Hyperbranched polyamide containing methylpiperazine and polytriphenylamine structure as well as preparation method and application of hyperbranched polyamide

Abstract

The invention relates to hyperbranched polyamide containing methylpiperazine and polytriphenylamine structures as well as a preparation method and application thereof. The invention relates to a monomer containing methyl piperazine and triphenylamine cores, namely N1, N1-bis (4-aminophenyl)-N4-(4-(bis (4-aminophenyl amino) phenyl) 4-(4-(4-methyl azine-1-yl) benzene) phenyl-1, 4-diamine and hyperbranched polyamide, and a preparation method and application of N1, N1-bis (4-aminophenyl)-N4-(4-(4-methyl azine-1-yl) benzene) phenyl-1, 4-diamine and hyperbranched polyamide. In order to solve the problems of low solubility, poor thermal stability, single color change, low optical contrast and poor electrochemical stability of a triphenylamine-based polyamide material in an organic solvent, a methyl piperazine electron-donating group and multiple electroactive centers are introduced in a molecular design process, and hyperbranched polyamide is synthesized; and the discoloration capability and the cycling stability of the polymer are improved. The solubility of the hyperbranched polyamide is remarkably improved, and the hyperbranched polyamide has excellent electrochromic performance including excellent cycling stability, multiple color changes and high optical contrast. The method is applied to the fields of electrochromic display, sensing, photoelectric detection and the like.

Description

Technical Field

[0001] The invention relates to a hyperbranched polyamide containing methylpiperazine and polytriphenylamine structures, and a preparation method and application thereof. Background Art

[0002] As a color-related electrical stimulus response material, electrochromic materials have attracted the attention of many scientific researchers due to their rich color changes, high optical contrast before and after color change, and relatively low price. They have been applied to smart windows, electronic tags, goggles and other fields. Among them, adjusting indoor light and temperature through color-changing smart windows has become an important link in achieving energy conservation in the construction and automobile industries to cope with the uncontrollability and periodic tension of energy supply. Triphenylamine is a helical molecule with high redox activity and excellent cationic stability. Triphenylamine-based derivatives or polymers are widely used in electrochromic materials. In addition, the introduction of electron-donating groups at the para position of the triphenylamine unit can reduce its oxidation potential and improve its electrochemical stability. The multi-triphenylamine structure can improve the thermal properties of the polymer, and can also achieve multiple color changes in photoelectrochemistry and show obvious near-infrared absorption optically. This patent is based on the methylpiperazine group with electron-donating ability, constructs a multi-triphenylamine structure, and synthesizes a new hyperbranched polyamide, in order to obtain electrochromic materials and devices with good solubility, easy film formation, strong stability, multiple color changes and high optical contrast. Summary of the invention

[0003] The purpose of the present invention is to solve the problems of poor solubility, poor thermal stability, single color change, low optical contrast and poor electrochemical stability of triphenylamine-based polyamide electrochromic materials in organic solvents, and proposes a hyperbranched polyamide containing methylpiperazine and polytriphenylamine structures, a preparation method thereof and an application in electrochromism. The hyperbranched polyamide structures obtained by polycondensation of diamine monomers containing methylpiperazine and polytriphenylamine structures and commercially available diacid monomers (including but not limited to 1,4-cyclohexanedicarboxylic acid, 4,4-diphenylsulfonyl dicarboxylic acid, 4,4'-dicarboxyoxy diphenyl ether and 2,2-bis(4-carboxyphenyl)hexafluoropropane, 4,4'-biphenyl dicarboxylic acid, 1,4-naphthalene dicarboxylic acid, 2,7-naphthalene dicarboxylic acid, terephthalic acid, isophthalic acid, 3,4-thiophene dicarboxylic acid, 3,4-furan dicarboxylic acid, succinic acid, etc.) are as follows: , where the degree of branching is 0.50 to 0.81. 2. The preparation method of the hyperbranched polyamide containing methylpiperazine and polytriphenylamine structure of the present invention is carried out according to the following steps: 1. Synthesis of N1,N1-bis(4-aminophenyl)-N4-(4-(bis(4-aminophenylamino)phenyl)4-(4-(4-methyloxazin-1-yl)benzene)phenyl-1,4-diamine monomer: ①. Under N2 atmosphere, 4-(4-methylpiperazine)aniline monomer, cesium fluoride, p-fluoronitrobenzene and dimethyl sulfoxide were placed in a three-necked flask, the system was heated to 120°C for reflux reaction, and the heat source was turned off after the reaction was judged to be completed by thin layer chromatography; the cooled mixed solution was poured into a mixed solution of deionized water and ethanol until the crude product was precipitated, filtered, and the crude product was recrystallized with methanol, filtered again, and the obtained product was vacuum dried to obtain a red powder M1; The ratio of the volume of dimethyl sulfoxide to the amount of 4-(4-methylpiperazine)aniline monomer in step 1① is (50-100) mL:10 mmol; The molar ratio of cesium fluoride to 4-(4-methylpiperazine)aniline monomer in step 1① is 2.2:1; The molar ratio of p-fluoronitrobenzene to 4-(4-methylpiperazine)aniline monomer in step 1① is 2.2:1; The vacuum drying temperature in step 1① is 45°C, the vacuum drying time is 48 hours, and the vacuum drying pressure is -30 to -29KPa; ②, under room temperature, add anhydrous ethanol, Pd / C and M1 into a three-necked flask and stir; under N2 condition, use a constant pressure funnel to drop hydrazine hydrate into the three-necked flask at a drop rate of 1 to 2 drops per second; heat the system to 80°C until the solution refluxes, filter and remove Pd / C while hot after the reaction is completed, pour the filtrate into brine under stirring, extract with dichloromethane solvent, and repeat 3 times; the obtained organic phase solution is dried over anhydrous magnesium sulfate to remove water, and a transparent solution is obtained after filtration; the filtrate is rotary evaporated and vacuum dried to obtain an off-white monomer M2; The ratio of the volume of anhydrous ethanol in step 1② to the amount of substance of M1 is (150-200) mL: 10 mmol; The ratio of the mass of Pd / C to the amount of M1 in step 1② is (1-1.2) g: 5 mmol; The ratio of the volume of hydrazine hydrate in step 1② to the amount of substance of M1 is 2.5mL:1mmol; The Pd / C in step 1② is a Pd C-doped composite material, and the mass fraction of Pd in ​​the Pd / C is 5%; The vacuum drying temperature in step 1② is 30°C, the vacuum drying time is 48 to 64 hours, and the vacuum drying pressure is -30 to -29KPa; ③. The specific preparation method of M3 is the same as step 1①, with the following differences: In step 1③, the raw material 4-(4-methylpiperazine)aniline monomer in step 1① is replaced by M2; The ratio of the volume of dimethyl sulfoxide to the amount of substance of M2 in step 1③ is (50-100) mL:10 mmol; The ratio of the amount of cesium fluoride to M2 in step 1③ is 4.8:1; The molar ratio of p-fluoronitrobenzene to M2 in step 1③ is 4.8:1; ④, N1,N1-bis(4-aminophenyl)-N4-(4-(bis(4-aminophenylamino)phenyl)4-(4-(4-methyloxazin-1-yl)phenyl)phenyl-1,4-diamine, also named M4, its specific preparation method is the same as step 1②, there are several differences as follows: In step 1④, replace M1 in step 1② with M3; The ratio of the volume of anhydrous ethanol in step 1④ to the amount of substance of M3 is (150-200) mL: 5 mmol; The ratio of the mass of Pd / C to the amount of substance of M3 in step 1④ is (2-2.4) g: 5 mmol; 2. Preparation of hyperbranched polyamide containing methylpiperazine and polytriphenylamine structure: N1,N1-bis(4-aminophenyl)-N4-(4-(bis(4-aminophenylamino)phenyl)4-(4-(4-methylpiperazine-1-yl)phenyl)phenyl-1,4-diamine (M4), diacid monomer, triphenyl phosphite, CaCl2, pyridine and N-methylpyrrolidone are mixed, and then stirred at 130° C. for 4 hours, and then poured into methanol after cooling to room temperature, and the precipitate is collected by filtration, and then fully washed with methanol, and finally Soxhlet extraction is performed with methanol to obtain a hyperbranched polyamide containing methylpiperazine and polytriphenylamine structures; In step 2, the ratio of the amount of M4 to the diacid monomer is 1:2; The ratio of the volume of triphenyl phosphite in step 2 to the amount of substance of M4 is 1.5 mL: 1 mmol; The ratio of the volume of pyridine in step 2 to the amount of substance of M4 is 1.5 mL: 1 mmol; The ratio of the volume of N-methylpyrrolidone in step 2 to the amount of substance of M4 is 3 mL: 1 mmol; The ratio of the mass of CaCl2 to the volume of N-methylpyrrolidone in step 2 is 0.3 g:6 mL; The ratio of the volume of methanol in step 2 to the amount of substance of M4 is 350 mL:1 mmol. The hyperbranched polyamide containing methylpiperazine and polytriphenylamine structures is used as an electrochromic material and is applied in the field of electrochromicity. The present invention is to prepare a polyamide material with excellent electrochromic comprehensive ability, improve the problems of poor solubility, poor thermal stability, single electrochromic, low optical contrast and electrochromic instability of polyamide, and synthesize a hyperbranched structure by introducing multiple helical triphenylamine units and methylpiperazine alkyl chains, and the solubility of polyamide can be increased by utilizing the larger steric hindrance and hyperbranched structure of triphenylamine; the introduction of multiple triphenylamine structures improves the thermal stability of hyperbranched polyamide; on the other hand, the methylpiperazine unit and multiple triphenylamine units provide multiple N electroactive centers, so that the polymer shows multiple color changes during the electrochromic process, and can also achieve high optical contrast before and after color change. In addition, the electron donation ability of methylpiperazine and the conjugation effect of multiple triphenylamines make it easier for electrons to delocalize, and the oxidation potential becomes lower, thereby improving the electrochromic cycle stability. Combining the above advantages, a triphenylamine hyperbranched polyamide containing a methylpiperazine structure is prepared, which has good solubility and thermal stability, and shows excellent performance of high transmittance and long cycle stability in electrochromism. The present invention has the following beneficial effects: 1. The hyperbranched polyamide containing methylpiperazine and polytriphenylamine structures of the present invention has significantly improved solubility and thermal stability due to the introduction of hyperbranched structures and polytriphenylamine units. It is easily soluble in polar solvents, and 0.1 to 0.2 grams can be dissolved per milliliter of polar solvent; the thermal stability of the hyperbranched polyamide is evaluated by thermal weight loss test under N2 atmosphere, and the hyperbranched polyamide containing methylpiperazine and polytriphenylamine structures begins to lose weight at 320°C; when the temperature is 800°C, the residual carbon rate is 47-61%, and the results show that the hyperbranched polyamide containing methylpiperazine and polytriphenylamine structures has good solubility and thermal stability. 2. The polymer of the present invention has excellent electrochromic properties Electrochromism refers to the phenomenon that when driven by an external voltage or current, a substance undergoes an electrochemical redox reaction and causes a color change. That is, under the action of an external electric field, the transmittance of the substance undergoes a stable and reversible change in the visible light range. The polymer of the present invention has multiple color changes during the electrochromic process, and polymers P1-P4 gradually change from colorless to yellow-green, light blue and dark blue; the optical contrast is high, among which the optical contrast of polymer P1 can reach up to 77%; in addition, the polymer has good cycle stability, and polymer P2 retains 80% of its optical contrast after 3720 cycles, showing excellent electrochromic stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] Figure 1 The hydrogen nuclear magnetic spectrum of N1,N1-bis(4-aminophenyl)-N4-(4-(bis(4-aminophenylamino)phenyl)4-(4-(4-methyloxazin-1-yl)benzene)phenyl-1,4-diamine monomer (M4) prepared in Example 1; Figure 2 Fourier transform infrared images of four hyperbranched polyamides containing methylpiperazine and polytriphenylamine structures prepared in Examples 1 to 4; Figure 3 Cyclic voltammograms of four hyperbranched polyamides containing methylpiperazine and polytriphenylamine structures prepared in Examples 1 to 4; Figure 4 Thermogravimetric analysis spectra of the hyperbranched polyamide containing methylpiperazine and polytriphenylamine structures prepared in Examples 1 to 4; Figure 5 The UV-visible-near infrared absorption graphs of four hyperbranched polyamides containing methylpiperazine and polytriphenylamine structures prepared in Examples 1 to 4; Figure 6 This is the electrochromic cycle stability diagram of the hyperbranched polyamide P1 containing methylpiperazine and polytriphenylamine structures prepared in Example 1. Figure 7 This is a diagram showing the mechanism of an electrochromic device made from a hyperbranched polyamide P1 film containing methylpiperazine and polytriphenylamine structures prepared in Example 1. DETAILED DESCRIPTION

[0005] The technical solution of the present invention is not limited to the specific implementation modes listed below, but also includes any reasonable combination of the specific implementation modes. Specific implementation method 1: The structural formulas of the monomers and hyperbranched polyamides containing methylpiperazine and polytriphenylamine structures in this implementation method are as follows: , where the degree of branching is 0.50 to 0.81. The present invention has the following beneficial effects: 1. The hyperbranched polyamide containing methylpiperazine and polytriphenylamine structures of the present invention has significantly improved solubility and thermal stability due to the introduction of hyperbranched structures and polytriphenylamine units. It is easily soluble in polar solvents, and 0.1 to 0.2 grams can be dissolved per milliliter of polar solvent; the thermal stability of the hyperbranched polyamide is evaluated by thermal weight loss test under N2 atmosphere, and the hyperbranched polyamide containing methylpiperazine and polytriphenylamine structures begins to lose weight at 320°C; when the temperature is 800°C, the residual carbon rate is 47-61%, and the results show that the hyperbranched polyamide containing methylpiperazine and polytriphenylamine structures has good solubility and thermal stability. 2. The polymer of the present invention has excellent electrochromic properties Electrochromism refers to the phenomenon that when driven by an external voltage or current, a substance undergoes an electrochemical redox reaction and causes a color change. That is, under the action of an external electric field, the transmittance of the substance undergoes a stable and reversible change in the visible light range. The polymer of the present invention has multiple color changes during the electrochromic process, and polymers P1-P4 gradually change from colorless to yellow-green, light blue and dark blue; the optical contrast is high, among which the optical contrast of polymer P1 can reach up to 77%; in addition, the polymer has good cycle stability, and polymer P2 retains 80% of its optical contrast after 3720 cycles, showing excellent electrochromic stability. Specific embodiment 2: The preparation method of the monomer containing methylpiperazine and polytriphenylamine structure and hyperbranched polyamide in this embodiment is carried out according to the following steps: 1. Synthesis of N1,N1-bis(4-aminophenyl)-N4-(4-(bis(4-aminophenylamino)phenyl)4-(4-(4-methyloxazin-1-yl)benzene)phenyl-1,4-diamine monomer: ①. Under N2 atmosphere, 4-(4-methylpiperazine)aniline monomer, cesium fluoride, p-fluoronitrobenzene and dimethyl sulfoxide were placed in a three-necked flask, the system was heated to 120°C for reflux reaction, and the heat source was turned off after the reaction was judged to be completed by thin layer chromatography; the cooled mixed solution was poured into a mixed solution of deionized water and ethanol until the crude product was precipitated, filtered, and the crude product was recrystallized with methanol, filtered again, and the obtained product was vacuum dried to obtain a red powder M1; The ratio of the volume of dimethyl sulfoxide to the amount of 4-(4-methylpiperazine)aniline monomer in step 1① is (50-100) mL:10 mmol; The molar ratio of cesium fluoride to 4-(4-methylpiperazine)aniline monomer in step 1① is 2.2:1; The molar ratio of p-fluoronitrobenzene to 4-(4-methylpiperazine)aniline monomer in step 1① is 2.2:1; The vacuum drying temperature in step 1① is 45°C, the vacuum drying time is 48 hours, and the vacuum drying pressure is -30 to -29KPa; ②, under room temperature, add anhydrous ethanol, Pd / C and M1 into a three-necked flask and stir; under N2 condition, use a constant pressure funnel to drop hydrazine hydrate into the three-necked flask at a drop rate of 1 to 2 drops per second; heat the system to 80°C until the solution refluxes, filter and remove Pd / C while hot after the reaction is completed, pour the filtrate into brine under stirring, extract with dichloromethane solvent, and repeat 3 times; the obtained organic phase solution is dried over anhydrous magnesium sulfate to remove water, and a transparent solution is obtained after filtration; the filtrate is rotary evaporated and vacuum dried to obtain an off-white monomer M2; The ratio of the volume of anhydrous ethanol in step 1② to the amount of substance of M1 is (150-200) mL: 10 mmol; The ratio of the mass of Pd / C to the amount of M1 in step 1② is (1-1.2) g: 5 mmol; The ratio of the volume of hydrazine hydrate in step 1② to the amount of substance of M1 is 2.5mL:1mmol; The Pd / C in step 1② is a Pd C-doped composite material, and the mass fraction of Pd in ​​the Pd / C is 5%; The vacuum drying temperature in step 1② is 30°C, the vacuum drying time is 48 to 64 hours, and the vacuum drying pressure is -30 to -29KPa; ③. The specific preparation method of M3 is the same as step 1①, with the following differences: In step 1③, the raw material 4-(4-methylpiperazine)aniline monomer in step 1① is replaced by M2; The ratio of the volume of dimethyl sulfoxide to the amount of substance of M2 in step 1③ is (50-100) mL:10 mmol; The ratio of the amount of cesium fluoride to M2 in step 1③ is 4.8:1; The molar ratio of p-fluoronitrobenzene to M2 in step 1③ is 4.8:1; ④, N1,N1-bis(4-aminophenyl)-N4-(4-(bis(4-aminophenylamino)phenyl)4-(4-(4-methyloxazin-1-yl)phenyl)phenyl-1,4-diamine, also named M4, its specific preparation method is the same as step 1②, there are several differences as follows: In step 1④, replace M1 in step 1② with M3; The ratio of the volume of anhydrous ethanol in step 1④ to the amount of substance of M3 is (150-200) mL: 5 mmol; The ratio of the mass of Pd / C to the amount of substance of M3 in step 1④ is (2-2.4) g: 5 mmol; 2. Preparation of hyperbranched polyamide containing methylpiperazine and polytriphenylamine structure: N1,N1-bis(4-aminophenyl)-N4-(4-(bis(4-aminophenylamino)phenyl)4-(4-(4-methylpiperazine-1-yl)phenyl)phenyl-1,4-diamine (M4), diacid monomer, triphenyl phosphite, CaCl2, pyridine and N-methylpyrrolidone are mixed, and then stirred at 130° C. for 4 hours, and then poured into methanol after cooling to room temperature, and the precipitate is collected by filtration, and then fully washed with methanol, and finally Soxhlet extraction is performed with methanol to obtain a hyperbranched polyamide containing methylpiperazine and polytriphenylamine structures; In step 2, the ratio of the amount of M4 to the diacid monomer is 1:2; The ratio of the volume of triphenyl phosphite in step 2 to the amount of substance of M4 is 1.5 mL: 1 mmol; The ratio of the volume of pyridine in step 2 to the amount of substance of M4 is 1.5 mL: 1 mmol; The ratio of the volume of N-methylpyrrolidone in step 2 to the amount of substance of M4 is 3 mL: 1 mmol; The ratio of the mass of CaCl2 to the volume of N-methylpyrrolidone in step 2 is 0.3 g:6 mL; The ratio of the volume of methanol in step 2 to the amount of substance of M4 is 350 mL:1 mmol. Specific implementation method three: In this implementation method, the hyperbranched polyamide containing methylpiperazine and polytriphenylamine structures is used as an electrochromic layer in an electrochromic device in electrochromic application. Specific embodiment 4: This embodiment is different from specific embodiment 3 in that the application of the hyperbranched polyamide containing methylpiperazine and polytriphenylamine structure as the electrochromic layer in the electrochromic device is carried out according to the following steps: The hyperbranched polyamide containing methylpiperazine and polytriphenylamine structures is used as the electrochromic layer in the electrochromic device, and the electrochromic layer is coated on a conductive substrate to prepare an electrochromic device, and the electrochromic layer produces electrochromism under the action of an external electric field. Other steps and parameters are the same as those in the fourth embodiment. Specific embodiment 5: This embodiment is different from specific embodiment 3 or 4 in that: the conductive substrate is conductive glass or ITO conductive resin film or transparent silver nanowire or transparent carbon nanotube electrode. Other steps and parameters are the same as those of specific embodiment 3 or 4. Specific embodiment 6: The added electrolyte is a solution or gel containing lithium ions or tert-butylammonium ions Specific implementation example 7: This implementation example is different from specific implementation example 3 or 4 in that the voltage of the externally applied electric field is 0 V to 2.50 V. The other steps and parameters are the same as those of specific implementation examples 3 to 6. The following examples are used to verify the beneficial effects of the present invention: Example 1: The structural formula of the hyperbranched polyamide P1 containing methylpiperazine and polytriphenylamine structures is as follows: , where the degree of branching is 0.70. 1. Synthesis of N1,N1-bis(4-aminophenyl)-N4-(4-(bis(4-aminophenylamino)phenyl)4-(4-(4-methyloxazin-1-yl)benzene)phenyl-1,4-diamine monomer: ①. Under N2 atmosphere, 4-(4-methylpiperazine)aniline monomer, cesium fluoride, p-fluoronitrobenzene and dimethyl sulfoxide were placed in a three-necked flask, the system was heated to 120°C for reflux reaction, and the heat source was turned off after the reaction was judged to be completed by thin layer chromatography; the cooled mixed solution was poured into a mixed solution of deionized water and ethanol until the crude product was precipitated, filtered, and the crude product was recrystallized with methanol, filtered again, and the obtained product was vacuum dried to obtain a red powder M1; The ratio of the volume of dimethyl sulfoxide to the amount of 4-(4-methylpiperazine)aniline monomer in step 1① is (50-100) mL:10 mmol; The molar ratio of cesium fluoride to 4-(4-methylpiperazine)aniline monomer in step 1① is 2.2:1; The molar ratio of p-fluoronitrobenzene to 4-(4-methylpiperazine)aniline monomer in step 1① is 2.2:1; The vacuum drying temperature in step 1① is 45°C, the vacuum drying time is 48 hours, and the vacuum drying pressure is -30 to -29KPa; ②, under room temperature, add anhydrous ethanol, Pd / C and M1 into a three-necked flask and stir; under N2 condition, use a constant pressure funnel to drop hydrazine hydrate into the three-necked flask at a drop rate of 1 to 2 drops per second; heat the system to 80°C until the solution refluxes, filter and remove Pd / C while hot after the reaction is completed, pour the filtrate into brine under stirring, extract with dichloromethane solvent, and repeat 3 times; the obtained organic phase solution is dried over anhydrous magnesium sulfate to remove water, and a transparent solution is obtained after filtration; the filtrate is rotary evaporated and vacuum dried to obtain an off-white monomer M2; The ratio of the volume of anhydrous ethanol in step 1② to the amount of substance of M1 is (150-200) mL: 10 mmol; The ratio of the mass of Pd / C to the amount of M1 in step 1② is (1-1.2) g: 5 mmol; The ratio of the volume of hydrazine hydrate in step 1② to the amount of substance of M1 is 2.5mL:1mmol; The Pd / C in step 1② is a Pd C-doped composite material, and the mass fraction of Pd in ​​the Pd / C is 5%; The vacuum drying temperature in step 1② is 30°C, the vacuum drying time is 48 to 64 hours, and the vacuum drying pressure is -30 to -29KPa; ③. The specific preparation method of M3 is the same as step 1①, with the following differences: In step 1③, the raw material 4-(4-methylpiperazine)aniline monomer in step 1① is replaced by M2; The ratio of the volume of dimethyl sulfoxide to the amount of substance of M2 in step 1③ is (50-100) mL:10 mmol; The ratio of the amount of cesium fluoride to M2 in step 1③ is 4.8:1; The molar ratio of p-fluoronitrobenzene to M2 in step 1③ is 4.8:1; ④, N1,N1-bis(4-aminophenyl)-N4-(4-(bis(4-aminophenylamino)phenyl)4-(4-(4-methyloxazin-1-yl)phenyl)phenyl-1,4-diamine, also named M4, its specific preparation method is the same as step 1②, there are several differences as follows: In step 1④, replace M1 in step 1② with M3; The ratio of the volume of anhydrous ethanol in step 1④ to the amount of substance of M3 is (150-200) mL: 5 mmol; The ratio of the mass of Pd / C to the amount of substance of M3 in step 1④ is (2-2.4) g: 5 mmol; 2. Preparation of hyperbranched polyamide containing methylpiperazine and polytriphenylamine structure: N1,N1-bis(4-aminophenyl)-N4-(4-(bis(4-aminophenylamino)phenyl)4-(4-(4-methylpiperazine-1-yl)phenyl)phenyl-1,4-diamine (M4), diacid monomer, triphenyl phosphite, CaCl2, pyridine and N-methylpyrrolidone are mixed, and then stirred at 130° C. for 4 hours, and then poured into methanol after cooling to room temperature, and the precipitate is collected by filtration, and then fully washed with methanol, and finally Soxhlet extraction is performed with methanol to obtain a hyperbranched polyamide containing methylpiperazine and polytriphenylamine structures; In step 2, the ratio of the amount of M4 to the diacid monomer is 1:2; The ratio of the volume of triphenyl phosphite in step 2 to the amount of substance of M4 is 1.5 mL: 1 mmol; The ratio of the volume of pyridine in step 2 to the amount of substance of M4 is 1.5 mL: 1 mmol; The ratio of the volume of N-methylpyrrolidone in step 2 to the amount of substance of M4 is 3 mL: 1 mmol; The ratio of the mass of CaCl2 to the volume of N-methylpyrrolidone in step 2 is 0.3 g:6 mL; The ratio of the volume of methanol in step 2 to the amount of substance of M4 is 350 mL:1 mmol. Examples 2 to 4: The structural formulas of the hyperbranched polyamides P2-P4 containing methylpiperazine and polytriphenylamine structures are similar to that of P1. The specific preparation method of P2 is the same as that of Example 1 P1, except that in Example 2, 4,4'-diphenylsulfone dicarboxylic acid is used as the raw material to replace 1,4-cyclohexanedicarboxylic acid, wherein the degree of branching is 0.87. The specific preparation method of P3 is the same as that of Example 1 P1, except that in Example 3, 4,4'-dicarboxy diphenyl ether is used as a raw material to replace 1,4-cyclohexanedicarboxylic acid, wherein the degree of branching is 0.50. The specific preparation method of P4 is the same as that of Example 1 P1, except that in Example 4, 2,2-bis(4-carboxyphenyl)hexafluoropropane is used as the raw material to replace 1,4-cyclohexanedicarboxylic acid, wherein the degree of branching is 0.81. Figure 1 This is a hydrogen nuclear magnetic spectrum of N1,N1-bis(4-aminophenyl)-N4-(4-(bis(4-aminophenylamino)phenyl)4-(4-(4-methyloxazin-1-yl)benzene)phenyl-1,4-diamine monomer (M4) prepared in Example 1; it illustrates that N1,N1-bis(4-aminophenyl)-N4-(4-(bis(4-aminophenylamino)phenyl)4-(4-(4-methyloxazin-1-yl)benzene)phenyl-1,4-diamine monomer (M4) was synthesized in Example 1; Figure 2 Fourier transform infrared images of four hyperbranched polyamides containing methylpiperazine and polytriphenylamine structures prepared in Examples 1 to 4; Figure 2 It can be seen that Figure 2 Medium 3299~3240cm -1 It is the characteristic absorption peak of -NH- in amide bond, 1663cm -1 The characteristic absorption peak of the carbonyl group in the amide bond is 1256 cm -1 is the characteristic absorption peak of NC in the amide bond; it indicates that the hyperbranched polyamide containing methylpiperazine and polytriphenylamine structure is synthesized in Example 2; Figure 3 The cyclic voltammograms of the hyperbranched polyamide containing methylpiperazine and polytriphenylamine structure prepared in Examples 1 to 4; Figure 3It can be seen that polymer P1 has three oxidation peaks at 0.56V, 0.79V, and 1.22V, and three reduction peaks at 0.98V, 0.54V, and 0.28V; polymer P2 has three oxidation peaks at 0.56V, 0.84V, and 1.25V, and three reduction peaks at 0.99V, 0.62V, and 0.37V; polymer P3 has three oxidation peaks at 0.55V, 0.79V, and 1.22V, and three reduction peaks at 0.96V, 0.61V, and 0.38V; Polymer P4 has three oxidation peaks at 0.42V, 0.94V, and 1.16V, and three reduction peaks at 0.99V, 0.61V, and 0.37V; this indicates that the hyperbranched polyamide containing methylpiperazine and polytriphenylamine structures prepared in Examples 1 to 4 undergoes an oxidation-reduction reaction under the condition of applied voltage, and the hyperbranched polyamide containing methylpiperazine and polytriphenylamine structures will produce color changes during the oxidation-reduction process; this indicates that the hyperbranched polyamide containing methylpiperazine and polytriphenylamine structures prepared in Examples 1 to 4 has electrochromic properties; Figure 4 Thermogravimetric analysis spectra of the hyperbranched polyamide containing methylpiperazine and polytriphenylamine structures prepared in Examples 1 to 4; Figure 4 It can be seen that the thermal decomposition temperature range of the hyperbranched polyamide containing methylpiperazine and polytriphenylamine structures is 422-458°C when the weight loss is 10% in a nitrogen atmosphere, indicating that these polymers have good thermodynamic stability. When the temperature is heated to 800°C, the residual carbon rate of the polymer is greater than 47%. This is because the polymer has a high content of aromatic structure, which can further indicate that the polymer has good thermal stability and can work in a high temperature environment; Figure 5 The electrochromic diagram of the hyperbranched polyamide containing methylpiperazine and polytriphenylamine structure prepared in Examples 1 to 4; its electrochromic properties are determined by testing the change of absorbance in its UV-Vis-NIR absorption spectrum with applied voltage. Taking the electrochromic properties of P1 as an example, as the voltage gradually increases, the absorption peak at 336nm gradually decreases, and the absorption peaks at 445nm and 1166nm gradually increase, and the P1 film changes from colorless to yellow-green; when the voltage increases to 0.9V, the absorption peak at 445nm gradually decreases, the absorption peak at 1166nm rises to the maximum, a new absorption peak appears at 643nm, and the P1 film turns light blue; when the potential is increased to 1.3V to achieve complete oxidation, the absorption peak at 1166nm gradually decreases, and at the same time a new absorption peak appears at 867nm, and the film turns dark blue; Figure 6 The dynamic curve of the transmittance of the hyperbranched polyamide P1 film containing methylpiperazine and polytriphenylamine structure prepared in Example 1 at 0.0V to 0.9V and 1166nm wavelength changes with time; Figure 6It can be seen that the optical contrast of P1 is 77%. After 1800 cycles, its optical contrast has basically not changed, indicating that polymer P1 has excellent optical contrast. Figure 7 This is a schematic diagram of an electrochromic device prepared from a hyperbranched polyamide P1 film containing methylpiperazine and polytriphenylamine structures prepared in Example 1. The P1 film is used as the electrochromic layer, the conductive layer is a conductive glass or ITO tube electrode, and the electrolyte is a solution or gel containing lithium ions or tert-butylammonium ions.

Claims

1. The monomer structure of N1,N1-bis(4-aminophenyl)-N4-(4-(bis(4-aminophenylamino)phenyl)4-(4-(4-methyloxazin-1-yl)benzene)phenyl-1,4-diamine is as follows:

2. The hyperbranched polyamide structures obtained by polycondensation of diamine monomers containing methylpiperazine and polytriphenylamine structures and commercially available diacid monomers (including but not limited to 1,4-cyclohexanedicarboxylic acid, 4,4-diphenylsulfonyldicarboxylic acid, 4,4'-dicarboxyoxydiphenyl ether and 2,2-bis(4-carboxyphenyl)hexafluoropropane, 4,4'-biphenyldicarboxylic acid, 1,4-naphthalene dicarboxylic acid, 2,7-naphthalene dicarboxylic acid, terephthalic acid, isophthalic acid, 3,4-thiophene dicarboxylic acid, 3,4-furan dicarboxylic acid, succinic acid, etc.) are as follows: Wherein the degree of branching is 0.50 to 0.

81.

3. The preparation method of the hyperbranched polyamide containing methylpiperazine and polytriphenylamine structure of the present invention is as follows:

1. Synthesis of N1,N1-bis(4-aminophenyl)-N4-(4-(bis(4-aminophenylamino)phenyl)4-(4-(4-methyloxazin-1-yl)benzene)phenyl-1,4-diamine monomer: ①. Under N2 atmosphere, 4-(4-methylpiperazine)aniline monomer, cesium fluoride, p-fluoronitrobenzene and dimethyl sulfoxide were placed in a three-necked flask, the system was heated to 120°C for reflux reaction, and the heat source was turned off after the reaction was judged to be completed by thin layer chromatography; the cooled mixed solution was poured into a mixed solution of deionized water and ethanol until the crude product was precipitated, filtered, and the crude product was recrystallized with methanol, filtered again, and the obtained product was vacuum dried to obtain a red powder M1; The ratio of the volume of dimethyl sulfoxide to the amount of 4-(4-methylpiperazine)aniline monomer in step 1① is (50-100) mL:10 mmol; The molar ratio of cesium fluoride to 4-(4-methylpiperazine)aniline monomer in step 1① is 2.2:1; The molar ratio of p-fluoronitrobenzene to 4-(4-methylpiperazine)aniline monomer in step 1① is 2.2:1; The vacuum drying temperature in step 1① is 45°C, the vacuum drying time is 48 hours, and the vacuum drying pressure is -30 to -29KPa; ②, under room temperature, add anhydrous ethanol, Pd / C and M1 into a three-necked flask and stir; under N2 condition, use a constant pressure funnel to drop hydrazine hydrate into the three-necked flask at a drop rate of 1 to 2 drops per second; heat the system to 80°C until the solution refluxes, filter and remove Pd / C while hot after the reaction is completed, pour the filtrate into brine under stirring, extract with dichloromethane solvent, and repeat 3 times; the obtained organic phase solution is dried over anhydrous magnesium sulfate to remove water, and a transparent solution is obtained after filtration; the filtrate is rotary evaporated and vacuum dried to obtain an off-white monomer M2; The ratio of the volume of anhydrous ethanol in step 1② to the amount of substance of M1 is (150-200) mL: 10 mmol; The ratio of the mass of Pd / C to the amount of M1 in step 1② is (1-1.2) g: 5 mmol; The ratio of the volume of hydrazine hydrate in step 1② to the amount of substance of M1 is 2.5mL:1mmol; The Pd / C in step 1② is a Pd C-doped composite material, and the mass fraction of Pd in ​​the Pd / C is 5%; The vacuum drying temperature in step 1② is 30°C, the vacuum drying time is 48 to 64 hours, and the vacuum drying pressure is -30 to -29KPa; ③. The specific preparation method of M3 is the same as step 1①, with the following differences: In step 1③, the raw material 4-(4-methylpiperazine)aniline monomer in step 1① is replaced by M2; The ratio of the volume of dimethyl sulfoxide to the amount of substance of M2 in step 1③ is (50-100) mL:10 mmol; The ratio of the amount of cesium fluoride to M2 in step 1③ is 4.8:1; The molar ratio of p-fluoronitrobenzene to M2 in step 1③ is 4.8:1; ④, N1,N1-bis(4-aminophenyl)-N4-(4-(bis(4-aminophenylamino)phenyl)4-(4-(4-methyloxazin-1-yl)phenyl)phenyl-1,4-diamine, also named M4, its specific preparation method is the same as step 1②, there are several differences as follows: In step 1④, replace M1 in step 1② with M3; The ratio of the volume of anhydrous ethanol in step 1④ to the amount of substance of M3 is (150-200) mL: 5 mmol; The ratio of the mass of Pd / C to the amount of substance of M3 in step 1④ is (2-2.4) g: 5 mmol; 2. Preparation of hyperbranched polyamide containing methylpiperazine and polytriphenylamine structure: N1,N1-bis(4-aminophenyl)-N4-(4-(bis(4-aminophenylamino)phenyl)4-(4-(4-methylpiperazine-1-yl)phenyl)phenyl-1,4-diamine (M4), diacid monomer, triphenyl phosphite, CaCl2, pyridine and N-methylpyrrolidone are mixed, and then stirred at 130° C. for 4 hours, and then poured into methanol after cooling to room temperature, and the precipitate is collected by filtration, and then fully washed with methanol, and finally Soxhlet extraction is performed with methanol to obtain a hyperbranched polyamide containing methylpiperazine and polytriphenylamine structures; In step 2, the ratio of the amount of M4 to the diacid monomer is 1:2; The ratio of the volume of triphenyl phosphite in step 2 to the amount of substance of M4 is 1.5 mL: 1 mmol; The ratio of the volume of pyridine in step 2 to the amount of substance of M4 is 1.5 mL: 1 mmol; The ratio of the volume of N-methylpyrrolidone in step 2 to the amount of substance of M4 is 3 mL: 1 mmol; The ratio of the mass of CaCl2 to the volume of N-methylpyrrolidone in step 2 is 0.3 g:6 mL; The ratio of the volume of methanol in step 2 to the amount of substance of M4 is 350 mL:1 mmol.

4. The method for preparing the hyperbranched polyamide containing methylpiperazine and polytriphenylamine structure according to claim 3, characterized in that: The diacid monomers obtained in step 2 are 1,4-cyclohexanedicarboxylic acid, 4,4'-dicarboxybiphenyl sulfone, 4,4'-dicarboxyoxydiphenyl ether and 2,2-bis(4-carboxyphenyl)hexafluoropropane, but are not limited to these four diacid monomers. The prepared polymers are P1, P2, P3 and P4, etc.

5. The method for preparing the hyperbranched polyamide containing methylpiperazine and polytriphenylamine structure according to claim 3, characterized in that: In step 2, 300 mL of methanol is used for Soxhlet extraction, and the extraction time is 72 hours.

6. Use of the hyperbranched polyamide containing methylpiperazine and polytriphenylamine structure as claimed in claim 2 as an electrochromic layer in an electrochromic device.

7. The use according to claim 6, characterized in that: The application of hyperbranched polyamide containing methylpiperazine and polytriphenylamine structure as electrochromic layer in electrochromic device in smart window and display is carried out according to the following steps: A hyperbranched polyamide containing methylpiperazine and polytriphenylamine structures is coated on a conductive substrate as an electrochromic layer, and an electrolyte solution is added between two electrodes to prepare an electrochromic device. The electrochromic device changes color under the action of an external electric field.

8. The use according to claim 6, characterized in that: The conductive substrate is ITO conductive glass or ITO conductive resin film or transparent silver nanowire or transparent carbon nanotube electrode.

9. The use according to claim 6, characterized in that: The added electrolyte is a solution or gel containing lithium ions or tert-butylammonium ions.

10. The use according to claim 6, characterized in that: The voltage of the externally applied electric field is 0-2.5V. The invention aims to prepare a polyamide material with excellent comprehensive electrochromic ability, improve the problems of poor solubility, poor thermal stability, single electrochromic, low optical contrast and electrochromic instability of polyamide, and synthesize a hyperbranched structure by introducing multiple triphenylamine units and methylpiperazine alkyl chains with a helical structure, and increase the solubility of polyamide by utilizing the larger steric hindrance and hyperbranched structure of triphenylamine; the introduction of multiple triphenylamine structures improves the thermal stability of hyperbranched polyamide; on the other hand, the methylpiperazine units and multiple triphenylamine units provide multiple N electroactive centers, so that the polymer shows multiple color changes during the electrochromic process, and can also achieve high optical contrast before and after the color change. In addition, the electron-donating ability of methylpiperazine and the conjugation effect of polytriphenylamine make electron delocalization easier and the oxidation potential lower, thereby improving the electrochromic cycle stability. Combining the above advantages, a triphenylamine hyperbranched polyamide containing a methylpiperazine structure is prepared, which has good solubility and thermal stability, and shows excellent performance of high transmittance and long cycle stability in electrochromism, and provides a hyperbranched polyamide containing methylpiperazine and polytriphenylamine structures, a preparation method thereof, and an electrochromic application.

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