-toughness acrylic rubber according to claim 12, characterized in that: Choose one of the following methods: The o-nitroalkylbenzene modified acrylate polymer, the monofunctional or multifunctional polymerizable monomer and the photoinitiator are directly mixed evenly and then cross-linked under light; or, The o-nitroalkylbenzene modified acrylate polymer, the monofunctional or multifunctional polymerizable monomer and the photoinitiator are uniformly mixed in a suitable solvent, and after removing the solvent, the cross-linking is formed by light irradiation; or, The acrylate polymer modified by o-nitroalkylbenzene, a monofunctional or multifunctional polymerizable monomer and a photoinitiator are uniformly mixed in a suitable solvent, and the solvent is removed after photo-crosslinking.

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