A polymer dielectric containing a bicyclo[1.1.1]pentane structure and a method for preparing the same

Abstract

The application discloses a polymer dielectric containing a bicyclo[1.1.1]pentane structure and a preparation method thereof. By addition reaction of [1.1.1]spiropropyl with mercapto, a monomer of formula I with various structures can be efficiently prepared through subsequent simple functional group conversion. The monomer containing a "sulfone-bicyclo[1.1.1]pentane" structural element shown in formula I is homopolymerized or copolymerized with other acrylate monomers to obtain a polymer, which is a dielectric material with high dielectric constant, low dielectric loss and high energy storage density. The connection of bicyclo[1.1.1]pentane and sulfone weakens the dipole-dipole interaction, reduces the dielectric material relaxation loss and improves the solubility of the polymer in low-polarity solvents. The copolymerization of the monomer of formula I with commercial acrylate monomers obtains a polymer dielectric with high charge and discharge efficiency (>95%).

Description

Technical Field

[0001] This invention relates to polymer dielectrics and their preparation methods, specifically to a polymer dielectric containing a special chemical structure of bicyclic [1.1.1]pentane, belonging to the field of polymer chemistry and physics. Background Technology

[0002] With increasing public concern about energy issues, capacitors, as electrical energy storage devices, have received widespread attention. The theoretical energy storage density (Ua) of linear dielectric materials... e U can be calculated using the following formula: e =0.5ε0ε r E 2 , where ε0, ε r E and E represent the vacuum permittivity, the relative permittivity of the material, and the electric field strength, respectively. Biaxially oriented polypropylene (BOPP) is a widely used commercial polymer dielectric with high breakdown strength, but its permittivity is very low (ε). r =2.2), the actual achievable energy storage density is not high (1.2 J cm⁻¹). -3 Increasing the dielectric constant of a material is beneficial for improving its energy storage density. The sulfone group is a highly polar group with a large dipole moment; introducing it into the side chain can effectively increase the dielectric constant of the polymer. However, while introducing sulfone groups can improve the dielectric constant, it can also lead to increased dielectric loss and decreased breakdown strength, which has an adverse effect on the energy storage properties of the material. Furthermore, polymers containing strong polar sulfone groups have poor solubility in commonly used low polar organic solvents, which makes polymer characterization and solution processing difficult [(1) Tang, C. et al. Prog. Polym. Sci. 2018, 80, 153-162. (2) Chen, S.; Luo, H. et al. Macromolecules 2021, 54, 8195-8206. (3) Litt, MH; Zhu, L. et al. ACS Appl. Mater. Interfaces 2015, 7, 5248-5257. (4) Zhang, Z.; Zhu, L. et al. Macromolecules 2018, 51, 6257-6266.]. In addition, there is still a lack of universal and efficient methods for synthesizing sulfone-based monomers, which limits the widespread application of sulfone-based polymers. Summary of the Invention

[0003] This invention aims to synthesize dielectric materials with tunable properties, high dielectric constant, low dielectric loss, and high energy density through novel molecular design.

[0004] In a first aspect of the present invention, a monomer containing a "sulfone-bicyclo[1.1.1]pentane" structural unit is provided, the structure of which is shown in Formula I below:

[0005]

[0006] In Formula I, the linking group R can be a linking chain of alkylene, oxaalkylene, arylene, or combinations thereof, such as -C a H 2a -,-C a H 2a -OC b H 2b -, -Ph-, -C a H 2a -O-Ph-, where the number of carbon atoms represented by a and b is preferably 1 to 6, a and b may be equal or unequal, and Ph represents a benzene ring.

[0007] The following are some structural examples of monomeric compounds of Formula I:

[0008]

[0009] In a second aspect of the invention, a polymer containing a "sulfone-bicyclo[1.1.1]pentane" structural unit is provided, the structure of which is shown in Formula II below:

[0010]

[0011] In Formula II, the linking group R is as described above, and n is an integer representing the degree of polymerization.

[0012] In a third aspect of the invention, a novel copolymer containing a "sulfone-bicyclo[1.1.1]pentane" structural unit is provided, the structure of which is shown in Formula III below:

[0013]

[0014] In Formula III, the linking group R is as described above, X can be alkyl (such as C1 to C6 alkyl), glycidyl, aryl (such as phenyl) or alkyl-substituted aryl, n and m are integers representing the degree of polymerization, and m / n is the ratio of two different structural units in the copolymer.

[0015] In a fourth aspect of the invention, a method is proposed for synthesizing the monomer shown in Formula I using [1.1.1]spiroline as a starting material. First, an intermediate of Formula V is obtained through an addition reaction of [1.1.1]spiroline with a mercapto group. Then, the thioether is converted to a sulfone through oxidation, and the hydroxyl group is converted to an acrylate group through a reaction with acryloyl chloride, thus synthesizing the monomer shown in Formula I. Specifically, depending on the reaction sequence and the different reaction substrates, there are four different synthetic routes.

[0016] The first route includes the following steps:

[0017]

[0018] 1a) Synthesizing a medium containing a bicyclic [1.1.1]pentane structure via the addition reaction of [1.1.1]spiroalkyl with thiophenol or thiol compound IV.

[0019] Interstitial V;

[0020] 1b) The sulfide of intermediate V is converted into sulfone by oxidation reaction to obtain intermediate VI;

[0021] 1c) Monomer I is synthesized by reacting the hydroxyl group of intermediate VI with acryloyl chloride.

[0022] The second route includes the following steps:

[0023]

[0024] 2a) Synthesizing a medium containing a bicyclic [1.1.1]pentane structure via the addition reaction of [1.1.1]spiroalkyl with thiophenol or thiol compound IV.

[0025] Interstitial V;

[0026] 2b) Intermediate VII is synthesized by reacting the hydroxyl group of intermediate V with acryloyl chloride;

[0027] 2c) The sulfide of intermediate VII is converted into sulfone by oxidation reaction to obtain monomer I.

[0028] The third route includes the following steps:

[0029]

[0030] 3a) An intermediate V' containing a bicyclic [1.1.1]pentane structure was synthesized via the addition reaction of [1.1.1]spiroline with thiophenol compound IV'.

[0031] Where R' is a aryl group;

[0032] 3b) To synthesize a bicyclic compound by converting the hydroxyl group in intermediate V' into an ether bond (e.g., substitution reaction of phenolic hydroxyl groups with halogens) [1.1.1]

[0033] Pentane intermediate V;

[0034] 3c) The sulfide of intermediate V is converted into sulfone by oxidation reaction to obtain intermediate VI;

[0035] 3d) Monomer I was synthesized by reacting the hydroxyl group of intermediate VI with acryloyl chloride.

[0036] The fourth synthetic route includes the following steps:

[0037]

[0038] 4a) An intermediate V' containing a bicyclic [1.1.1]pentane structure was synthesized by the addition reaction of [1.1.1]spiroalkyl with thiophenol compound IV', wherein R' is an arylene group;

[0039] 4b) To synthesize intermediate V containing a bicyclic [1.1.1]pentane structure by converting the hydroxyl group in intermediate V' into an ether bond (such as the substitution reaction of phenolic hydroxyl groups with halogens);

[0040] 4c) Intermediate VII is synthesized by reacting the hydroxyl group of intermediate V with acryloyl chloride;

[0041] 4d) The sulfide of intermediate VII is converted into sulfone by oxidation reaction to synthesize monomer I.

[0042] In a fifth aspect of the invention, a method is provided for synthesizing a polymer containing a "sulfone-bicyclo[1.1.1]pentane" structural motif. The monomer shown in Formula I can be homopolymerized or copolymerized with other acrylate monomers VIII (such as methyl acrylate, glycidyl acrylate, etc.) to obtain the polymer shown in Formula II or the copolymer shown in Formula III, respectively. Generally, the polymerization initiator is azobisisobutyronitrile (AIBN), the polymerization temperature range is 60–80°C, preferably 70°C, and the polymerization time is 8–24 hours, preferably 12 hours.

[0043]

[0044] Compared with the prior art, the present invention has the following technical advantages:

[0045] 1. For the first time, a variety of acrylate monomers containing the "sulfonyl-bicyclo[1.1.1]pentane" structural motif were obtained through a general synthetic route. The addition reaction of [1.1.1]spiroalkyl with mercapto group does not require a catalyst, is fast and efficient, has high yield, and a wide substrate range. Based on this reaction and subsequent simple functional group transformation, monomers with diverse structures can be prepared efficiently.

[0046] 2. Introducing sulfone groups, while improving the dielectric constant, also brings problems such as increased dielectric loss and poor solubility. The bicyclic...

[0047] [1.1.1]The pentane group is linked to a sulfone group, which weakens the dipole-dipole interaction, reduces the relaxation loss of the dielectric material, and improves the solubility of the polymer in low-polarity solvents. The bicyclic [1.1.1]pentane structure introduced in this invention provides a new and effective tool for regulating and improving polymer properties.

[0048] 3. By selecting acrylate monomers containing epoxy groups to copolymerize with monomer I proposed in this invention, the disadvantage of sulfone-containing polymers being brittle is improved on the one hand, and charge traps are introduced into the polymer on the other hand, reducing electrical conductivity loss.

[0049] The present invention proposes a method for synthesizing acrylate monomers containing the "sulfonyl-bicyclo[1.1.1]pentane" structural unit through the addition reaction and conversion of [1.1.1]spiroalkyl with mercapto and copolymerizing with commercial acrylate monomers. This method significantly improves the solubility of sulfonyl-containing polymers and reduces losses, resulting in polymer dielectrics with high charge-discharge efficiency (>95%). Detailed Implementation

[0050] The preparation process of the polymer dielectric material of the present invention is further described below through examples, but these examples do not limit the scope of the present invention in any way.

[0051] Example 1: Synthesis of Monomer B1

[0052]

[0053] Add 56 mL of [1.1.1] propeller ethyl ether solution (0.407 M, 22.8 mmol, 1 eq.) and 1.4 mL of 2-mercaptoethanol (20.5 mmol, 0.9 eq.) to a 100 mL round-bottom flask equipped with a magnetic stir bar, and stir at room temperature for 15 minutes. Reduce the solvent by rotary evaporation, and separate the crude product by column chromatography (petroleum ether / ethyl acetate = 2 / 1, v / v) to give 2.61 g of compound 2 (colorless liquid, yield 88%). 1 H NMR (400MHz, CDCl3, δ): 3.70 (t, J = 6.2Hz, 2H), 2.85–2.64 (m, 3H), 2.18 (s, 1H), 1.97 (s, 6H). 13 C NMR (101MHz, CDCl3, δ): 61.39, 54.06, 44.18, 34.55, 28.74.

[0054] Add 2.61 g of compound 2 (18 mmol, 1 eq.) to a 100 mL round-bottom flask equipped with a magnetic inlet, and purge the flask under a nitrogen atmosphere. Using a syringe, add 50 mL of dichloromethane and 3.8 mL of triethylamine (27 mmol, 1.5 eq.) to the flask. Add 1.8 mL of acryloyl chloride (21.6 mmol, 1.2 eq.) while cooling in an ice-water bath. Remove the ice-water bath and react at room temperature for 1 hour. Quench the reaction with saturated NaCl solution. After separation, extract the aqueous phase three times with dichloromethane, combine the organic phases, and dry them over anhydrous Na₂SO₄. Reverse the solvent, and separate the crude product by column chromatography (petroleum ether / ethyl acetate = 24 / 1, v / v) to give 2.53 g of compound 3 (colorless liquid, 71% yield). 1 H NMR (400MHz, CDCl3, δ): 6.41 (dd, J=17.3, 1.4Hz, 1H), 6.11 (dd, J=17.3, 10.4Hz, 1H ),5.83(dd,J=10.4,1.5Hz,1H),4.37–4.12(m,2H),2.87–2.63(m,3H),1.98(s,6H). 13 C NMR (101MHz, CDCl3, δ): 166.02, 131.22, 128.32, 63.96, 53.92, 44.32, 29.51, 28.57.

[0055] 2.53 g of compound 3 (12.8 mmol, 1 eq.) and 45 mL of dichloromethane were added to a 100 mL round-bottom flask equipped with a magnetic stir bar. 7.8 g of mCPBA (m-chloroperoxybenzoic acid) (38.3 mmol, 3 eq.) was added under ice-water bath cooling. The ice-water bath was removed, and the reaction was allowed to proceed at room temperature for 15 minutes. The reaction was quenched with saturated Na₂SO₃ solution. After separation, the aqueous phase was extracted three times with dichloromethane. The combined organic phases were washed with saturated NaHCO₃ solution and dried over anhydrous Na₂SO₄. The solvent was evaporated, and the crude product was separated by column chromatography (petroleum ether / ethyl acetate = 2 / 1, v / v) to give 2.60 g of monomer B1 (white solid, 88% yield). 1 H NMR (400MHz, CDCl3, δ): 6.45 (dd, J=17.3, 1.3Hz, 1H), 6.12 (dd, J=17.3, 10.5Hz, 1H), 5.89 (dd ,J=10.5,1.3Hz,1H),4.56(t,J=6.6Hz,2H),3.29(t,J=6.6Hz,2H),2.78(s,1H);2.26(s,6H). 13C NMR (101MHz, CDCl3, δ): 165.69, 132.29, 127.61, 57.21, 54.46, 50.91, 49.27, 26.70.

[0056] Example 2: Synthesis of monomer B2

[0057]

[0058] Add 20 mL of [1.1.1] propeller ether solution (0.45 M, 9 mmol, 1 eq.) and 1.1 mL of 6-mercaptohexanol (8.1 mmol, 0.9 eq.) to a 100 mL round-bottom flask equipped with a magnetic stir bar. React at room temperature for 15 minutes. Reduce the solvent by rotary evaporation to obtain the crude product of compound 4 (colorless liquid), which was used directly in the next reaction. Add 1.94 g of compound 4 (9.68 mmol, 1 eq.) to a 100 mL round-bottom flask equipped with a magnetic stir bar, and add 50 mL of dichloromethane. Add 5.01 g of mCPBA (29.05 mmol, 3 eq.) under ice-water bath cooling. Remove the ice-water bath and react at room temperature for 15 minutes. Quench the reaction with saturated NaHCO3 solution. After separation, extract the aqueous phase three times with ethyl acetate, combine the organic phases, and dry them over anhydrous Na2SO4. The solvent was removed by rotary evaporation, and the crude product was separated by column chromatography (petroleum ether / ethyl acetate = 1 / 2, volume ratio) to give 1.46 g of compound 5 (white solid, overall yield of the two-step reaction was 78%). 1 H NMR (400MHz, CDCl3, δ): 3.59 (td, J=6.5, 1.5Hz, 2H), 2.92–2.82 (m, 2H), 2.74 (d, J=1.5Hz, 1H), 2.22 (d, J= 1.6Hz, 6H), 2.04 (s, 1H), 1.81 (p, J = 7.4Hz, 2H), 1.54 (p, J = 6.8Hz, 2H), 1.41 (dq, J = 19.1, 6.5, 5.3Hz, 4H). 13 C NMR (101MHz, CDCl3, δ): 62.51, 54.04, 50.91, 49.69, 32.30, 28.45, 26.70, 25.31, 21.28.

[0059] 1.46 g of compound 5 (6.28 mmol, 1 eq.) was added to a 100 mL round-bottom flask equipped with a magnetic inlet, and the flask was purged under a nitrogen atmosphere. 15 mL of dichloromethane and 1 mL of triethylamine (7.54 mmol, 1.2 eq.) were added to the flask using a syringe. 0.51 mL of acryloyl chloride (6.28 mmol, 1 eq.) was added while cooling in an ice-water bath. The ice-water bath was removed, and the reaction was allowed to proceed at room temperature for 1 hour. The reaction was quenched by adding saturated NaCl solution. After separation, the aqueous phase was extracted three times with dichloromethane, and the combined organic phases were dried over anhydrous Na₂SO₄. The solvent was evaporated, and the crude product was separated by column chromatography (petroleum ether / ethyl acetate = 2 / 1, v / v) to give 0.86 g of monomer B₂ (white solid, 48% yield). 1 H NMR (400MHz, CDCl3, δ): 6.39 (dd, J=17.3, 1.5Hz, 1H), 6.11 (dd, J=17.4, 10.4Hz, 1H), 5.82 (dd, J=10.4, 1.5Hz, 1H), 4.15 (t, J=6.6Hz, 2 H),2.94–2.85(m,2H),2.77(s,1H),2.25(s,6H),1.91–1.79(m,2H),1.68(q,J=7.0Hz,2H),1.46(dddd,J=19.5,16.9,13.1,8.2Hz,4H). 13 C NMR (101MHz, CDCl3, δ): 166.41, 130.79, 128.63, 64.36, 54.16, 51.02, 49.76, 28.45, 28.43, 26.80, 25.66, 21.32.

[0060] Example 3: Synthesis of monomer B3

[0061]

[0062] Add 21 mL of [1.1.1] propeller ether solution (0.45 M, 9.45 mmol, 1 eq.) and 0.96 mL of 2-mercaptoethoxyethanol (8.5 mmol, 0.9 eq.) to a 100 mL round-bottom flask equipped with a magnetic stir bar, and react at room temperature for 15 minutes. Recycle the solvent to obtain the crude product of compound 6 (colorless liquid), which was used directly in the next reaction. Add 1.92 g of compound 6 (10.2 mmol, 1 eq.) to a 100 mL round-bottom flask equipped with a magnetic stir bar, and add 50 mL of dichloromethane. Add 5.3 g of mCPBA (30.6 mmol, 3 eq.) under ice-water bath cooling. Remove the ice-water bath and react at room temperature for 15 minutes. Quench the reaction with saturated NaHCO3 solution. After separation, extract the aqueous phase twice with ethyl acetate, combine the organic phases, and dry them over anhydrous Na2SO4. The solvent was removed by rotary evaporation, and the crude product was separated by column chromatography (petroleum ether / ethyl acetate = 1 / 2, volume ratio) to give 1.17 g of compound 7 (colorless liquid, overall yield of the two-step reaction was 62%). 1 H NMR (400MHz, CDCl3, δ): 3.90 (t, J=5.9Hz, 2H), 3.76–3.66 (m, 2H), 3.59 (dd, J= 5.3, 3.7Hz, 2H), 3.20 (t, J = 5.9Hz, 2H), 2.75 (s, 1H), 2.58 (s, 1H), 2.24 (s, 6H). 13 CNMR (101MHz, CDCl3, δ): 72.53, 63.40, 61.36, 54.65, 50.82, 50.48, 26.52.

[0063] 1.17 g of compound 7 (5.31 mmol, 1 eq.) was added to a 100 mL round-bottom flask equipped with a magnetic inlet, and the flask was purged under a nitrogen atmosphere. 15 mL of dichloromethane and 0.9 mL of triethylamine (6.37 mmol, 1.2 eq.) were added to the flask using a syringe. 0.43 mL of acryloyl chloride (5.31 mmol, 1 eq.) was added while cooling in an ice-water bath. The ice-water bath was removed, and the reaction was allowed to proceed at room temperature for 1 hour. The reaction was quenched by adding saturated NaCl solution. After separation, the aqueous phase was extracted twice with ethyl acetate, and the combined organic phases were dried over anhydrous Na₂SO₄. The solvent was evaporated, and the crude product was separated by column chromatography (petroleum ether / ethyl acetate = 2 / 1, v / v) to give 0.75 g of monomer B3 (colorless liquid, 51% yield). 1H NMR (400MHz, CDCl3, δ): 6.40 (dd, J=17.4, 1.4Hz, 1H), 6.11 (dd, J=17.3, 10.4Hz, 1H), 5.83 (dd, J=10.4, 1.4Hz, 1H ),4.33–4.24(m,2H),3.86(t,J=6.0Hz,2H),3.75–3.65(m,2H),3.18(t,J=6.0Hz,2H),2.71(s,1H),2.22(s,6H). 13 C NMR (101MHz, CDCl3, δ): 166.03, 131.35, 128.13, 69.26, 64.06, 63.35, 54.57, 51.14, 50.78, 26.48.

[0064] Example 4: Synthesis of monomer C1

[0065]

[0066] Add 20 mL of [1.1.1] propane ethyl ether solution (0.47 M, 9.4 mmol, 1 eq.) and 1.1 g of 4-hydroxythiophenol (8.5 mmol, 0.9 eq.) to a 100 mL round-bottom flask equipped with a magnetic stir bar, and react at room temperature for 5 minutes. Recycle the solvent to obtain the crude product of compound 8 (yellow liquid), which was used directly in the next reaction. Add 2.22 g of compound 8 (11.5 mmol, 1 eq.) to a 100 mL round-bottom flask equipped with a magnetic stir bar, and purge the flask under a nitrogen atmosphere. Add 30 mL of dichloromethane and 2.4 mL of triethylamine (17.3 mmol, 1.5 eq.) to the flask using a syringe. Add 1.2 mL of acryloyl chloride (13.9 mmol, 1.2 eq.) under ice-water bath cooling. Remove the ice-water bath and react at room temperature for 10 minutes. Quench the reaction with saturated NaCl solution, separate the aqueous phase, and extract twice with ethyl acetate. Combine the organic phases and dry them with anhydrous Na2SO4. Recycle the solvent and separate the crude product by column chromatography (petroleum ether / ethyl acetate = 24 / 1, v / v) to give 1.79 g of compound 9 (colorless liquid, overall yield of 85% for both steps). 1 H NMR (400MHz, CDCl3, δ): 7.55–7.38 (m, 2H), 7.20–6.99 (m, 2H), 6.60 (dd, J=17.3, 1.3Hz, 1H ), 6.31 (dd, J=17.3, 10.4Hz, 1H), 6.02 (dd, J=10.4, 1.3Hz, 1H), 2.73 (s, 1H), 1.88 (s, 6H). 13CNMR (101MHz, CDCl3, δ): 164.39, 150.26, 134.84, 132.90, 131.42, 127.91, 121.98, 54.03, 45.75, 28.77.

[0067] 1.79 g of compound 9 (7.3 mmol, 1 eq.) was added to a 100 mL round-bottom flask equipped with a magnetic stirrup, followed by 25 mL of dichloromethane. 3.8 g of mCPBA (21.8 mmol, 3 eq.) was added under ice-water bath cooling. The ice-water bath was removed, and the reaction was allowed to proceed at room temperature for 10 minutes. The reaction was quenched by adding saturated Na₂SO₃ solution. After separation, the aqueous phase was extracted twice with ethyl acetate. The combined organic phases were washed with saturated NaHCO₃ solution and dried over anhydrous Na₂SO₄. The solvent was evaporated, and the crude product was separated by column chromatography (petroleum ether / ethyl acetate = 4 / 1, v / v) to give 1.37 g of monomer C1 (white solid, 67% yield). 1 H NMR (400MHz, CDCl3, δ): 7.95–7.82 (m, 2H), 7.42–7.29 (m, 2H), 6.64 (dd, J = 17.2, 1.1Hz, 1H ), 6.32(dd,J=17.3,10.5Hz,1H),6.08(dd,J=10.5,1.1Hz,1H),2.73(s,1H),2.09(s,6H). 13 C NMR (101MHz, CDCl3, δ): 163.69, 154.77, 134.26, 133.88, 130.42, 127.40, 122.45, 55.19, 50.54, 26.94.

[0068] Example 5: Synthesis of monomer C2

[0069]

[0070] Add 35 mL of [1.1.1] propane diethyl ether solution (0.38 M, 13.3 mmol, 1 eq.) and 1.68 g of 4-hydroxythiophenol (13.3 mmol, 1 eq.) to a 100 mL round-bottom flask equipped with a magnetic stir bar. React at room temperature for 15 minutes. Recycle the solvent to obtain the crude product of compound 8 (yellow liquid), which can be used directly in the next reaction. Add 2.68 g of compound 8 (14 mmol, 1 eq.), 40 mL of LDMF, 7.7 g of K₂CO₃ (56 mmol, 4 eq.), and 2 mL of 2-bromoethanol (28 mmol, 2 eq.) to a 100 mL round-bottom flask equipped with a magnetic stir bar. Place the flask in an oil bath at 100 °C and react for 3 hours. After cooling to room temperature, evaporate the solvent. Dissolve the residue in dichloromethane and wash the organic phase with saturated NaCl solution. After separation, extract the aqueous phase twice with dichloromethane, combine the organic phases, and dry with anhydrous Na₂SO₄. The solvent was evaporated, and the crude product was separated by column chromatography (petroleum ether / ethyl acetate = 4 / 1, volume ratio) to give 1.47 g of compound 10 (white solid, overall yield of the two-step reaction was 47%). 1 H NMR (400MHz, CDCl3, δ): 7.45–7.31 (m, 2H), 6.95–6.77 (m, 2H), 4.07 (dd, J = 5.2, 3.8Hz, 2H), 3.96 (dd, J = 5.2, 3.8Hz, 2H), 2.69 (s, 1H), 2.12 (s, 1H), 1.88 (s, 6H). 13 C NMR (101MHz, CDCl3, δ): 158.68, 136.03, 125.14, 115.03, 69.36, 61.52, 53.80, 46.19, 28.47.

[0071] 2.09 g of compound 10 (8.8 mmol, 1 eq.) was added to a 100 mL round-bottom flask equipped with a magnetic buoy, and the flask was purged under a nitrogen atmosphere. 25 mL of dichloromethane and 1.8 mL of triethylamine (13.3 mmol, 1.5 eq.) were added to the flask using a syringe. 0.9 mL of acryloyl chloride (10.6 mmol, 1.2 eq.) was added while the flask was cooled in an ice-water bath. The ice-water bath was removed, and the reaction was allowed to proceed at room temperature for 40 minutes. The reaction was quenched with saturated NaCl solution, and the aqueous phase was extracted twice with dichloromethane after separation. The combined organic phases were dried over anhydrous Na₂SO₄. The solvent was evaporated, and the crude product was separated by column chromatography (petroleum ether / ethyl acetate = 15 / 1, v / v) to give 2.28 g of compound 11 (colorless liquid, 89% yield). 1H NMR (400MHz, CDCl3, δ): 7.49–7.30 (m, 2H), 6.95–6.75 (m, 2H), 6.44 (dd, J = 17.3, 1.4Hz, 1H), 6.16 (dd, J = 17.3, 10. 4Hz,1H),5.85(dd,J=10.4,1.4Hz,1H),4.62–4.39(m,2H),4.20(dd,J=5.5,4.1Hz,2H),2.69(s,1H),1.87(s,6H). 13 C NMR (101MHz, CDCl3, δ): 166.17, 158.53, 136.00, 131.52, 128.15, 125.22, 115.08, 66.03, 62.94, 53.79, 46.17, 28.47.

[0072] 2.28 g of compound 11 (7.85 mmol, 1 eq.) was added to a 100 mL round-bottom flask equipped with a magnetic stirrup, followed by 30 mL of dichloromethane. 4.8 g of mCPBA (23.56 mmol, 3 eq.) was added under ice-water bath cooling. The ice-water bath was removed, and the reaction was allowed to proceed at room temperature for 15 minutes. The reaction was quenched by adding saturated Na₂SO₃ solution. After separation, the aqueous phase was extracted twice with ethyl acetate, and the combined organic phases were dried over anhydrous Na₂SO₄. The solvent was evaporated, and the crude product was separated by column chromatography (petroleum ether / ethyl acetate = 3 / 1, v / v) to give 1.99 g of monomer C₂ (white solid, 79% yield). 1 H NMR (400MHz, CDCl3, δ): 7.88–7.66 (m, 2H), 7.13–6.93 (m, 2H), 6.45 (dd, J = 17.3, 1.4Hz, 1H), 6.16 (dd, J = 17.3, 10. 4Hz,1H),5.88(dd,J=10.4,1.4Hz,1H),4.65–4.44(m,2H),4.29(dd,J=5.5,4.0Hz,2H),2.71(s,1H),2.06(s,6H). 13 CNMR (101MHz, CDCl3, δ): 166.10, 162.68, 131.79, 130.93, 129.08, 128.00, 114.98, 66.36, 62.57, 55.37, 50.47, 26.80.

[0073] Example 6: Synthesis of monomer C3

[0074]

[0075] Add 20 mL of [1.1.1] propane diethyl ether solution (0.47 M, 9.4 mmol, 1 eq.) and 1.07 g of 4-hydroxythiophenol (8.5 mmol, 0.9 eq.) to a 100 mL round-bottom flask equipped with a magnetic stir bar. React at room temperature for 5 minutes. Recycle the solvent to obtain the crude product of compound 8 (yellow liquid), which can be used directly in the next reaction. Add 1.98 g of compound 8 (10 mmol, 1 eq.), 30 mL of DMF, 3 g of K₂CO₃ (20 mmol, 2 eq.), and 1.4 mL of 6-bromo-1-hexanol (10 mmol, 1 eq.) to a 100 mL round-bottom flask equipped with a magnetic stir bar. Place the flask in an oil bath at 70 °C and react for 2 hours. After cooling to room temperature, evaporate the solvent. Dissolve the residue in dichloromethane and wash the organic phase with saturated NaCl solution. After separation, extract the aqueous phase twice with dichloromethane, combine the organic phases, and dry with anhydrous Na₂SO₄. The solvent was evaporated, and the crude product was separated by column chromatography (petroleum ether / ethyl acetate = 4 / 1, volume ratio) to give a mixture of 1.46 g of compound 12 and unreacted 6-bromo-1-hexanol (colorless liquid), which was used directly in the next reaction.

[0076] 1.46 g of compound 12 (5 mmol, 1 eq.) was added to a 100 mL round-bottom flask equipped with a magnetic stirrup, followed by 25 mL of dichloromethane. 2.58 g of mCPBA (15 mmol, 3 eq.) was added under ice-water bath cooling. The ice-water bath was removed, and the reaction was allowed to proceed at room temperature for 15 minutes. The reaction was quenched by adding saturated Na₂SO₃ solution. After separation, the aqueous phase was extracted twice with ethyl acetate, and the combined organic phases were dried over anhydrous Na₂SO₄. The solvent was evaporated, and the crude product was separated by column chromatography (petroleum ether / ethyl acetate = 1 / 1, v / v) to give 1.18 g of compound 13 (colorless liquid, overall yield of 43% in the three steps). 1 H NMR (400MHz, CDCl3, δ): 7.84–7.63 (m, 2H), 7.04–6.92 (m, 2H), 4.02 (t, J = 6.4Hz, 2H), 3.66 (t, J = 6.5Hz, 2H), 2 .70(s,1H),2.05(s,6H),1.81(dt,J=8.2,6.4Hz,2H),1.73(s,1H),1.60(p,J=6.7Hz,2H),1.55–1.39(m,4H). 13 C NMR (101MHz, CDCl3, δ): 163.37, 130.80, 128.12, 114.84, 68.46, 62.89, 55.37, 50.42, 32.70, 29.11, 26.74, 25.91, 25.61.

[0077] 1.18 g of compound 13 (3.64 mmol, 1 eq.) was added to a 100 mL round-bottom flask equipped with a magnetic buoy, and the flask was purged under a nitrogen atmosphere. 10 mL of dichloromethane and 0.8 mL of triethylamine (5.46 mmol, 1.5 eq.) were added to the flask using a syringe. 0.4 mL of acryloyl chloride (4.37 mmol, 1.2 eq.) was added under ice-water bath cooling. The ice-water bath was removed, and the reaction was allowed to proceed at room temperature for 10 minutes. The reaction was quenched with saturated NaCl solution, and the aqueous phase was extracted twice with ethyl acetate after separation. The organic phases were combined and dried over anhydrous Na₂SO₄. The solvent was evaporated, and the crude product was separated by column chromatography (petroleum ether / ethyl acetate = 3 / 1, v / v) to give 0.54 g of monomer C3 (colorless liquid, 39% yield). 1 H NMR (400MHz, CDCl3, δ): 7.88–7.61 (m, 2H), 7.10–6.85 (m, 2H), 6.39 (dd, J = 17.3 ,1.5Hz,1H),6.11(dd,J=17.3,10.4Hz,1H),5.82(dd,J=10.4,1.5Hz,1H),4.17( t,J=6.6Hz,2H),4.02(t,J=6.4Hz,2H),2.70(s,1H),2.06(s,6H),1.82(dt,J=8. 0, 6.4Hz, 2H), 1.72 (q, J=7.1Hz, 2H), 1.50 (dddd, J=22.1, 13.8, 7.6, 3.1Hz, 4H). 13 C NMR (101MHz, CDCl3, δ): 166.44, 163.34, 130.84, 130.73, 128.67, 128.25, 114.83, 68.40, 64.55, 55.40, 50.45, 29.05, 28.66, 26.75, 25.81, 25.80.

[0078] To compare the bicyclic [1.1.1]pentane structure with the benzene ring, we synthesized acrylate monomers containing a benzene ring in the following examples.

[0079] Example 7: Synthesis of Monomer A

[0080]

[0081] A 250 mL round-bottom flask equipped with a magnetic stir bar was purged under a nitrogen atmosphere. 100 mL of dichloromethane, 5 mL of 2-phenylthioethanol (37 mmol, 1 eq.), and 7.8 mL of triethylamine (56 mmol, 1.5 eq.) were added to the flask using a syringe. 3.6 mL of acryloyl chloride (44 mmol, 1.2 eq.) was added while the flask was cooled in an ice-water bath. The reaction was then carried out at a constant temperature for 2 hours after the ice-water bath was removed. The reaction was quenched with saturated sodium chloride solution. After separation, the aqueous phase was extracted twice with dichlorohexane. The combined organic phases were dried over anhydrous Na₂SO₄. The solvent was evaporated, and the crude product (petroleum ether / ethyl acetate = 24 / 1, v / v) was separated by column chromatography to give 7.57 g of compound 1 (98% yield). 1 H NMR (400MHz, CDCl3, δ): 7.46–7.36 (m, 2H), 7.34–7.27 (m, 2H), 7.25–7.17 (m, 1H), 6.38 (dd, J=17.3, 1.4Hz, 1H ), 6.09 (dd, J = 17.3, 10.4Hz, 1H), 5.83 (dd, J = 10.4, 1.4Hz, 1H), 4.32 (t, J = 7.0Hz, 2H), 3.18 (t, J = 7.0Hz, 2H). 13 C NMR (101MHz, CDCl3, δ): 166.01, 135.19, 131.32, 130.04, 129.19, 128.19, 126.73, 63.15, 32.44.

[0082] 7.57 g of compound 1 (36 mmol, 1 eq.) and 150 mL of dichloromethane were added to a 250 mL round-bottom flask equipped with a magnetic stir bar. 18.8 g of m-chloroperoxybenzoic acid (mCPBA) (109 mmol, 3 eq.) was added under ice-water bath cooling. The ice-water bath was removed, and the reaction was allowed to proceed at room temperature for 30 minutes. The reaction was quenched by adding saturated Na₂SO₃ solution. After separation, the aqueous phase was extracted twice with ethyl acetate. The combined organic phases were washed with saturated NaHCO₃ and dried over anhydrous Na₂SO₄. The solvent was evaporated, and the crude product (petroleum ether / ethyl acetate = 3 / 1, v / v) was separated by column chromatography to give 7.61 g of monomer A (white solid, 88% yield). 1 H NMR (400MHz, CDCl3, δ): 7.93 (dd, J=7.4, 1.8Hz, 2H), 7.71–7.62 (m, 1H), 7.57 (dd, J=8.5, 7.0Hz, 2H), 6.21 (dd, J=17.1, 1.6Hz, 1H), 5.85 (dd, J=17.0, 10.5Hz, 1H), 5.75 (dd, J=10.5, 1.6Hz, 1H), 4.50 (t, J=6.1Hz, 2H), 3.51 (t, J=6.1Hz, 2H).13 C NMR (101MHz, CDCl3, δ): 165.40, 139.60, 134.09, 131.98, 129.52, 128.27, 127.39, 57.93, 55.22.

[0083] Example 8: Synthesis of homopolymer PB1 of monomer B1

[0084]

[0085] 200 mg of monomer B1 (0.87 mmol, 50 eq.), 3 mg of AIBN (0.017 mmol, 1 eq.), and 0.2 mL of 1,4-dioxane were added to a 10 mL Shrek tube equipped with a magnetic magnet. The Shrek tube was frozen in liquid nitrogen and then connected to a vacuum line. The vacuum-thawing-freezing operation was repeated three times. The Shrek tube was then placed in an oil bath at 70 °C for polymerization for 12 hours. After polymerization, the reaction solution was precipitated by adding methanol dropwise. The polymer was dissolved in chloroform, and precipitated by adding methanol dropwise. The dissolution-precipitation operation was repeated twice. The precipitated polymer was placed in a vacuum oven at 50 °C to remove residual solvent, yielding PB1 (188 mg, 94% yield).

[0086] The homopolymers of the remaining monomers were synthesized using the same procedures as in Example 8. The polymer structure was confirmed by 1H NMR spectroscopy. The thermal properties of the polymer were characterized by TGA and DSC. The copolymer exhibited good thermal stability. d,5％ The glass transition temperature of homopolymers ranges from 292 to 338℃. Depending on the side group structure, the glass transition temperature of homopolymers ranges from 19 to 142℃.

[0087] Table 1. Molecular weight and thermal properties of homopolymers

[0088]

[0089] a Tetrahydrofuran phase SEC determination; b TGA assay, T d,5％ For a sample mass loss of 5%

[0090] The temperature at that time; c DSC determination, T g The glass transition temperature during the second heating process.

[0091] Example 9: Synthesis of monomer B1 and an equivalent glycidyl acrylate (GA) copolymer B1-GA1

[0092]

[0093] Add 600 mg monomer B1 (2.6 mmol, 25 eq.), 300 μL glycidyl acrylate (GA, 2.6 mmol, 25 eq.), 17 mg AIBN (0.104 mmol, 1 eq.), and 2.5 mL DMF to a 25 mL Shrek tube equipped with a magnetic magnet. Freeze the Shrek tube in liquid nitrogen and then connect it to a vacuum line. Repeat the vacuum-thawing-freezing operation three times. Place the Shrek tube in an oil bath at 70 °C for polymerization for 12 hours. After polymerization, take a small amount of the reaction solution for further processing. 1 ¹H NMR characterization confirmed complete monomer conversion, and the remaining solution was precipitated with methanol. The polymer was dissolved in chloroform, and precipitated with methanol; this dissolution-precipitation process was repeated twice. The precipitated polymer was placed in a vacuum oven at 50°C to remove residual solvent, yielding B1-GA1 (812 mg, yield 87%).

[0094] The remaining copolymers were synthesized using the same procedures as in Example 9. The structure of the polymers was confirmed by 1H NMR spectroscopy. Changing the feed ratio of the two comonomers allowed for adjustment of the composition of the resulting copolymers, thereby controlling their properties. The thermal properties of the polymers were characterized by TGA and DSC. The copolymers exhibited good thermal stability, with T... d,5％Between 278 and 335 °C. The composition of the copolymer conforms to the Fox equation with respect to its glass transition temperature, indicating that the copolymer has a random sequence and its glass transition temperature can be accurately predicted before the copolymer is synthesized. Thin film samples used for dielectric properties, breakdown strength, and energy storage properties testing were all prepared by hot pressing. Polymer powder was sandwiched between two polytetrafluoroethylene films and hot-pressed for half an hour at a temperature 20 °C higher than the glass transition temperature. After cooling to room temperature, the resulting polymer film was peeled off from the polytetrafluoroethylene film, and circular gold electrodes of a certain size were sprayed on both sides of the film by magnetron sputtering. The dielectric constant and dielectric loss of the copolymer were characterized by broadband dielectric spectroscopy. When the amount of GA doping was fixed, the dielectric constant of copolymers containing different structural units increased in the following order: A-GA1 (containing sulfone-benzene ring structural unit), C2-GA1 (containing benzene ring-sulfone-bicyclo[1.1.1]pentane structural unit), and B1-GA1 (containing sulfone-bicyclo[1.1.1]pentane structural unit). B1-GA1, containing the sulfone-bicyclo[1.1.1]pentane structural unit, exhibits the highest dielectric constant, 6.82 at 100 Hz at room temperature. This is because the size of the bicyclo[1.1.1]pentane is smaller than that of the benzene ring, which facilitates dipole reversal under an applied electric field and enhances orientation polarization. When the structural unit is fixed, the dielectric constant of the copolymer increases with increasing GA incorporation. The dielectric loss of the copolymer is lower than that of sulfone-containing polymers reported in the literature, and also lower than that of PMMA without strongly polar groups. This is partly because copolymerization with GA introduces epoxy groups into the polymer, which act as charge traps to capture space charges and reduce conductivity loss. On the other hand, the direct connection between the bicyclo[1.1.1]pentane structure and the sulfone group weakens dipole-dipole interactions, reducing relaxation loss. When using low-polarity methyl acrylate (MA) as a comonomer, A-MA1 exhibits a lower dielectric constant and dielectric loss, as well as a higher glass transition temperature, compared to A-GA1 which uses GA as a comonomer. B1-GA1, which has the highest dielectric constant, was selected, and its energy storage properties were tested using a ferroelectric testing instrument. B1-GA1 showed a dielectric constant of 225 mV / m. -1 The discharge energy density under the electric field strength can reach 1.78 J / cm². -3 At this point, the material has a charge / discharge efficiency of up to 95%.

[0095] Table 2. Composition, molecular weight and properties of copolymers

[0096]

[0097] a The copolymer composition was obtained by integrating the proton NMR spectrum. b Tetrahydrofuran phase GPC determination; c TGA assay, T d,5％ The temperature at which the sample mass loss is 5%;d DSC determination, T g Glass transition temperature during the second heating process; e Dielectric constant and dielectric loss of the copolymer at 100 Hz at room temperature (23°C).

Claims

1. The compound shown in Formula I: In Formula I, R is selected from alkylene, oxaalkylene, arylene, or combinations thereof as a linking group.

2. The compound of formula I as claimed in claim 1, characterized in that, R is selected from -C a H 2a -,-C a H 2a -OC b H 2b -, -Ph-, -C a H 2a -O-Ph-, where a and b represent 1 to 6 carbon atoms, and Ph represents a benzene ring.

3. The compound of formula I as described in claim 1, characterized in that, The compound of formula I is selected from one of the following compounds: .

4. The polymer shown in Formula II: In Formula II, R is selected from alkylene, oxaalkylene, arylene, or combinations thereof as a linking group, and n represents the degree of polymerization.

5. The polymer of formula II as described in claim 4, characterized in that, R is selected from -C a H 2a -,-C a H 2a -OC b H 2b -, -Ph-, -C a H 2a -O-Ph-, where a and b represent 1 to 6 carbon atoms, and Ph represents a benzene ring.

6. The polymer shown in Formula III: In Formula III, R is selected from alkylene, oxaalkylene, arylene, or combinations thereof as a linking group, X is alkyl, glycidyl, aryl, or alkyl-substituted aryl, and n and m represent the degree of polymerization.

7. The polymer of formula III as described in claim 6, characterized in that, R is selected from -C a H 2a -,-C a H 2a -OC b H 2b -, -Ph-, -C a H 2a -O-Ph-, where a and b represent 1 to 6 carbon atoms, Ph represents a benzene ring, and X is a C1 to C6 alkyl, glycidyl, or phenyl group.

8. A method for preparing the compound of formula I according to claim 1, selected from one of the following four synthetic routes: the first synthetic route includes steps 1a) to 1c). 1a) Intermediate V containing a bicyclic [1.1.1]pentane structure is synthesized by addition reaction of [1.1.1]spiroalkyl with thiophenol or thiol compound IV; 1b) The thioether of intermediate V is converted to sulfone by oxidation reaction to obtain intermediate VI; 1c) Compound I is synthesized by reaction of the hydroxyl group of intermediate VI with acryloyl chloride; The second synthetic route includes steps 2a) to 2c). 2a) Intermediate V containing a bicyclic [1.1.1]pentane structure is synthesized by the addition reaction of [1.1.1]spiroalkyl with thiophenol or thiol compound IV; 2b) Intermediate VII is synthesized by the reaction of the hydroxyl group of intermediate V with acryloyl chloride; 2c) The thioether of intermediate VII is converted to sulfone by oxidation reaction to obtain the compound shown in Formula I; The third synthetic route includes steps 3a) to 3d). 3a) An intermediate V' containing a bicyclic [1.1.1]pentane structure is synthesized by the addition reaction of [1.1.1]spiroalkyl with thiophenol compound IV', wherein R' is an arylene group; 3b) The hydroxyl group in intermediate V' is converted to an ether bond to obtain intermediate V containing a bicyclic [1.1.1]pentane structure; 3c) The thioether of intermediate V is converted to a sulfone by an oxidation reaction to obtain intermediate VI; 3d) The hydroxyl group of intermediate VI is reacted with acryloyl chloride to synthesize the compound shown in formula I; The fourth synthetic route includes steps 4a) to 4d). 4a) Intermediate V' containing a bicyclic [1.1.1]pentane structure was synthesized by the addition reaction of [1.1.1]spiroalkyl with thiophenol compound IV', wherein R' is an arylene group; 4b) The hydroxyl group in intermediate V' was converted into an ether bond to synthesize intermediate V containing a bicyclic [1.1.1]pentane structure; 4c) Intermediate VII was synthesized by the reaction of the hydroxyl group of intermediate V with acryloyl chloride; 4d) The thioether of intermediate VII was converted into a sulfone by an oxidation reaction to obtain the compound shown in Formula I.

9. A method for preparing the polymer of formula II according to claim 4, comprising using the compound of formula I according to any one of claims 1 to 3 as a monomer, and subjecting it to a homopolymerization reaction to obtain the polymer of formula II: in, R is selected from alkylene, oxaalkylene, arylene, or combinations thereof as a linking group, and n represents the degree of polymerization.

10. A method for preparing the polymer of formula III according to claim 6, comprising copolymerizing the compound of formula I according to any one of claims 1 to 3 as the first monomer with the acrylate monomer of formula VIII to obtain the polymer of formula III: in, R is selected from alkylene, oxaalkylene, arylene, or combinations thereof as a linking group; X is alkyl, glycidyl, aryl, or alkyl-substituted aryl; and n and m represent the degree of polymerization.

11. The use of the polymer of Formula II as claimed in claim 4 or the polymer of Formula III as claimed in claim 6 as a dielectric material.

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