A quaternized triazole imide polymer, its preparation method and application, a quaternized triazole imide battery separator and its application

Abstract

The present invention provides a quaternized triazole imide polymer, a preparation method and application thereof, a quaternized triazole imide battery separator and an application thereof, belonging to the technical field of imide materials. The quaternized triazole imide polymer provided by the present invention not only has excellent heat resistance, with a glass transition temperature (Tg) of 260-271 °C, a Td5% reaching 532.9-553.2 °C, and a Td10% reaching 543.6-564.2 °C, but also can be dissolved in common organic solvents (DMSO, DMF, DMAc), having excellent processability; and has excellent conductivity, with a room temperature conductivity of 4.1×10-6-9.2×10-6 S·cm-1, good thermal conductivity, with a thermal conductivity of 0.49-0.7 W·(m·K)-1, and can be applied to fields such as ultra-thin semiconductor packaging, battery separators, liquid crystal displays, light-emitting diodes, etc.

Description

Technical Field

[0001] The present invention relates to the technical field of imide materials, and particularly relates to a quaternized triazole imide polymer, a preparation method and application thereof, a quaternized triazole imide battery separator, and an application thereof. Background Art

[0002] With the rapid development of intelligent power systems such as electric vehicles and microelectronic devices, lithium batteries have become the only choice for high-performance batteries due to their high energy density and cycle stability. A lithium battery consists of a cathode, an anode, an electrolyte, and a separator, among which the separator plays a crucial role because it directly affects the cycle performance and safety of the battery. Currently, commercial lithium battery separators are mainly polyolefin materials, such as polyethylene and polypropylene. Polyolefin separators have certain electrochemical stability and mechanical properties, and are inexpensive and non-toxic, which are suitable for actual production. However, polyolefin materials as separators also have some limitations and disadvantages, such as poor compatibility with the electrolyte caused by high polarity, which may lead to safety problems and low ionic conductivity, large thermal shrinkage rate at high temperatures, and poor thermal stability, which are prone to cause fires and explosions, etc., and thus cannot meet the growing high-performance and safety requirements, restricting the long-term use of such materials. Therefore, it is urgent to solve the problems of poor thermal stability and low ionic conductivity of traditional commercial lithium battery separators.

[0003] Azaheterocyclic polymer materials containing imide rings in the main chain, due to the high bond energy of carbon-nitrogen bonds and imide bonds, make the polymers of this structure more difficult to break at high temperatures, showing extremely strong thermal stability and thermal decomposition temperature. For example, Patent CN118507980B provides a sponge-like polyimide battery separator with good thermal stability, simple synthesis, and high structural uniformity. Patent CN115353622B discloses a poly-1,5-substituted triazole, which has good processability and high thermal stability, and various functional groups can be introduced. However, the problems of poor thermal stability of lithium battery separators and poor thermal conductivity leading to unsafe and easy ignition have not been solved. Summary of the Invention

[0004] The purpose of the present invention is to provide a quaternized triazole imide polymer, a preparation method and application thereof, a quaternized triazole imide battery separator, and an application thereof, to overcome the problems of poor thermal stability of existing battery separators and poor thermal conductivity leading to unsafe and easy ignition.

[0005] In order to achieve the above-mentioned invention purpose, the present invention provides the following technical solutions:

[0006] The present invention provides a quaternized triazole imide polymer having the structure shown in Formula I:

[0007] Formula I;

[0008] In formula I, R is , or ;

[0009] Ar is ;

[0010] X is I, Br or Cl;

[0011] n is an integer from 21 to 45.

[0012] The present invention provides a method for preparing the quaternized triazole imide polymer described in the above technical solution, comprising the following steps:

[0013] Mix the arylimide triazole polymer with the structure shown in formula II, an alkylating agent and an organic solvent, and carry out a nucleophilic substitution reaction to obtain a quaternized triazole imide polymer;

[0014] The alkylating agent is methyl iodide, methyl bromide or methyl chloride;

[0015] Formula II;

[0016] In formula II, R is , or ;

[0017] Ar is ;

[0018] n is an integer from 21 to 45.

[0019] Preferably, the molar ratio of the arylimide triazole polymer to the alkylating agent is 1:(2 - 5).

[0020] Preferably, the temperature of the nucleophilic substitution reaction is 50 - 100 °C, and the time is 12 - 36 h.

[0021] Preferably, the organic solvent includes dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide or N-methylpyrrolidone.

[0022] The present invention provides the application of the quaternized triazole imide polymer described in the above technical solution or the quaternized triazole imide polymer prepared by the preparation method described in the above technical solution in the fields of ultra-thin semiconductor packaging, battery separator, liquid crystal display or light-emitting diode.

[0023] The present invention provides a quaternized triazole imide battery separator, which is prepared by a film drawing method, a casting method or a spin coating method using the quaternized triazole imide polymer described in the above technical solution.

[0024] The present invention provides the application of the quaternized triazole imide battery separator described in the above technical solution in the preparation of a heat-resistant lithium battery separator.

[0025] The present invention provides a quaternized triazole imide polymer. In the main chain of this polymer, the rigid and flexible groups play different roles. The main chain structure has rigid imide rings and triazole rings, which restrict the free rotation and movement of the molecular chain, improve the thermal stability of the polymer, increase the decomposition temperature, and thus improve the heat resistance. Moreover, it can improve the mechanical properties of the polymer. The presence of flexible groups such as ether bonds and methylene groups increases the mobility of the molecular chain, and can better disperse stress when subjected to external forces, improving the solubility of the polymer. By introducing quaternary ammonium groups with positive charges into the polymer chain, the ion concentration is increased, the ion mobility is improved, the conductivity of the film is enhanced, and the wettability with the electrolyte can be increased. Moreover, the introduction of positive ions can, through electrostatic action, inhibit phonon scattering and reduce the interfacial thermal resistance, improving the thermal conductivity. Therefore, it is not prone to fire under high-temperature conditions and is relatively safe. Thus, the battery separator made of the quaternized triazole imide of the present invention simultaneously solves the problems of poor solubility and poor thermal conductivity of commercial battery separators, and improves the safety performance of the separator through the improvement of thermal conductivity without reducing the thermal stability.

[0026] The azacyclic structure in the triazole ring has a high bond energy, resulting in strong thermal stability, and the nitrogen atom has strong nucleophilicity and is prone to substitution reactions. The present invention simultaneously introduces imide rings and triazole rings into the main chain, which can not only improve the thermal stability of the polymer material but also introduce reaction sites to improve the solubility and conductivity of the material. Specifically, the quaternized triazole imide of the present invention not only has excellent heat resistance, with a glass transition temperature (Tg) of 260 - 271 °C, T d5% reaching 532.9 - 553.2 °C, T d10% reaching 543.6 - 564.2 °C, but can also be dissolved in common organic solvents (DMSO, DMF, DMAc), having excellent processability; and it has excellent conductivity, with a room-temperature conductivity of 4.1×10 -6 ~9.2×10 -6 S·cm -1 , good thermal conductivity, with a thermal conductivity of 0.49 - 0.7 W·(m·K) -1 , and it has good ion transport performance and safety for high-temperature use as a battery separator.

[0027] The present invention efficiently prepares quaternized triazole imide from arylimide triazole polymer and alkylating reagent, with high yield and mild reaction conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1FT-IR spectra of the quaternized triazole imide polymers in CDCl3 for Examples 1 to 3;

[0029] Figure 2 DSC curves of the quaternized triazole imide polymers prepared in Examples 1 to 3;

[0030] Figure 3 TGA diagrams of the quaternized triazole imide polymers prepared in Examples 1 to 3;

[0031] Figure 4 For [PTAI-n] in Examples 1 to 3 + I - Conductivity diagrams;

[0032] Figure 5 For [PTAI-n] in Examples 1 to 3 + I - Thermal conductivity diagrams at different temperatures. Detailed implementation mode

[0033] In the present invention, unless otherwise specified, the raw materials or reagents required for preparation are all commercially available products well-known to those skilled in the art.

[0034] The present invention provides a quaternized triazole imide polymer having the structure shown in Formula I:

[0035] Formula I;

[0036] In Formula I, R is , or ;

[0037] Ar is ;

[0038] X is I, Br or Cl;

[0039] n is an integer from 21 to 45.

[0040] In the present invention, n is more preferably from 26 to 40, and further preferably from 28 to 32.

[0041] In the present invention, the quaternized triazole imide polymer is preferably

[0042] ,

[0043]

[0044] or .

[0045] The present invention provides a method for preparing the quaternized triazole imide polymer described in the above technical solution, comprising the following steps:

[0046] Mix an arylimide triazole polymer having the structure shown in Formula II, an alkylating agent, and an organic solvent, and carry out a nucleophilic substitution reaction to obtain a quaternized triazole imide polymer;

[0047] The alkylating agent is methyl iodide, methyl bromide, or methyl chloride;

[0048] Formula II;

[0049] In Formula II, R is , or ;

[0050] Ar is ;

[0051] n is an integer from 21 to 45.

[0052] In the present invention, the arylimide triazole polymer having the structure shown in Formula II is preferably prepared according to the method described in Patent CN 119161734 A, and at the same time, the dianhydride monomer having the structure shown in Formula III in that patent is replaced with bisphenol A type diether dianhydride.

[0053] In addition, when R in Formula I of the present invention is , 4,4'-diazido compound in the raw materials for preparing the diamine monomer having the structure shown in Formula II in Patent CN 119161734 A is replaced with 4,4'-diazidodiphenylmethane; the 4,4'-diazidodiphenylmethane is prepared by the method disclosed in Example 4 of Patent CN118684885A.

[0054] In the present invention, the alkylating agent has the structure shown in Formula III:

[0055] Formula III.

[0056] In Formula II, Y is I, Br, or Cl.

[0057] In the present invention, the molar ratio of the arylimide triazole polymer to the alkylating agent is preferably 1:(2 - 5), more preferably 1:3.

[0058] In the present invention, the organic solvent preferably includes dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide, or N-methylpyrrolidone. The present invention has no special limitation on the dosage of the organic solvent, and it can be adjusted according to actual needs to ensure the smooth progress of the reaction.

[0059] Preferably, the arylimide triazole polymer of the present invention is dissolved in an organic solvent, and then an alkylating agent is added, and the reaction is carried out under light-shielded conditions.

[0060] In the present invention, the temperature of the nucleophilic substitution reaction is preferably 50-100 °C, more preferably 60-80 °C, and the time is preferably 12-36 h, more preferably 24 h.

[0061] After the nucleophilic substitution reaction is completed, preferably, it is precipitated in deionized water and filtered by suction. The filter cake is washed repeatedly with deionized water and absolute ethanol until the pH of the filtrate is 7, and then freeze-dried to obtain the quaternized triazole imide polymer. The present invention has no special limitation on the suction filtration, washing and drying, and it can be carried out in a manner well-known in the art.

[0062] The present invention provides the application of the quaternized triazole imide polymer described in the above technical solution or the quaternized triazole imide polymer prepared by the preparation method described in the above technical solution in the fields of ultra-thin semiconductor packaging, battery separator, liquid crystal display or light-emitting diode.

[0063] The present invention provides a quaternized triazole imide battery separator, which is prepared by a film drawing method, a casting method or a spin coating method using the quaternized triazole imide polymer described in the above technical solution.

[0064] The present invention has no special limitation on the film drawing, casting and spin coating, and the quaternized triazole imide can be made into a film according to a process well-known in the art. In the examples of the present invention, specifically, the quaternized triazole imide is dissolved in anhydrous DMAc to obtain a solution with a solid content of 15 wt%, cast on a clean glass plate, treated in a vacuum drying oven at 100 °C for 2 h, and after cooling to room temperature, the glass plate is immersed in deionized water, peeled off and dried to obtain the quaternized triazole imide film.

[0065] The present invention provides the application of the quaternized triazole imide battery separator described in the above technical solution in the preparation of heat-resistant lithium battery separators. The present invention has no special limitation on the application method, and it can be applied according to a method well-known in the art.

[0066] The specific embodiments of the present invention will be described in detail below, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the protection scope of the present invention. The experimental methods described in the embodiments of the present invention are all conventional methods unless otherwise specified.

[0067] The following experimental methods and detection methods are all conventional methods unless otherwise specified; the following reagents and raw materials are all commercially available unless otherwise specified.

[0068] Example 1

[0069] (1) Add 0.01 mol of 4,4'-diazidodiphenyl sulfone (prepared according to Patent CN 118684885 A) and 100 mL of N,N-dimethylacetamide to a 250 mL three-necked flask equipped with a nitrogen gas protection and magnetic stirring heating device. After dissolution, add 0.02 mol of m-aminophenylacetylene, then sequentially add 0.005 mol of copper sulfate pentahydrate and 0.01 mol of sodium ascorbate. Heat and stir at 60 °C for 6 h. After the reaction is completed, drop the obtained product solution into the stirred saturated aqueous solution of disodium ethylenediaminetetraacetate to obtain a pale yellow precipitate. After filtration and precipitation, freeze-dry to obtain the diamine monomer Diamine-1;

[0070] Add 0.01 mol of the diamine monomer Diamine-1 and 100 mL of N,N-dimethylacetamide to a 250 mL three-necked flask equipped with a nitrogen gas protection and magnetic stirring heating device. After stirring and dissolving at room temperature, add 0.0102 mol of 4,4'-oxybisphthalic anhydride in three portions under an ice bath. Continue the reaction at 5 °C for 6 h. Add 0.02 mol of dehydrating agent acetic anhydride and 0.01 mol of catalyst triethylamine, and stir at 25 °C for 4 h. Pour the obtained solution into deionized water for precipitation, and filter and wash with deionized water three times until the pH value of the filtrate is 7. Dry the obtained precipitate product in a freeze dryer for 24 h to obtain the arylimide triazole polymer, denoted as PTAI-1, and the structural formula is

[0071] ;

[0072] (2) Add a DMSO solution (20 mL) of 2 mmol of PTAI-1 to a 50 mL three-necked flask equipped with a magnetic stirring heating device and nitrogen protection. After dissolution, add 6 mmol of CH3I, and react at 60 °C in the dark for 24 h. Precipitate in deionized water and filter. Wash the filter cake repeatedly with deionized water and absolute ethanol until the pH of the filtrate is 7, and then freeze-dry to obtain the quaternized triazole imide polymer, denoted as [PTAI-1] + I - and the structural formula is

[0073] .

[0074] Example 2

[0075] (1) Add 0.01 mol of 4,4'-diazido diphenyl ether (prepared according to Patent CN 118684885 A) and 100 mL of N,N-dimethylacetamide to a 250 mL three-necked flask equipped with a nitrogen gas protection and magnetic stirring heating device. After dissolution, add 0.02 mol of m-aminophenylacetylene, then sequentially add 0.005 mol of copper sulfate pentahydrate and 0.01 mol of sodium ascorbate. Heat and stir at 60 °C for 6 h. After the reaction is completed, drop the obtained product solution into the stirred saturated aqueous solution of disodium ethylenediaminetetraacetate to obtain a pale yellow precipitate. After filtration and precipitation, freeze-dry to obtain the diamine monomer Diamine-2;

[0076] Add 0.01 mol of the diamine monomer Diamine-2 and 100 mL of N,N-dimethylacetamide to a 250 mL three-necked flask equipped with a nitrogen gas protection and magnetic stirring heating device. After stirring and dissolving at room temperature, add 0.0102 mol of 4,4'-oxybisphthalic anhydride in three portions under an ice bath. Continue the reaction at 5 °C for 6 h. Add 0.02 mol of dehydrating agent acetic anhydride and 0.01 mol of catalyst triethylamine, stir at 25 °C for 4 h. Pour the obtained solution into deionized water to precipitate, and filter and wash with deionized water three times until the pH value of the filtrate is 7. Dry the obtained precipitate product in a freeze dryer for 24 h to obtain the arylimide triazole polymer PTAI-2, and the structural formula is as follows;

[0077] ;

[0078] (2) Add a DMSO solution (20 mL) of 2 mmol of PTAI-2 to a 50 mL three-necked flask equipped with a magnetic stirring heating device and nitrogen protection. After dissolution, add 6 mmol of CH3I, react in the dark at 60 °C for 24 h, precipitate in deionized water and filter. Wash the filter cake repeatedly with deionized water and absolute ethanol until the pH of the filtrate is 7, and freeze-dry to obtain the quaternized triazole imide polymer, denoted as [PTAI-2] + I - , and the structural formula is

[0079] .

[0080] Example 3

[0081] (1) In a flask containing 0.5948 g (3 mmol) of 4,4'-diaminodiphenylmethane, 20 mL of deionized water and 12 mL of concentrated hydrochloric acid with a concentration of 12 mol / L were added. The mixture was stirred until the solid was completely dissolved, and the system became milky white. The temperature of the mixture was controlled at 0 °C under an ice bath. 9 mL (0.6216 g, 9 mmol) of an aqueous solution of sodium nitrite with a concentration of 1 mol / L was added dropwise. After stirring for 1 h, the temperature was controlled at 0 °C, and 9 mL (0.4681 g, 7.2 mmol) of an aqueous solution of sodium azide with a concentration of 1 mol / L was added dropwise. The system gradually turned light yellow, with light yellow powder precipitating and nitrogen gas evolving. After the addition of sodium azide was completed, the system was transferred to room temperature for reaction and stirred for 3 h. The reaction was stopped and left to stand for 12 h. It was found that the precipitate and the solution were clear, and the solid was located in the upper layer of the system. It was filtered by suction, and the filter cake was washed 3 times with deionized water and dried in vacuo at 50 °C for 12 h to obtain a light yellow powder, 4,4'-di(azidophenyl)methane;

[0082] 0.01 mol of 4,4'-di(azidophenyl)methane and 100 mL of N,N-dimethylacetamide were added to a 250 mL three-necked flask equipped with a nitrogen gas protection and magnetic stirring heating device. After dissolution, 0.02 mol of m-aminophenylacetylene was added. Then, 0.005 mol of copper sulfate pentahydrate and 0.01 mol of sodium ascorbate were added successively. The mixture was heated and stirred at 60 °C for 6 h. After the reaction was completed, the resulting product solution was dropped into a stirred aqueous solution of disodium ethylenediaminetetraacetate to obtain a light yellow precipitate. After filtration by suction and precipitation, it was freeze-dried to obtain the diamine monomer Diamine-2;

[0083] 0.01 mol of the diamine monomer Diamine-3 and 100 mL of N,N-dimethylacetamide were added to a 250 mL three-necked flask equipped with a nitrogen gas protection and magnetic stirring heating device. After stirring and dissolving at room temperature, 0.0102 mol of 4,4'-oxybisphthalic anhydride was added in three portions under an ice bath. The reaction continued at 5 °C for 6 h. 0.02 mol of dehydrating agent acetic anhydride and 0.01 mol of catalyst triethylamine were added, and the mixture was stirred at 25 °C for 4 h. The resulting solution was poured into deionized water for precipitation, filtered by suction with deionized water and washed 3 times until the pH value of the filtrate was 7. The obtained precipitate product was dried in a freeze dryer for 24 h to obtain the arylimine triazole polymer PTAI-3, and the structural formula is shown as follows;

[0084] ;

[0085] (2) Add 2 mmol of the DMSO solution (20 mL) of PTAI-3 to a 50 mL three-necked flask with a magnetic stirring heating device and nitrogen protection. After it dissolves, add 6 mmol of CH3I and react at 60 °C in the dark for 24 h. Precipitate in deionized water and filter by suction. Wash the filter cake repeatedly with deionized water and absolute ethanol until the pH of the filtrate is 7, and then freeze-dry to obtain the quaternized triazole imide polymer, denoted as [PTAI-3]. + I - , and the structural formula is

[0086] .

[0087] Example 4

[0088] Replace CH3I in Example 1 with CH3Br, and keep other conditions unchanged, to obtain a structural formula consistent with that of Example 1.

[0089] Example 5

[0090] Replace CH3I in Example 2 with CH3Cl, and keep other conditions unchanged, to obtain a structural formula consistent with that of Example 2.

[0091] Application Example 1

[0092] Dissolve the quaternized triazole imide polymers prepared in Examples 1-5 in anhydrous DMAc respectively to obtain solutions with a solid content of 15 wt%. Cast them on clean glass plates and treat them in a vacuum drying oven at 100 °C for 2 h. After cooling to room temperature, immerse the glass plates in deionized water, peel and dry to obtain the quaternized triazole imide films.

[0093] Application Example 2

[0094] Dissolve the quaternized triazole imide polymers prepared in Examples 1-5 in anhydrous DMF respectively to obtain solutions with a solid content of 15 wt%. Spin-coat them on clean glass plates and treat them in a vacuum drying oven at 100 °C for 2 h. After cooling to room temperature, immerse the glass plates in deionized water, peel and dry to obtain the quaternized triazole imide films.

[0095] Application Example 3

[0096] Dissolve the quaternized triazole imide polymers prepared in Examples 1-5 in anhydrous NMP respectively to obtain solutions with a solid content of 15 wt%. Spread them on clean glass plates by the film-drawing method and treat them in a vacuum drying oven at 100 °C for 2 h. After cooling to room temperature, immerse the glass plates in deionized water, peel and dry to obtain the quaternized triazole imide films.

[0097] Testing

[0098] 1) Infrared testing

[0099] Figure 1 FT-IR spectra of the quaternized triazole imide polymers in Examples 1 to 3, from Figure 1 it can be seen that the stretching vibration peak of C=O of the ester group exists at 1727 cm -1 , indicating that the ester group structure during the polymerization process is not damaged. The characteristic absorption peaks of -C=C- and -N=N- in the triazole ring appear at 1619 cm -1 and 1442 cm -1 , and the vibration absorption peak of the triazole ring appears at 3071 cm -1 . The methyl peak at 2931 cm -1 appears, indicating successful quaternization and the successful preparation of the quaternized triazole imide polymer.

[0100] 2) Thermal property test

[0101] The thermal properties of the quaternized triazole imide polymers in Examples 1 to 3 were tested.

[0102] The process and conditions of DSC test were: heating from 50 °C to 350 °C at a heating rate of 20 °C / min, then cooling to 50 °C at a cooling rate of 20 °C / min, and finally heating to 350 °C at a heating rate of 20 °C / min. The second heating curve was taken, and the results are shown in Figure 2 and Table 1.

[0103] Figure 2 DSC curves of the quaternized triazole imide polymers prepared in Examples 1 to 3, from Figure 2 it can be seen that the glass transition temperatures of [PTAI-n] + I - are all higher than 270 °C. The introduction of quaternary ammonium ions enhances the conjugation and intermolecular forces, so it has a very high glass transition temperature.

[0104] The process and conditions of TGA were: in a nitrogen atmosphere, the flow rate of the protective gas was 30 mL / min, the flow rate of the purge gas was 30 mL / min, and heating from 50 °C to 800 °C at a heating rate of 20 °C / min. The results are shown in Figure 3 and Table 1.

[0105] Figure 3 TGA spectra of the quaternized triazole imide polymers prepared in Examples 1 to 3, from Figure 3 it can be seen that the temperatures of 5% mass loss (T d5% ) and 10% mass loss (T d10% ) are higher than 530 °C and 540 °C respectively, having a relatively high thermal decomposition temperature.

[0106] Table 1 Thermal property test results of the quaternized triazole imides in Examples 1 to 3

[0107]

[0108] From Figure 2 、 Figure 3 and Table 1, it can be seen that [PTAI-n] + I - has good high-temperature resistance and thermal decomposition temperature.

[0109] 3) Solubility test

[0110] Test the solubility of [PTAI-1] + I - , [PTAI-2] + I - and [PTAI-3] + I - in Test Examples 1 to 3. The test process is as follows: Accurately weigh 0.1 g of [PTAI-n] + I - (n = 1, 2, or 3) and add them to 5 mL of different solvents (see Table 2) respectively. Stir with a magnetic stirrer at room temperature. After 3 h, let it stand. After the solid phase is completely precipitated, take the upper layer solution for analysis after 2 h. After the concentrations of the two are basically the same, end the test. Compare the solubility. If there is no residue of the analyte, it is defined as completely dissolved; if the residue amount of the analyte is 1 - 90%, it is defined as partially dissolved; if the partial residue amount of the analyte is greater than 90%, it is defined as insoluble.

[0111] The test results are shown in Table 2, where, "++" indicates completely dissolved; "+" indicates partially dissolved; "-" indicates insoluble.

[0112] Table 2 Solubility test results of [PTAI-n] + I -

[0113] solvent Example 1 Example 2 Example 3 THF + + + DMSO ++ ++ ++ DMF ++ ++ ++ DMAc ++ ++ ++ <![CDATA[CH2Cl2]]> - - - acetone - - - ethanol - - -

[0114] From Table 2, it can be seen that the polymer [PTAI-n] + I - has certain solubility, is soluble in most strongly polar solvents, and has good processing performance and electrolyte wettability.

[0115] 4) Conductivity test

[0116] For [PTAI-n] in Examples 1 to 3 + I -Conductivity testing was carried out. Using the alternating current impedance method, the electrochemical impedance spectroscopy (EIS) of the separator was obtained through an electrochemical workstation (two-electrode method), and the ionic conductivity of the separator was calculated according to formula (1).

[0117]

[0118] Among them, σ (S cm -1 ) is the proton conductivity, L (cm) is the distance between the two electrodes, R (Ω) is the membrane resistance obtained from the low intersection point of the high-frequency semicircle and the real axis (Z) on the complex impedance plane, and A (cm 2 ) is the cross-sectional area of the test sample.

[0119] Figure 4 For [PTAI-n] + I - in Examples 1 to 3, the conductivity diagrams are shown. It can be seen that after quaternization, the increase in free volume in the membrane improves the proton conductivity of the membrane. [PTAI-2] Figure 4 I + contains a large number of ether bonds, which can weaken the electrostatic interaction between anions and cations, making it easier for anions and cations to dissociate. Therefore, at the same temperature, the conductivity of [PTAI-2] - I + >[PTAI-3] - I + >[PTAI-1] - I + >[PTAI-1] - . Their corresponding room temperature ionic conductivities are 4.1×10 -6 , 9.2×10 -6 and 6.1×10 -6 S·cm -1 respectively, indicating that the polymer has a relatively high ionic conductivity at room temperature. As the temperature increases from room temperature to 200 °C, the ionic conductivity of the polymer increases significantly, and the highest ionic conductivity reaches 2.4×10 -4 S·cm -1 (200 °C). This is because as the temperature increases, the segmental motion accelerates, promoting the migration of ions.

[0120] 5) Thermal conductivity testing

[0121] For [PTAI-n] + I -The thermal conductivity was tested. The thermal conductivity was measured by the laser flash method (LFA), with five shots, each lasting 30 milliseconds, and the signal was fitted by the Cape-Lehman algorithm using Netzsch's Proteus analysis software. The diameter of the test sample was 12.7 mm. The thermal conductivity was calculated using Equation (2).

[0122] λ = ρ × c × α (2)

[0123] where λ (W·(m·K) -1 ) is the thermal conductivity, ρ (g / cm 3 ), c ((J / (g·K)) and α (mm 2 / s) represent density, specific heat capacity, and thermal diffusivity, respectively.

[0124] At 200 °C, the thin film was annealed thermally for 1 h, taken out after returning to room temperature, and the thermal conductivity was measured again.

[0125] Figure 5 For [PTAI-n] + I - in Examples 1 to 3, the thermal conductivity diagrams at different temperatures are shown. It can be seen that after quaternization, the electrostatic interaction between positive and negative charges enhances the intermolecular force, making the polymer have excellent thermal conductivity at room temperature (25 °C). The thermal conductivities of [PTAI-1] Figure 5 I + I - [PTAI-2] + I - and [PTAI-3] + I - are 0.7, 0.49, and 0.62 W·(m·K) -1 respectively. And due to the thermal annealing at 200 °C, which is much lower than the glass transition temperature of [PTAI-n] + I - , the thermal conductivity after thermal annealing basically remains unchanged.

[0126] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can still be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A quaternized triazole imide polymer, characterized in that, It has the structure shown in Formula I: Formula I; In formula I, R is , or ; Ar is ; X is I, Br or Cl; n is an integer from 21 to 45.

2. The preparation method of the quaternized triazole imide polymer according to claim 1, characterized in that, It includes the following steps: Mix an arylimide triazole polymer with the structure shown in Formula II, an alkylating agent and an organic solvent, and carry out a nucleophilic substitution reaction to obtain a quaternized triazole imide polymer; The alkylating agent is methyl iodide, methyl bromide or methyl chloride; Formula II; In formula II, R is , or ; Ar is ; n is an integer from 21 to 45.

3. The preparation method according to claim 2, characterized in that, The molar ratio of the arylimide triazole polymer to the alkylating agent is 1:(2 - 5).

4. The preparation method according to claim 2, characterized in that, The temperature of the nucleophilic substitution reaction is 50 - 100 °C, and the time is 12 - 36 h.

5. The preparation method according to claim 2, characterized in that The organic solvent includes dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide or N-methylpyrrolidone.

6. Use of the quaternized triazole imide polymer according to claim 1 or the quaternized triazole imide polymer prepared by the preparation method according to any one of claims 2 - 5 in the fields of ultra-thin semiconductor packaging, battery separators, liquid crystal displays or light-emitting diodes.

7. A quaternized triazole imide battery separator, characterized in that, It is prepared by a film drawing method, a casting method or a spin coating method using the quaternized triazole imide polymer according to claim 1.

8. Use of the quaternized triazole imide battery separator according to claim 7 in the preparation of a heat-resistant lithium battery separator.

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