Ferroelectric nematic phase liquid crystal molecular monomer, polymer thereof and preparation method of ferroelectric nematic phase liquid crystal molecular monomer

Abstract

The invention discloses a ferroelectric nematic phase liquid crystal molecular monomer, a polymer thereof and a preparation method of the polymer, and belongs to the technical field of ferroelectric nematic phase liquid crystal molecules. The liquid crystal molecular monomer presenting a stable ferroelectric nematic phase is designed for the first time, and the ferroelectric liquid crystal polymer is prepared through polymerization. The ferroelectric nematic liquid crystal molecular monomer and the ferroelectric liquid crystal polymer both have strong polarity, and show the characteristics of strong nonlinear optical response, high dielectric constant, high saturation polarization value and the like. The ferroelectric liquid crystal polymer prepared by the method is a brand-new reformation ferroelectric polymer, and has a wide application prospect in the fields of flexible electronics, nonlinear optics and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of ferroelectric nematic liquid crystal molecules, and more particularly relates to a ferroelectric nematic liquid crystal molecule monomer and a polymer thereof and a preparation method thereof. Background Art

[0002] Liquid crystal is a type of anisotropic soft matter with broad application prospects. The most mature and widely used technical field is liquid crystal display. As the mainstream solution in the global information display industry, liquid crystal display technology is widely used in various display devices, including TV screens, computer monitors, and various large, medium and small display terminals. In addition, due to its excellent dielectric tunable properties in the microwave, millimeter wave and terahertz bands, liquid crystal materials are also widely used in fifth-generation mobile communication (5G) networks, phase shifters, filters, phased array radars and other radio frequency and optoelectronic devices. In addition to anisotropic optical properties, liquid crystal materials also have excellent responsiveness and can produce reversible responses to a variety of external stimuli, including electric fields, light, temperature, pressure and other factors, with multi-dimensional response control capabilities. Therefore, liquid crystal materials also show important application potential in the fields of optical modulation, optical sensing, temperature sensing, pressure sensing and so on.

[0003] In recent years, liquid crystal technology has continued to develop to meet the higher performance demands of devices in emerging fields such as virtual reality (VR), augmented reality (AR), flexible displays, and in-vehicle displays. It is foreseeable that liquid crystal materials will remain, and will continue to be, indispensable core functional materials in the fields of information display and intelligent optoelectronics. However, traditional liquid crystal systems are mostly non-polar fluids, lack spontaneous polarization properties, and have low dielectric constants. This has led to certain limitations in dielectric properties, electro-optical response speed, and the development of new optoelectronic functions. Therefore, the design and development of liquid crystal materials with strong polarity or ferroelectricity has become a major topic in the fields of liquid crystal science and soft matter materials, which urgently needs breakthroughs.

[0004] As early as 1916, Born first predicted the ferroelectric nematic phase. F However, after nearly a century of exploration, this idea was not discovered until 2017 by Dr. Nishikawa's team in Japan and the Goodby team in the UK, respectively, who independently discovered the first liquid polar nematic liquid crystal materials with strong spontaneous polarization. Subsequently, the Clark team in the United States further confirmed its ferroelectricity, officially confirming the ferroelectric nematic phase (N F ) Liquid crystal is a new phase.

[0005] Compared with traditional liquid crystals and other soft matter systems, ferroelectric nematic liquid crystals exhibit a variety of revolutionary physical properties. First, N FLiquid crystal has an ultra-high spontaneous polarization intensity due to its ferroelectric ordered structure, and the measured saturation polarization value can reach 6μC / cm 2 . Secondly, N F The dielectric constant of liquid crystal systems in the frequency range of 1 to 10 kHz generally exceeds 10 3 , some materials can even reach 10 4 , reaching and surpassing most inorganic ferroelectric or relaxor ferroelectric materials, becoming the most excellent class of materials in the current soft matter system in terms of dielectric properties. Third, thanks to its strong polarity characteristics, N F Liquid crystals are highly sensitive to electric fields. An electric field as low as 1V / cm can drive changes in their molecular orientation. Their response speed can reach milliseconds to microseconds, combining high sensitivity and fast response capabilities that traditional inorganic ferroelectric materials do not possess. F Liquid crystals also exhibit excellent nonlinear optical response performance, and their second harmonic generation (SHG) signal intensity can reach tens or even hundreds of times that of quartz crystals, approaching the level of inorganic ferroelectric crystals. The combination of ferroelectricity and fluid liquid crystal properties not only gives N F The unique dielectric, electro-optical and nonlinear optical properties of liquid crystals have also brought about many new physical phenomena that have not yet been fully revealed, and have stimulated a new round of widespread attention and in-depth research in the field of soft matter science.

[0006] Liquid crystal elastomers (LCEs) are a class of intelligent soft materials that couple the ordered structure of liquid crystals with a polymer elastic network. They combine the anisotropy of liquid crystals with the deformability of elastomers. Compared to traditional ferroelectric polymers and dielectric elastomers, LCEs can achieve significant macroscopic responsive deformations under external field stimuli such as electric, thermal, and optical fields, and possess unique dielectric anisotropy, giving them distinct advantages in low-field drive and efficient actuation. Main-chain LCEs, in particular, have superior mechanical properties and responsiveness due to the direct embedding of liquid crystal units into the polymer backbone, making them a hot topic in current research on LC actuated materials. In recent years, research on the dielectric response characteristics of LCEs has continued to advance, demonstrating their broad application prospects in soft robotics, intelligent devices, and high-performance drive systems.

[0007] With N F Reports on liquid crystals and their excellent electro-optical properties continue to reveal that the design and application of materials around this phase has become an important research direction in the field of liquid crystals. However, the existing ferroelectric nematic liquid crystal systems are almost entirely limited to small molecule liquid crystals. In order to expand the application of ferroelectric liquid crystals in electro-optical devices, some studies have attempted to combine N F By blending or grafting small liquid crystal molecules with polymer matrices, the electro-optical properties of ferroelectric nematic liquid crystals can be introduced into oligomer, polymer, or elastomer systems. These studies demonstrate the potential for applications in high-dielectric and optically tunable devices.

[0008] However, the design of polymerizable liquid crystal monomers with ferroelectric nematic behavior and the polymerization of corresponding polymers have not yet been achieved. F Liquid crystal doping or microphase separation methods rely on the polarity alignment of small molecules, rather than the ordered arrangement of polymer chains, to form polar ordered domains. This blending strategy suffers from small molecule phase separation, poor stability, and limited processability, and it is difficult to achieve controllable regulation of polarity orientation at the molecular level.

[0009] From the perspective of materials science and polymer physics, we have developed a novel nanostructured polymer that can spontaneously form N F The ferroelectric liquid crystal polymer of the phase has important scientific value and application significance. Compared with the small molecule system, the liquid crystal polymer material has both the flexibility of the polymer chain and the order of the liquid crystal phase. If the appropriate high dipole moment configuration and aspect ratio can be introduced in the molecular design, the polymer itself can form N F The ability to change phases will bring the following advantages to the ferroelectric liquid crystal material system: ① Improve the stability and memory effect of polar orientation to meet the long-term working reliability requirements of flexible electronic devices and wearable technologies; ② Achieve large-area uniform orientation and shape processability, and provide new material solutions for high-end display devices, sensors and photonic devices; ③ Expand the application scenarios of ferroelectric liquid crystals in new stretchable and high dielectric constant materials, especially in the fields of flexible energy storage, electrochromism and nonlinear optics.

[0010] Therefore, designing and synthesizing polymerizable ferroelectric nematic liquid crystal monomers and polymerizing them to obtain ferroelectric liquid crystal polymer systems will not only break through the existing small molecule N F The limitations of liquid crystal material systems will also open up new research directions for the structural design and functional device development of polar liquid crystal materials. Summary of the Invention

[0011] The purpose of the present invention is to provide a ferroelectric nematic liquid crystal molecule monomer and polymer and preparation method thereof, so as to solve the problems existing in the above-mentioned prior art, design and synthesize polymerizable ferroelectric nematic liquid crystal molecule monomer, and realize polymerization to obtain ferroelectric liquid crystal polymer system, which not only breaks through the existing small molecule N F The limitations of liquid crystal material systems also open up new research directions for the structural design and functional device development of polar liquid crystal materials.

[0012] In order to solve the problem that existing ferroelectric nematic liquid crystal materials are mainly limited to small molecule systems, the primary purpose of the present invention is to propose a design concept and preparation method for a ferroelectric nematic liquid crystal molecule monomer that can be polymerized and its corresponding polymer. The designed ferroelectric nematic liquid crystal monomer molecule must contain functional groups that can participate in the polymerization reaction. Based on the compatibility of the chemical structure and the feasibility of the synthesis process, acrylate functional groups are preferred as polymerization units. At the same time, by regulating the length of the flexible alkyl chain and the position of the oxygen atom in the flexible chain, the molecular conformation can be precisely adjusted, thereby effectively controlling the N F The phase behavior and temperature window of ferroelectric nematic phases. It is particularly critical to introduce structural units with sufficiently large dipole moments into the mesogens to enhance the intermolecular dipole-dipole interactions and thus improve the phase stability of the ferroelectric nematic phase. This can be achieved by introducing electron-withdrawing groups or high-density fluorine atom substitution in the same direction.

[0013] A second objective of the present invention is to further polymerize the designed and synthesized ferroelectric nematic liquid crystal molecule monomers to produce ferroelectric liquid crystal polymers, thereby expanding the ferroelectric nematic liquid crystal material system into the polymer field. To enhance the polarization retention capability of the polymer system, liquid crystal monomers with dual polymerization functional groups are designed as crosslinking agents to construct a ferroelectric liquid crystal polymer system with a three-dimensional polymer network. This type of ferroelectric liquid crystal polymer not only retains the excellent electro-optical properties of the ferroelectric nematic small molecule liquid crystal system, but also further expands the material's performance, showing broad application prospects in novel electro-optical device applications.

[0014] To achieve the above object, the present invention provides the following solutions:

[0015] One of the technical solutions of the present invention is to provide a ferroelectric nematic liquid crystal molecule monomer, wherein the chemical structure of the ferroelectric nematic liquid crystal molecule monomer is one of Formulas I to IV:

[0016]

[0017] In formulas I to IV, R1, R2, R3, R4, R5, R6, R7, R8, and E are all substituted groups;

[0018] Wherein, R1, R2, R3, R4, R5, R6, R7, and R8 are independently selected from one of F, OCH3, CF3, and H, and the number of substituents in Formula III and Formula IV is selected to be substituted by F is not less than two;

[0019] E is a strong electron-pulling group selected from one of CN, F, CF3, and NO2;

[0020] n, m, and x all represent the number of carbon atoms contained in the alkyl chain at that position, wherein n=1-10, m=0-1, and x=1-10.

[0021] Preferably, the ferroelectric nematic liquid crystal molecular monomers with different chemical structures can be randomly combined and polymerized to form a ferroelectric liquid crystal polymer.

[0022] Preferably, the ferroelectric nematic liquid crystal molecule monomer can present a stable ferroelectric liquid crystal phase, including a ferroelectric nematic phase (N F ), ferroelectric smectic phase (SmA F 、SmC F ) and the antiferroelectric transition phase (N x )wait.

[0023] Preferably, the ferroelectric nematic liquid crystal monomer has a high saturation polarization value of >6 μC / cm 2 , ultra-high dielectric constant>20000, strong second harmonic signal SHG>30 times that of quartz.

[0024] The second technical solution of the present invention is to provide the application of the above-mentioned ferroelectric nematic liquid crystal molecule monomer in the preparation of ferroelectric liquid crystal polymer.

[0025] The third technical solution of the present invention is to provide a method for preparing a ferroelectric liquid crystal polymer, comprising the following steps:

[0026] The ferroelectric nematic liquid crystal molecular monomers with different chemical structures are blended and polymerized to prepare a ferroelectric liquid crystal polymer.

[0027] Preferably, the mass percentage of the ferroelectric nematic liquid crystal monomers of different chemical structural formulas blended is:

[0028] The ferroelectric nematic liquid crystal molecule monomer shown in formula I is selected to include 1 to 10 ferroelectric nematic liquid crystal molecule monomers with different chemical structures, and the mass fraction thereof is a, wherein a=0 to 100%;

[0029] The ferroelectric nematic liquid crystal molecule monomer represented by formula II comprises 1 to 10 ferroelectric nematic liquid crystal molecule monomers with different chemical structures, and the mass fraction thereof is b, wherein b=0 to (100%-a);

[0030] The ferroelectric nematic liquid crystal molecule monomer represented by formula III is selected to include 1 to 10 bifunctional ferroelectric nematic liquid crystal molecule monomers with different chemical structures, and the mass fraction thereof is c, wherein c=0 to (100%-ab);

[0031] The ferroelectric nematic liquid crystal molecule monomer represented by formula IV comprises 1 to 10 bifunctional ferroelectric nematic liquid crystal molecule monomers with different chemical structures, and the mass fraction thereof is d, wherein d=100%-abc;

[0032] And c+d≤70%.

[0033] The fourth technical solution of the present invention: provides a ferroelectric liquid crystal polymer prepared by the above preparation method.

[0034] Preferably, the number of repeating units of the ferroelectric liquid crystal polymer is an integer of 5 to 1000.

[0035] Preferably, the ferroelectric liquid crystal polymer has ferroelectricity, presents a stable polar liquid crystal phase in a specific temperature range, and exhibits polarization characteristics similar to those of ferroelectric nematic liquid crystal monomers, including a high saturation polarization value of >2μC / cm 2 , ultra-high dielectric constant>100, strong second harmonic signal SHG>10 times that of quartz.

[0036] The present invention discloses the following technical effects:

[0037] (1) The present invention provides for the first time a design scheme for a polymerizable ferroelectric nematic liquid crystal molecule monomer, which can not only spontaneously form an indeterminate ferroelectric nematic phase, but can also be further polymerized to prepare a ferroelectric liquid crystal polymer.

[0038] (2) The ferroelectric nematic liquid crystal molecule monomers provided by the present invention can be combined and blended in any proportion to form a ferroelectric liquid crystal polymer network, which well retains the ferroelectricity of the monomers in the polymer and exhibits strong polarity and strong nonlinear optical response. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a POM image of the cooling process of the ferroelectric nematic liquid crystal monomer synthesized in Example 1;

[0040] Figure 2 This is a POM image of the cooling process of the ferroelectric nematic liquid crystal monomer synthesized in Example 2;

[0041] Figure 3 This is a POM image of the cooling process of the ferroelectric nematic liquid crystal monomer synthesized in Example 3;

[0042] Figure 4 This is a POM image of the cooling process of the ferroelectric nematic liquid crystal monomer synthesized in Example 4;

[0043] Figure 5 This is a POM image of the cooling process of the ferroelectric nematic liquid crystal monomer synthesized in Example 5;

[0044] Figure 6 This is a POM image of the cooling process of the ferroelectric nematic liquid crystal monomer synthesized in Example 6;

[0045] Figure 7This is a POM image of the cooling process of the ferroelectric nematic liquid crystal monomer synthesized in Example 7;

[0046] Figure 8 This is a POM image of the cooling process of the ferroelectric nematic liquid crystal monomer synthesized in Example 9;

[0047] Figure 9 The evolution of the second harmonic generation (SHG) signal intensity of the ferroelectric liquid crystal polymer represented by Example 21 during the cooling process before and after polymerization, wherein (a) is the SHG result of the sample after the ferroelectric nematic liquid crystal molecular monomers are uniformly blended in proportion, and (b) is the SHG result after the monomers are polymerized into a ferroelectric liquid crystal polymer. DETAILED DESCRIPTION

[0048] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0049] It should be understood that the terms described herein are intended only to describe particular embodiments and are not intended to limit the present invention. In addition, for numerical ranges herein, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. The intermediate value within any stated value or stated range, and each smaller range between any other stated value or intermediate value within the stated range, is also encompassed within the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded within the scope.

[0050] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of any conflict with any incorporated document, the contents of this specification shall prevail.

[0051] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments described herein without departing from the scope or spirit of the invention. Other embodiments will be apparent to those skilled in the art from the description of the invention. The description and examples are intended to be illustrative only.

[0052] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0053] It should be pointed out that the matters not described in detail in the present invention are conventional operating means in this field and are not the focus of the present invention.

[0054] The ferroelectric nematic liquid crystal monomers having the general chemical structures of Formulas I to IV can be synthesized according to the following steps: first, the head group portion is synthesized, and then the tail groups are synthesized according to the characteristics of each chemical structure, and then combined to form the corresponding chemical structure in the general formula. Because the ferroelectric nematic liquid crystal monomers involved in the present invention have similar chemical structures, the synthesis paths and reaction conditions are highly similar. The specific reaction formula is as follows:

[0055]

[0056] Synthesis route of the head portion with acrylate functional group (Compound A-4):

[0057] Depending on the number of carbon chains m, two cases are possible: when m = 0, a brominated alkyl alcohol and a hydroxybenzaldehyde derivative are reacted with K2CO3 to produce compound A-2 through etherification. When m = 1, an n-alkyl glycol and a brominated benzyl derivative are reacted with NaH to produce compound A-1. Then, under an N2 atmosphere, lithium diisopropylamide (LDA) is added and the reaction is continued at -78°C to produce compound A-2. Compound A-3 is produced by reacting the compound with acryloyl chloride and triethylamine (TEA). Compound A-3 is oxidized to a carboxyl group by adding NaClO2 and NaH2PO4 to produce compound A-4. The specific implementation method is as follows: Taking m=1, n=3, R1=R2=F as an example, (1) 1,3-propylene glycol (5 equivalents) is dispersed in anhydrous DMF, and NaH (1.2 equivalents) is slowly added to the previously obtained solution under ice bath (0°C). After stirring for 1 hour, 3,5-difluorobenzyl bromide (1 equivalent) is added to the obtained solution under ice bath. After removing the ice bath, the reaction is carried out at room temperature for 8-12 hours until the reaction of 3,5-difluorobenzyl bromide is complete. The reaction can be detected by thin layer chromatography. After the reaction, the mixture was poured into 5-8 times the volume of the reaction solution of water and extracted with EA three times. The organic phase was collected and extracted once with saturated brine. The water in the organic phase was removed with anhydrous sodium sulfate and filtered. The mixture was concentrated in vacuo to an appropriate solvent and then mixed with silica gel powder. The mixture was separated and purified by chromatography. The elution system was PE / EA. The product A-1 (m=1, n=3, R1=R2=F) was obtained with a yield of 80-90%. (2) A-1 (m=1, n=3, R1=R2=F, 1 equivalent) was dispersed in anhydrous THF. The solution was placed at -78°C. Under N2 atmosphere, LDA (2 equivalents) was slowly added dropwise to the solution obtained above. After the reaction for 1 hour, DMF (4 equivalents) was slowly added dropwise to the reaction solution with a syringe. The reaction was continued at room temperature for 8-12 hours until the reaction of A-1 (m=1, n=3, R1=R2=F) was complete. The reaction was detected by thin layer chromatography.After the reaction, most of the solvent was dried and 1 mol / L dilute hydrochloric acid (2 equivalents) was added to the mixture, and then 5-8 times the volume of water of the reaction solution was added, and the mixture was extracted with EA three times. The water in the organic phase was removed with anhydrous sodium sulfate and filtered. After vacuum concentration to an appropriate solvent, silica gel powder was added and purified by chromatography column separation. The elution system was PE / EA to obtain the product A-2 (m = 1, n = 3, R1 = R2 = F) with a yield of 40-50%; (3) A-2 (m = 1, n = 3, R1 = R2 = F, 1 equivalent) was mixed with TEA (1 .2 equivalents) were dispersed in anhydrous DCM, and acryloyl chloride (1.2 equivalents) was slowly added to the previously obtained solution under ice bath (0°C). After returning to room temperature, the mixture was stirred for 6 to 8 hours and then the reaction was stopped. Silica gel powder was added and column chromatography was performed for separation. The eluent was PE / DCM to obtain product A-3 (m=1, n=3, R1=R2=F) with a yield of 65 to 80%. (4) A-3 (m=1, n=3, R1=R2=F, 1 equivalent) was dissolved in DMSO / H2O solvent with a volume ratio of 4 / 1, and the reaction solution was then placed in an ice bath. Sodium chlorite (3.5 equivalents) and sodium dihydrogen phosphate (4 equivalents) were dissolved in an appropriate volume of water, and the brine was slowly added dropwise to the above mixed solution. The solution was exothermic and the addition was complete. At this time, the DMSO / H2O volume ratio of the reaction solution was generally 4 / 3. The solution was returned to room temperature and continued to stir for 12 to 16 hours. The reaction was terminated, and the reaction solution was poured into 4 to 6 volumes of water. The pH of the mixed solution was then adjusted to 1 to 2 with 2 mol / L dilute hydrochloric acid, and extracted again with EA three times. The resulting organic phase was extracted once with saturated brine, dried over anhydrous sodium sulfate, filtered, and rotary evaporated. Silica gel powder was added and separated by column chromatography using PE / EA as the eluent to obtain product A-4 (m=1, n=3, R1=R2=F) with a yield of 85 to 95%.

[0058] The reaction formula of the ferroelectric nematic liquid crystal molecule monomer having the chemical structure of general formula I is as follows:

[0059]

[0060] First, the hydroxyl group of a hydroxybenzoic acid derivative was protected, and p-TsOH and THP were added to synthesize compound B-1. Compound B-1 was then esterified with a phenol derivative under the catalysis of EDC and DMAP to synthesize compound B-2. Subsequently, the THP protection of the phenolic hydroxyl group was removed, and PPTS was added to react in a 1 / 1 CH3OH / THF mixed solvent to obtain deprotected compound B-3. Finally, compound B-3 was esterified with the previously prepared compound A-4 under the catalysis of EDC and DMAP to synthesize a ferroelectric nematic liquid crystal monomer having the chemical structure of general formula I. The specific implementation method is as follows: Taking m=1, n=3, R1=R2=F, R3=R4=H, R5=R6=F, E=CN as an example, (1) p-Hydroxybenzaldehyde (1 equivalent) is dispersed in anhydrous ether, the mixture is placed in an ice bath, tetrahydropyran (1.1-1.3 equivalents) is slowly added dropwise with a syringe, stirred in an ice bath for 1 hour, then returned to room temperature and stirred for 6-14 hours, the reaction is stopped, and the reaction is quenched with a saturated sodium bicarbonate solution, then extracted twice with DCM, and then washed once with saturated brine. The organic phase is dried over anhydrous sodium sulfate and heated to room temperature. The mixture was dried and mixed with silica gel powder, and separated and purified by column chromatography. The eluent was PE / EA system, and the product B-1 (R3=R4=H) was obtained with a yield of 55-70%. (2) B-1 (R3=R4=H, 1 equivalent), 2,6-difluoro-4-hydroxybenzonitrile (1 equivalent), EDC (1.5 equivalents), and DMAP (0.06 equivalents) were added to anhydrous DCM and reacted at room temperature for 6-8 hours. The mixture was then mixed with silica gel powder and separated by column chromatography. The eluent was PE / DCM, and the product B-2 (R3=R4=H, R5=R6=F, E=CN), yield 75~85%; (3) B-2 (R3=R4=H, R5=R6=F, E=CN, 1 equivalent) was dissolved in a THF / MeOH=1 / 1 mixed solution, 4-methylbenzenesulfonic acid pyridinium (PPTS, 1 equivalent) was added, and then the solution was heated to 60℃ until the reaction was complete as detected by thin layer chromatography, and then returned to room temperature, a large amount of water was added, and extracted with EA, and the organic phase was dried over anhydrous sodium sulfate. After being spin-dried, the crude product B-2 (R3=R4=H, R5=R6=F) can be directly fed to the next step reaction, and the yield is 90 ~95%; (4) B-2 (R3=R4=H, R5=R6=F, E=CN), 1 equivalent), A-4 (m=1, n=3, R1=R2=F, 1 equivalent), EDC (1.5 equivalents), DMAP (0.06 equivalents) were added to anhydrous DCM, reacted at room temperature for 10 min, then mixed with silica gel powder, separated by column chromatography, and PE / DCM was selected as the eluent to obtain product I (m=1, n=3, R1=R2=F, R3=R4=H, R5=R6=F, E=CN) with a yield of 50%-60%.

[0061] The reaction formula of the ferroelectric nematic liquid crystal molecule monomer having the chemical structure of general formula II is as follows:

[0062]

[0063]

[0064] First, based on the desired chemical structure, the phenolic hydroxyl groups of the corresponding p-hydroxybenzoic acid derivatives were protected with THP, followed by the addition of p-TsOH and THP to synthesize compounds C-1 and C-2, respectively. Compound C-2 was then esterified with a phenol derivative in the presence of EDC and DMAP to synthesize compound C-3. The THP protection of the phenolic hydroxyl group was then removed, and PPTS was added to react in a 1 / 1 CH3OH / THF mixture to obtain deprotected compound C-4. Compound C-4 was then esterified with C-1 in the presence of EDC and DMAP to synthesize compound C-5. The THP protection of the phenolic hydroxyl group was then removed, and PPTS was added to react in a 1 / 1 CH3OH / THF mixture to obtain deprotected compound C-6. Finally, compound C-6 was esterified with the previously prepared compound A-4 in the presence of EDC and DMAP to synthesize a ferroelectric nematic liquid crystal monomer having the chemical structure of Formula II.The specific implementation method is as follows: Taking m=1, n=3, R1=R2=F, R3=R4=R5=R6=H, R7=R8=F, E=CN as an example, (1) the synthesis method of product C-1 (R3=R4=H) is the same as that of B-1 (R3=R4=H); (2) the synthesis method of product C-2 (R5=R6=H) is the same as that of B-1 (R3=R4=H); (3) the synthesis method of product C-3 (R5=R6=H, R7=R8=F, E=CN) is the same as that of B-2 ((R3=R4=H, R5=R6=F, E=CN); (4) the synthesis method of product C-4 (R The synthesis method of C-5 (R3=R4=H, R5=R6=F, E=CN) is the same as that of B-3 ((R3=R4=H, R5=R6=F, E=CN); (5) C-1 (R3=R4=H, 1 equivalent), C-4 (R5=R6=H, R7=R8=F, E=CN, 1 equivalent), EDC (1.5 equivalents), and DMAP (0.06 equivalents) were added to anhydrous DCM and reacted at room temperature for 10 min. Silica gel powder was then added and the mixture was separated by column chromatography using PE / DCM as the eluent to obtain the product C-5 (R3=R4=R5=R6=H, R7=R8=F, E=CN). =F, E=CN), yield 50-60%; (6) B-2 (R3=R4=H, R5=R6=F, E=CN, 1 equivalent) was dissolved in a THF / MeOH=1 / 1 mixed solution, 4-methylbenzenesulfonic acid pyridinium (PPTS, 1 equivalent) was added, and the solution was then heated to 60°C until the reaction was complete as detected by thin layer chromatography, returned to room temperature, a large amount of water was added, and extracted with EA, the organic phase was dried over anhydrous sodium sulfate, and the crude product C-6 (R3=R4=R5=R6=H, R7=R8=F, E=CN) after spin drying was directly fed to the next step reaction, with a yield of 90~95%; (7) C-6 (R3=R4=R5=R6=H, R7=R8=F, E=CN, 1 equiv), A-4 (m=1, n=3, R1=R2=F, 1 equiv), EDC (1.5 equiv), DMAP (0.06 equiv) were added to anhydrous DCM, reacted at room temperature for 10 min, then mixed with silica gel powder, separated by column chromatography, and PE / DCM was selected as the eluent to obtain product II (m=1, n=3, R1=R2=F, R3=R4=R5=R6=H, R7=R8=F, E=CN) with a yield of 50~60%.

[0065] The synthetic route of the ferroelectric nematic liquid crystal molecule monomer having the chemical structure of formula III is as follows:

[0066] Compound A-4 was esterified with a p-hydroxybenzaldehyde derivative under the catalysis of EDC and DMAP to synthesize Compound D-1. Compound D-1 was oxidized to a carboxyl group by the addition of NaClO2 and NaH2PO4 to synthesize Compound D-2. Compound D-2 was esterified with a p-hydroxybenzaldehyde derivative under the catalysis of EDC and DMAP to synthesize Compound D-3. Compound D-3 was oxidized to a carboxyl group by the addition of NaClO2 and NaH2PO4 to synthesize Compound D-4. Compound D-4 was esterified with an alkyl alcohol derivative with an acrylate functional group under the catalysis of EDC and DMAP to synthesize a ferroelectric nematic liquid crystal monomer having the chemical structure of Formula III. The specific implementation method is as follows: Taking m = 1, n = 3, x = 2, R1 = R2 = R3 = R4 = R5 = R6 = F as an example, (1) A-4 (m = 1, n = 3, R1 = R2 = F, 1 equivalent), 2,6-difluoro-4-hydroxybenzaldehyde (1 equivalent), EDC (1.5 equivalents), DMAP (0.06 equivalents) were added to anhydrous DCM, reacted at room temperature for 10 minutes, and then mixed with silica gel powder, column chromatography was performed, and PE / DCM was selected as the eluent to obtain product D-1 (m = 1, n = 3

[0067] , R1=R2=R3=R4=F), yield 50~60%; (2) D-1 (m=1, n=3, R1=R2=R3=R4=F, 1 equivalent) was dissolved in DMSO / H2O solvent with a volume ratio of 4 / 1, and then the reaction solution was placed in an ice bath. Sodium chlorite (3.5 equivalents) and sodium dihydrogen phosphate (4 equivalents) were dissolved in an appropriate volume of water, and the salt solution was slowly added dropwise to the above mixed solution. The solution was exothermic and the addition was complete. At this time, the DMSO / H2O volume ratio of the reaction solution was generally 4 / 3. The solution was returned to room temperature and continued to stir for 12-16 hours. The reaction was terminated, and the reaction solution was poured into 4-6 volumes of water. The pH of the mixed solution was then adjusted to 1-2 with 2 mol / L dilute hydrochloric acid, and extracted again with EA three times. The resulting organic phase was extracted once with saturated brine, dried over anhydrous sodium sulfate, filtered, and rotary evaporated. Silica gel powder was added and separated by column chromatography. PE / EA was selected as the eluent to obtain product D-2 (m=1, n=3, R1=R2=R3=R4=F) with a yield of 85~95%; (3) D-2 (m=1, n=3, R1=R2=R3=R4=F, 1 eq), 2,6-difluoro-4-hydroxybenzaldehyde (1 eq), EDC (1.5 eq), DMAP (0.06 eq) were added to anhydrous DCM, reacted at room temperature for 10 min, then mixed with silica gel powder, separated by column chromatography, and PE / DCM was selected as the eluent to obtain product D-3 (m=1, n=3, R1=R2=R3=R4=R5=R6=F), with a yield of 50~60%; (4) D-3 (m=1, n=3, R1=R2=R3=R4=R5=R6=F, 1 eq) was dissolved in DMSO / H2O solvent with a volume ratio of 4 / 1, and then the reaction solution was placed in an ice bath.Sodium chlorite (3.5 equivalents) and sodium dihydrogen phosphate (4 equivalents) were dissolved in an appropriate volume of water, and the brine was slowly added dropwise to the above mixed solution. The solution was exothermic and the addition was completed. At this time, the DMSO / H2O volume ratio of the reaction solution was generally 4 / 3. The solution was returned to room temperature and continued to stir for 12 to 16 hours. The reaction was terminated, and the reaction solution was poured into 4 to 6 times the volume of water. The mixed solution was then adjusted to pH 1 to 2 with 2 mol / L dilute hydrochloric acid, and extracted again with EA 3 times. The obtained organic phase was extracted once with saturated brine, and the organic phase was dried over anhydrous sodium sulfate, filtered and rotary evaporated, mixed with silica gel powder, and separated by column chromatography. The eluent was PE / E A, to obtain product D-4 (m = 1, n = 3, R1 = R2 = R3 = R4 = R5 = R6 = F), with a yield of 85-95%; (5) D-4 (m = 1, n = 3, R1 = R2 = R3 = R4 = R5 = R6 = F, 1 equivalent), hydroxyethyl acrylate (1 equivalent), EDC (1.5 equivalents), DMAP (0.06 equivalents) were added to anhydrous DCM, reacted at room temperature for 12 hours, then mixed with silica gel powder, and separated by column chromatography, with PE / DCM as the eluent, to obtain product III (m = 1, n = 3, x = 2, R1 = R2 = R3 = R4 = R5 = R6 = F), with a yield of 50-60%.

[0068] The synthetic route of the ferroelectric nematic liquid crystal molecule monomer having the chemical structure of formula IV is as follows:

[0069] Compound D-4 was esterified with a p-hydroxybenzaldehyde derivative in the presence of EDC and DMAP to synthesize Compound E-1. Compound E-1 was oxidized to a carboxyl group by the addition of NaClO2 and NaH2PO4 to synthesize Compound E-2. Compound E-2 was esterified with an alkyl alcohol derivative with an acrylate functional group in the presence of EDC and DMAP to synthesize a ferroelectric nematic liquid crystal monomer having the general chemical structure of Formula IV. The specific implementation method is as follows: Taking m=1, n=3, x=2, R1=R2=R3=R4=R5=R6=R7=R8=F as an example, (1) D-4 (m=1, n=3, R1=R2=R3=R4=R5=R6=F, 1 equivalent), 2,6-difluoro-4-hydroxybenzaldehyde (1 equivalent), EDC (1.5 equivalents), DMAP (0.06 equivalents) were added to anhydrous DCM and reacted at room temperature for 10 minutes, and then Silica gel powder was added and the mixture was separated by column chromatography. PE / DCM was selected as the eluent to obtain the product E-1 (m=1, n=3, R1=R2=R3=R4=R5=R6=R7=R8=F) with a yield of 50-60%. (2) E-1 (m=1, n=3, R1=R2=R3=R4=R5=R6=R7=R8=F, 1 equivalent) was dissolved in DMSO / H2O solvent with a volume ratio of 4 / 1, and the reaction solution was then placed in an ice bath. Sodium chlorite (3.5 equivalents) and sodium dihydrogen phosphate (4 equivalents) were dissolved in an appropriate volume of water, and the salt solution was slowly added dropwise to the above mixed solution. The solution was exothermic and the addition was complete. At this time, the volume ratio of DMSO / H2O in the reaction solution was generally 4 / 3. The solution was returned to room temperature and continued to stir for 12 to 16 hours. The reaction was terminated, and the reaction solution was poured into 4 to 6 volumes of water. The mixed solution was then adjusted to pH 1 to 2 with 2 mol / L dilute hydrochloric acid, and extracted again with EA three times. The resulting organic phase was extracted once with saturated brine, dried over anhydrous sodium sulfate, filtered, and then rotary evaporated. Silica gel powder was added and separated by column chromatography. PE / EA was selected as the eluent to obtain product E-2 ( m=1, n=3, R1=R2=R3=R4=R5=R6=R7=R8=F), with a yield of 85~95%; (3) E-2 (m=1, n=3, R1=R2=R3=R4=R5=R6=R7=R8=F, 1 equivalent), hydroxyethyl acrylate (1 equivalent), EDC (1.5 equivalents), and DMAP (0.06 equivalents) were added to anhydrous DCM, and the reaction was carried out at room temperature for 12 hours. Then, silica gel powder was added, and the mixture was separated by column chromatography. The eluent was PE / DCM, and the product IV (m=1, n=3, x=2, R1=R2=R3=R4=R5=R6=R7=R8=F) was obtained with a yield of 50~60%.

[0070] The ferroelectric nematic liquid crystal monomers described in the following examples are all prepared by the above method.

[0071] Example 1

[0072] 4-(4-cyano-3,5-difluorophenoxy)carbonylphenyl 4-[(2-(acryloyloxy)ethoxy)methyl]-2,6-difluorobenzoate:

[0073]

[0074] Example 2

[0075] 4-(4-cyano-3,5-difluorophenoxy)carbonylphenyl 4-[(3-(acryloyloxy)propoxy)methyl]-2,6-difluorobenzoate:

[0076]

[0077] Example 3

[0078] 4-(4-cyano-3,5-difluorophenoxy)carbonylphenyl 4-[(3-(acryloyloxy)butoxy)methyl]-2,6-difluorobenzoate:

[0079] Example 4

[0080] 4-(4-cyano-3,5-difluorophenoxy)carbonylphenyl 4-[(3-(acryloyloxy)pentyloxy)methyl]-2,6-difluorobenzoate:

[0081]

[0082] Example 5

[0083] 4-(4-cyano-3,5-difluorophenoxy)carbonylphenyl 4-[(3-(acryloyloxy)hexyloxy)methyl]-2,6-difluorobenzoate:

[0084]

[0085] Example 6

[0086] 4-(4-cyano-3,5-difluorophenoxy)carbonylphenyl 4-[(3-(acryloyloxy)heptyloxy)methyl]-2,6-difluorobenzoate:

[0087]

[0088] Example 7

[0089] 4-(4-cyano-3,5-difluorophenoxy)carbonylphenyl 4-[(3-(acryloyloxy)octyloxy)methyl]-2,6-difluorobenzoate:

[0090]

[0091] Example 8

[0092] 4-(3,4,5-trifluorophenoxy)carbonylphenyl 4-[(3-(acryloyloxy)propoxy)methyl]-2,6-difluorobenzoate:

[0093]

[0094] Example 9

[0095] 4-(4-cyano-3,5-difluorophenoxy)carbonylphenyl 4-[2-(acryloyloxy)propoxy]-2,6-difluorobenzoate:

[0096]

[0097] Example 9

[0098] 4-[4-(3,5-difluoro-4-nitrophenoxy)carbonylphenoxy]carbonyl-3-(trifluoromethyl)phenyl 4-[(3-(acryloyloxy)propoxy)methyl]-2,6-difluorobenzoate:

[0099]

[0100] Example 10

[0101] 4-[4-(4-cyano-3,5-difluorophenoxy)carbonyl-3,5-difluorophenoxy]carbonyl-3,5-difluorophenyl 4-(4-(acryloyloxy)butoxy)-2,6-difluorobenzoate:

[0102]

[0103] Example 11

[0104] 4-[4-(3-(acryloyloxy)propoxy)carbonyl-3,5-difluorophenoxy]carbonyl-3,5-difluorophenyl 4-[(3-(acryloyloxy)propoxy)methyl]-2,6-difluorobenzoate

[0105]

[0106] Example 12

[0107] 4-[4-(4-(acryloyloxy)butoxy)carbonyl-3,5-difluorophenoxy]carbonyl-3,5-difluorophenyl 4-[(4-(acryloyloxy)butoxy)methyl]-2,6-difluorobenzoate:

[0108]

[0109] Example 13

[0110] 4-[4-(4-(acryloyloxy)butoxy)carbonyl-3,5-difluorophenoxy]carbonyl-3,5-difluorophenyl 4-[(5-(acryloyloxy)pentyl)oxy]-2,6-difluorobenzoate:

[0111]

[0112] Example 14

[0113] 4-[4-[4-(3-(acryloyloxy)propoxy)carbonyl-3,5-difluorophenoxy]carbonyl-3,5-difluorophenoxy]carbonyl-3,5-difluorophenyl 4-[(2-(acryloyloxy)ethoxy)methyl]-2,6-difluorobenzoate:

[0114]

[0115] Example 15

[0116] 4-[4-(4-(acryloyloxy)butoxy)carbonyl-3,5-difluorophenoxy]carbonyl-3,5-difluorophenyl 4-[(5-(acryloyloxy)pentyl)oxy]-2,6-difluorobenzoate:

[0117]

[0118] Example 16

[0119] The following monomers Add 1 wt% of an initiator (AIBN or a photoinitiator) and chloroform as a solvent. Oscillate for 10 minutes and sonicate for 10 minutes to evenly mix the initiator into the liquid crystal monomer. Dry the solvent in a 65°C oven. Heat the resulting mixture to 100°C or initiate polymerization with UV light to obtain the ferroelectric liquid crystal polymer Polymer-1.

[0120] Polymer-1

[0121]

[0122] Example 17

[0123] The following monomers Weigh 1:1 and add 1 wt% of the total weight of an initiator (AIBN or a photoinitiator). Add chloroform as the solvent, shake for 10 minutes, and sonicate for 10 minutes to evenly mix the initiator into the liquid crystal monomer. Dry the solvent in a 65°C oven. Heat the resulting mixture to 100°C or initiate polymerization with UV light to obtain the ferroelectric liquid crystal polymer Polymer-2.

[0124] Polymer-2

[0125]

[0126] Example 18

[0127] The following monomers Weighing the mixture in a 1:1 ratio, add 1 wt% of the total weight of an initiator (AIBN or a photoinitiator), add chloroform as the solvent, and shake for 10 minutes, ultrasonicate for 10 minutes, and evenly mix the initiator into the liquid crystal monomer. Dry the solvent in a 65°C oven. The resulting mixture is heated to 100°C or irradiated with UV light to initiate polymerization, yielding the ferroelectric liquid crystal polymer Polymer-3.

[0128] Polymer-3

[0129]

[0130] Example 19

[0131] The following monomers

[0132] Weigh 1:1 and add 1 wt% of the total weight of an initiator (AIBN or a photoinitiator). Add chloroform as the solvent, shake for 10 minutes, and sonicate for 10 minutes to evenly mix the initiator into the liquid crystal monomer. Dry the solvent in a 65°C oven. Heat the resulting mixture to 100°C or initiate polymerization with UV light to obtain the ferroelectric liquid crystal polymer Polymer-4.

[0133] Polymer-4

[0134]

[0135] Example 20

[0136] The following monomers Weighing the mixture in a 1:1 ratio, add 1 wt% of the total weight of an initiator (AIBN or a photoinitiator), add chloroform as the solvent, and shake for 10 minutes, ultrasonicate for 10 minutes, and evenly mix the initiator into the liquid crystal monomer. Dry the solvent in a 65°C oven. The resulting mixture is heated to 100°C or irradiated with UV light to initiate polymerization, yielding the ferroelectric liquid crystal polymer, Polymer-5.

[0137] Polymer-5

[0138]

[0139] Example 21

[0140] The following monomers Weigh the mixture in a 9:1 ratio and add 1 wt% of the total weight of an initiator (AIBN or a photoinitiator). Add chloroform as the solvent, shake for 10 minutes, and sonicate for 10 minutes to evenly mix the initiator into the liquid crystal monomer. Dry the solvent in a 65°C oven. Heat the resulting mixture to 100°C or initiate polymerization with UV light to obtain the ferroelectric liquid crystal polymer Polymer-6.

[0141] Polymer-6

[0142]

[0143] Example 22

[0144] The following monomers An initiator (AIBN or a photoinitiator) was added at a ratio of 3:3:1, and chloroform was added as the solvent. The mixture was shaken for 10 minutes and ultrasonicated for 10 minutes to uniformly mix the initiator into the liquid crystal monomer. The solvent was then dried in an oven at 65°C. The resulting mixture was heated to 100°C or irradiated with UV light to initiate polymerization, yielding the ferroelectric liquid crystal polymer Polymer-7.

[0145] Polymer-7

[0146]

[0147] Example 23

[0148] The following monomers An initiator (AIBN or a photoinitiator) was added at a ratio of 3:3:1:1, and 1 wt% of the total weight was added. Chloroform was added as the solvent, and the mixture was shaken for 10 minutes and ultrasonicated for 10 minutes to uniformly mix the initiator into the liquid crystal monomer. The solvent was then dried in an oven at 65°C. The resulting mixture was heated to 100°C or irradiated with UV light to initiate polymerization, yielding the ferroelectric liquid crystal polymer Polymer-8.

[0149] Polymer-8

[0150]

[0151] Figure 1 This is a POM diagram of the cooling process of the ferroelectric nematic liquid crystal monomer synthesized in Example 1. The phase transition path is: Iso-(105℃)N-(99℃)N x -(95℃)N F , and it will not crystallize even when cooled to room temperature (~30℃);

[0152] Figure 2This is the POM diagram of the cooling process of the ferroelectric nematic liquid crystal monomer synthesized in Example 2. The phase transition path is: Iso-(87℃)N-(78℃)N x -(74℃)N F , and it will not crystallize even when cooled to room temperature (~30℃);

[0153] Figure 3 This is the POM diagram of the cooling process of the ferroelectric nematic liquid crystal monomer synthesized in Example 3. The phase transition path is: Iso-(104℃)N-(98℃)N x -(95℃)N F , and it will not crystallize even when cooled to room temperature (~30℃);

[0154] Figure 4 This is a POM diagram of the cooling process of the ferroelectric nematic liquid crystal monomer synthesized in Example 4. The phase transition path is: Iso-(86℃)N-(65℃)N x -(42℃)N F , and it will not crystallize even when cooled to room temperature (~30℃);

[0155] Figure 5 This is a POM diagram of the cooling process of the ferroelectric nematic liquid crystal monomer synthesized in Example 5. The phase transition path is: Iso-(91℃)N-(68℃)N F , and it will not crystallize even when cooled to room temperature (~30℃);

[0156] Figure 6 This is a POM diagram of the cooling process of the ferroelectric nematic liquid crystal monomer synthesized in Example 6. The phase transition path is: Iso-(76℃)N-(51℃)N x -(32℃)Cryst, crystallizes when cooled to 32℃;

[0157] Figure 7 This is a POM diagram of the cooling process of the ferroelectric nematic liquid crystal monomer synthesized in Example 7. The phase transition path is: Iso-(74℃)N-(63℃)N x -(40℃)N F -(31)Cryst, crystallizes when cooled to 31°C;

[0158] Figure 8 This is a POM diagram of the cooling process of the ferroelectric nematic liquid crystal monomer synthesized in Example 9. The phase transition path is: Iso-(153℃)N-(98℃)N x -(78℃)N F , and it will not crystallize even when cooled to room temperature (~30℃);

[0159] Figure 9The evolution of the second harmonic generation (SHG) signal intensity of the ferroelectric liquid crystal polymer represented by Example 21 during the cooling process before and after polymerization, wherein (a) is the SHG result of the sample after the ferroelectric nematic liquid crystal molecular monomers are uniformly blended in proportion, and (b) is the SHG result after the monomers are polymerized into a ferroelectric liquid crystal polymer.

[0160] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0161] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A ferroelectric nematic liquid crystal molecule monomer, characterized in that: The chemical structure of the ferroelectric nematic liquid crystal monomer is generally one of Formulas I to IV: In formulas I to IV, R1, R2, R3, R4, R5, R6, R7, R8, and E are all substituted groups; Wherein, R1, R2, R3, R4, R5, R6, R7, and R8 are independently selected from one of F, OCH3, CF3, and H, and the number of substituents in Formula III and Formula IV is selected to be substituted by F is not less than two; E is a strong electron-pulling group selected from one of CN, F, CF3, and NO2; n, m, and x all represent the number of carbon atoms contained in the alkyl chain at that position, wherein n=1-10, m=0-1, and x=1-10.

2. The ferroelectric nematic liquid crystal molecule monomer according to claim 1, characterized in that: The ferroelectric nematic liquid crystal molecular monomers with different chemical structures can be arbitrarily combined and polymerized to form a ferroelectric liquid crystal polymer.

3. The ferroelectric nematic liquid crystal molecule monomer according to claim 1, characterized in that: The ferroelectric nematic liquid crystal molecule monomer can present a stable ferroelectric liquid crystal phase, including a ferroelectric nematic phase (N F ), ferroelectric smectic phase (SmA F 、SmC F ) and the antiferroelectric transition phase (N x ).

4. The ferroelectric nematic liquid crystal molecule monomer according to claim 1, characterized in that: The saturation polarization value of the ferroelectric nematic liquid crystal molecule monomer is greater than 6 μC / cm 2 , dielectric constant>20000, second harmonic signal>30 times that of quartz.

5. Use of the ferroelectric nematic liquid crystal molecule monomer according to claim 1 in the preparation of ferroelectric liquid crystal polymers.

6. A method for preparing a ferroelectric liquid crystal polymer, characterized in that: The steps include: The ferroelectric nematic liquid crystal molecular monomers with different chemical structures are blended and polymerized to prepare a ferroelectric liquid crystal polymer.

7. The preparation method according to claim 6, characterized in that: The mass percentage of the ferroelectric nematic liquid crystal molecule monomers with different chemical structural formulas blended is: The ferroelectric nematic liquid crystal molecule monomer shown in formula I is selected to include 1 to 10 ferroelectric nematic liquid crystal molecule monomers with different chemical structures, and the mass fraction thereof is a, wherein a=0 to 100%; The ferroelectric nematic liquid crystal molecule monomer represented by formula II comprises 1 to 10 ferroelectric nematic liquid crystal molecule monomers with different chemical structures, and the mass fraction thereof is b, wherein b=0 to (100%-a); The ferroelectric nematic liquid crystal molecule monomer represented by formula III is selected to include 1 to 10 bifunctional ferroelectric nematic liquid crystal molecule monomers with different chemical structures, and the mass fraction thereof is c, wherein c=0 to (100%-ab); The ferroelectric nematic liquid crystal molecule monomer represented by formula IV comprises 1 to 10 bifunctional ferroelectric nematic liquid crystal molecule monomers with different chemical structures, and the mass fraction thereof is d, wherein d=100%-abc; And c+d≤70%.

8. The ferroelectric liquid crystal polymer prepared by the preparation method according to claim 6 or 7.

9. The ferroelectric liquid crystal polymer according to claim 8, characterized in that The number of repeating units of the ferroelectric liquid crystal polymer is an integer of 5 to 1000.

10. The ferroelectric liquid crystal polymer according to claim 8, characterized in that The ferroelectric liquid crystal polymer has ferroelectricity, presents a stable polar liquid crystal phase in a specific temperature range, and exhibits polarization characteristics similar to those of ferroelectric nematic liquid crystal molecule monomers, with a saturation polarization value of >2μC / cm 2 , dielectric constant>100, second harmonic signal>10 times that of quartz.

Images