A diphenol monomer containing a photocurable cinnamate group, a preparation method thereof, a photosensitive polyaryletherketone, a preparation method thereof and applications

Abstract

The present invention provides a diphenol monomer containing a photocurable cinnamate group, a preparation method thereof, a photosensitive polyaryletherketone, a preparation method thereof and an application, relating to the technical field of macromolecular compounds. The diphenol monomer containing a photocurable cinnamate group provided by the present invention has a structure shown in Formula I. Starting from the molecular perspective, the present invention designs and synthesizes a diphenol monomer containing a photocurable cinnamate group. Copolymerization of this monomer and a commercial monomer can obtain a photosensitive polyaryletherketone with a controllable proportion of photocurable groups. The photosensitive polyaryletherketone provided by the present invention has good solubility and is convenient for processing, and can be used as a polymer matrix for photocurable 3D printing. The advantage of this method is that the crosslinking degree of the photosensitive polyaryletherketone can be controlled by adjusting the proportion of photocurable groups, and the mechanical properties of the obtained parts can be further precisely regulated, solving the problem that the content of grafted photocurable groups is not clear in the existing methods.

Description

Technical Field

[0001] The present invention relates to the technical field of high molecular compounds, and particularly relates to a diphenol monomer containing a photocurable cinnamate group, a preparation method thereof, a photosensitive polyaryletherketone, a preparation method thereof and an application thereof. Background Art

[0002] Polyaryletherketone (polyarylethersulfone) is a high-performance polymer composed of repeating units containing carbonyl groups (sulfone groups) and ether bonds in the main chain structure, and has good mechanical properties, thermal stability and chemical corrosion resistance. At the same time, polyaryletherketone (polyarylethersulfone) also has excellent wear resistance and self-lubricating characteristics, and has been widely used in the preparation of mechanical parts such as bearings and gears. Traditional manufacturing methods result in more waste when preparing parts with precise structures, while 3D printing, which accumulates materials layer by layer, can greatly reduce material loss on the basis of preparing complex parts. Polyaryletherketone (polyarylethersulfone) has good fluidity at high temperatures and good heat resistance, so it will not decompose in the molten state, and has now been widely used in fused deposition 3D printing. This printing technology can prepare relatively precise polyaryletherketone (polyarylethersulfone) parts, but compared with digital light processing and stereolithography 3D printing technologies based on ultraviolet light curing, the precision is still lacking. Commonly used polyaryletherketone (polyarylethersulfone) lacks photocurable groups, thus limiting its application in the field of photocuring. At present, there is little research on the preparation of photocurable polyaryletherketone (polyarylethersulfone), and the methods used are all to first synthesize polyaryletherketone (polyarylethersulfone) polymers, and then introduce photosensitive groups into the molecules through the side groups of the polymers. The advantage of this method is that photocurable polymers can be obtained quickly, however, the content of photosensitive groups in the polymers cannot be accurately controlled. Summary of the Invention

[0003] The purpose of the present invention is to provide a diphenol monomer containing a photocurable cinnamate group, a preparation method thereof, a photosensitive polyaryletherketone, a preparation method thereof and an application thereof. Starting from the molecular perspective, the present invention designs and synthesizes a diphenol monomer containing a photocurable cinnamate group. This monomer copolymerizes with commercial monomers to obtain a photosensitive polyaryletherketone with a controllable proportion of photocurable groups. The photosensitive polyaryletherketone provided by the present invention has good solubility and is convenient for processing, and can be used as a polymer matrix for photocuring 3D printing. The advantage of this method is that the crosslinking degree of the photosensitive polyaryletherketone can be controlled by adjusting the proportion of photocurable groups, and further accurately regulate the mechanical properties of the obtained parts, solving the problem that the content of grafted photocurable groups is not clear in the existing methods. By directly introducing photosensitive groups into the monomer side chain through molecular design, the photocuring performance of the polymer can be accurately regulated by photoactive monomers, which has important research significance.

[0004] In order to achieve the above-mentioned invention purpose, the present invention provides the following technical solutions:

[0005] The present invention provides a diphenol monomer containing a photocurable cinnamate group, having the structure shown in Formula I:

[0006]

[0007] In Formula I, R 1 is H, CF 3 or CH 3 ; R 2 is H, F or CH 3 .

[0008] Preferably, when the R 1 is H, the R 2 is H, F or CH 3 ; when the R 1 is CF 3 , the R 2 is H; when the R 1 is CH 3 , the R 2 is CH 3 .

[0009] The present invention provides a preparation method of the diphenol monomer containing a photocurable cinnamate group as described in the above technical solution, including the following steps:

[0010] Mix an aromatic diamine, di-tert-butyl dicarbonate, a catalyst and a first organic solvent, and carry out a substitution reaction to obtain Compound 1;

[0011] Mix the Compound 1, an acid-binding agent, a second organic solvent and cinnamoyl chloride, and carry out a nucleophilic addition reaction to obtain Compound 2;

[0012] Heat the Compound 2 to obtain the diphenol monomer containing a photocurable cinnamate group with the structure shown in Formula I;

[0013] The structure of the aromatic diamine is

[0014] The structure of the Compound 1 is

[0015] The structure of the Compound 2 is

[0016] Preferably, the molar ratio of the aromatic diamine to di-tert-butyl dicarbonate is 10:20 - 25.

[0017] Preferably, the molar ratio of the Compound 1 to the acid-binding agent is 10:21 - 25; the molar ratio of the Compound 1 to cinnamoyl chloride is 10:21 - 25.

[0018] Preferably, the heating temperature is 170 - 220 °C.

[0019] The present invention provides a photosensitive polyaryletherketone having the structure shown in Formula II:

[0020]

[0021] In Formula II, R 1 is H, CF 3 or CH 3 ; R 2 is H, F or CH 3 ; R 3 is C=O or SO 2 .

[0022] Preferably, when the R 1 is H and R 2 is H, R 3 is C=O or SO 2 ; when the R 1 is H and R 2 is F, R 3 is C=O or SO 2 ; when the R 1 is H and R 2 is CH 3 , R 3 is C=O or SO 2 ; when the R 1 is CF 3 , R 2 is H, R 3 is C=O or SO 2 ; when the R 1 is CH 3 , R 2 is CH 3 , R 3 is C=O or SO 2 .

[0023] The present invention provides a preparation method of the photosensitive polyaryletherketone described in the above technical solution, comprising the following steps:

[0024] Mix the diphenol monomer containing a photocurable cinnamate group described in the above technical solution or the diphenol monomer containing a photocurable cinnamate group prepared by the preparation method described in the above technical solution, a commercial binary halogenated monomer, a commercial diphenol monomer, potassium carbonate and a third organic solvent, and carry out a copolymerization reaction to obtain a photosensitive polyaryletherketone having the structure shown in Formula II; the commercial binary halogenated monomer includes 4,4'-difluorobenzophenone; the commercial diphenol monomer includes bisphenol AF.

[0025] The present invention provides the use of the photosensitive polyaryletherketone described in the above technical solution or the photosensitive polyaryletherketone prepared by the preparation method described in the above technical solution in the preparation of polyaryletherketone films or polyaryletherketone parts.

[0026] The present invention provides a diphenol monomer containing a photocurable cinnamate group, having the structure shown in Formula I. The present invention copolymerizes the diphenol monomer containing a photocurable cinnamate group with a commercial diphenol monomer and a commercial dihalide monomer to obtain a photosensitive polyaryletherketone (PSPEEK), which can be used as a matrix for photocurable 3D printing.

[0027] The present invention provides a preparation method of the diphenol monomer containing a photocurable cinnamate group described in the above technical solution. In the present invention, the amino groups on both sides of the commercial monomer 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane are protected with di-tert-butyl dicarbonate, and then the phenolic hydroxyl group on the side chain reacts with the chlorine atom in cinnamoyl chloride to introduce a photocurable cinnamate group into the molecule. Finally, the amino protection is removed first at high temperature, and then the ester bond undergoes an ammonolysis reaction to obtain a diphenol monomer containing a cinnamate group in the molecule. In the present invention, the preparation process of the diphenol monomer containing a photocurable cinnamate group is simple, and only three steps are required to introduce a photocurable functional group into the commercial monomer.

[0028] The photosensitive polyaryletherketone obtained by copolymerizing the diphenol monomer containing a photocurable cinnamate group provided by the present invention with a commercial monomer has good solubility. This is because a large-volume side chain is introduced into the polymer through the diphenol monomer, breaking the close packing of the polymer, thereby reducing its crystallinity and improving its solubility. The photosensitive polyaryletherketone can be well dissolved in acetone, tetrahydrofuran and chloroform, and can also be dissolved in the active diluent N-vinylpyrrolidone required for photocuring. The polymer has good film-forming properties, and a uniform and tough photocured polyaryletherketone film can be obtained after ultraviolet photocuring. The film has high mechanical properties and good thermal properties. Description of the Drawings

[0029] Figure 1 1H NMR spectrum of Compound 1 prepared in Example 1;

[0030] Figure 2 1H NMR spectrum of Compound 2 prepared in Example 1;

[0031] Figure 3 Single crystal structure diagram of Compound 2 prepared in Example 1;

[0032] Figure 4 1H NMR spectrum of the diphenol monomer containing a photocurable cinnamate group having the structure shown in Formula III prepared in Example 1;

[0033] Figure 5FT-IR spectra of PEEK-0 and photosensitive PSPEEK;

[0034] Figure 6 UV-Vis spectra of PEEK-0 and photosensitive PSPEEK;

[0035] Figure 7 XRD characterization of PEEK-0 and photosensitive PSPEEK;

[0036] Figure 8 FT-IR characterization of PSPEEK-10 before and after photocuring;

[0037] Figure 9 FT-IR spectra of PEEK-0 and photocured UV-PSPEEK films;

[0038] Figure 10 XRD characterization of PEEK-0 and photocured UV-PSPEEK films;

[0039] Figure 11 Gel fraction of PEEK-0 and photocured UV-PSPEEK films;

[0040] Figure 12 (a) Stress-strain curves, (b) tensile strength, elongation at break and tensile modulus of PEEK-0 and photocured UV-PSPEEK films;

[0041] Figure 13 TGA curves of PEEK-0 and photocured UV-PSPEEK films;

[0042] Figure 14 SEM images of the surface and tensile fracture surfaces of PEEK-0 and photocured UV-PSPEEK films;

[0043] Figure 15 Physical picture of 3D printed polyaryletherketone parts. Detailed implementation mode

[0044] The present invention provides a diphenol monomer containing a photocurable cinnamate group, having the structure shown in Formula I:

[0045]

[0046] In Formula I, R 1 is H, CF 3 or CH 3 ; R 2 is H, F or CH 3 .

[0047] In the present invention, when the R 1 is H, the R2 Preferably H, F or CH 3 ; when the R 1 is CF 3 , the R 2 is preferably H; when the R 1 is CH 3 , the R 2 is preferably CH 3 .

[0048] The present invention provides a method for preparing the diphenol monomer containing a photocurable cinnamate group described in the above technical solution, comprising the following steps:

[0049] Mix an aromatic diamine, di-tert-butyl dicarbonate, a catalyst and a first organic solvent, and carry out a substitution reaction to obtain Compound 1;

[0050] Mix the Compound 1, an acid-binding agent, a second organic solvent and cinnamoyl chloride, and carry out a nucleophilic addition reaction to obtain Compound 2;

[0051] Heat the Compound 2 to obtain a diphenol monomer containing a photocurable cinnamate group with the structure shown in Formula I;

[0052] The structure of the aromatic diamine is

[0053] The structure of the Compound 1 is

[0054] The structure of the Compound 2 is

[0055] In the present invention, an aromatic diamine, di-tert-butyl dicarbonate, a catalyst and a first organic solvent are mixed, and a substitution reaction is carried out to obtain Compound 1. In the present invention, the aromatic diamine is preferably 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane. In the present invention, the molar ratio of the aromatic diamine to di-tert-butyl dicarbonate is preferably 10:20 - 25, more preferably 10:21. In the present invention, the catalyst is preferably nano-ferroferric oxide. In the present invention, the dosage ratio of di-tert-butyl dicarbonate to the catalyst is preferably 21 mmol: 0.2 - 0.4 g, more preferably 21 mmol: 0.28 g. In the present invention, the first organic solvent is preferably anhydrous ethanol or methanol. In the present invention, the dosage ratio of di-tert-butyl dicarbonate to the first organic solvent is preferably 21 mmol: 40 - 100 mL, more preferably 21 mmol: 60 mL.

[0056] In the present invention, the temperature of the substitution reaction is preferably room temperature; the time of the substitution reaction is preferably 6 - 15 h, more preferably 12 h. In the present invention, the atmosphere of the substitution reaction is preferably an air atmosphere.

[0057] Preferably after the substitution reaction, the present invention uses a 0.45 μm organic filter membrane to filter out the catalyst, and spin-dries the reaction solution; the crude product is dissolved in ethyl acetate, and washed with saturated ammonium chloride solution to remove the excessive di-tert-butyl dicarbonate, and after liquid separation, it is spin-dried to obtain Compound 1.

[0058] After obtaining Compound 1, the present invention mixes the Compound 1, an acid-binding agent, a second organic solvent, and cinnamoyl chloride to carry out a nucleophilic addition reaction to obtain Compound 2. In the present invention, the acid-binding agent is preferably triethylamine or pyridine. In the present invention, the molar ratio of the Compound 1 to the acid-binding agent is preferably 10:21 to 25, more preferably 10:22; the molar ratio of the Compound 1 to cinnamoyl chloride is preferably 10:21 to 25, more preferably 10:22. In the present invention, the second organic solvent is preferably dichloromethane or chloroform.

[0059] In the present invention, the mixing of the Compound 1, the acid-binding agent, the second organic solvent, and cinnamoyl chloride preferably includes: mixing the Compound 1, the acid-binding agent, and a part of the second organic solvent to obtain a Compound 1 solution; mixing cinnamoyl chloride and the remaining second organic solvent to obtain a cinnamoyl chloride solution; dropping the cinnamoyl chloride solution into the Compound 1 solution. In the present invention, the dosage ratio of the Compound 1 to a part of the second organic solvent is preferably 10 mmol: 25 to 40 mL, more preferably 10 mmol: 30 mL; the dosage ratio of cinnamoyl chloride to the remaining second organic solvent is preferably 22 mmol: 15 to 30 mL, more preferably 22 mmol: 20 mL. In the present invention, the mixing is preferably carried out under ice bath conditions.

[0060] In the present invention, the nucleophilic addition reaction is preferably carried out under ice bath conditions, and the time of the nucleophilic addition reaction is preferably 25 to 40 min, more preferably 30 min.

[0061] Preferably after the nucleophilic addition reaction, the present invention adds saturated sodium bicarbonate solution to the obtained reaction system, and the precipitate gradually dissolves; it is washed with saturated sodium bicarbonate solution to remove the excessive cinnamoyl chloride and hydrochloride by-products (triethylamine hydrochloride or pyridine hydrochloride) in the reaction solution, separated by liquid separation and the organic phase is collected, dehydrated with anhydrous sodium sulfate, and then the reaction solvent is removed by distillation under reduced pressure to obtain a crude product; the crude product is purified by pulping with dichloromethane and filtered through a sintered glass funnel to obtain Compound 2.

[0062] After obtaining Compound 2, the present invention heats the Compound 2 to obtain a diphenol monomer containing a photocurable cinnamate group with the structure shown in Formula I. In the present invention, the heating temperature is preferably 170 - 220 °C, more preferably 210 °C. The present invention has no special limitation on the heating time, until no more bubbles are generated. In the present invention, the heating is preferably carried out in an oil bath.

[0063] The present invention preferably adds dichloromethane for pulping and purification after the heating, and then filters with a sintered glass funnel to obtain a diphenol monomer containing a photocurable cinnamate group.

[0064] The present invention provides a photosensitive polyaryletherketone having the structure shown in Formula II:

[0065]

[0066] In Formula II, R 1 is H, CF 3 or CH 3 ; R 2 is H, F or CH 3 ; R 3 is C=O or SO 2 .

[0067] In the present invention, when the R 1 is H and R 2 is H, R 3 is preferably C=O or SO 2 ; when the R 1 is H and R 2 is F, R 3 is preferably C=O or SO 2 ; when the R 1 is H and R 2 is CH 3 , R 3 is preferably C=O or SO 2 ; when the R 1 is CF 3 , R 2 is H, R 3 is preferably C=O or SO 2 ; when the R 1 is CH 3 , R 2 is CH 3 , R 3 is preferably C=O or SO 2 .

[0068] In the present invention, in the formula II, x is the molar percentage of the unit containing a cinnamate group, and x + y = 1. In the present invention, the x is preferably 2 to 30%, more preferably 10 to 20%. In the present invention, the number average molecular weight of the photosensitive polyaryletherketone is preferably 6000 to 20000 g / mol.

[0069] The present invention provides a method for preparing the photosensitive polyaryletherketone described in the above technical solution, comprising the following steps:

[0070] Mix the diphenol monomer containing a photocurable cinnamate group described in the above technical solution or the diphenol monomer containing a photocurable cinnamate group prepared by the preparation method described in the above technical solution, a commercial binary halogenated monomer, a commercial diphenol monomer, potassium carbonate and a third organic solvent, and carry out a copolymerization reaction to obtain a photosensitive polyaryletherketone having the structure shown in formula II; the commercial binary halogenated monomer includes 4,4'-difluorobenzophenone; the commercial diphenol monomer includes bisphenol AF.

[0071] In the present invention, the commercial binary halogenated monomer preferably includes 4,4'-difluorobenzophenone. In the present invention, the molar ratio of the diphenol monomer containing a photocurable cinnamate group to the commercial binary halogenated monomer is preferably 0.1 to 1.62:5 to 20, more preferably 0.2 to 0.35:7.5 to 15, specifically preferably 1.5:15, 0.1:5, 0.2:5, 0.35:5, 1.5:7.5, 1.5:5, 1.5:20, 1.62:7.5 or 1.6:4. In the present invention, the molar ratio of the diphenol monomer containing a photocurable cinnamate group to the commercial diphenol monomer is preferably 0.1 to 1.62:1.6 to 13.5, more preferably 0.2 to 0.35:4.65 to 6, specifically preferably 1.5:13.5, 0.1:4.9, 0.2:4.8, 0.35:4.65, 1.5:6, 1.5:3.5, 1.62:3.78 or 1.6:1.6. In the present invention, the molar ratio of the diphenol monomer containing a photocurable cinnamate group to potassium carbonate is preferably 0.1 to 1.62:4.8 to 22.5, more preferably 0.2 to 0.35:7.5 to 9, specifically preferably 1.5:22.5, 0.1:7.5, 0.2:7.5, 0.35:7.5, 1.5:9, 1.5:6, 1.62:8.1 or 1.6:4.8. In the present invention, the potassium carbonate is preferably anhydrous potassium carbonate, and its function is to promote the nucleophilic reaction. In the present invention, the third organic solvent is preferably a mixed solvent of dimethyl sulfoxide (DMSO) and toluene; the volume ratio of dimethyl sulfoxide to toluene in the mixed solvent of dimethyl sulfoxide and toluene is preferably 2:0.8 to 1.2, more preferably 2:1. In the present invention, the dosage ratio of the diphenol monomer containing a photocurable cinnamate group to the third organic solvent is preferably 0.1 to 1.62 mmol:8.7 to 51 mL, more preferably 0.2 to 0.35 mmol:9 to 24 mL, specifically preferably 1.5 mmol:27 mL, 0.1 mmol:8.7 mL, 0.2 mmol:9 mL, 0.35 mmol:9 mL, 1.5 mmol:24 mL, 1.5 mmol:15 mL, 1.5 mmol:51 mL, 1.62 mmol:19.5 mL or 1.6 mmol:12 mL.

[0072] In the present invention, the copolymerization reaction preferably includes: first refluxing at 120 to 140 °C for 2.5 to 4 h until no more water is produced in the system, then raising the temperature to 143 to 150 °C and reacting for 2 to 3.5 h; more preferably includes: first refluxing at 135 °C for 3 h until no more water is produced in the system, then raising the temperature to 145 °C and reacting for 3 h.

[0073] Preferably after the copolymerization reaction, the obtained reaction system is poured into distilled water while it is still hot to precipitate a yellow solid, and the yellow solid is washed with distilled water until neutral; it is dried in a vacuum drying oven at 120 °C for 12 h to obtain the photosensitive polyaryletherketone.

[0074] The present invention provides the use of the photosensitive polyaryletherketone described in the above technical solution or the photosensitive polyaryletherketone prepared by the preparation method described in the above technical solution in the preparation of polyaryletherketone films or polyaryletherketone parts.

[0075] In the present invention, the use preferably includes: mixing the photosensitive polyaryletherketone, an organic solvent and a photoinitiator to obtain a photosensitive polyaryletherketone solution; subjecting the photosensitive polyaryletherketone solution to ultraviolet curing to obtain a polyaryletherketone film. In the present invention, the organic solvent is preferably N-methylpyrrolidone, N,N-dimethylformamide or N,N-dimethylacetamide. In the present invention, the photoinitiator is preferably phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (photoinitiator 819). In the present invention, the mass ratio of the photosensitive polyaryletherketone, the organic solvent and the photoinitiator is preferably 0.25: 3.5-5: 0.08-0.1, more preferably 0.25: 4: 0.086. In the present invention, the mixing is preferably ultrasonic mixing. In the present invention, the ultraviolet curing preferably includes: pouring the photosensitive polyaryletherketone solution onto a substrate and performing ultraviolet curing. In the present invention, the power of the ultraviolet lamp for the ultraviolet curing is preferably 15-30 W, more preferably 20 W; the wavelength of the ultraviolet lamp is preferably 405 nm; the time for the ultraviolet curing is preferably 2-5 min, more preferably 3 min.

[0076] Preferably after the ultraviolet curing, the present invention further includes performing heat treatment, water immersion and drying in sequence. In the present invention, the heat treatment preferably includes: heating at a rate of 4 °C / min, and heating at 80 °C and 200 °C for 120 min and 100 min respectively. In the present invention, the water immersion is preferably carried out in hot water, and the temperature of the hot water is preferably 70 °C. In the present invention, the polymer film naturally peels off through water immersion. In the present invention, the drying is preferably vacuum drying; the drying temperature is preferably 120 °C; the drying time is preferably 10 h.

[0077] In the present invention, the thickness of the polyaryletherketone film is preferably 30-40 μm.

[0078] In the present invention, the application preferably includes: mixing the photosensitive polyaryletherketone, the reactive diluent, the photo-crosslinking agent and the photoinitiator to obtain an ink; performing photocuring 3D printing on the ink to obtain a polyaryletherketone part. In the present invention, the reactive diluent is preferably N-vinylpyrrolidone; the photo-crosslinking agent is preferably trimethylolpropane triacrylate (TMPTA); the photoinitiator is preferably photoinitiator 819. In the present invention, the mass ratio of the photosensitive polyaryletherketone, the reactive diluent, the photo-crosslinking agent and the photoinitiator is preferably 40-50:40-50:8:2. In the present invention, the photocuring 3D printing is preferably carried out under ultraviolet light conditions; the wavelength of the ultraviolet light is preferably 405 nm.

[0079] Next, the technical solutions in the present invention will be clearly and completely described in conjunction with the embodiments in the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

[0080] Example 1

[0081] (1) Protect the commercial monomer compound 1 with di-tert-butyl dicarbonate, and the structural formula is as follows:

[0082]

[0083] The preparation method of this compound 1 is:

[0084] Add 10 mmol of 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (6FOHA), 21 mmol of di-tert-butyl dicarbonate (Boc anhydride) and 0.28 g of nano-ferroferric oxide to 60 mL of absolute ethanol, and react at room temperature for 12 h; after determining the completion of the reaction by thin layer chromatography (TLC) analysis, use a 0.45 μm organic filter membrane to filter out the nano-ferroferric oxide, and spin-dry the reaction solution; dissolve the crude product in ethyl acetate, wash with saturated ammonium chloride solution to remove the excess Boc anhydride, separate the layers and spin-dry to obtain a white solid compound 1 with a yield of 96.8%.

[0085] Characterization results of compound 1: 1 H NMR(400MHz,DMSO-d 6 )δ10.32(s,2H),7.84(s,2H),7.77(s,2H),6.86(d,J=8.7Hz,2H),6.79(d,J=8.4Hz,2H),1.42(s,18H);

[0086] 13CNMR (101 MHz, DMSO-d6) δ 153.11, 148.06, 126.58, 125.58, 123.19, 122.20, 115.05, 79.98, 28.45.

[0087] IR (KBr, cm -1 ): 3427, 3379, 3280, 3108, 2935, 2874, 2754, 2599, 2291, 2171, 2109, 1854, 1709, 1673, 1609, 1543, 1518, 1439, 1394, 1370, 1320, 1254, 1162, 1132, 1080, 1056, 997, 962, 887, 850, 810, 776, 736, 714, 638, 548, 528, 470.

[0088] HRMS: C 25 H 28 F 6 N 2 NaO 6 for [M+Na] + , calculated 589.1744, found 589.1740.

[0089] (2) The compound 2 containing a photocurable cinnamate group has the following structural formula:

[0090]

[0091] The preparation method of the compound 2 is as follows:

[0092] Add 10 mmol of the compound 1 and 22 mmol of the acid-binding agent triethylamine into a flask containing 30 mL of dichloromethane, and stir well until completely dissolved; then place the flask in an ice bath. After cooling for 10 min, slowly add a mixed solution of 22 mmol of cinnamoyl chloride and 20 mL of dichloromethane dropwise into the flask through a constant-pressure dropping funnel; white precipitate will form during the dropping process, and this precipitate is triethylamine hydrochloride formed by the reaction of the by-product hydrogen chloride gas and triethylamine; remove the ice bath and react at room temperature for 30 min. After determining the completion of the reaction by thin-layer chromatography (TLC), add saturated sodium bicarbonate solution to the flask, and the precipitate will gradually dissolve; wash with saturated sodium bicarbonate solution to remove the excess cinnamoyl chloride and triethylamine hydrochloride in the reaction solution, separate the layers and collect the organic phase. After drying with anhydrous sodium sulfate, distill off the reaction solvent under reduced pressure to obtain the crude product; purify the crude product by trituration with dichloromethane and filter through a sintered glass funnel to obtain the compound 2 with a yield of 53.6%.

[0093] Characterization results of the compound 2: 1¹H NMR (400 MHz, DMSO-d 6 ) δ 9.15 (s, 2H), 7.95 (s, 2H), 7.83 (d, J = 15.9 Hz, 2H), 7.81 (d, J = 9.8 Hz, 4H), 7.49–7.46 (m, 6H), 7.33 (d, J = 8.8 Hz, 2H), 7.02 (d, J = 8.0 Hz, 2H), 6.89 (d, J = 16.1 Hz, 2H), 1.41 (s, 18H).

[0094] 13 ¹³C NMR (101 MHz, DMSO-d 6 ) δ 164.80, 153.32, 146.30, 142.34, 134.49, 131.79, 131.31, 129.93, 129.56, 129.06, 125.60, 124.34, 124.03, 121.67 (dd, J = 571.9, 285.4 Hz), 118.43, 80.27, 64.24 (p, J = 25.0 Hz), 28.50.

[0095] IR (KBr, cm -1 ) ν: 3452, 2978, 2934, 1736, 1722, 1636, 1603, 1578, 1538, 1478, 1451, 1430, 1393, 1368, 1330, 1312, 1240, 1224, 1193, 1153, 1134, 1048, 996, 965, 916, 891, 862, 831, 766, 741, 720, 706, 683, 563.

[0096] HRMS: C 43 H 40 F 6 N 2 NaO 8 for [M+Na] + , calculated 849.2581, found 849.2584.

[0097] (3) Prepare a diphenol monomer containing a photocurable cinnamate group with the structure shown in Formula III,

[0098]

[0099] The preparation method of the diphenol monomer containing a photocurable cinnamate group is as follows:

[0100] Place 10 mmol of the compound 2 into a 250 mL single-necked flask connected to a bubbler, immerse it in an oil bath and heat to 210 °C; the compound in the flask will gradually melt from a light yellow powder into a yellow liquid, and a large number of bubbles will be generated in the liquid; when the bubbles no longer form, it indicates that the reaction has ended, and at this time, the flask contains a yellow solid; after the flask cools, add dichloromethane for pulping and purification, and then filter it through a sintered glass funnel to obtain a diphenol monomer containing a photocurable cinnamate group with the structure shown in Formula III, with a yield of 98.3%.

[0101] Characterization results of the diphenol monomer containing a photocurable cinnamate group with the structure shown in Formula III: 1 HNMR(400MHz,DMSO-d 6 )δ10.51(s,2H),9.50(s,2H),8.23(s,2H),7.59–7.54(m,4H),7.51(d,J=15.7Hz,2H),7.42–7.33(m,6H),7.14(d,J=15.6Hz,2H),6.93–6.86(m,4H).

[0102] 13 C NMR(101MHz,DMSO-d 6 )δ164.69,148.45,141.16,135.40,130.27,129.47,128.34,127.02,126.48,123.55,123.47,122.71,115.70,63.92(p,J=24.5Hz).

[0103] IR(KBr,cm -1 ):3410,3108,3086,3032,2974,2877,2735,2624,1752,1664,1626,1598,1579,1542,1512,1450,1379,1345,1300,1281,1253,1221,1207,1185,1163,1125,1073,1029,999,973,899,850,820,811,762,744,734,707,682,633,570,546,528.

[0104] HRMS:C 33 H 24 F 6 N 2 NaO 4 for[M+Na] + ,calculated 649.1532,found649.1528.

[0105] Example 2

[0106] Prepare a photosensitive poly(aryl ether ketone) having the structure shown in Formula IV,

[0107]

[0108] The preparation method of the photosensitive poly(aryl ether ketone) is as follows:

[0109] In a 50 mL three-necked flask equipped with a water separator, magnetic stirring, and an argon atmosphere, add 15 mmol of 4,4'-difluorobenzophenone, 1.5 mmol of the diphenol monomer containing a photocurable cinnamate group shown in Formula III, 13.5 mmol of bisphenol AF, and 22.5 mmol of anhydrous potassium carbonate. Measure 18 mL of dimethyl sulfoxide (DMSO) and 9 mL of toluene and add them to the flask together. Heat the mixture in an oil bath to 135 °C and reflux for 3 h. At this time, toluene and water in the system carry out azeotropic distillation, and the water in the lower layer of the water separator is released in small portions until no more water is produced in the system. Then heat to 145 °C, and it can be observed that the viscosity of the polymer solution in the flask gradually increases. After reacting for 3 h, the rotation speed of the magnetic stirrer becomes very slow. Stop the reaction and pour the solution into distilled water while it is still hot to precipitate a yellow solid. Wash the polymer with distilled water until it is neutral. Dry it in a vacuum drying oven at 120 °C for 12 h to obtain the photosensitive poly(aryl ether ketone). The molar content of the unit containing a cinnamate group in the photosensitive poly(aryl ether ketone) is 10%, denoted as PSPEEK-10, and the number average molecular weight is 20000 g / mol.

[0110] The characterization results of the photosensitive poly(aryl ether ketone): 1 H NMR (400 MHz, DMSO-d6) δ 7.83–7.67 (m, 1H), 7.44–7.30 (m, 1H), 7.24–7.06 (m, 2H).

[0111] 13 C NMR (101 MHz, DMSO-d6) δ 193.17, 159.46, 156.38, 132.65, 132.22, 131.76, 127.76, 125.45, 122.59, 119.17, 118.39, 63.07. IR

[0112] (KBr, cm -1): 3421, 3055, 2971, 2926, 2588, 2425, 2035, 1919, 1781, 1659, 1596, 1500, 1413, 1308, 1246, 1205, 1172, 1135, 1016, 968, 953, 927, 874, 855, 832, 765, 736, 705, 685, 637, 609, 569, 559, 545, 523, 500, 488.

[0113] Example 3

[0114] It is basically the same as the preparation method of Example 2, except that the dosage of 4,4'-difluorobenzophenone is adjusted to 5 mmol, the dosage of the diphenol monomer containing a photocurable cinnamate group with the structure shown in Formula III is adjusted to 0.1 mmol, the dosage of bisphenol AF is adjusted to 4.9 mmol, the dosage of anhydrous potassium carbonate is adjusted to 7.5 mmol, the dosage of DMSO is adjusted to 5.8 mL, and the dosage of toluene is adjusted to 2.9 mL, to obtain a photosensitive polyaryletherketone with a molar content of the unit containing a cinnamate group of 2%, denoted as PSPEEK-2.

[0115] Example 4

[0116] It is basically the same as the preparation method of Example 2, except that the dosage of 4,4'-difluorobenzophenone is adjusted to 5 mmol, the dosage of the diphenol monomer containing a photocurable cinnamate group with the structure shown in Formula III is adjusted to 0.2 mmol, the dosage of bisphenol AF is adjusted to 4.8 mmol, the dosage of anhydrous potassium carbonate is adjusted to 7.5 mmol, the dosage of DMSO is adjusted to 6 mL, and the dosage of toluene is adjusted to 3 mL, to obtain a photosensitive polyaryletherketone with a molar content of the unit containing a cinnamate group of 4%, denoted as PSPEEK-4.

[0117] Example 5

[0118] It is basically the same as the preparation method of Example 2, except that the dosage of 4,4'-difluorobenzophenone is adjusted to 5 mmol, the dosage of the diphenol monomer containing a photocurable cinnamate group with the structure shown in Formula III is adjusted to 0.35 mmol, the dosage of bisphenol AF is adjusted to 4.65 mmol, the dosage of anhydrous potassium carbonate is adjusted to 7.5 mmol, the dosage of DMSO is adjusted to 6 mL, and the dosage of toluene is adjusted to 3 mL, to obtain a photosensitive polyaryletherketone with a molar content of the unit containing a cinnamate group of 7%, denoted as PSPEEK-7.

[0119] Example 6

[0120] Basically the same as the preparation method of Example 2, except that the amount of 4,4'-difluorobenzophenone is adjusted to 7.5 mmol, the amount of the diphenol monomer containing a photocurable cinnamate group with the structure shown in Formula III is adjusted to 1.5 mmol, the amount of bisphenol AF is adjusted to 6 mmol, the amount of anhydrous potassium carbonate is adjusted to 9 mmol, the amount of DMSO is adjusted to 16 mL, and the amount of toluene is adjusted to 8 mL, to obtain a photosensitive polyaryletherketone with a molar content of the unit containing a cinnamate group of 20%, denoted as PSPEEK-20.

[0121] Example 7

[0122] Basically the same as the preparation method of Example 2, except that the amount of 4,4'-difluorobenzophenone is adjusted to 5 mmol, the amount of the diphenol monomer containing a photocurable cinnamate group with the structure shown in Formula III is adjusted to 1.5 mmol, the amount of bisphenol AF is adjusted to 3.5 mmol, the amount of anhydrous potassium carbonate is adjusted to 6 mmol, the amount of DMSO is adjusted to 10 mL, and the amount of toluene is adjusted to 5 mL, to obtain a photosensitive polyaryletherketone with a molar content of the unit containing a cinnamate group of 30%, denoted as PSPEEK-30.

[0123] Comparative Example 1

[0124] Basically the same as the preparation method of Example 2, except that the diphenol monomer containing a photocurable cinnamate group with the structure shown in Formula III is not added, and the obtained polyaryletherketone is denoted as PSPEEK-0.

[0125] Application Example

[0126] Preparation of Photocurable Polyaryletherketone Film

[0127] Weigh 0.25 g of the polyaryletherketone prepared in Examples 2 to 7 and Comparative Example 1, respectively, and dissolve them in 4 g of N-methylpyrrolidone (NMP) to obtain a polyaryletherketone solution; add 0.086 g of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (photoinitiator 819) to the polyaryletherketone solution, and completely dissolve it by ultrasound, centrifuge the above polymer solution, and let the insoluble matter settle at the bottom; then pour the solution on a 76 mm × 26 mm glass slide, place it in a muffle furnace, and irradiate it with an ultraviolet lamp with a wavelength of 405 nm and a power of 20 W for 3 min; after the irradiation, heat it at a rate of 4 ° C / min, and heat it at 80 ° C and 200 ° C for 120 min and 120 min, respectively. 100min; after the muffle furnace is cooled to room temperature, the glass slide is immersed in 70°C hot water, the polymer film falls off naturally, and is dried in a vacuum drying oven at 120°C for 10h to remove moisture to obtain a photocurable polyaryletherketone film having a thickness of 35 to 37 μm, denoted as UV-PSPEEK-x, where x represents the molar content of the unit containing a cinnamate group in the polyaryletherketone (the photocurable polyaryletherketone films corresponding to Examples 2 to 7 and Comparative Example 1 are UV-PSPEEK-10, UV-PSPEEK-2, UV-PSPEEK-4, UV-PSPEEK-7, UV-PSPEEK-20, UV-PSPEEK-30, and UV-PSPEEK-0, respectively).

[0128] Test Example 1 Infrared Characterization of Polyaryletherketone

[0129] Instrument model: Thermo Fisher Nicoletis 5 infrared spectrometer. Test conditions: room temperature, test wave number range 4000cm -1 -500cm -1 . Test method: Mix spectral grade potassium bromide with powder sample at a mass ratio of 1:100, grind thoroughly in an agate mortar and press into tablets for testing. Film samples can be tested directly. The structure is discussed and analyzed based on the peak position and peak intensity in the compound and polymer. Infrared characterization of polyaryletherketone Figure 5 As shown in the figure, the main characteristic peaks of poly(aryletherketone) are ketone carbonyl, aromatic ether and aromatic ring. -1 The peak at 1596 cm is the stretching vibration peak of the ketone carbonyl group conjugated with two benzene rings. -1 and 1500cm -1 The peak of the Ar-O-Ar benzene ring vibration is 1306 cm -1 is the in-plane vibration absorption peak of Ar-CO-Ar benzene ring, 1016cm -1 It is the absorption peak of the CH plane bending vibration of the benzene ring in the aromatic ether or aromatic ketone structure, 927cm -1is the symmetric stretching vibration peak of Ar-CO-Ar, 855 cm -1 is the out-of-plane rocking vibration peak of two adjacent hydrogens on the benzene ring. The co-occurrence of these peaks indicates the successful synthesis of polyaryletherketone. In the infrared spectrum, it can be observed that there are obvious changes in the photosensitive polyaryletherketone compared with PEEK-0 at 1631 cm -1 where it is the stretching vibration peak of C=C. The infrared spectrum can also show that photosensitive double bonds have been introduced into the polymer.

[0130] Test Example 2 UV Characterization of Polyaryletherketone

[0131] Figure 6 is the UV-visible absorption spectrum of the photosensitive polyaryletherketone in NMP. Instrument model: Purkinje T700 UV spectrometer. Test conditions: carried out at room temperature, the test wavelength is 200 - 800 nm. Test method: Use a capillary to take a small amount of polymer powder and dissolve it in NMP, and test the position of the UV absorption peak of the polymer.

[0132] The results show that PEEK-0 has a maximum absorption peak at 288 nm. As the content of the diphenol monomer in the copolymer increases, new absorption peaks appear at 320 - 420 nm, and this peak has a maximum absorption wavelength at 324 - 377 nm. There is a C=O chromophore in PEEK-0, and the transition of valence electrons from n→π* can produce an absorption band with an absorption wavelength greater than 270 nm. And there is also a C=O unsaturated group in PSPEEK, and the electron transitions in different chemical environments produce a broad peak with an absorption wavelength of 320 - 420 nm. Introducing photosensitive double bonds into polyaryletherketone will expand the wavelength range of the polymer's UV absorption. In order to avoid competition in the absorption of UV light between the polymer and the photoinitiator, photoinitiator 819 with an absorption wavelength of 405 nm was selected. Compared with other wavelengths, the UV absorption of the photosensitive polyaryletherketone at 405 nm wavelength is relatively less. Irradiate the polymer solution with a UV lamp with an irradiation wavelength of 405 nm, and the photoinitiator 819 in the solution undergoes homolytic cleavage to generate free radicals, and then the carbon-carbon double bond of the cinnamate is opened for photopolymerization. The UV absorption peak position of the photosensitive polyaryletherketone plays a key role in the selection of the irradiation wavelength and the photoinitiator.

[0133] Test Example 3 XRD Characterization of Polyaryletherketone

[0134] The XRD characterization of the photosensitive polyaryletherketone was carried out, and the results are as Figure 7 shown. Instrument model: X'pert pro X-ray diffractometer. Test conditions: carried out at room temperature, the test angle is 5° - 90°. Test method: Place the powder sample in a glass sample cell, flatten it and then carry out the test. The thin film sample can be directly placed on the sample cell for testing.

[0135] All polyaryletherketones exhibit a broad peak near the position of 2θ = 16.4°, indicating that the polymer has poor crystallinity and is in an amorphous state. Polyaryletherketones are a class of semi-crystalline polymer materials, and the presence of crystallization in the polymer will affect its solubility and thus increase the processing difficulty. The photosensitive polyaryletherketone prepared in the present invention does not have a sharp crystallization peak in the polymer form, indicating that it does not have good crystallization performance, which is convenient for dissolving the polymer and subsequent processing.

[0136] Test Example 4 Solubility Test of Polyaryletherketone

[0137] Due to the poor solubility of the polymer, it is not easy to observe the effect of different monomer addition amounts on the solubility of the photosensitive polyaryletherketone. Therefore, oligomers with a number-average molecular weight of 6000 g / mol were designed and synthesized for solubility testing. The preparation method of the oligomers with a number-average molecular weight of 6000 g / mol is basically the same as that of Example 2, except that the amount of 4,4'-difluorobenzophenone is adjusted to 3 mmol, the amount of bisphenol AF is adjusted to 2.5 mmol, the amount of anhydrous potassium carbonate is adjusted to 3.6 mmol, the amount of DMSO is adjusted to 5.2 mL, and the amount of toluene is adjusted to 2.6 mL to obtain PEEK-0-L with a molecular weight of 6000 g / mol. The amount of 4,4'-difluorobenzophenone is adjusted to 20 mmol, the amount of the diphenol monomer containing a photocurable cinnamate group shown in Formula III is adjusted to 1.5 mmol, the amount of bisphenol AF is adjusted to 13.5 mmol, the amount of anhydrous potassium carbonate is adjusted to 22.5 mmol, the amount of DMSO is adjusted to 34 mL, and the amount of toluene is adjusted to 17 mL to obtain PSPEEK-10-L with a molecular weight of 6000 g / mol. The amount of 4,4'-difluorobenzophenone is adjusted to 7.5 mmol, the amount of the diphenol monomer containing a photocurable cinnamate group shown in Formula III is adjusted to 1.62 mmol, the amount of bisphenol AF is adjusted to 3.78 mmol, the amount of anhydrous potassium carbonate is adjusted to 8.1 mmol, the amount of DMSO is adjusted to 13 mL, and the amount of toluene is adjusted to 6.5 mL to obtain PSPEEK-30-L with a molecular weight of 6000 g / mol. The amount of 4,4'-difluorobenzophenone is adjusted to 4 mmol, the amount of the diphenol monomer containing a photocurable cinnamate group shown in Formula III is adjusted to 1.6 mmol, the amount of bisphenol AF is adjusted to 1.6 mmol, the amount of anhydrous potassium carbonate is adjusted to 4.8 mmol, the amount of DMSO is adjusted to 8 mL, and the amount of toluene is adjusted to 4 mL to obtain PSPEEK-50-L with a molecular weight of 6000 g / mol. The results are shown in Table 1. Test method: Weigh 5 mg of the fully dried photosensitive polyaryletherketone, add it to 1 mL of the solvent, and observe its dissolution at room temperature. High-boiling aprotic solvents such as NMP and N,N-dimethylformamide (DMF) and photocurable reactive diluents such as N-vinylpyrrolidone (NVP), N-vinylformamide (NVF), and polyethylene glycol diacrylate (PEGDA), as well as common polar solvents such as toluene, acetone, tetrahydrofuran, and chloroform, were respectively selected to qualitatively analyze the change in the solubility of the polymer before and after the introduction of the photosensitive side group.

[0138] PEEK-0-L and photosensitive PEEK-L (oligomer with a number average molecular weight of 6000 g / mol) have good solubility in high-boiling aprotic solvents NMP and DMF. Among the UV-curable reactive diluents NVP, NVF, and PEGDA required for photocuring 3D printing, the solubility of photosensitive PEEK-L is NVP > NVF > PFGDA, and the solubility increases with the increase in the content of diphenol monomers. In common organic solvents, PEEK-0-L has good solubility. The solubility of photosensitive PEEK-L is tetrahydrofuran > acetone > chloroform > toluene, and the solubility in each solvent also increases with the increase in the content of diphenol monomers. Introducing bulky side groups into the photosensitive polymer can effectively reduce the packing density of the polymer, inhibit the crystallization behavior of molecules, and thus improve solubility. In the present invention, bulky side groups containing photocuring groups are introduced into polyaryletherketone, increasing the solubility of polyaryletherketone in reactive diluents and showing its application potential in photocuring 3D printing.

[0139] Table 1 Solubility of PEEK-0-L and photosensitive polymers PSPEEK-10-L, PSPEEK-30-L, PSPEEK-50-L

[0140]

[0141] In Table 1, the experiments were carried out at 25 °C. ++: Completely dissolved, +-: Partially dissolved, -: Hardly dissolved. NMP: N-methylpyrrolidone, DMF: N,N-dimethylformamide, NVP: N-vinylpyrrolidone, NVF: N-vinylformamide, PEGDA: Polyethylene glycol diacrylate, Toluene: Toluene, Acetone: Acetone, THF: Tetrahydrofuran, CHCl 3 : Chloroform.

[0142] Test Example 5 Photoresponse Performance Test of Polyaryletherketone

[0143] To determine the photocuring ability of the photosensitive polyaryletherketone, its photosensitivity was tested. Take 0.05 g of photosensitive polyaryletherketone PSPEEK-10, dissolve it in 2 g of NMP, and add 0.041 g of photoinitiator 819 to prepare a photosensitive polymer solution. Pour this solution onto a glass slide, level it, and irradiate it with a UV lamp with an irradiation wavelength of 405 nm for 3 min. Then dry the solvent in a vacuum drying oven at 60 °C to obtain a photocured polymer film UV-PSPEEK-10. The infrared spectra of the polymer before and after irradiation are as Figure 8 shown. Comparing the infrared spectra of PSPEEK-10 before and after photocuring, it can be observed that 1631 cm -1The intensity of the C=C stretching vibration peak at [specific location] significantly weakens. It can thus be proven that under ultraviolet light irradiation, PSPEEK can undergo photocuring through the initiation of photoinitiator 819, indicating the application potential of photosensitive poly(aryl ether ketone) in the field of photocuring.

[0144] Test Example 6 Structural Characterization of Photocured Poly(aryl ether ketone) Film

[0145] (1) FT-IR Characterization of Photocured PEEK Film

[0146] The infrared spectrum of poly(aryl ether ketone) after photocuring is as Figure 9 shown. The main characteristic peaks of poly(aryl ether ketone) are all marked in the figure. 1659 cm -1 is the stretching vibration peak of the carbonyl C=O conjugated with the benzene ring, 1596 cm -1 , 1500 cm -1 are the ring vibration peaks of the Ar-O-Ar benzene ring, 1306 cm -1 is the ring vibration peak of the Ar-CO-Ar benzene ring, 1016 cm -1 is the C-H bending vibration peak of the benzene ring in aryl ether or aryl ketone, 927 cm -1 is the symmetric stretching vibration peak of Ar-CO-Ar, 855 cm -1 is the out-of-plane rocking vibration peak of two adjacent hydrogens on the benzene ring. These peaks are Figure 5 consistent with [reference], indicating that the nature of poly(aryl ether ketone) has not changed after ultraviolet light irradiation. The disappearance of the C=C stretching vibration peak at 1631 cm -1 indicates that the photosensitive double bonds have fully participated in the reaction.

[0147] (2) XRD Characterization of Photocured PEEK Film

[0148] Figure 10 shows the XRD characterization of the photocured poly(aryl ether ketone) film. According to the results, the PEEK-0 film exhibits an amorphous morphology, while the photocured poly(aryl ether ketone) film shows a sharp peak at 5.48°. As the monomer content in the copolymer continuously increases, the intensity of this peak also increases, and when the content of the comonomer increases to 30%, the intensity decreases, indicating the presence of crystallization in the poly(aryl ether ketone) film. The intensity of the XRD diffraction peak is related to the crystal phase content. In the polymer film, as the content of the photosensitive double bonds increases, the crystal proportion also increases. The photocured film UV-PSPEEK-20 has the highest degree of crystallization. The poly(aryl ether ketone) prepared in this invention shows no obvious crystallization phenomenon in the polymer form, while obvious crystallization appears after photocuring, indicating that photocuring effectively tightens the intermolecular structure of the polymer. Moderate crystallization behavior can improve the mechanical properties of the polymer, while the non-crystallization of photosensitive poly(aryl ether ketone) in the polymer form improves its processability, and the appearance of crystallization after photocuring improves its comprehensive properties. The whole process is relatively ideal.

[0149] Test Example 7 Gel Fraction of Photo-Cured Polyaryletherketone Film

[0150] Gel fraction test:

[0151] Test method: Weigh the photo-cured polyaryletherketone film UV-PSPEEK-x with a mass of W 1 and place it in a Soxhlet extractor for extraction with NMP as the solvent. After extraction for 12 h, dry the remaining film in a vacuum drying oven at 120 °C for 10 h, and record the mass of the remaining film as W 2 . The percentage of the mass of the remaining film to the mass of the initial film is the gel fraction. The calculation method of the gel fraction is shown in Equation (1).

[0152]

[0153] Calculate the gel fraction of the polyaryletherketone film according to Equation (1), and the results are as Figure 11 shown. According to the results, PEEK-0 is soluble in NMP. The growth trend of the gel fraction of the photosensitive polymer is basically consistent with the change in the content of the diphenol monomer in the polymer. It shows that when the same preparation method is used, the higher the content of the photosensitive double bond in the system, the tighter the cross-linked structure generated during ultraviolet light irradiation, and the greater the gel coefficient of the photo-cured film. This result indicates that the UV-PSPEEK-x polyaryletherketone films are all cross-linked, and the degree of cross-linking increases with the increase in the double bond content in the system.

[0154] Test Example 8 Mechanical Properties of Photo-Cured Polyaryletherketone Film

[0155] Mechanical properties are important performance indicators of polyaryletherketone films. The mechanical properties of PEEK-0 and photo-cured polyaryletherketone films were tested. Instrument model: EZ-Test SHIMADZU universal material testing machine. Test conditions: Conducted at room temperature, test speed 1 mm / min. Test method: Cut the polymer film into rectangular strips with dimensions of 40 mm × 5 mm, and conduct tensile tests on the testing machine. At least 5 specimens are tested for each group of samples, and reasonable data are selected and averaged.

[0156] According to the results, adding a certain amount of photosensitive diphenol monomer (diphenol monomer containing a photo-curable cinnamate group) can increase the mechanical properties of the photo-cured film. When the addition amounts are 7% and 10%, the tensile strength reaches the maximum, about 68 MPa. When the monomer addition amount continues to increase, the tensile strength will rapidly decrease, and the mechanical properties of UV-PSPEEK-20 are even lower than 20 MPa. According to Figure 12As can be seen from (b) of , the elongation at break of the polymer film decreases significantly after adding the photosensitive diphenol monomer, indicating that the increase in crosslinking degree and the appearance of crystallization lead to the enhancement of the film's rigidity. The mechanical properties of the photocured film UV-PSPEEK-20 show that excessive crosslinking and excessive crystallization will make the material brittle, hard and the mechanical strength decrease. The photocured film UV-PSPEEK-30 is too brittle to be cut into tensile splines for testing. From the perspective of material application, UV-PSPEEK-7 and UV-PSPEEK-10 have the best tensile properties and can be used as the photocured 3D printing polymer matrix for subsequent research.

[0157] Test Example 9 Thermal Properties of Photocured Polyaryletherketone Films

[0158] Thermal stability is one of the important application parameters of polyaryletherketone films. Thermogravimetric tests were carried out on all polyaryletherketone films, and the results are as Figure 13 shown in Table 2.

[0159] Thermogravimetric analysis (TGA): Instrument model: NETZSCH-STA449F3 synchronous thermal analyzer. Test conditions: Heating from 25 °C to 800 °C at a rate of 10 °C / min under a nitrogen atmosphere. Test method: Put 3 - 5 mg of the sample into an alumina crucible and place it in the instrument for testing. The thermal stability is measured according to the mass change.

[0160] According to the thermogravimetric curve, adding the photosensitive diphenol monomer will lead to a decrease in the thermal stability of the polymer film, and the thermal stability of the polymer film continuously decreases with the increase in the content of the photosensitive diphenol monomer. This is because there are -NH- groups in the photosensitive polymer that are unstable at high temperatures, so the thermal stability is worse than that of PEEK-0. According to the data in Table 2, the char yield of the photocured polyaryletherketone film is lower than that of PEEK-0, but there is no obvious rule in the change of the char yield and the content of the photosensitive monomer.

[0161] Table 2 Thermal Property Data of PEEK-0 and Photocured UV-PSPEEK Films

[0162]

[0163] Test Example 10 Morphology Characterization of Photocured Polyaryletherketone Films

[0164] As Figure 14 shown are the surface morphology and tensile fracture morphology of the photocured polyaryletherketone film. Instrument model: JEOL JSM-IT200(LA) desktop scanning electron microscope. Test conditions: Conducted at room temperature, test voltage 5.0 kV. Test method: Stick the surface or tensile fracture of the polymer film face up on the sample stage, perform gold spraying for 15 s, and observe the surface morphology and tensile fracture morphology of the polymer film.

[0165] According to the results of scanning electron microscopy, the surface of the polymer film is relatively smooth, with occasional scratches and impurities, but it is relatively uniform overall. When the polymer film breaks under tension, the cross section of PEEK-0 is the smoothest, with almost no other morphology. The tensile cross section of the photosensitive polymer film is relatively rough, with an uneven fracture. Polyaryletherketone film is a semi-crystalline polymer that exhibits brittle fracture below the glass transition temperature. When the polymer film is subjected to tensile stress, silver streaks are generated at some weak structures and defects of the film, resulting in voids inside the material. As the strain increases further, these voids expand into holes, and further expansion between different holes leads to final fracture. PEEK-0 film is a linear polymer with uniform overall distribution. Its fracture is the result of the tensile strength of the polymer main chain reaching its limit. In the photocurable film, the short chain in the cross-linked network is a weak structure, which leads to microcracks appearing first during stretching, further generating voids and thus breaking, so the cross section is relatively rough.

[0166] According to the above test results, it can be seen that the present invention designs and synthesizes a new photosensitive diphenol monomer FAAMBH from the perspective of molecular structure, copolymerizes it with commercial monomers 4,4'-difluorobenzophenone and bisphenol AF, successfully synthesizes polyaryletherketone with photosensitive double bonds in the molecule, and obtains a series of photocurable polyaryletherketone films by ultraviolet light. Characterization of it leads to the following conclusions: (1) The photosensitive polyaryletherketone does not crystallize in the polymer form, but crystallizes after photocuring. This phenomenon increases the solubility of the polymer while obtaining a photocurable film with good mechanical properties. (2) The infrared spectrum shows that under 405nm ultraviolet light, the photosensitive polyaryletherketone is photocured under the action of photoinitiator 819, and can be used in the field of photocuring. (3) Compared with PEEK-0 film, the mechanical properties of the photocurable PEEK film are improved when the molar content of the photosensitive monomer is 2%, 4%, 7%, and 10%. Among them, the photocurable films UV-PEEK-7 and UV-PEEK-10 have the best tensile properties and can be used as the matrix of photocurable 3D printing ink.

[0167] Test Example 11

[0168] In parts by weight, 45 parts of the photosensitive polyaryletherketone prepared in Example 2, 2 parts of the photoinitiator 819, 8 parts of the photocrosslinker TMPTA and 45 parts of N-vinylpyrrolidone were mixed to obtain ink; the ink was subjected to photocuring 3D printing and cured under ultraviolet light to obtain the following: Figure 15 The polyaryletherketone part shown.

[0169] Depend on Figure 15 It can be seen that the photosensitive polyaryletherketone provided by the present invention can be used to prepare ink for photocuring 3D printing to obtain polyaryletherketone parts with higher precision.

[0170] 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 be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A diphenol monomer containing a photocurable cinnamate group, having the structure shown in Formula I: In formula I, R 1 is H or CH 3 ; R 2 is H, F or CH 3 .

2. The diphenol monomer containing a photocurable cinnamate group according to claim 1, wherein, When the R 1 is H, the R 2 is H, F or CH 3 ; when the R 1 is CH 3 , the R 2 is CH 3 .

3. A method for preparing the diphenol monomer containing a photocurable cinnamate group according to any one of claims 1 to 2, comprising the following steps: Mix an aromatic diamine, di-tert-butyl dicarbonate, a catalyst and a first organic solvent, and carry out a substitution reaction to obtain Compound 1; Mix the Compound 1, an acid-binding agent, a second organic solvent and cinnamoyl chloride, and carry out a nucleophilic addition reaction to obtain Compound 2; Heat the Compound 2 to obtain a diphenol monomer containing a photocurable cinnamate group having the structure shown in Formula I; The structure of the aromatic diamine is The structure of the said Compound 1 is The structure of the said Compound 2 is 4. The preparation method according to claim 3, wherein, the molar ratio of the aromatic diamine to di-tert-butyl dicarbonate is 10:20 - 25.

5. The preparation method according to claim 3, wherein, the molar ratio of the Compound 1 to the acid-binding agent is 10:21 - 25; the molar ratio of the Compound 1 to cinnamoyl chloride is 10:21 - 25.

6. The preparation method according to claim 3, wherein, the heating temperature is 170 - 220 °C.

7. A photosensitive polyaryletherketone, wherein, having the structure shown in Formula II: In formula II, R 1 is H or CH 3 ; R 2 is H, F or CH 3 ; R 3 is C=O or SO 2 .

8. The photosensitive polyaryletherketone according to claim 7, wherein, When the said R 1 is H, R 2 is H, R 3 is C=O or SO 2 ; when the said R 1 is H, R 2 is F, R 3 is C=O or SO 2 ; when the said R 1 is H, R 2 is CH 3 , R 3 is C=O or SO 2 ; when the said R 1 is CH 3 , R 2 is CH 3 , R 3 is C=O or SO 2 .

9. A method for preparing the photosensitive polyaryletherketone according to any one of claims 7 to 8, comprising the following steps: Mix the diphenol monomer containing a photocurable cinnamate group according to any one of claims 1 to 2 or the diphenol monomer containing a photocurable cinnamate group prepared by the preparation method according to any one of claims 3 to 6, a commercial binary halogenated monomer, a commercial diphenol monomer, potassium carbonate and a third organic solvent, and carry out a copolymerization reaction to obtain a photosensitive polyaryletherketone having the structure shown in Formula II; the commercial binary halogenated monomer includes 4,4'-difluorobenzophenone; the commercial diphenol monomer includes bisphenol AF.

10. Use of the photosensitive polyaryletherketone according to any one of claims 7 to 8 or the photosensitive polyaryletherketone prepared by the preparation method according to claim 9 in the preparation of polyaryletherketone films or polyaryletherketone parts.

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