Preparation method of phosphimide polycondensation monomer, phosphimide precursor polymer and polyaryletherketone

Abstract

The present invention provides a phosphinimide polycondensation monomer and a preparation method thereof. The present application also provides a phosphinimide precursor polymer and a preparation method thereof. The present application also provides a method for preparing polyaryletherketone based on the phosphinimide precursor polymer. The solubility of the phosphinimide precursor polymer provided by the present application is improved because the large steric hindered side groups on the main chain hinder the stacking of molecular chains, thus facilitating the solution processing of polyaryletherketone polymers; at the same time, the high polarity of the phosphinimide side groups allows the side groups of the precursor polymer to fall off quickly under acidic conditions, thereby preparing polyaryletherketone polymers with excellent performance.

Description

Technical Field

[0001] The present invention relates to the technical field of polyaryletherketone, and in particular to a phosphimide polycondensation monomer, a preparation method thereof, a phosphimide precursor polymer, a preparation method thereof and a preparation method of polyaryletherketone. Background Art

[0002] Polyaryletherketones (PAEKs) are a class of high-performance polymers that generally have high heat resistance, good processability, excellent mechanical properties, electrical insulation, chemical resistance and dimensional stability. The material synthesis is simple and cost-effective. It has attracted extensive attention in the fields of aviation and aerospace, automobiles, electronics, precision machinery, etc. Representative products of polyaryletherketones (PAEKs) include polyetherketone (PEK), polyetheretherketone (PEEK) and polyetherketoneketone (PEKK). Due to their excellent performance, polyaryletherketone polymers are widely used in industrial fields such as electronics, electrical, machinery, medical, automobiles and aerospace, and are recognized as high-performance engineering plastics. In the structures of PEEK and PEK, there are only structural units of benzophenone and phenyl ether in the molecular chain. The molecular chain is rigid and has extremely strong π-π stacking. Therefore, this type of polyaryletherketone has very excellent solvent resistance, corrosion resistance, oxidation resistance and other anti-adversity properties, but it also means that it can only be processed by melt processing and is difficult to be processed into a film by solvent method.

[0003] Zhang Suobo et al. (CN 110052178 A) used a PEEK polymer precursor containing a phenylimine Schiff base side group to process PEEK in solution, that is, to configure it into a casting solution, and after the asymmetric membrane was prepared by phase inversion, the asymmetric membrane was placed in an acid solution for acidification, and the imine in the main chain structure of the membrane was hydrolyzed and converted into a ketone, and the main chain structure was converted into PEEK with excellent performance. As in the case in this patent, PEEK itself cannot be processed using solvents, let alone configured into a casting solution, but the introduced phenylimine side groups hinder the stacking between molecular chains and greatly increase the solubility of the polymer. After being processed into an asymmetric membrane, the side groups can be removed by chemical reaction to convert the molecular chains into PEEK with excellent performance, giving the prepared asymmetric membrane excellent solvent resistance. However, although the phenylimine-type structure synthesized from aniline and dihalobenzophenone can participate in condensation polymerization, the prepared polymer precursor has a slow hydrolysis rate under acidic conditions. Moreover, although the solubility of this type of polymer has been improved, a single structure still lacks universality and flexibility for different processing methods and application scenarios. Summary of the invention

[0004] The technical problem solved by the present invention is to provide a phosphimide-type precursor polymer, wherein the phosphimide side group of the precursor polymer can be rapidly hydrolyzed under acid conditions to obtain a polyaryletherketone with excellent performance.

[0005] In view of this, the present application provides a phosphimide polycondensation monomer as shown in formula (I),

[0006]

[0007] wherein X is selected from halogen;

[0008] R 1 and R 2 Independently selected from cyano, substituted or unsubstituted C1-C10 alkyl, substituted or unsubstituted C1-C5 alkenyl, substituted or unsubstituted C6-C20 aryl.

[0009] Preferably, the R 1 and R 2 Independently selected from the following but not limited to one of the following groups:

[0010]

[0011] The present application also provides a method for preparing the phosphinimide polycondensation monomer as shown in formula (I), comprising the following steps:

[0012] A) mixing 4,4'-dihalobenzophenone as shown in formula (II), hydroxylamine hydrochloride and sodium acetate in an organic solvent, heating and refluxing to obtain 4,4'-dihalobenzophenone oxime as shown in formula (III);

[0013] B) reacting the 4,4'-dihalobenzophenone oxime with a phosphine halide compound as shown in formula (IV) in a weakly alkaline environment to obtain a phosphinimide polycondensation monomer as shown in formula (I);

[0014]

[0015] wherein X is selected from halogen;

[0016] R 1 and R 2 Independently selected from cyano, substituted or unsubstituted C1-C10 alkyl, substituted or unsubstituted C1-C5 alkenyl, substituted or unsubstituted C6-C20 aryl.

[0017] Preferably, in step A), the molar ratio of the 4,4'-dihalobenzophenone to hydroxylamine hydrochloride is 1:1.1-1:1.6, and the molar ratio of the 4,4'-dihalobenzophenone to the sodium acetate is 1:1.6-1:2.0; the heating reflux time is 12-36 hours; and the organic solvent is a mixed solvent of ethanol and water in a volume ratio of (6-1):1.

[0018] Preferably, in step B), the molar ratio of the 4,4'-dihalobenzophenone oxime to the weak base is 1:(1.1-1.5), the reaction temperature is -80-0°C, and the weak base is selected from one or more of triethylamine, trimethylamine and N,N-diisopropylethylamine.

[0019] The present application also provides a phosphimide-type precursor polymer of formula (V),

[0020]

[0021] Among them, R 1 and R 2 Independently selected from cyano, substituted or unsubstituted C1-C10 alkyl, substituted or unsubstituted C1-C5 alkenyl, substituted or unsubstituted C6-C20 aryl;

[0022] R 3 is selected from substituted or unsubstituted C5-C30 aryl or heteroaryl;

[0023] n is the degree of polymerization.

[0024] Preferably, the R 3 Selected from one of the following groups:

[0025]

[0026]

[0027] The present application also provides a method for preparing the phosphinimide-type precursor polymer as shown in formula (V), comprising the following steps:

[0028] The alcohol solution of the diphenol monomer represented by formula (VI) is mixed with sodium hydroxide to react to obtain sodium phenolate;

[0029] reacting a phenol sodium salt with a phosphimide polycondensation monomer as shown in formula (I) to obtain a phosphimide-type precursor polymer as shown in formula (V);

[0030] HO-R 3 -OH(VI);

[0031]

[0032] wherein X is selected from halogen;

[0033] R 1 and R 2 Independently selected from cyano, substituted or unsubstituted C1-C10 alkyl, substituted or unsubstituted C1-C5 alkenyl, substituted or unsubstituted C6-C20 aryl;

[0034] R 3 is selected from substituted or unsubstituted C5-C30 aryl or heteroaryl;

[0035] n is the degree of polymerization.

[0036] Preferably, the preparation method of the phosphimide type precursor polymer is specifically as follows:

[0037] A) mixing an alcohol solution of a diphenol monomer with a strongly polar aprotic solvent, adding solid sodium hydroxide under nitrogen protection, reacting to obtain a sodium phenolate;

[0038] B) heating the reaction system obtained in step A) to 80-100° C. to remove alcohol, then adding toluene, heating to 140-160° C., and removing water by azeotropic method; then adding phosphimide condensation monomer, heating to 150-200° C., and obtaining phosphimide type precursor polymer after reaction.

[0039] The present application also provides a method for preparing a polyaryletherketone as shown in formula (VII), comprising:

[0040] The phosphinimide precursor polymer as shown in formula (V) is mixed with an acidic solution and hydrolyzed to obtain a polyaryletherketone as shown in formula (VII);

[0041]

[0042] Among them, R 1 and R 2 Independently selected from cyano, substituted or unsubstituted C1-C10 alkyl, substituted or unsubstituted C1-C5 alkenyl, substituted or unsubstituted C6-C20 aryl;

[0043] R 3 is selected from substituted or unsubstituted C5-C30 aryl or heteroaryl;

[0044] n is the degree of polymerization.

[0045] The present application provides a phosphinimide-type precursor polymer as shown in formula (V), the solubility of which is improved because the large steric hindrance side groups on the main chain hinder the stacking of molecular chains, thereby facilitating the solution processing of polyaryletherketone polymers; at the same time, due to the high polarity of the phosphinamide structure, the side groups of the precursor polymer can be quickly hydrolyzed and detached under acidic conditions, thereby preparing polyaryletherketone polymers (PAEKs) with excellent performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 The NMR spectrum of the monomer represented by formula (9) prepared in Example 1 of the present invention;

[0047] Figure 2This is the NMR spectrum of the polymer represented by formula (11) prepared in Example 2 of the present invention;

[0048] Figure 3 This is the NMR spectrum of the polymer represented by formula (13) prepared in Example 3 of the present invention;

[0049] Figure 4 This is the NMR spectrum of the polymer represented by formula (15) prepared in Example 4 of the present invention;

[0050] Figure 5 This is a graph showing the variation of the phosphonamide shedding rate in the polyaryletherketone prepared in Example 5 of the present invention over time;

[0051] Figure 6 This is a curve diagram showing the change of aniline shedding rate over time in the polyetheretherketone prepared in Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0052] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the present invention.

[0053] In view of the problem that the hydrolysis rate of the precursor for preparing polyaryletherketone polymers in the prior art is slow, which affects its processing and application, the present application provides a new type of phosphimide precursor polymer from the perspective of the structural design of the precursor polymer, which realizes the solubilization of polyaryletherketone polymers and the rapid hydrolysis and release of the solubilizing side groups, and realizes more flexible processing and application of PAEK polymers. Specifically, the embodiment of the present invention first discloses a phosphimide condensation monomer as shown in formula (I),

[0054]

[0055] wherein X is selected from halogen;

[0056] R 1 and R 2 Independently selected from cyano, substituted or unsubstituted C1-C10 alkyl, substituted or unsubstituted C1-C5 alkenyl, substituted or unsubstituted C6-C20 aryl.

[0057] In the present application, in the phosphinimide polycondensation monomer, X is preferably F or Cl; R 1 and R 2 independently selected from substituted or unsubstituted C1-C6 alkyl groups, wherein the substituted groups may be vinyl groups, substituted or unsubstituted C6-C12 aryl groups, wherein the substituted groups may be methyl groups, more specifically, the R 1 and R 2Independently selected from the following but not limited to one of the following groups:

[0058]

[0059]

[0060] The above-mentioned phosphimide condensation monomer in the present application is a phosphimide monomer that can participate in condensation polymerization.

[0061] The present application also provides a method for preparing a phosphimide polycondensation monomer as shown in formula (I), comprising the following steps:

[0062] A) mixing 4,4'-dihalobenzophenone as shown in formula (II), hydroxylamine hydrochloride and sodium acetate in an organic solvent, heating and refluxing to obtain 4,4'-dihalobenzophenone oxime as shown in formula (III);

[0063] B) reacting the 4,4'-dihalobenzophenone oxime with a phosphine halide compound as shown in formula (IV) in a weakly alkaline environment to obtain a phosphinimide polycondensation monomer as shown in formula (I);

[0064]

[0065] wherein X is selected from halogen;

[0066] R 1 and R 2 Independently selected from cyano, substituted or unsubstituted C1-C10 alkyl, substituted or unsubstituted C1-C5 alkenyl, substituted or unsubstituted C6-C20 aryl.

[0067] In the above preparation process, in step A), the molar ratio of the 4,4'-dihalobenzophenone to hydroxylamine hydrochloride is 1:1.1 to 1:1.6, and the molar ratio of the 4,4'-dihalobenzophenone to the sodium acetate is 1:1.6 to 1:2; the heating reflux time is 12 to 36 hours; and the organic solvent is a mixed solvent of ethanol and water in a volume ratio of (6 to 1):1. The specific reaction formula of the above steps is as follows:

[0068]

[0069] In step B), the molar ratio of the 4,4'-dihalobenzophenone oxime to the weak base is 1: (1.1-1.5), the reaction temperature is -80-0°C, and the weak base is selected from one or more of common organic weak bases such as triethylamine, trimethylamine, N,N-diisopropylethylamine, etc.; more specifically, the molar ratio of the 4,4'-dihalobenzophenone oxime to the weak base is 1: (1.1-1.2), and the reaction temperature is -35-0°C. The solvent for the above reaction is selected from one or more of dichloromethane, ethyl acetate and acetonitrile. Specifically, the solvent for the reaction is selected from dichloromethane. The reaction formula of the above reaction is specifically shown as follows:

[0070]

[0071] Furthermore, the present application also provides a phosphimide-type precursor polymer prepared from the above-mentioned phosphimide condensation monomer to obtain a polymer as shown in formula (V),

[0072]

[0073] Among them, R 1 and R 2 Independently selected from cyano, substituted or unsubstituted C1-C10 alkyl, substituted or unsubstituted C1-C5 alkenyl, substituted or unsubstituted C6-C20 aryl;

[0074] R 3 It is selected from substituted or unsubstituted C5-C30 aryl or heteroaryl groups.

[0075] More specifically, the R 3 Selected from but not limited to one of the following groups:

[0076]

[0077]

[0078] The present application also provides a method for preparing a phosphinimide-type precursor polymer as shown in formula (V), comprising the following steps:

[0079] The alcohol solution of the diphenol monomer represented by formula (VI) is mixed with sodium hydroxide to react to obtain sodium phenolate;

[0080] reacting a phenol sodium salt with a phosphimide polycondensation monomer as shown in formula (I) to obtain a phosphimide-type precursor polymer as shown in formula (V);

[0081] GO-R 3 -OH(VI);

[0082]

[0083] wherein X is selected from halogen;

[0084] R 1 and R 2 Independently selected from cyano, substituted or unsubstituted C1-C10 alkyl, substituted or unsubstituted C1-C5 alkenyl, substituted or unsubstituted C6-C20 aryl;

[0085] R 3 is selected from substituted or unsubstituted C5-C30 aryl or heteroaryl;

[0086] n is the degree of polymerization, preferably 10 to 5,000.

[0087] According to the present invention, the preparation method of the phosphimide type precursor polymer is more specifically:

[0088] A) mixing an alcohol solution of a diphenol monomer with a strongly polar aprotic solvent, adding solid sodium hydroxide under nitrogen protection, reacting to obtain a sodium phenolate;

[0089] B) heating the reaction system obtained in step A) to 80-100° C. to remove alcohol, then adding toluene, heating to 140-160° C., and removing water by azeotropic method; then adding phosphimide condensation monomer, heating to 150-200° C., and obtaining phosphimide type precursor polymer after reaction.

[0090] In the above preparation method, in step A), the highly polar aprotic solvent is selected from one or more of N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, N-methylpyrrolidone, diphenyl sulfone and cyclopentane sulfone; the alcohol solution is selected from one or more of methanol, ethanol and isopropanol. The molar ratio of the diphenol monomer to the phosphimide polycondensation monomer is 1:1. The reaction formula for preparing the phosphimide precursor polymer is specifically:

[0091]

[0092] After the phosphinimide-type precursor polymer is obtained, it is hydrolyzed under acidic conditions to remove the phosphinamide side groups to obtain a polyaryletherketone as shown in formula (VII), specifically:

[0093] The phosphinimide precursor polymer as shown in formula (V) is mixed with an acidic solution and hydrolyzed to obtain a polyaryletherketone as shown in formula (VII);

[0094]

[0095] Among them, R 1 and R 2Independently selected from cyano, substituted or unsubstituted C1-C10 alkyl, substituted or unsubstituted C1-C5 alkenyl, substituted or unsubstituted C6-C20 aryl;

[0096] R 3 is selected from substituted or unsubstituted C5-C30 aryl or heteroaryl;

[0097] n is the degree of polymerization, preferably 10 to 5,000.

[0098] In the process of preparing polyaryletherketone, the phosphinimide precursor polymer can be in the form of filaments, powders, blocks or films, and this application has no particular restrictions. Phosphamide has poor solubility in water. In order to facilitate the hydrolysis of the detached phosphamide and dissolve it in the acid solution, an organic solvent can be added to the acid solution. The mass ratio of the organic solvent to water in the acid solution is 10:1 to 1:10. Specifically, the mass ratio of the organic solvent to water is 3:1 to 1:5. The organic solvent can be selected from common organic solvents that are miscible with water, and can be selected from one or more of methanol, ethanol, isopropanol, acetone, butanone, acetonitrile, tetrahydrofuran, dioxane, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide and N-methylpyrrolidone; the acid in the acid solution can be selected from hydrochloric acid, sulfuric acid, acetic acid or phosphoric acid. The preparation process of the polyaryletherketone is specifically as follows:

[0099]

[0100] Based on the phosphinilide condensation monomer, the present application provides a phosphinilide precursor polymer, from which polyaryletherketone polymers are finally prepared; compared with aniline Schiff base, phosphinamide Schiff base has a large polarity of phosphinamide, so the imine group is easily attacked and hydrolyzed, and the obtained precursor polymer can be rapidly hydrolyzed in a weak acid and at a relatively low temperature, eliminating the long acid boiling process, thereby making it possible to prepare polyaryletherketone polymers more flexibly.

[0101] In order to further understand the present invention, the phosphinimide condensation monomer, its preparation method, phosphinimide precursor polymer, its preparation method and polyaryletherketone preparation method provided by the present invention are described in detail below in conjunction with the embodiments. The protection scope of the present invention is not limited to the following embodiments.

[0102] Example 1 Synthesis of the monomer structure represented by formula (9)

[0103] 33g (0.1415mol) of the structure shown in (8) is added to a 500ml three-necked flask with a nitrogen inlet, mechanical stirring and a constant pressure dropping funnel, 250ml of dichloromethane is added to the flask as a solvent, the mechanical stirring is turned on, the nitrogen is connected, and the flask is placed in an ice ethanol bath at -35°C; after the system temperature is stabilized, 21.63ml (0.1557mol) of triethylamine is added to the system, and 30.71ml (0.1698mol) of diphenylphosphine chloride is added to the constant pressure dropping funnel; diphenylphosphine chloride is slowly dripped into the reaction system, and after all the dripping is completed, the reaction is allowed to react for 1h and then the reaction is restored to room temperature; water is added to quench the unreacted diphenylphosphine chloride, and the organic system is washed with water, and the organic system is recrystallized to obtain the final product N-(4,4'-difluorodiphenylmethylene)-P,P-diphenylphosphine amide, a monomer of the structure shown in formula (9), and the nuclear magnetic resonance spectrum of the structure shown in formula (9) is as follows Figure 1 The above reaction is specifically shown as follows:

[0104]

[0105] Example 2 The monomer structure represented by formula (9) and the monomer structure represented by formula (10) are condensed to form a polymer structure represented by formula (11)

[0106] 6.6066 g (0.06 mol) of the compound represented by the structure of formula (10) was added into a 500 ml three-necked flask equipped with a nitrogen inlet, a mechanical stirrer, a water separator and a columnar condenser, and 70 ml of dimethyl sulfoxide and an appropriate amount of methanol (50 ml) were added to dissolve and disperse; a reaction device was built, and nitrogen was connected to blow out the air in the system, and then 5.0 g of NaOH (purity 96%, 0.12 mol) solid was added under nitrogen flow, and mechanical stirring was turned on to fully react to prepare a diphenol sodium salt solution; an oil bath was turned on and heated to the system temperature The temperature is 110°C, and the methanol in the system is blown into the water separator with nitrogen. The methanol in the water separator is drained, 30 ml of toluene is added to the system to fill the water separator with toluene, and the temperature is raised to 150°C. Toluene is used to azeotropically remove water and residual methanol in the system. After ensuring that the water is fully removed, the toluene in the system is drained and blown out, and 25.046 g (0.06 mol) of the monomer shown in formula (9) is added; the temperature is raised to 160°C, and after polymerization for 6 hours, a polymer with the structure shown in formula (11) is obtained. The nuclear magnetic resonance spectrum of the polymer with the structure shown in formula (11) is shown as follows: Figure 2 The specific process of the above preparation is as follows:

[0107]

[0108] Example 3 The monomer structure represented by formula (9) and the monomer structure represented by formula (12) are condensed to form a polymer structure represented by formula (13)

[0109] 12.8530 g (0.06 mol) of the compound represented by the structure of formula (12) was added into a 500 ml three-necked flask equipped with a nitrogen inlet, a mechanical stirrer, a water separator and a columnar condenser, 70 ml of dimethyl sulfoxide and an appropriate amount of methanol (50 ml) were added to dissolve and disperse, a reaction device was built, and nitrogen was connected. After blowing out the air in the system, 5.0 g of NaOH (purity 96%, 0.12 mol) solid was added under nitrogen flow, mechanical stirring was turned on, and diphenol sodium salt solution was fully reacted; an oil bath was turned on and heated to the system temperature. The temperature is 110°C, and the methanol in the system is blown into the water separator with nitrogen. The methanol in the water separator is drained, 30 ml of toluene is added to the system to fill the water separator with toluene, and the temperature is raised to 150°C. The water and residual methanol in the system are removed by toluene azeotropy. After ensuring that the water is fully removed, the toluene in the system is drained and blown out, and 25.046 g (0.06 mol) of the monomer of the structure shown in formula (9) is added; the temperature is raised to 160°C, and after polymerization for 6 hours, a polymer of the structure shown in formula (13) is obtained. The NMR spectrum of the polymer of the structure shown in formula (13) is as follows: Figure 3 As shown, the specific process is as follows:

[0110]

[0111] Example 4 The monomer structure represented by formula (9) and the monomer structure represented by formula (14) are condensed to form a polymer structure represented by formula (15)

[0112] 13.6974 g (0.06 mol) of the compound represented by the structure of formula (14) was added into a 500 ml three-necked flask equipped with a nitrogen inlet, a mechanical stirrer, a water separator and a cylindrical condenser, 70 ml of dimethyl sulfoxide and an appropriate amount of methanol (50 ml) were added to dissolve and disperse, a reaction device was built, and nitrogen was connected to blow away the air in the system, and then 5.0 g of NaOH (purity 96%, 0.12 mol) solid was added under nitrogen flow, mechanical stirring was turned on, and the reaction was fully reacted to prepare a diphenol sodium salt solution;

[0113] Open the oil bath and heat to the system temperature of 110°C. Combine nitrogen to blow the methanol in the system into the water separator and drain the methanol in the water separator. Add 30 ml of toluene to the system to fill the water separator with toluene, raise the temperature to 150°C, use toluene to azeotropically remove the water and residual methanol in the system, ensure that the water is fully removed, drain the toluene in the system and blow it out, add 25.046 g (0.06 mol) of the structural monomer shown in formula (9), raise the temperature to 160°C, and after polymerization for 6 hours, obtain the structural polymer shown in formula (15). The NMR spectrum of the polymer shown in formula (15) is as follows: Figure 4 As shown, the specific process is as follows:

[0114]

[0115] Example 5 Acidic hydrolysis of the polymer represented by formula (11)

[0116] The polymer filaments of the structure shown in formula (11) are put into a 1 mol / L hydrochloric acid solution of water: ethanol = 3:1 at 60°C to obtain polyaryletherketone after reaction. The specific reaction process is shown below; the side group shedding effect is determined by detecting the change of the side group content in the solution by an ultraviolet spectrophotometer;

[0117]

[0118] By testing the change in the ultraviolet absorption intensity of the structure shown in formula (16) under different time conditions in the acid solution, the side group shedding rate and ratio are determined, such as Figure 5 shown.

[0119] Comparative Example 1

[0120] According to the content of patent CN 110052178 A, polyetheretherketone (PEEKt) modified with phenylimine side groups was prepared, and the specific reaction process is as follows; PEEKt was made into filaments and tested under the same acidity conditions;

[0121]

[0122] By testing the change in the ultraviolet absorption intensity of the structure shown in formula (17) in the acid solution, the side group shedding rate and ratio were determined. The results are as follows: Figure 6 shown.

[0123] Depend on Figure 5 and Figure 6 It can be seen that the shedding rate of the phosphamide side group of the polymer represented by formula (11) is much higher than the shedding rate of the aniline side group of PEEKt in the comparative example.

[0124] The above embodiments are only used to help understand the method and core idea of ​​the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0125] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A phosphimide polycondensation monomer as shown in formula (I), in, X is selected from halogen; R1 and R2 are independently selected from unsubstituted C1-C10 alkyl, unsubstituted C1-C5 alkenyl, and unsubstituted C6-C20 aryl.

2. The phosphimide polycondensation monomer according to claim 1, characterized in that: The R1 and R2 are independently selected from one of the following:

3. The method for preparing the phosphimide polycondensation monomer of formula (I) as claimed in claim 1, comprising the following steps: A) mixing 4,4'-dihalobenzophenone as shown in formula (II), hydroxylamine hydrochloride and sodium acetate in an organic solvent, heating and refluxing to obtain 4,4'-dihalobenzophenone oxime as shown in formula (III); B) reacting the 4,4'-dihalobenzophenone oxime with a phosphine halide compound as shown in formula (IV) in a weakly alkaline environment to obtain a phosphinimide polycondensation monomer as shown in formula (I); wherein X is selected from halogen; R1 and R2 are independently selected from unsubstituted C1-C10 alkyl, unsubstituted C1-C5 alkenyl, and unsubstituted C6-C20 aryl.

4. The preparation method according to claim 3, characterized in that: In step A), the molar ratio of the 4,4'-dihalobenzophenone to hydroxylamine hydrochloride is 1:1.1-1:1.6, and the molar ratio of the 4,4'-dihalobenzophenone to the sodium acetate is 1:1.6-1:2.0; the heating reflux time is 12-36 hours; and the organic solvent is a mixed solvent of ethanol and water in a volume ratio of (6-1):

1.

5. The preparation method according to claim 3, characterized in that: In step B), the molar ratio of the 4,4'-dihalobenzophenone oxime to the weak base is 1:(1.1-1.5), the reaction temperature is -80-0°C, and the weak base is selected from one or more of triethylamine, trimethylamine and N,N-diisopropylethylamine.

6. A phosphimide-type precursor polymer of formula (V), in, R1 and R2 are independently selected from unsubstituted C1-C10 alkyl, unsubstituted C1-C5 alkenyl, and unsubstituted C6-C20 aryl; R3 is selected from unsubstituted C5-C30 aryl or heteroaryl; n is the degree of polymerization.

7. The phosphimide precursor polymer according to claim 6, characterized in that: The R3 is selected from one of the following groups:

8. The method for preparing the phosphinimide precursor polymer of formula (V) as claimed in claim 6, comprising the following steps: The alcohol solution of the diphenol monomer represented by formula (VI) is mixed with sodium hydroxide to react to obtain sodium phenolate; reacting a phenol sodium salt with a phosphimide polycondensation monomer as shown in formula (I) to obtain a phosphimide-type precursor polymer as shown in formula (V); HO-R3-OH(Ⅵ); wherein X is selected from halogen; R1 and R2 are independently selected from unsubstituted C1-C10 alkyl, unsubstituted C1-C5 alkenyl, and unsubstituted C6-C20 aryl; R3 is selected from unsubstituted C5-C30 aryl or heteroaryl; n is the degree of polymerization.

9. The preparation method according to claim 8, characterized in that: The preparation method of the phosphimide type precursor polymer is specifically as follows: A) mixing an alcohol solution of a diphenol monomer with a strongly polar aprotic solvent, adding solid sodium hydroxide under nitrogen protection, reacting to obtain a sodium phenolate; B) heating the reaction system obtained in step A) to 80-100° C. to remove alcohol, then adding toluene, heating to 140-160° C., and removing water by azeotropic method; then adding phosphimide condensation monomer, heating to 150-200° C., and obtaining phosphimide type precursor polymer after reaction.

10. A method for preparing a polyaryletherketone as shown in formula (VII), comprising: The phosphinimide precursor polymer as shown in formula (V) is mixed with an acidic solution and hydrolyzed to obtain a polyaryletherketone as shown in formula (VII); Wherein, R1 and R2 are independently selected from unsubstituted C1-C10 alkyl, unsubstituted C1-C5 alkenyl, and unsubstituted C6-C20 aryl; R3 is selected from unsubstituted C5-C30 aryl or heteroaryl; n is the degree of polymerization.

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