A trifluoromethyl-containing polyamide ester, and a preparation method and application thereof
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HEBEI UNIV OF SCI & TECH
- Filing Date
- 2026-05-13
- Publication Date
- 2026-06-23
AI Technical Summary
In the existing technology, traditional all-aromatic polyimides have poor solubility, high dielectric constant, many processing difficulties and high energy consumption. Furthermore, the esterification method containing trifluoromethyl polyamide ester is violent and has poor selectivity, making it difficult to stably obtain materials with uniform structure and excellent performance.
Polyamic acid is formed by polymerizing a trifluoromethyl-containing diamine monomer and a dianhydride monomer in a polar solvent. Then, it is alkylated by a mild alkylation reaction using alkylating agents such as dimethyl carbonate or iodomethane in the presence of an acid-binding agent to obtain a trifluoromethyl-containing polyamide ester.
The efficient preparation of trifluoromethyl polyamide esters was achieved under mild reaction conditions and high selectivity, which broadened the application of the material in high-end electronics, improved organic solvent solubility and reduced dielectric constant, and met the needs of high-frequency communication and microelectronics. Moreover, the process is simple and the cost is controllable.
Smart Images
Figure CN122255473A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of photoresist resin technology, and in particular to a trifluoromethyl polyamide ester, its preparation method, and its application. Background Technology
[0002] Polyimide (PI) is widely used in microelectronics, flexible displays, and other fields due to its excellent heat resistance, mechanical properties, and insulation properties. Traditional fully aromatic PI is usually prepared by high-temperature thermal imidization of polyamic acid (PAA) precursors. However, its molecular chain is rigid and highly symmetrical, which not only presents processing challenges such as poor solubility and high melting temperature, but also limits its application in high-frequency communication due to its high dielectric constant. At the same time, PAA precursors have poor storage stability and are easily degraded, and high-temperature imidization (>250℃) is energy-intensive and prone to side reactions, which seriously restricts the preparation of high-performance PI.
[0003] Introducing trifluoromethyl (-CF3) compounds can significantly improve the solubility and dielectric properties of polyimide (PI). Replacing polyamide ester (PAA) with polyamide ester (PAE) as a PI precursor effectively enhances precursor storage stability and film-forming properties, making it an ideal route for the mild preparation of fluorinated PI. However, existing post-modification esterification methods for trifluoromethyl PAA often require highly reactive reagents such as acyl chlorides, resulting in vigorous reactions, poor selectivity, and a lack of efficient and controllable esterification processes at room temperature, making it difficult to stably obtain structurally uniform and high-performance trifluoromethyl PAEs. Therefore, developing a mild, highly selective, and industrially suitable method for preparing trifluoromethyl polyamide esters is of great significance for promoting the low-cost, high-quality synthesis of high-performance fluorinated polyimides. Summary of the Invention
[0004] The purpose of this invention is to provide a trifluoromethyl polyamide ester and its preparation method to solve the problems existing in the prior art.
[0005] To achieve the above objectives, the present invention provides a method for preparing trifluoromethyl polyamide ester, comprising the following steps: S1. Under an inert atmosphere, a diamine monomer containing trifluoromethyl and a dianhydride monomer are dissolved in a polar solvent and stirred to carry out a polymerization reaction to obtain polyamic acid. S2. Add an alkylating agent to polyamic acid to carry out an alkylation reaction to obtain trifluoromethyl polyamide ester.
[0006] The synthesis route is shown below: ; In the formula, X represents a tetravalent organic group, selected from one of the following tetravalent residues remaining after removing two anhydride groups from a dianhydride monomer: 3,3',4,4'-benzophenone tetracarboxylic dianhydride residue, 3,3',4,4'-biphenyltetracarboxylic dianhydride residue, 4,4'-oxophthalic anhydride residue, 4,4'-(hexafluoroisopropyl)phthalic anhydride residue, 2,3,6,7-naphthalenetetracarboxylic dianhydride residue, 3,3',4,4'-diphenylsulfone tetracarboxylic dianhydride residue, 3,4,9,10-perylenetetracarboxylic dianhydride residue, 4,4'-(1,4-phenyldioxy)phthalic anhydride residue, 9,9-bis(3,4-dicarboxyphenyl) 4,4'-(4,4'-isopropyldiphenoxy)bis(phthalic anhydride) residues, 1,2,3,4-cyclobutanetetracarboxylic anhydride residues, 5,5'-(propane-2,2-diyl)bis(isobenzofuran-1,3-dione) residues, 4,4'-methylenebis(phthalic anhydride) residues, triphenylmethane-3,3',4,4'-tetracarboxylic anhydride residues, and 3,3'-bis(trifluoromethyl)-4,4',5,5'-biphenyltetracarboxylic anhydride residues; The aromatic rings of the aforementioned compound residues can be independently substituted by 1-4 substituents, each of which is independently selected from: C1-C6 alkyl, C1-C6 alkoxy, fluorine, chlorine, bromine or iodine; the substituents are attached to carbon atoms on the aromatic ring that are not directly bonded to the anhydride group; when multiple substituents exist on the same aromatic ring, they may be the same or different from each other.
[0007] The Y represents a divalent organic group selected from at least one of the following divalent residues remaining after removing two amino groups from a trifluoromethyl diamine monomer: 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl residues, 3,3'-bis(trifluoromethyl)-4,4'-diaminodiphenyl sulfone residues, 2,2'-bis(trifluoromethyl)-4,4'-diaminodiphenyl ether residues, 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane residues, 3,3'-dihydroxybenzidine residues, 4,4'-[1,4-phenylbis(oxy)]bis[3-(trifluoromethyl)aniline] residues, 2,2-bis(4-aminophenyl)hexafluoropropane residues, 3,3'- Bis(trifluoromethyl)-[1,1'-biphenyl]-4,4'-diamine residues, 3,3'-bis(trifluoromethyl)-4,4'-diaminodiphenyl ether residues, 2,2-bis(3-amino-4-hydroxyphenyl)propane residues, 2,2'-bis(trifluoromethyl)-[1,1'-biphenyl]-4,4'-diamine residues, 2,2-bis[3-(4-aminobenzamido)-4-hydroxyphenyl]hexafluoropropane residues, 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane residues; Furthermore, except for the 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane residue, the aromatic rings of the aforementioned compound residues can be independently substituted by 1-4 substituents, each of which is independently selected from: C1-C6 alkyl, C1-C6 alkoxy, fluorine, chlorine, bromine, or iodine; the substituents are attached to carbon atoms on the aromatic ring that are not directly bonded to the amino group; when multiple substituents are present on the same aromatic ring, they may be the same or different from each other.
[0008] R is selected from at least one of the following groups: .
[0009] Preferably, in S1, the trifluoromethyl-containing diamine monomer includes at least one of the following compounds: 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 3,3'-bis(trifluoromethyl)-4,4'-diaminodiphenyl sulfone, 2,2'-bis(trifluoromethyl)-4,4'-diaminodiphenyl ether, 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane, 3,3'-dihydroxybenzidine, 4,4'-[1,4-phenylbis(oxy)]bis[3-(trifluoromethyl)aniline], 2,2-bis(4-aminophenyl)hexafluoropropane, 3,3'-bis(trifluoro) The structural formulas of the following compounds are as follows: methyl)-[1,1'-biphenyl]-4,4'-diamine, 3,3'-bis(trifluoromethyl)-4,4'-diaminodiphenyl ether, 2,2-bis(3-amino-4-hydroxyphenyl)propane, 2,2'-bis(trifluoromethyl)-[1,1'-biphenyl]-4,4'-diamine, 2,2-bis[3-(4-aminobenzamido)-4-hydroxyphenyl]hexafluoropropane, and 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane are: ; Furthermore, except for 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, the aromatic rings of the aforementioned compounds may be independently substituted by 1-4 substituents, each of which is independently selected from: C1-C6 alkyl, C1-C6 alkoxy, fluorine, chlorine, bromine, or iodine; the substituents are attached to carbon atoms on the aromatic ring that are not directly bonded to the amino group; when multiple substituents are present on the same aromatic ring, they may be the same or different from each other.
[0010] Preferably, in S1, the dianhydride monomer includes one of the following compounds: 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 4,4'-oxophthalic anhydride, 4,4'-(hexafluoroisopropyl)phthalic anhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3',4,4'-diphenylsulfone tetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 4,4'-(1,4-phenyldioxy)phthalic anhydride, 9,9-bis(3,4-dicarboxyphenyl) Fluorene dianhydride, pyromellitic dianhydride, 4,4'-(4,4'-isopropyldiphenoxy)bisphthalic anhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 5,5'-(propane-2,2-diyl)bis(isobenzofuran-1,3-dione), 4,4'-methylenebisphthalic anhydride, triphenylmethane-3,3',4,4'-tetracarboxylic dianhydride, 3,3'-bis(trifluoromethyl)-4,4',5,5'-biphenyltetracarboxylic dianhydride, with the following structural formulas: ; The aromatic rings of the aforementioned compounds may be independently substituted by 1-4 substituents, each of which is independently selected from: C1-C6 alkyl, C1-C6 alkoxy, fluorine, chlorine, bromine or iodine; the substituents are attached to carbon atoms on the aromatic ring that are not directly bonded to an anhydride group; when multiple substituents exist on the same aromatic ring, they may be the same or different from each other.
[0011] Preferably, in S1, the organic solvent is selected from at least one of N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone and γ-butyrolactone; the molar mass ratio of the trifluoromethyl diamine monomer, the dianhydride monomer and the organic solvent is 0.08-0.1 mol: 0.08-0.1 mol: 200-350 g.
[0012] Preferably, a capping agent may also be added to S1. The capping agent is selected from 3-aminophenol, and the mass of the capping agent is 0.9%-6% of the total mass of the trifluoromethyl diamine monomer and the dianhydride monomer. Adding a capping agent can further control the molecular weight and molecular weight distribution of the polymer. The alkylation method of the present invention has a good alkylation effect regardless of whether a capping agent is added.
[0013] Preferably, in S1, the polymerization reaction process is as follows: first, react in an ice-water bath at a temperature below 5°C for 10-14 hours, then raise the temperature to 25-40°C and hold for 4-12 hours.
[0014] Preferably, in S2, the alkylating agent includes at least one of iodomethane, iodoethane, dimethyl carbonate, diethyl carbonate, and (trimethylsilane)diazomethane, and the molar ratio of polyamic acid (based on the amount of carboxyl group in the repeating unit of polyamic acid) to the alkylating agent is 1:1.2-5.
[0015] In this invention, when the alkylating agent is iodomethane, iodoethane, dimethyl carbonate, or diethyl carbonate, the alkylation reaction is carried out under acid-binding agent conditions; the acid-binding agent is selected from at least one of triethylamine, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 4-dimethylaminopyridine (DMAP), and potassium carbonate; the amount of acid-binding agent is usually 1.0-1.5 eq (relative to the number of moles of PAA carboxyl groups).
[0016] In this invention, when the alkylating agent is (trimethylsilane)diazomethane, the alkylation reaction is carried out under conditions without an acid binder.
[0017] Preferably, in S2, the alkylation reaction temperature is 25-45℃.
[0018] In this invention, the selection of alkylating agents is based on the core criteria of "mild reaction conditions, high alkylation efficiency, easy removal of byproducts, and no degradation of the polyamic acid backbone". After systematic screening, dimethyl carbonate and iodomethane were determined to be the best alkylating agents that can be used independently. Among them, dimethyl carbonate, due to its low cost, low toxicity, and moderate boiling point (90°C), can stably improve the conversion rate of carboxyl groups of polyamic acid repeating units by reacting at 70-90°C and atmospheric pressure -0.3MPa (autogenous pressure) for 6-12 hours in the presence of acid-binding agents such as DBU or DMAP (1.0-1.5 eq, relative to the number of carboxyl groups in PAA). Regardless of whether an organic base (such as triethylamine or DBU) or an inorganic base (such as potassium carbonate) is used as an acid-binding agent, the reaction byproducts are all quaternary ammonium salts, hydrohalides, or inorganic salts with excellent water solubility. By injecting the reaction solution into an acidic aqueous solution, all alkali residues and byproduct salts can be efficiently extracted to the aqueous phase and completely removed by simple filtration and washing, eliminating the need for cumbersome operations such as column chromatography or recrystallization. This post-processing method is mild, easy to operate, and yields high-quality products (>95%) with excellent purity, making it suitable for industrial-scale production. The absence of metal ion residues has no negative impact on the transmittance of subsequent optical films, making it suitable for large-scale industrial production. Iodomethane possesses ultra-high methylation activity, achieving high carboxyl conversion at low temperatures (25-40°C), making it particularly suitable for high-end optical film formulations that are heat-sensitive and require strict inhibition of main-chain degradation. However, due to its high price and volatility, it is recommended to control the dosage at 2.0-3.0 eq of PAA carboxyl molar amount and conduct the reaction in a closed system to minimize volatilization losses. Both reagents, used independently, can achieve high alkylation efficiency and low side reactions, constituting the optimal alkylation reagent selection for step S2 of this invention.
[0019] In an embodiment of the present invention, after obtaining a polyamic acid solution in S1, deionized water is added to precipitate the polyamic acid. The solution is then filtered, washed, and dried to obtain solid polyamic acid. In S2, the solid polyamic acid is dissolved in an organic solvent. The precipitation and subsequent dissolution are to separate the precipitated polymer and remove small molecule impurities.
[0020] The present invention also provides a trifluoromethyl polyamide ester, which is prepared by the above preparation method.
[0021] The present invention also provides an application of trifluoromethyl polyamide ester, wherein the above-mentioned trifluoromethyl polyamide ester is used to synthesize polyimide.
[0022] Therefore, the present invention, by employing the above-mentioned trifluoromethyl polyamide ester, its preparation method, and its application, has the following beneficial effects: (1) This invention achieves efficient preparation of trifluoromethyl polyamide ester through a two-step method (first synthesizing polyamic acid, and then alkylating it under room temperature or low temperature heating conditions). The reaction conditions are mild, with few side reactions and high selectivity, which solves the problem of high temperature processing and broadens the application of the material in the field of high-end electronics.
[0023] (2) The introduction of trifluoromethyl in this invention increases the free volume and asymmetry of the molecular chain, and disrupts the close packing of the molecular chain, thereby greatly improving the organic solvent solubility of the final polyimide, while effectively reducing the dielectric constant, adapting to the low dielectric requirements of high frequency communication, microelectronics and other fields, and taking into account heat resistance, mechanical properties and insulation.
[0024] (3) The alkylating reagent in this invention has low toxicity and the byproducts are easy to remove. The post-processing only requires simple water washing and filtration to obtain high-purity products with a yield of >92% and no metal ion residue. The process is simple, the cost is controllable, and it is suitable for large-scale industrial scale-up.
[0025] (4) The trifluoromethyl polyamide ester prepared by the present invention can be directionally converted into high-performance fluorinated polyimide, which is perfectly suited to scenarios with stringent requirements for material processability, stability, optical and electrical properties, such as photoresist, flexible display, and high-frequency electronic devices, and provides a new path for customized design of polyimide structure.
[0026] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description
[0027] Figure 1 This is the infrared absorption spectrum of the trifluoromethyl polyamide ester prepared in Example 1 of this invention; Figure 2 This is the infrared absorption spectrum of the trifluoromethyl polyamide ester prepared in Example 6 of this invention; Figure 3 This is a gel chromatogram of the trifluoromethyl polyamide ester prepared in Example 1 of the present invention. Detailed Implementation
[0028] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.
[0029] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.
[0030] In this invention, unless otherwise specified, the test materials and instruments are all conventional test materials in the field and can be purchased through commercial channels.
[0031] Example 1 A method for preparing trifluoromethyl polyamide ester includes the following steps: S1. Under a nitrogen atmosphere, 0.1 mol (32.03 g) of 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (a trifluoromethyl diamine monomer) and 0.1 mol (32.22 g) of 3,3',4,4'-benzophenone tetracarboxylic dianhydride (dianhydride monomer) were dissolved in 300 g of N-methylpyrrolidone (organic solvent). The reaction was first carried out in an ice-water bath at 3°C for 12 h, and then the temperature was raised to 25°C and maintained for 6 h to obtain a polyamic acid solution. 3 L of deionized water was slowly added to the polyamic acid solution, and a white flocculent precipitate was formed. The precipitate was filtered, washed three times with deionized water, and dried under vacuum at 50°C for 72 h to obtain solid polyamic acid. The yield of solid polyamic acid was 96%. S2. Under a nitrogen atmosphere, 16.1 g of the polyamic acid obtained in S1 (0.05 mol based on repeating carboxyl groups) was placed in a 250 mL three-necked flask, and 91 g of [unclear text - possibly a typo, should be 0.05 mol] was added. N-methylpyrrolidone (organic solvent) was stirred at 25°C until completely dissolved to obtain a homogeneous solution with a mass fraction of 15%. Iodomethane (alkylating agent) 21.29 g (0.15 mol) was added in three batches at 25°C, with each batch spaced 10 min apart. After the addition was complete, stirring was continued for 12 h in the dark. Subsequently, triethylamine (acid-binding agent) 7.67 mL (0.055 mol) was slowly added dropwise over 30 min through a constant-pressure funnel, with the temperature controlled at 25°C during the addition. After the addition was complete, stirring was continued for 48 h to obtain a deep yellow viscous reaction solution. The obtained reaction solution was injected into 1.1 L of 1% hydrochloric acid aqueous solution in a thin stream, and stirred rapidly at 600 rpm for 30 min to completely precipitate a yellow powdery precipitate. The precipitate was filtered, washed with deionized water until the pH of the washing solution reached 6, and then dried under vacuum at 50°C for 72 h to obtain 16.1 g of yellow powder containing trifluoromethyl polyamide ester, with a yield of 96%.
[0032] Example 2 This embodiment operates the same as Example 1, except that in S1, the trifluoromethyl-containing diamine monomer is 3,3'-bis(trifluoromethyl)-4,4'-diaminodiphenyl sulfone, and the amount added is 0.08 mol (30.74 g); the dianhydride monomer is 3,3',4,4'-biphenyltetracarboxylic dianhydride, and the amount added is 0.08 mol (23.52 g); the amount of N-methylpyrrolidone (organic solvent) used is 320 g; and the yield of polyamic acid solid is 95%. In S2, the amount of polyamic acid used is... 13.56 g (0.04 mol based on repeating carboxyl groups), 76.84 g of N-methylpyrrolidone (organic solvent) was added; the alkylating agent added was dimethyl carbonate, 18 mL (0.2 mol); the acid-binding agent added was 1,8-diazabicyclo[5.4.0]undec-7-ene, 7.31 g (0.048 mol); the alkylation reaction temperature was 45 °C; 13 g of yellow powder containing trifluoromethyl polyamide ester was obtained, with a yield of 92%.
[0033] Example 3 This embodiment operates similarly to Example 1, except that in S1, the trifluoromethyl-containing diamine monomer is 2,2'-bis(trifluoromethyl)-4,4'-diaminodiphenyl ether, and the amount added is 0.09 mol (30.26 g); the dianhydride monomer is 4,4'-(1,4-phenyldioxy)bisphthalic anhydride, and the amount added is 0.09 mol (36.21 g), with a polyamic acid solid yield of 95%; in S2, the amount of polyamic acid used is 18.46 g. The amount of N-methylpyrrolidone (organic solvent) used was 105 g (based on repeating carboxyl groups, 0.05 mol); the alkylating agent added was (trimethylsilane)diazomethane, and the amount added was 22.16 mL (0.15 mol); the alkylating agent was added at 0 °C and added dropwise over 1 h, then the temperature was raised to 25 °C and stirred for 12 h in the dark to obtain a deep yellow viscous reaction solution; 18.2 g of yellow powder containing trifluoromethyl polyamide ester was obtained, with a yield of 98%.
[0034] Example 4 This embodiment operates similarly to Example 1, except that in S1, the trifluoromethyl-containing diamine monomer is 2,2'-bis(trifluoromethyl)-4,4'-diaminodiphenyl ether, and the amount added is 0.1 mol (33.62 g); the dianhydride monomer is 3,3',4,4'-biphenyltetracarboxylic dianhydride, and the amount added is 0.1 mol (29.42 g); the organic solvent is N,N-dimethylformamide, and the amount added is 280 g, resulting in a polyamic acid solid yield of 94%; in S2, the amount of polyamic acid used is 15.7 g. 6 g (0.05 mol based on repeating carboxyl groups), 90 g of N-methylpyrrolidone (organic solvent) was added; the alkylating agent added was diethyl carbonate, 23.6 g (0.2 mol); the acid-binding agent added was 1,8-diazabicyclo[5.4.0]undec-7-ene, 10.7 g (0.07 mol); the alkylation reaction temperature was 35 °C, and the stirring time was 20 h; 16.1 g of yellow powder containing trifluoromethyl polyamide ester was obtained, with a yield of 94%.
[0035] Example 5 This embodiment operates the same as Example 1, except that in S1, the trifluoromethyl-containing diamine monomers are 2,2'-bis(trifluoromethyl)-4,4'-diaminodiphenyl ether and 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, with addition amounts of 0.07 mol (23.54 g) and 0.01 mol (2.49 g), respectively; the dianhydride monomer is 4,4'-(1,4-phenyldioxy)bisphthalic anhydride, with an addition amount of 0.085 mol (34.2 g); the amount of N-methylpyrrolidone (organic solvent) is 200 g; after dissolving the trifluoromethyl-containing diamine monomer and the dianhydride monomer in the organic solvent, the mixture is first reacted in an ice-water bath at 3°C for 12 h, then heated to 25°C and held at that temperature for 6 h, and subsequently... 0.005 mol (0.55 g) of 3-aminophenol, the end-capping agent, was added, and the reaction was continued for 2 h to obtain a polyamic acid solution with a polyamic acid solid yield of 95%. In S2, the amount of polyamic acid used was 14.5 g (0.04 mol based on the repeating carboxyl group), and the amount of N-methylpyrrolidone (organic solvent) used was 82.5 g. The alkylating agent added was dimethyl carbonate, with an amount of 16.2 g (0.18 mol). The acid-binding agent added was 1,8-diazabicyclo[5.4.0]undec-7-ene, with an amount of 6.85 g (0.045 mol). The alkylation reaction temperature was 40 °C, and the stirring time was 24 h. 14.3 g of yellow powder containing trifluoromethyl polyamide ester was obtained with a yield of 95%.
[0036] Example 6 This embodiment is operated in the same way as Example 1, except that in S1, the trifluoromethyl-containing diamine monomer is 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane, and the amount added is 0.1 mol (36.62 g); the dianhydride monomer is 4,4'-oxobisphthalic anhydride, and the amount added is 0.1 mol (31.02 g); the organic solvent is N,N-dimethylacetamide, and the amount added is 280 g; after reacting in an ice-water bath for 8 h, the temperature is raised to room temperature (25°C) and kept at that temperature for 12 h, and the yield of polyamic acid solid is 94%. In S2, under a nitrogen atmosphere, 16.82 g of the polyamic acid obtained in S1 (0.05 mol based on repeating carboxyl groups) was placed in a 250 mL three-necked flask, and 95.3 g of [unspecified substance] was added. N,N-Dimethylacetamide (organic solvent) was stirred at 25°C until completely dissolved to obtain a homogeneous solution with a mass fraction of 15%. Iodomethane (alkylating agent) 21.29 g (0.15 mol) was added in three batches at 25°C, with each batch spaced 10 min apart. After addition, stirring was continued for 12 h in the dark. Subsequently, potassium carbonate (acid-binding agent) 10.37 g (0.075 mol) was added, and stirring was continued for another 12 h. After the reaction was complete, the reaction solution was injected into 1.1 L of 1% hydrochloric acid aqueous solution in a thin stream and stirred rapidly at 600 rpm for 30 min to completely precipitate a yellow powdery precipitate. The precipitate was filtered, washed with deionized water until the pH of the washing solution reached 6, and then dried under vacuum at 50°C for 72 h to obtain 16.29 g of yellow powder containing trifluoromethyl polyamide ester, with a yield of 93%.
[0037] Example 7 This embodiment operates the same as Example 1, except that in S1, the trifluoromethyl diamine monomer is 3,3'-dihydroxybenzidine, and the amount added is 0.1 mol (21.62 g); the dianhydride monomer is 4,4'-(hexafluoroisopropyl)bisphthalic anhydride, and the amount added is 0.1 mol (44.42 g); the amount of N-methylpyrrolidone added is 320 g; and the yield of polyamic acid solid is 95%. In S2, under a nitrogen atmosphere, 16.51 g of polyamic acid obtained in S1 (0.05 mol based on repeating carboxyl groups) was placed in a 250 mL three-necked flask, and 93.6 g of N-methylpyrrolidone (organic solvent) was added. The mixture was stirred at 25 °C until completely dissolved, yielding a homogeneous solution with a mass fraction of 15%. At 0 °C, 6.85 g (0.06 mol) of (trimethylsilane)diazomethane (alkylating agent) was slowly added dropwise over 1 hour. The temperature was then raised to 35 °C, and stirring was continued for 12 hours in the dark. After the reaction was complete, the reaction solution was injected into 1.1 L of a 1% hydrochloric acid aqueous solution in a thin stream. The solution was stirred rapidly at 600 rpm for 30 minutes to allow a yellow powdery precipitate to completely form. The precipitate was filtered, washed with deionized water until the pH of the washings reached 6, and then dried under vacuum at 50 °C for 72 hours to obtain 16.01 g of yellow powder containing trifluoromethyl polyamide ester, with a yield of 93%.
[0038] Example 8 This embodiment operates the same as Example 1, except that in S1, the trifluoromethyl-containing diamine monomer is 2,2-bis[3-(4-aminobenzamido)-4-hydroxyphenyl]hexafluoropropane, and the amount added is 0.1 mol (60.4 g); the dianhydride monomer is 3,3'-bis(trifluoromethyl)-4,4',5,5'-biphenyltetracarboxylic dianhydride, and the amount added is 0.1 mol (43.02 g); the organic solvent is γ-butyrolactone, and the amount added is 300 g; the yield of polyamic acid solid is 96%. In S2, under a nitrogen atmosphere, 25.86 g of the polyamic acid obtained in S1 (0.05 mol based on repeating carboxyl groups) was placed in a 250 mL three-necked flask, and 146.5 g of [unspecified substance] was added. γ-Butyrolactone (organic solvent) was stirred at 25°C until completely dissolved to obtain a homogeneous solution with a mass fraction of 15%. Diethyl carbonate (alkylating agent) 29.53 g (0.25 mol) was added in three batches at 40°C, with each batch spaced 10 min apart, and stirring continued for 10 h after each addition. Subsequently, 10.66 g (0.07 mol) of 1,8-diazabicyclo[5.4.0]undec-7-ene (acid-binding agent) was added, and stirring continued for 12 h. After the reaction was complete, the reaction solution was injected into 1.1 L of 1% hydrochloric acid aqueous solution in a thin stream, and rapidly stirred at 600 rpm for 30 min to completely precipitate a yellow powdery precipitate. The precipitate was filtered, washed with deionized water until the pH of the washing solution reached 6, and then vacuum dried at 50°C for 72 h to obtain 25.62 g of yellow powder containing trifluoromethyl polyamide ester, with a yield of 94%.
[0039] Example 9 This embodiment operates the same as Example 1, except that in S1, the trifluoromethyl diamine monomer is 4,4'-[1,4-phenylbis(oxy)]bis[3-(trifluoromethyl)aniline], and the amount added is 0.1 mol (42.83 g); the dianhydride monomer is 2,3,6,7-naphthalenetetracarboxylic dianhydride, and the amount added is 0.1 mol (26.82 g); the organic solvent is N,N-dimethylformamide, and the amount added is 350 g; the yield of polyamic acid solid is 93%. In S2, under a nitrogen atmosphere, 17.41 g of the polyamic acid obtained in S1 (0.05 mol based on repeating carboxyl groups) was placed in a 250 mL three-necked flask, and 98.7 g of [unspecified substance] was added. N,N-Dimethylformamide (organic solvent) was stirred at 25°C until completely dissolved to obtain a homogeneous solution with a mass fraction of 15%. Iodoethane (20.28 g, 0.13 mol) was added in three batches at 25°C, with each batch spaced 10 min apart. The mixture was stirred for 12 h in the dark after each addition. Then, triethylamine (0.055 mol, approximately 7.7 mL) was added, and the mixture was stirred for another 12 h. After the reaction was complete, the reaction solution was injected into 1.1 L of a 1% hydrochloric acid aqueous solution in a thin stream. The solution was stirred rapidly at 600 rpm for 30 min to completely precipitate a yellow powder. The precipitate was filtered, washed with deionized water until the pH of the washings reached 6, and then dried under vacuum at 50°C for 72 h to obtain 17.50 g of a yellow powder containing trifluoromethyl polyamide ester, with a yield of 93%.
[0040] Example 10 This embodiment operates the same as Example 1, except that in S1, the trifluoromethyl-containing diamine monomer is 2,2-bis(4-aminophenyl)hexafluoropropane, and the amount added is 0.1 mol (33.43 g); the dianhydride monomer is 3,3',4,4'-diphenylsulfone tetracarboxylic dianhydride, and the amount added is 0.1 mol (35.82 g); the amount of N-methylpyrrolidone added is 290 g; and the yield of polyamic acid solid is 97%. In S2, under a nitrogen atmosphere, 17.31 g of the polyamic acid obtained in S1 (0.05 mol based on repeating carboxyl groups) was placed in a 250 mL three-necked flask, and 98.1 g of [unspecified substance] was added. N-methylpyrrolidone was stirred at 25°C until completely dissolved to obtain a homogeneous solution with a mass fraction of 15%. Iodoethane (0.125 mol) was added in three batches at 25°C, with each batch spaced 10 min apart. The mixture was stirred for 12 h in the dark after each addition. Then, potassium carbonate (0.075 mol) was added, and stirring continued for 24 h. After the reaction was complete, the reaction solution was injected into 1.1 L of a 1% hydrochloric acid aqueous solution in a thin stream. The solution was stirred rapidly at 600 rpm for 30 min to completely precipitate a yellow powder. The precipitate was filtered, washed with deionized water until the pH of the washing solution reached 6, and then dried under vacuum at 50°C for 72 h to obtain 17.77 g of a yellow powder containing trifluoromethyl polyamide ester, with a yield of 95%.
[0041] The trifluoromethyl polyamide ester prepared in Example 1 was characterized by infrared spectroscopy, and the results are as follows: Figure 1 As shown. From Figure 1 It can be seen from this that 3450cm -1 The broad but weak absorption peak is attributed to a small amount of residual moisture or the stretching vibration of the terminal carboxyl group; 2950 cm⁻¹ -1 and 2850cm -1 This is a saturated CH stretching vibration, originating from the -CH3 group of the methyl ester group and the methylene group in the main chain; 1730 cm⁻¹ -1 The strong absorption peak at 1660 cm⁻¹ is due to the stretching vibration of the carbonyl group (C=O, methyl ester); -1 The intermediate absorption peak at 1600 cm⁻¹ is due to the stretching vibration of the amide carbonyl group (C=O, amide I band); -1 1500cm -1 It is a C=C stretching vibration of the aromatic ring skeleton; 1540cm -1 The absorption peak is at 1380 cm⁻¹, corresponding to the amide II band (NH bending + CN stretching). -1 This is a symmetrical bending vibration of the methyl group; 1300~1200 cm⁻¹ -1 The multiple peaks at 1100 cm⁻¹ indicate the CF stretching vibration (trifluoromethyl); -1 1020cm -1 The point is the COC stretching vibration (ester bond); 830 cm⁻¹ -1 720cm -1 The presence of out-of-plane bending vibrations of the aromatic ring (CH) indicates a benzene ring substitution mode. These characteristic peaks confirm that the product contains an aromatic ring, an amide bond, a methyl ester group, and a trifluoromethyl functional group, consistent with the target structure.
[0042] The trifluoromethyl polyamide ester prepared in Example 6 was characterized by infrared spectroscopy, and the results are as follows: Figure 2 As shown. From Figure 2 It can be seen from this that it is approximately 3448cm -1 A broad but weak absorption peak appears nearby, attributed to the OH stretching vibration of unreacted phenolic hydroxyl / carboxyl groups; approximately 2951 cm⁻¹. -1 and 2850cm -1 The saturated CH stretching vibration at 1730 cm⁻¹ originates from the -CH₃ group of the methyl ester group; -1 The strong absorption peak nearby is due to the stretching vibration of the ester carbonyl group (C=O, methyl ester); 1660 cm⁻¹ -1 The intermediate absorption peak at 1600 cm⁻¹ is due to the stretching vibration of the amide carbonyl group (C=O, amide I band); -1 1500cm -1 The absorption peak at 1540 cm⁻¹ is attributed to the C=C stretching vibration of the aromatic ring skeleton. -1 The absorption peak at 1380 cm⁻¹ is the amide II band (NH bending + CN stretching); -1 The absorption peak at 1300~1200 cm⁻¹ corresponds to the symmetric bending vibration of the methyl group. -1 Multiple strong absorption peaks within the range correspond to the CF stretching vibration (trifluoromethyl); 1100 cm⁻¹ -1 1020 cm -1 The absorption peak at 830 cm⁻¹ is due to the COC stretching vibration (ester bond); -1 720cm -1 The absorption peak at [location] indicates the out-of-plane bending vibration of the aromatic ring CH, suggesting a substitution mode of the benzene ring. These characteristic peaks confirm that the product contains an aromatic ring, an amide bond, a methyl ester group, and a trifluoromethyl functional group, consistent with the target structure.
[0043] The weight-average molecular weight of the trifluoromethyl polyamide ester prepared in Example 1 was determined by gel permeation chromatography (GPC), and the results are as follows: Figure 3 As shown in the figure. The horizontal axis represents retention time, and the vertical axis represents the response signal intensity of the differential refractive index detector. From... Figure 3 As can be seen from the spectrum, a single symmetrical peak indicates that the product has a uniform molecular weight distribution. After calibration and integration using the GPC system, the number-average molecular weight (M0.05) of the product is calculated. n The weight-average molecular weight (M) is 28247 g / mol. w The concentration was 44250 g / mol, and the peak molecular weight (M) was... p The Z-average molecular weight (M) is 48037 g / mol. z The concentration of M is 61166 g / mol. z+1 It is 75627 g / mol, and the viscosity-average molecular weight (M) is... vThe concentration of polydispersity index (PDI) is 41779 g / mol, and the polydispersity index (PDI) is M. w / M n The value is 1.567, showing a moderately narrow distribution.
[0044] Therefore, this invention employs the above-mentioned trifluoromethyl polyamide ester, its preparation method, and its application. First, a polyamic acid precursor is synthesized through dianhydride monomers and diamine monomers. The introduction of trifluoromethyl groups increases the free volume and asymmetry of the molecular chains, disrupting the close packing of the molecular chains. Then, a suitable alkylating agent is selected to carry out the reaction to obtain the polyamide ester. The reaction conditions are mild, with few side reactions and high selectivity, solving the problem of high-temperature processing and broadening the application of the material in the high-end electronics field.
[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.
Claims
1. A method for preparing trifluoromethyl polyamide ester, characterized in that: Includes the following steps: S1. Under an inert atmosphere, a diamine monomer containing trifluoromethyl and a dianhydride monomer are dissolved in an organic solvent and stirred to carry out a polymerization reaction to obtain polyamic acid; S2. Add an alkylating agent to polyamic acid to carry out an alkylation reaction to obtain trifluoromethyl polyamide ester.
2. The method for preparing a trifluoromethyl polyamide ester according to claim 1, characterized in that: In S1, the trifluoromethyl-containing diamine monomer includes at least one of the following compounds: 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 3,3'-bis(trifluoromethyl)-4,4'-diaminodiphenyl sulfone, 2,2'-bis(trifluoromethyl)-4,4'-diaminodiphenyl ether, 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane, 3,3'-dihydroxybenzidine, 4,4'-[1,4-phenylbis(oxy)]bis[3-(trifluoromethyl)aniline], 2,2-bis(4-aminophenyl)hexafluoropropane, 3,3'-bis... (trifluoromethyl)-[1,1'-biphenyl]-4,4'-diamine, 3,3'-bis(trifluoromethyl)-4,4'-diaminodiphenyl ether, 2,2-bis(3-amino-4-hydroxyphenyl)propane, 2,2'-bis(trifluoromethyl)-[1,1'-biphenyl]-4,4'-diamine, 2,2-bis[3-(4-aminobenzamido)-4-hydroxyphenyl]hexafluoropropane, 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane; Furthermore, except for 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, the aromatic rings of the aforementioned compounds may be independently substituted by 1-4 substituents, each of which is independently selected from: C1-C6 alkyl, C1-C6 alkoxy, fluorine, chlorine, bromine, or iodine; the substituents are attached to carbon atoms on the aromatic ring that are not directly bonded to the amino group; when multiple substituents are present on the same aromatic ring, they may be the same or different from each other.
3. The method for preparing a trifluoromethyl polyamide ester according to claim 1, characterized in that: In S1, the dianhydride monomer includes one of the following compounds: 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 4,4'-oxophthalic anhydride, 4,4'-(hexafluoroisopropyl)phthalic anhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3',4,4'-diphenylsulfone tetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 4,4'-(1,4-phenyldioxy)phthalic anhydride, 9,9-bis(3,4-dicarboxyphenyl) 4,4'-(4,4'-isopropyldiphenoxy)bisphthalic anhydride, 1,2,3,4-cyclobutanetetracarboxylic anhydride, 5,5'-(propane-2,2-diyl)bis(isobenzofuran-1,3-dione), 4,4'-methylenebisphthalic anhydride, triphenylmethane-3,3',4,4'-tetracarboxylic anhydride, 3,3'-bis(trifluoromethyl)-4,4',5,5'-biphenyltetracarboxylic anhydride; The aromatic rings of the aforementioned compounds may be independently substituted by 1-4 substituents, each of which is independently selected from: C1-C6 alkyl, C1-C6 alkoxy, fluorine, chlorine, bromine or iodine; the substituents are attached to carbon atoms on the aromatic ring that are not directly bonded to an anhydride group; when multiple substituents exist on the same aromatic ring, they may be the same or different from each other.
4. The method for preparing a trifluoromethyl polyamide ester according to claim 1, characterized in that: In S1, the organic solvent is selected from at least one of N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, and γ-butyrolactone; The molar mass ratio of the trifluoromethyl-containing diamine monomer, dianhydride monomer, and organic solvent is 0.08-0.1 mol: 0.08-0.1 mol: 200-350 g.
5. The method for preparing a trifluoromethyl polyamide ester according to claim 1, characterized in that: An end-capping agent may also be added to S1. The end-capping agent is selected from 3-aminophenol, and the mass of the end-capping agent is 0.9%-6% of the total mass of the trifluoromethyl diamine monomer and the dianhydride monomer.
6. The method for preparing a trifluoromethyl polyamide ester according to claim 1, characterized in that: In S1, the polymerization process is as follows: first, react in an ice-water bath below 5°C for 10-14 hours, then raise the temperature to 25-40°C and hold for 4-12 hours.
7. The method for preparing a trifluoromethyl polyamide ester according to claim 1, characterized in that: In S2, the alkylating agent includes at least one of iodomethane, iodoethane, dimethyl carbonate, diethyl carbonate, and (trimethylsilane)diazomethane, and the molar ratio of polyamic acid to alkylating agent is 1:1.2-5 based on the amount of carboxyl group in the polyamic acid repeating unit.
8. The method for preparing a trifluoromethyl polyamide ester according to claim 1, characterized in that: In S2, the alkylation reaction temperature is 25-45℃.
9. A trifluoromethyl polyamide ester, characterized in that: It is prepared by the method for preparing a trifluoromethyl polyamide ester according to any one of claims 1-8.
10. An application of trifluoromethyl polyamide ester, characterized in that: The polyamide ester prepared by the method of preparing a trifluoromethyl polyamide ester according to any one of claims 1-8 is used to synthesize polyimide.