Liquid crystal monomers and polymers containing ferrocene and uses thereof

Abstract

The application relates to the field of liquid crystal polymer materials, and particularly discloses a liquid crystal polymer monomer containing ferrocene, a polymer and a preparation method thereof. A protecting agent is introduced into n-bromo-1-n-alkanol, and reacts with vinyl terephthalic acid to obtain a vinyl terephthalic acid derivative; the protecting agent of the vinyl terephthalic acid derivative is removed, and esterification is carried out with ferrocene formic acid to obtain a liquid crystal polymer monomer containing ferrocene, and then polymerization is carried out to obtain a liquid crystal polymer polymer containing ferrocene. The polymer has the advantages of complete monomer polymerization, good liquid crystal property, heat stability and electrochemical performance, high conversion rate, relatively narrow dispersity, suitability for industrial production and applicability to preparation of electrode materials.

Description

TECHNICAL FIELD

[0001] The present application relates to liquid crystal polymer materials, and in particular to a ferrocene-containing liquid crystal polymer monomer, a polymer and uses thereof. BACKGROUND

[0002] The side chain of the existing chitinous liquid crystal polymer can have various functional groups, such as triphenylene, oligomeric silsesquioxane, cholesterols, and rod-like molecules containing biphenyl structures, etc. By increasing the functional groups, the formation of the liquid crystal property of the polymer can be affected, and new functions including photoelectric response, fluorescence or electrical conductivity, etc. can be imparted.

[0003] Ferrocene can be used to prepare multifunctional materials, such as conductive materials, magnetic ceramic precursors, and high refractive index materials, due to its electron-rich structure. In addition, it also has very wide applications in the fields of catalysis, drug delivery, and electrochemistry. Since the ferrocene group is prone to lose electrons and undergo redox reactions, it can be used to transport charges. In early studies, it was found that the charge transport rate in a liquid crystal film containing ferrocene was more than 1000 times higher than that in a solution, which greatly reduced the activation energy of the reaction in the electrochemical catalytic process.

[0004] Some studies have reported the preparation of ferrocene-containing polymers using ferrocene groups and simple esterification reactions, but their structures are simple and their functions are limited. The present application proposes a new ferrocene-containing liquid crystal polymer monomer and polymer with more complex structure and more abundant functions. SUMMARY

[0005] The present application aims to provide a ferrocene-containing liquid crystal polymer monomer, a polymer and a preparation method thereof, which aims to solve the problem of simple structure and poor functionality of the existing chitinous liquid crystal polymer containing ferrocene. By introducing long-chain alkyl side chains, the resulting polymer has better mechanical properties, thermal stability and liquid crystal properties, expanding its application range in the field of high-performance materials.

[0006] In order to achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0007] A ferrocene-containing liquid crystal polymer monomer, the structure is shown as formula 1:

[0008]

[0009] Wherein n is an integer ≥1, R includes C2-C6 alkenyl.

[0010] Further, n is an integer of 6-20.

[0011] Further, n is an integer of 6-12, and R is C2-C3 alkenyl.

[0012] Further, n is 6, and R is vinyl.

[0013] A method for preparing the above-mentioned ferrocene-containing liquid crystal monomer, comprising the following steps:

[0014] Introducing a hydroxyl protecting group to n-bromo-1-n-alkanol, and then reacting with C2-C6 alkenyl terephthalic acid to obtain a C2-C6 alkenyl terephthalic acid derivative;

[0015] Removing the hydroxyl protecting group from the C2-C6 alkenyl terephthalic acid derivative, and then performing esterification with ferrocene carboxylic acid to obtain the ferrocene-containing liquid crystal monomer;

[0016] The n-bromo-1-n-alkanol includes 6-bromo-1-hexanol, 16-bromo-1-hexadecanol, and 20-bromo-1-eicosanol.

[0017] Further, the protecting group is a tert-butyldimethylsilyl group; and the catalyst used in the introduction of the hydroxyl protecting group is Et3N and DMAP.

[0018] Further, in the reaction of the n-bromo-1-n-alkanol after introducing the hydroxyl protecting group with the vinyl terephthalic acid, the water absorbing agent is EDCI, and the catalyst is DMAP.

[0019] Further, in the esterification reaction of the C2-C6 alkenyl terephthalic acid derivative after removing the protecting group with the ferrocene carboxylic acid, the water absorbing agent is EDCI, and the catalyst is DMAP.

[0020] The present application also protects a liquid crystal polymer, and the structure of the polymer is shown in formula 2:

[0021]

[0022] wherein m represents the degree of polymerization, m is an integer of 10-500, and n is an integer of 6-20.

[0023] Further, m is 50 or 100, and n is 6.

[0024] A method for preparing the above-mentioned liquid crystal polymer, comprising the following steps:

[0025] Performing RAFT polymerization on the above-mentioned liquid crystal monomer to obtain the final liquid crystal polymer, and the RAFT reagent used in the RAFT polymerization includes dimercaptodialkyldithiophosphates and alkyl sulfates.

[0026] Further, the polymer obtained by the method for preparing the above-mentioned liquid crystal polymer, R is vinyl.

[0027] The application also protects a liquid crystal material, which comprises the liquid crystal polymer as described above.

[0028] The application also protects a battery, which comprises the liquid crystal material as described above.

[0029] The application also provides a synthesis method of the liquid crystal polymer containing ferrocene.

[0030]

[0031] In the above process, the n-bromo-1-n alkyl alcohol and the TBSCL are reacted for 2 hours to introduce the TBS protective group, and the catalyst is Et3N and DMAP;

[0032] The n-bromo-1-n alkyl alcohol with the introduced TBS protective group is reacted with the vinyl terephthalic acid for 24 hours to obtain the vinyl terephthalic acid derivative, the catalyst is DMAP, and the water absorption agent is EDCI;

[0033] The vinyl terephthalic acid derivative is mixed with CH3CN / H2O and HF / THF to remove the TBS protective group, and the vinyl terephthalic acid derivative with the removed protective group is obtained;

[0034] The vinyl terephthalic acid derivative with the removed protective group is subjected to esterification reaction with ferrocene formic acid, and the reaction is carried out for 24 hours to obtain the liquid crystal polymer monomer containing ferrocene, the catalyst is DMAP, and the water absorption agent is EDCI;

[0035] The liquid crystal polymer monomer containing ferrocene is subjected to RAFT polymerization to obtain the liquid crystal polymer containing ferrocene.

[0036] The liquid crystal polymer containing ferrocene obtained by the application has the monomer completely polymerized and has good liquid crystal properties and electrochemical properties.

[0037] The application introduces a long alkyl chain to make the ferrocene group have better movement ability, promote the ordered arrangement of the molecular group, and have good liquid crystal properties and electrochemical properties.

[0038] The liquid crystal polymer obtained by the application has good film-forming properties and is convenient for processing and application.

[0039] The liquid crystal polymer containing ferrocene obtained by the application also has good thermal stability.

[0040] The liquid crystal polymer containing ferrocene prepared by the preparation method of the application has high conversion rate and good dispersion rate, and is suitable for industrial production. BRIEF DESCRIPTION OF DRAWINGS

[0041] In order to make the technical solutions of the embodiments of the present application or the prior art clearer, the accompanying drawings needed in the embodiments or prior art description will be briefly introduced. Obviously, the accompanying drawings described below are only some embodiments of the present application, and all other drawings obtained by those of ordinary skill in the art without creative effort based on these drawings belong to the protection scope of the present application.

[0042] Figure 1 SAXS graph of the ferrocene-containing liquid crystal polymer obtained in Example 2;

[0043] Figure 2 Cyclic voltammogram of the ferrocene-containing liquid crystal polymer obtained in Example 1;

[0044] Figure 3 : Figure 3 (a) Oxidation current V 1 / 2 versus time graph of the ferrocene-containing liquid crystal polymer obtained in Example 1; Figure 3 (b) Reduction current V 1 / 2 versus time graph of the ferrocene-containing liquid crystal polymer obtained in Example 1;

[0045] Figure 4 Cyclic voltammogram of the ferrocene-containing liquid crystal polymer obtained in Example 2;

[0046] Figure 5 : Figure 5 (a) Oxidation current V 1 / 2 versus time graph of the ferrocene-containing liquid crystal polymer obtained in Example 2; Figure 5 (b) Reduction current V 1 / 2 versus time graph of the ferrocene-containing liquid crystal polymer obtained in Example 2;

[0047] Figure 6 SAXS graph of the ferrocene-containing polymer obtained in Comparative Example 1-2. DETAILED DESCRIPTION

[0048] In order to make the technical solutions of the embodiments of the present application or the prior art clearer, the accompanying drawings needed in the embodiments or prior art description will be briefly introduced. Obviously, the accompanying drawings described below are only some embodiments of the present application, and all other drawings obtained by those of ordinary skill in the art without creative effort based on these drawings belong to the protection scope of the present application.

[0049] Example 1

[0050] Preparation of ferrocene-containing liquid crystal polymer

[0051] S1, 6-bromo-1-hexanol (0.2 mol) was reacted with TBSCL (0.25 mol) to introduce a TBS protecting group, with Et3N (0.1 mL) and DMAP (0.1 mol) as catalysts, and reacted for 2 h;

[0052] S2, 6-bromo-1-hexanol (0.5 mol) with a TBS protecting group was reacted with vinyl benzenedicarboxylic acid (0.23 mol) with a water absorbent and a catalyst to obtain a vinyl p-terphenyl dicarboxylic acid derivative, with EDCI (1 mol) as the water absorbent and DMAP (0.1 mol) as the catalyst, and reacted for 24 h;

[0053] S3, the vinyl p-terphenyl dicarboxylic acid derivative was reacted with CH3CN / H2O (CH3CN and H2O in a volume ratio of 3:1) and HF / THF (HF and THF in a volume ratio of 1:1) to remove the TBS protecting group, to obtain a vinyl p-terphenyl dicarboxylic acid derivative with a protecting group removed;

[0054] S4, the vinyl p-terphenyl dicarboxylic acid derivative with a protecting group removed obtained in step S3 was esterified with ferrocene carboxylic acid, with DMAP as a catalyst and EDCI as a water absorbent, and reacted for 24 h to obtain a ferrocene-containing liquid crystal polymer monomer;

[0055] The structure of the ferrocene-containing liquid crystal polymer monomer is as follows:

[0056]

[0057] The ferrocene-containing liquid crystal polymer monomer obtained in step S4 was subjected to a RAFT polymerization reaction to obtain a final liquid crystal polymer, and a RAFT reagent used in the RAFT polymerization reaction was dimercaptodialkyldithiophosphoric acid ester, and the molar ratio of dimercaptodialkyldithiophosphoric acid ester to the ferrocene-containing liquid crystal polymer monomer was 1:50, to obtain a liquid crystal polymer (P50).

[0058] The structure of the liquid crystal polymer (P50) is as follows:

[0059]

[0060] Example 2

[0061] Preparation of a ferrocene-containing liquid crystal polymer:

[0062] The ferrocene-containing liquid crystal polymer monomer obtained in Example 1 is subjected to a RAFT polymerization reaction to obtain a final liquid crystal polymer, and a RAFT reagent used in the RAFT polymerization reaction is dimercapto dialkyl dithiophosphoric acid ester, a molar ratio of the dimercapto dialkyl dithiophosphoric acid ester to the ferrocene-containing liquid crystal polymer monomer is 1:100, and a liquid crystal polymer (P100) is obtained.

[0063] A structural formula of the liquid crystal polymer (P100) is as follows:

[0064]

[0065] Example 3

[0066] Preparation of a ferrocene-containing liquid crystal polymer:

[0067] S1, 20-bromo-1-eicosanol (0.2 mol) and TBSCL (0.25 mol) are reacted in the presence of Et3N (0.1 mL) and DMAP (0.1 mol) to introduce a TBS protective group, and a catalyst is Et3N and DMAP, and a solvent is DCM;

[0068] S2, the 20-bromo-1-eicosanol after the TBS protective group is introduced (0.5 mol) is reacted with vinyl terephthalic acid (0.23 mol) to obtain a vinyl terephthalic acid derivative, and a water absorbent is EDCI (1 mol), and a catalyst is DMAP (0.1 mol);

[0069] S3, the vinyl terephthalic acid derivative is subjected to a TBS protective group removal reaction in CH3CN / H2O (a volume ratio of 3:1) and HF / THF (a volume ratio of 1:1), and is subjected to an esterification reaction with ferrocene formic acid to obtain a ferrocene-containing liquid crystal polymer monomer, and a water absorbent is EDCI, and a catalyst is DMAP;

[0070] S4, the ferrocene-containing liquid crystal polymer monomer obtained in step S3 is subjected to a RAFT polymerization reaction to obtain a final liquid crystal polymer, and a RAFT reagent used in the RAFT polymerization reaction is dimercapto dialkyl dithiophosphoric acid ester, and a liquid crystal polymer is obtained, and a molar ratio of the dimercapto dialkyl dithiophosphoric acid ester to the ferrocene-containing liquid crystal polymer monomer is 1:500.

[0071] Example 4

[0072] Preparation of a ferrocene-containing liquid crystal polymer:

[0073] S1, 16-bromo-1-hexadecanol (0.2 mol) and TBSCL (0.25 mol) were reacted in the presence of Et3N (0.1 mL) and DMAP (0.1 mol), the catalyst was Et3N and DMAP, and the solvent was DCM, to introduce a TBS protecting group;

[0074] S2, 16-bromo-1-hexadecanol (0.5 mol) with a TBS protecting group was reacted with vinyl terephthalic acid (0.23 mol) to obtain a vinyl terephthalic acid derivative, the water absorbent was EDCI (1 mol), and the catalyst was DMAP (0.1 mol);

[0075] S3, the vinyl terephthalic acid derivative was subjected to TBS protecting group removal in CH3CN / H2O (volume ratio of 3:1) and HF / THF (volume ratio of 1:1), and esterification reaction with ferrocene carboxylic acid to obtain a ferrocene-containing liquid crystal high molecular monomer, the water absorbent was EDCI, and the catalyst was DMAP;

[0076] S4, the ferrocene-containing liquid crystal high molecular monomer obtained in step S3 was subjected to RAFT polymerization reaction to obtain the final liquid crystal high molecular polymer, the RAFT reagent used in the RAFT polymerization reaction was dimercaptodialkyldithiophosphoric acid ester, the liquid crystal high molecular polymer was obtained, and the molar ratio of dimercaptodialkyldithiophosphoric acid ester to the ferrocene-containing liquid crystal high molecular monomer was 1:10.

[0077] Comparative Example 1

[0078] Comparative Example 1 is a high molecular polymer containing norbornene;

[0079] The corresponding polymer structure is:

[0080]

[0081] Comparative Example 2

[0082] Comparative Example 2 is a high molecular polymer containing norbornene;

[0083] The high molecular polymer structure is:

[0084]

[0085] The high molecular monomer structure used to prepare the high molecular polymers of Comparative Examples 1 and 2 is as follows:

[0086]

[0087] The ferrocene-containing liquid crystal high molecular polymer obtained in Examples 1-2 was detected:

[0088] The thermal properties of the polymers were characterized by TGA (thermogravimetric analysis) and DSC (differential scanning calorimetry) to obtain the 5% decomposition temperature and the glass transition temperature. The 5% decomposition temperature of the polymer obtained in Example 1 was 349°C, and the glass transition temperature was 82°C. The 5% decomposition temperature of the polymer obtained in Example 2 was 353°C, and the glass transition temperature was 84°C, both of which had good thermal stability.

[0089] It can be seen from the SAXS curve of the ferrocene-containing liquid crystal polymer obtained in Example 2 that Figure 1 It can be seen that it has good liquid crystal properties. Figure 1 It can be seen from the SAXS curve of the ferrocene-containing liquid crystal polymer obtained in Example 2 that

[0090] It can be seen from the SAXS curve of the ferrocene-containing liquid crystal polymer obtained in Example 2 that Figures 2-5 The cyclic voltammograms of the ferrocene-containing liquid crystal polymers of Examples 1-2 and the current-voltage (I-V) change relationship diagrams are shown in Figures 1 and 2. 1 / 2 The cyclic voltammograms of the ferrocene-containing liquid crystal polymers of Examples 1-2 and the current-voltage (I-V) change relationship diagrams are shown in Figures 1 and 2. Figure 3 (a) is the change relationship diagram of the oxidation current V 1 / 2 of the ferrocene-containing liquid crystal polymer obtained in Example 1, Figure 3 (b) is the change relationship diagram of the reduction current V 1 / 2 of the ferrocene-containing liquid crystal polymer obtained in Example 1, Figure 5 (a) is the change relationship diagram of the oxidation current V 1 / 2 of the ferrocene-containing liquid crystal polymer obtained in Example 2, Figure 5 (b) is the change relationship diagram of the reduction current V 1 / 2 of the ferrocene-containing liquid crystal polymer obtained in Example 2.

[0091] The solvent used in the test was dichloromethane, the electrolyte was tetrabutylammonium hexafluorophosphate, the reference electrode was Ag, the working electrode was glassy carbon, and the counter electrode was Pt. The cyclic voltammetry (CV) curves of the two polymers at different scan rates were tested.

[0092] The oxidation-reduction peak potential Epi (V) of the two polymers at different scan rates was stable, and the peak-to-peak potential difference ΔEp (V) gradually increased with the increase of the scan rate, which was mainly due to the ohmic drop of the solution after the increase of the scan rate. For P50, the peak-to-peak potential difference ΔEp (V) was 64 mV (10 mV / s) at low scan rate, close to the theoretical value of the reversible oxidation-reduction process, but the ratio of the oxidation current to the reduction current i / ie was less than the theoretical value 1, so the oxidation-reduction process was irreversible at low scan rate, and ip / i gradually increased and tended to 1 with the increase of the scan rate, but it was still irreversible. For the polymer P100, the peak-to-peak potential difference ΔEp (V) was 39 mV (25 mV / s) at low scan rate, which was significantly less than the theoretical value 59 mV of the reversible oxidation-reduction process, indicating that adsorption may occur on the electrode surface, and the oxidation-reduction process is irreversible.

[0093] Depend on Figure 2 and Figure 3 As can be seen, the current of polymer P50 obtained in Example 1 is proportional to the half-power of the scan rate, indicating that the electrode process is diffusion-controlled; Figure 4 and Figure 5 As can be seen, the current of polymer P100 obtained in Example 2 is proportional to the scan rate, indicating that the electrode process is adsorption controlled.

[0094] Figure 6 The SAXS plots of the ferrocene-containing polymers obtained in Comparative Examples 1-2 are shown below. Figure 6 It is evident that no obvious diffraction peaks appeared, meaning that the polymers obtained in Comparative Examples 1 and 2 did not exhibit liquid crystal properties. Ferrocene itself does not possess the characteristic of ordered arrangement. Furthermore, in Comparative Examples 1 and 2, the ferrocene building blocks also disrupted the liquid crystal structure of MILCP itself.

Claims

1. A ferrocene-containing liquid crystalline polymer monomer, characterized by, The structure of the liquid crystal polymer monomer is shown in formula 1: Formula 1 wherein n is an integer of 6-20, and R is C2-C6 alkenyl.

2. The liquid crystalline monomer according to claim 1, wherein R is C2-C3 alkenyl, and n is an integer of 6-16.

3. The liquid crystalline monomer according to claim 1, wherein R is vinyl, and n is 6.

4. A method for preparing the ferrocene-containing liquid crystal polymer monomer according to any one of claims 1-3, comprising the following steps: introducing a hydroxyl protecting group to n-bromo-1-n-alkanol, and then reacting with an alkenyl-containing terephthalic acid to obtain an alkenyl-containing terephthalic acid derivative; removing the hydroxyl protecting group from the alkenyl-containing terephthalic acid derivative, and then performing esterification with ferrocene carboxylic acid to obtain the ferrocene-containing liquid crystal polymer monomer.

5. The method of claim 4, wherein, The hydroxyl protecting group is a tert-butyldimethylsilyl group.

6. A liquid crystalline macromolecule, characterized by, The polymer structure is shown in formula 2: Formula 2 wherein m represents the degree of polymerization, m is an integer of 10-500, and n is an integer of 6-20.

7. The liquid crystalline polymer of claim 6, wherein m is an integer of 50-100, and n is an integer of 6-16.

8. A method for preparing the liquid crystal polymer according to claim 6, comprising the following steps: performing RAFT polymerization on the liquid crystal polymer monomer according to any one of claims 1-3 to obtain the final liquid crystal polymer, and the RAFT polymerization uses a RAFT reagent comprising dimercapto dialkyl dithiophosphoric acid ester and alkyl sulfate.

9. A liquid crystal material, characterized by The liquid crystal material comprises the liquid crystal polymer according to claim 6 or 7 or the liquid crystal polymer obtained by the method according to claim 8.

10. A battery, characterized by The battery comprises the liquid crystal material according to claim 9.

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