Method for forming photopolymerizable polyimide precursors

Abstract

A method of forming a functionalized polyimide precursor includes reacting a dianhydride with a hydroxyl-functional molecule in a solvent in the presence of a basic catalyst to form an esterified product, followed by reacting the esterified product with a diamine in the presence of a phosphonic acid anhydride and a coreagent that facilitates amide formation and reacting at a temperature less than 45℃ to form the photopolymerizable precursor.

Description

Method for Forming Photopolymerizable Polyimide Precursors CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application which claims priority to U.S. Provisional Patent Application No.63 / 574,543 filed April 4, 2024, of which is incorporated by reference herein in its entirety. FIELD OF THE INVENTION

[0002] The present invention relates to a method of forming photopolymerizable polyimide precursors, such as polyamic acids and / or polyamic acid esters. BACKGROUND OF THE INVENTION

[0003] Polyimides are useful in electronic applications as a dielectric layer or film in such devices as capacitors and semiconductors. U.S.4,551,522 disclosed a method of making photopolymerizable aromatic polyamic acid derivatives. This method can require lengthy process times and significant requirements related to control of process conditions. The method can also use fluorinated species.

[0004] It is desired to develop simpler methods for forming functionalized, and preferably photopolymerizable, polyimide precursors. SUMMARY OF THE INVENTION

[0005] Disclosed herein is a method of forming a functionalized polyimide precursor comprising reacting a dianhydride with a hydroxyl-functional molecule in a solvent in the presence of a basic catalyst to form an esterified product, and reacting the esterified product with a diamine in the presence of a phosphonic acid anhydride and a coreagent that facilitates amide formation at a temperature less than 45℃ to form the photopolymerizable precursor. DETAILED DESCRIPTION OF THE INVENTION

[0006] The polyimide precursor made by this method can have can comprise, for example, by repeat units represented by the formula (1)In the formula (1), X1is a tetravalent aromatic, alicyclic, or aliphatic group preferably an aromatic group where the —COOR1group and —CONH— group are on ortho-position to each other and the —COOR2 group and —CO— group are on ortho-position to each other.Y1is a divalent aromatic, alicyclic, or aliphatic group, preferably an aromatic group; R1and R2are independently a hydrogen atom, a group represented by the following formula (2) or (3), or an aliphatic hydrocarbon group having 1 to 4 carbon atoms, and at least one of R1 and R2is a group represented by the formula (2) or (3). -[ (3)and (3), R', R'' and R''' are independently a hydrogen atom or an aliphatic hydrocarbon group having 1 to 3 carbon atoms, and m is an integer of 1 to 10, preferably an integer of 2 to 5, more preferably 2 or 3, n is 1 or 2, preferably 1, p is 0 or 1, preferably 0, q is 1 to 3, preferably 1, Z2 is a divalent hydrocarbon linking group such as – (CH ) 2 m– or a trivalent hydrocarbon linking group.

[0008] The tetravalent aromatic group of the X1 of the formula (1) may be a tetravalent aromatic hydrocarbon group or a tetravalent aromatic heterocyclic group. A tetravalent aromatic hydrocarbon group is preferred. Examples of the tetravalent aromatic hydrocarbon group of the X1 of the formula (1) include, but are not limited to, a group represented by one of the following:lfide group (—S—) (—O— is preferable) and X and Y independently represent a divalent group which is not conjugated to a benzene ring to which each is bonded, or a single bond, preferably —O—, —S—, a methylene group, a bis(trifluoromethyl)methylene group, or a difluoromethylene group, more preferably —O—.

[0009] The divalent aromatic group of the Y1 of the formula (1) may be a divalent aromatic hydrocarbon group or a divalent aromatic heterocyclic group. A divalent aromatic hydrocarbon group is preferable. The divalent aromatic hydrocarbon group of the Y1of the formula (1) can include, but is not limited to, a group represented by one of the following.hydrocarbon group, or a monovalent organic group having a halogen atom. Examples of the monovalent aliphatic hydrocarbon group (preferably having 1 to 10 carbon atoms, more preferably having 1 to 6 carbon atoms) include a methyl group and the like. For example, R12 and R15 to R19 may be hydrogen atoms, and R13 and R14 may be monovalent aliphatic hydrocarbon groups. The monovalent organic group having a halogen atom (preferably a fluorine atom) can have 1 to 10 carbon atoms, preferably having 1 to 6 carbon atoms. A specific example is a trifluoromethyl group.

[0010] The aliphatic hydrocarbon group having 1 to 4 carbon atoms (preferably 1 or 2) of the R1and R2of the formula (1) includes a methyl group, an ethyl group, an n-propyl group, a 2-propyl group, an n-butyl group, and the like.

[0011] At a portion of the R1 and R2 in the formula (1) is a group represented by the formula (2) or (3). The aliphatic hydrocarbon group having 1 to 3 carbon atoms (preferably 1 or 2) in the R3 to R5 of the formula (2) includes a methyl group, an ethyl group, an n-propyl group, a 2-propyl group, and the like. A methyl group is preferable.

[0012] In a first step of the method disclosed herein, an esterified dianhydride is produced. This can be produced by reaction of a dianhydride with a hydroxyl-functional molecule. The hydroxyl-functional molecule can include ethylenic unsaturation to enable later photopolymerization of the polyimide precursor. For example, the hydroxyl-functional molecule can be an ethylenically unsaturated alcohol having at least 3 carbon atoms, preferably up to no more than 8, up to 7, up to 6, or up to 5 carbon atoms. As another example, the hydroxyl-functional molecule can be a hydroxyalkyl (meth)acrylate.

[0013] A generic example of this step can be shown as:where X1 can be as described above and R1 can be of the structure (2) or (3) as describe above. R2can be the same as R1or can be a hydrogen atom. Preferably, in at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95% of the occurrences R2 is the same as R1.

[0014] A “(meth)acrylate" as used herein encompasses, acrylates, methacrylates, and mixtures thereof. For example, the hydroxyalkyl (meth)acrylate can have a structure: CH2=CZ1-C(O)-O-L1-OH, where Z1 is H for acrylates, or is CH3 for methacrylates, and L1 can be a hydrocarbon group, such as an alkyl, preferably having 1 to 5 carbon atoms, more preferably ethyl or propyl. The hydroxyalyl (meth)acrylate can be a primary alcohol, such as, for example, CH2=CZ1-C(O)-O-(CH2)n-OH where n is an integer of at least 1 andpreferably 2 to 5, more preferably 2 to 3 carbon atoms. Specific examples of such primary alcohols include hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxypropyl methacrylate, hydroxypropyl acrylate, hydroxybutyl methacrylate, and hydroxybutyl acrylate. Alternatively, hydroxyalkyl (meth)acrylate can be a secondary alcohol, such as, for example, the CH2=CZ1-C(O)-O-Y1(OH)-O-(O)C-CZ2=CH2, where Z1 and Z2 are H or CH3. Specific examples of a secondary alcohol include glycerol dimethacrylate and 3-(acryloyloxy)-2- hydroxypropyl methacrylate.

[0015] Examples of ethylenically unsaturated alcohols include allyl alcohol, 3-buten- 1-ol, 4-penten-1-ol, ethylene glycol vinyl ether, and di(ethylene glycol) vinyl ether.

[0016] The dianhydride can be, for example, pyromellitic dianhydride (PMDA), 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA), 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA), 3,3',4,4'- diphenylsulfonetetracarboxylic dianhydride (DSDA), 1,2,4,5-benzenetetracarboxylic dianhydride (BTDA), faphthalene-1,4,5,8-tetracarboxylic dianhydride (NTDA), 1,2,3,4- cyclopentanetetracarboxylic dianhydride (CPDA), 4,4'-oxydiphthalic anhydride (ODPA), 1,4,5,8-naphthalenetetracarboxylic dianhydride (NDPA), 1,2,3,4-cyclohexanetetracarboxylic dianhydride (CHDA), 2,3,3',4'-Biphenyltetracarboxylic dianhydride (HBPDA), 1,2,3,4,5,6- Hexaphthalenetetracarboxylic dianhydride (HPTDA), 1,2,3,4-Cycloheptanetetracarboxylic dianhydride (CyC7DA), 1,3,6,8-pyrenetetracarboxylic dianhydride (PTCDA), 4,4'-diphenyl ether dianhydride (DPEDA), 1,2,3,4-cyclooctanetetracarboxylic dianhydride (COTDA), 1,4,5,8-anthracyclotetracarboxylic dianhydride (ANTCDA), 4,4'-diphenylenedianhydride (DPD), 1,3-bis(3-aminophenoxy)benzene dianhydride (3-BAPBDA), 3,4,9,10- perylenetetracarboxylic dianhydride (PTCDA), 2,3,6,7-Naphthalenetetracarboxylic dianhydride (NTCDA), 1,2,3,4,5,6-hexaphthalenehexacarboxylic dianhydride (HHPCDA), 1,2,3,4-cyclooctene-1,3,4,6-tetracarboxylic dianhydride (CODA), 1,3,5,7-cyclooctatetraene tetracarboxylic dianhydride (COTCDA), 4,4'-Oxybis(2,6-dimethylphthalic anhydride) (ODMDPA), 1,3,6,8-Pyrenetetracarboxylic dianhydride (PyreneDA), 1,2,3,4- Cyclohexanetetracarboxylic dianhydride (Cy6DA), p-phenylenebis(trimellitate anhydride (TMHQ), 4,4'-Bisphenol A dianhydride (BPADA), Hydroquinone diphthalic anhydride (HQDEA), 2,2'-Bis-(3,4-Dicarboxyphenyl) hexafluoropropane dianhydride (6-FDA), Tetrahydro-1H-5,9-methanopyrano[3,4-d]oxepine-1,3,6,8(4H)-tetraone (TCA), 1,2,3,4- Butanetetracarboxylic dianhyride (BDA) or a mixture or two or more thereof.

[0017] The reaction can be catalyzed using a basic catalyst such as an organic base. Examples of such organic base catalyst include organic amines such as pyridine, 3-picoline, 1,4-Diazabicyclo[2.2.2]octane, 4-Dimethylaminopyridine, 5-Ethyl-2-methylpyridine, 1,8- Diazabicyclo(5.4.0)undec-7-ene, 1,5-Diazabicyclo(4.3.0)non-5-ene, diisopropylethylamine amine, or triethyl amine.

[0018] The reaction can occur in a solvent, preferably an aprotic solvent. Examples of such solvents include N,N-dimethylpropanamide (DMPr); N-methyl-2-pyrrolidone (NMP); dimethylacetamide (DMAc); 3-methoxy-N,N-dimethylpropanamide (KJCMP-100); dimethylformamide (DMF); imethyl sulfoxide (DMSO); gamma-butyrolactone (BLO); propylene carbonate (PC); and tetrahydrofuran (THF).

[0019] The mole ratio of dianhydride to hydroxy-functional molecule (e.g., the hydroxyalkyl (meth)acrylate or the ethylenically unsaturated alcohol) can be adjusted to provide the degree of esterification of the dianhydride desired. The ethylenic unsaturated groups on the esterified dianhydride will provide photoactivity for the resulting polyimide precursor product. For example, the dianhydride and the hydroxy-functional molecule can be provided at a mole ratio of from 1:3, from 1:2.5, or from 1:2 up to 4:1, up to 3:1 or up to 2:1.

[0020] The concentration of the dianhydride in the solvent can be, for example, from 0.05, 0.1, from 0.15, or from 0.2 moles / liter up to 1, up to 0.8, up to 0.668, up to 0.6, up to 0.5, up to 0.4, or up to 0.3 moles / liter. The concentration of the hydroxyl-functional monomer (e.g., the hydroxyalkyl (meth)acrylate or the ethylenically unsaturated alcohol) in the solvent can be, for example, from 0.1, from 0.15, or from 0.2 moles / liter up to 1, up to 0.8, up to 0.6 or 0.5 moles / liter.

[0021] The amount of basic catalyst used can be, for example, in a mole ratio of catalyst to dianhydride of at least 0.005:1, at least 0.01:1. Optionally, where the basic catalyst is the same as a co-reagent used in the second step of the synthesis, excess amount of the catalyst can be added or during the esterification reaction. In this instance, the amount of co-reagent added before the second step of the synthesis can be reduced or even eliminated if sufficient excess is added in the first step. If excess basic catalyst is added before or during esterification rather the amount can at a mole ratio to dianhydride of less than 4:1.

[0022] The reaction of the dianhydride with the hydroxyalkyl (meth)acrylate can occur at a temperature of, for example 10 to 100℃ or 15 to 50℃. The reaction can be run at room temperature. The time for the reaction can be, for example, from 10 minutes, or from 30 minutes, up to 24 hours, up to 12 hours, up to 5 hours, or up to to 4 hours. At room temperature, for example, the reaction time can be from 1 hour to 3 hours.

[0023] The product of esterifying the dianhydride is then reacted with a multifunctional amine, preferably a diamine, to form a polyimide precursor. In this step, a coreagent and a phosphonic acid anhydride are used to facilitate the reaction.

[0024] This reaction can be represented as follows:where X1, Y1, R1 and R2 are as described herein.

[0025] The multi-functional amine can have the structure H2N-R3-(NH2)n, where n is 1 or 2, preferably 1 and R3is a divalent linking group such as an aromatic group, an aliphatic group or the like. Examples of diamines that can be used include 4,4'-diaminodiphenyl ether (ODA), 4,4'-diaminodiphenylmethane (DDM), 4,4'-diaminodiphenylsulfone (DDS), 4,4'- methylenedianiline (MDA), 3,3'-diaminobenzidine (DAB), 4,4'-diaminostilbene (DAS), p- phenylenediamine (PPD), 1,3,5-Tris(aminophenoxy)benzene (TAPB), 1,3-Bis(3- aminophenoxy)benzene (3,3'-BAPB), 2,2’-Dimethylbenzidine) (DMAP), 9,9'-Bis (4- aminophenyl) fluorene (FDA), 1-(4-Aminophenyl)-1,3,3-trimethyl-2H-inden-5-amine (PIDA), diamine (4,4′-(1,4-Phenylenediisopropylidene)bisaniline (BisP), 2,2-bis(4-(4- aminephenoxy)phenyl)propane (BAPP), 3,3'-Diaminodiphenyl sulfone (3,3’-DDS), Bis[4-(4- aminophenoxy)phenyl] Sulfone (BAPS), trans-1,4-Diaminocyclohexane (1,4-CHDA), 1,3- Bis(3-aminophenoxy) Benzene (133-APB), Isophorone diamine, 4,4’-Diaminobenzanilide (DABA), Bis(aminomethyl)norbornane; or hydroxy diamines such as 2,2-Bis(3-amino-4- hydroxyphenyl)hexafluoropropane (6FAP), 3,3'-Diamino-4,4'-dihydroxydiphenyl Sulfone(DAHPS), 3,3’-Dihydroxy-4,4’Diamino-biphenyl (HAB), or 2,2-Bis(3-amino-4- hydroxylphenyl)propane (BHAPP); or a mixture of two or more thereof.

[0026] The multi-functional amine is generally used in a substantially stoichiometric amount relative to the dianhydride. Thus, the mole ratio of amine groups from the multi- functional amine to the ratio of anhydride groups from the dianhydride is from 0.7:1, from 0.8:1 or from 0.9:1 up to 1:0.7, up to 1:0.8, or up to 1:0.9. Running the reaction at a mole ratio of 1:1 can lead to higher molecular weights. If it is desired to limit or lower the molecular weight, the reaction can be run slightly off of stoichiometric ratios.

[0027] The coreagent facilitates the amide formation after phosphonic acid anhydride is added. This coreagent participates in the amide formation reaction but leaves once the amide(target structure) was formed. The coreagent acts assists reaction in a manner as a catalyst but is added in higher amounts than are catalysts. Particularly, mole ratio of coreagent to dianhydride can be from 2:1, or from 3:1 up to 8:1, up to 7:1, up to 6:1, or up to 5:1. The coreagent can be added in these amounts before esterification, during esterification, or after esterification. Examples of suitable coreagents include organic amines. Examples of specific suitable organic amines include isoquinoline, quinoline, pyridine and pyridine derivatives, such as alkyl pyridines (e.g. picoline (i.e. methyl pyridine, such as 3-methyl pyridine and 5-ethyl-2-methylpyridine)), alkyoxy pyridines (e.g., methoxypyridines, such as 4-methoxy pyridine and 2,6-dimethoxy pyridine), and alkylamino pyridines (e.g., dialkyl amino pyridines (DAAPs), such as 4-dimethylaminopyridines, or cycloalkylamino pyridine, such as 4-piperidinopyridine and 4-pyrrolidinopyridine). Other examples include aliphatic amines such as N,N-diisopropylethylamine, triethylamine, or cycloaliphatic amines, such as 1,4-Diazabicyclo[2.2.2]octane and 1,8-Diazabicyclo[5.4.0]undec-7-ene, and ethylmorpholine.

[0028] The functioning of the coreagent can be seen in the following more detailed example of the reaction scheme:where X1, Y1, R1 and R2 are as described herein and R28, R29, R30 are aliphatic or aromatic groups, and R31is an aliphatic hydrocarbon group.

[0029] The phosphonic acid anhydride can form a cyclic structure preferably from 3 phosphonic acid molecules. The phosphonic acid anhydride can be for example propylphosphonic acid anhydride, or ethylphosphonic acid anhydride. The amount of phophonic acid anhydride can be at a mole ratio relative to moles dianhydride of, for example, from 2:1 to 4:1.

[0030] The multi-functional amine, the coreagent and the phosphonic acid anhydride can be added to the solution of the esterified dianhydride. In one example, the multi- functional amine and the coreagent can be added simultaneously or in any order to a solution (e.g. the solution from step (a) after reaction) of the esterified dianhydride. The mixture can be stirred to ensure good mixing and dissolution of the ingredients. The phosphonic acid anhydride can then be added. Adding the phosphonic acid anhydride after the other ingredients has been found to produce higher molecular weights in the polyimide precursor.

[0031] The multifunctional amine can be predispersed in the reaction solvent prior to addition to the solution of the esterified dianhydride. The coreagent can be predispersed in the reaction solvent prior to addition to the solution of the esterified dianhydride. The coreagent can optionally be present when the first reaction step occurs. The phosphonic acid anhydride can be predispersed in the reaction solvent prior to addition to the solution of the esterified dianhydride. .

[0032] The reaction can occur without heating. The reaction is exothermic and can occur at a temperature of less than 45℃, or less than 40℃. The time of the reaction can be, for example, from 15 to 120 minutes or from 20 to 50 minutes.

[0033] Optionally, the reaction may be quenching by addition of water, acid (e.g acetic acid, oxalic acid, citric acid), or both of water and acid, e.g., four equivalents water or acid per mole of phosphonic acid anhydride. This quench can fully hydrolyze the phosphonic acid anhydride to phosphonic acid which may simplify purification of the polyimide precursor.

[0034] The polyimide precursor can be separated from the reaction mixture, for example by precipitation and filtration. Additional wash with water, solvent, or a combination thereof can be used to remove any impurities such as residual phosphonic acid.

[0035] The polyimide precursor is an oligomeric, pre-polymeric, or polymeric species. The polyimide precursor preferably has a weight average molecular weight of at least 10,000, at least 15,000, or at least 20,000 grams per mole up to, for example 130,000, up to 100,000, or up to 80,000 grams per mole as determined by gel permeation chromatography (GPC) using a polystyrene standard. For example, the GPC instrument can be an Agilent 1250 Inifity II, with Shodex columns KD-802, KD-801, KD-807M, and / or KD-806M. The effluent can be, for example, dimethylacetamide with trace amount of lithium chloride and p- toluenesulfonic acid. Other conditions can be, for example, flow rate: 1.0 mL / min; column temperature: 40 C; injection volume: 100 µL, and / or sample concentration: 0.2% by mass.

[0036] The polyimide precursor preferably has a polydispersity (weight average molecular weight / number average molecular weight) of less than 3, of no greater than 2.5, or of no greater than 2.0.

[0037] The polyimide precursor is a polyamic acid ester. Preferably the amount of esterification with ethylenically unsaturated hydroxyl-functional monomers, is at least 70%, preferably 75 to 90% based on total number of acid and ester groups (e.g., the total number of R1and R2groups shown in the polyimide precursor of formula 1). This can be measured for example using1H NMR proton integration the characteristic vinyl proton peaks on the esters and the characteristic peaks of protons on dianhydrides or diamines or both. EXAMPLES Example 1 – Demonstration of Efficacy of Method with a Variety of Dianhydrides and Diamines Samples A-G

[0038] Samples A-G were prepared as described using hydrroxyethylmethacrylate (HEMA) to esterify the dianhydride. N,N-dimethylpropanimide (DMPr) was used as the solvent. After esterification, the esterified dianhydride was reacted with a diamine in the presence of propyl phosphonic acid anhydride (T3P) in dimethylformamide (DMF) and a coreagent to form the photopolymerizable polyimide precursor. For Samples A-G 4- dimethylaminopyridine (4-dmap) was used as a coreagent. For Sample H, triethylamine (TEA) was used ass the coreagent) Molecular weight and polydispersity were using gel permeation chromatography (with a polystyrene standard). Percent esterification with groups having ethylenic unsaturation was determined using1H NMR proton integration ratio of HEMA vinyl protons to the aromatic proton from dianhydride or diamine or both. The Results are shown in Table 1. Table 1 Sample Dianhydride Diamine Weight Polydispersity Percent Av r (Mw / Mn) E t rifi tionSample A.

[0039] An oven-dried 1 L 4-necked round-bottom flask was equipped with overhead stirrer and flushed with nitrogen for 1 hour. To the flask was charged with 50 g DMPr (N,N- Dimethylpropanamide, CAS 758-96-3) and tuned the agitation to 150 rpm. Followed by the addition of 15.511 g ODPA (50 mmol, Oxydiphthalic anhydride, CAS 1823-59-2, which is 0.575 mole / L at initial concentration in the initial reaction mixture) and 13.014 g HEMA (100 mmol, (Hydroxyethyl)methacrylate, CAS 868-77-9) and rinsed with 15 g DMPr. Then, to the flask were charged with 0.027 g BQ (0.25 mmol, 1,4-Benzoquinone, CAS 106-54-2) and 0.112 g DABCO (1 mmol, 1,4-Diazabicyclo[2.2.2]octane, CAS 280-57-9) and rinsed with 15 g DMPr. After stirring at rt for 3 hours, 90 g of DMPr was added and the agitation was tuned to 300 rpm. To the reaction was charged with 24.434 g 4-DMAP (200 mmol, 4- Dimethylaminopyridine, CAS 1122-58-3) in one portion and rinsed with 10 g of DMPr. The resulting mixture was stirred at rt for 15 min. The reaction temperature dropped to 18 ˚C from 21 ˚C. Then 95.455 g T3P® (150 mmol, Propylphosphonic anhydride, 50 wt% in DMF, CAS 68957-94-8) was added through additional funnel in 5 min. The reaction temperature rose to 30 ˚C. Followed by adding 9.554 g DMAP (45 mmol, 2,2’-Dimethylbenzidine, CAS 84-67-4) in portions. The reaction temperature rose to 38 ˚C right after the DMAP addition. The resulting mixture was stirred at rt for 30 min then quenched by adding a solution of 10.8 g DI water in 100 g DMPr, followed by 25 g of Oxalic acid dihydrate (CAS 6153-56-6). After stirring at rt for 30 min, the reaction mass was precipitated into 2.5 L DI water. The washed and dried powder was weighed as 29.8 g (81.7% yield) and had a Mw by GPC of 26,657 with 1.67 polydispersity. % Ester by NMR was 99.4% based on integration of two vinyl proton peaks of HEMA at 5.5 to 6.5 ppm and aromatic C-H peaks at 7 – 9 ppm. Sample B.

[0040] A 1-L Reaction Kettle was equipped with mechanical stirrer, nitrogen purge, and heating mantle with thermocouple and PID temperature controller. The reactor was loaded with 13.80 g ODPA (Oxydiphthalic Anhydride, CAS 1823-59-2, which is 0.468 mole / L at initial concentration in the initial reaction mixture), 8.73g BPDA (1,1'-Biphenyl- 3,3',4,4'-tetracarboxylic dianhydride, CAS# 2420-87-3), 0.136g DABCO (1,4- Diazabicyclo[2.2.2]octane), 19.27g HEMA (Hydroxyethyl methacrylate), 0.088g BQ (benzoquinone) and 145.8 g DMPr (N,N-Dimethylpropionamide, CAS 758-96-3), heated to 65C and mixed for 1.5 hr. After cooling to room temperature, 36.2g 4-Dimethylamino pyridine followed by 0.78 g 2,2'-Dimethyl-4,4'-diaminobiphenyl and 7.46g p-Phenylenediamine in 82.6 g DMPr and mixed for 30 minutes. Over 3 minutes, 141.4g T3P (Propylphosphonic anhydride 50% in DMF) followed by 38.4g DMPr. The reaction exothermed to 41.3oC and was allowed to proceed for 2.5 hrs at room temperature during which time the viscosity increased to 33.03 cPs. The reaction was quenched with acetic acid and then precipitated in 70% IPA / water. The washed and dried powder had a Mw by GPC of 34,644 with 1.748 polydispersity. % Ester by NMR was 87.6% based on integration of HEMA =CH2 peaks at 5.5 to 6.5 ppm and Aromatic C-H peaks at 7 – 9 ppm. Sample C.

[0041] A 1-L Reaction Kettle was equipped with mechanical stirrer, nitrogen purge, and heating mantle with thermocouple and PID temperature controller. The reactor was loaded with 22.272 g BPDA (1,1'-Biphenyl-3,3',4,4'-tetracarboxylic dianhydride, CAS# 2420-87-3 is 0.406 mole / L at initial concentration in the initial reaction mixture),0.149g DABCO (1,4-Diazabicyclo[2.2.2]octane), 19.954g HEMA (Hydroxyethyl methacrylate), 0.091g BQ (benzoquinone) and 171.599g DMPr (N,N-Dimethylpropionamide, CAS 758-96-3), heated to 65C and mixed for 1 hr. After cooling to room temperature, 36.96g 4-Dimethylamino pyridine and 11.41 g DMPr followed by 8.04g p-Phenylenediamine in 48.23 g DMPr and mixed for 30 minutes. Over 1 minutes, 145.47g T3P (Propylphosphonic anhydride 50% in DMF) followed by 33.31g DMPr. The reaction exothermed to 43.2oC and was allowed to proceed for 2 hrs at room temperature during which time the viscosity increased to 37.04 cPs. The reaction was quenched with acetic acid and then precipitated in 70% IPA / water. The washed and dried powder had a Mw by GPC of 38,653 with 1.748 polydispersity. % Ester by NMR was 96.0% based on integration of HEMA =CH2 peaks at 5.5 to 6.5 ppm and Aromatic C-H peaks at 7 – 9 ppm. Sample D.

[0042] A 1-L Reaction Kettle was equipped with mechanical stirrer, nitrogen purge, and heating mantle with thermocouple and PID temperature controller. The reactor was loaded with 16.18 g PMDA (Pyromellitic dianhydride, CAS# 89-32-7 which is 0.398 mole / L at initial concentration in the initial reaction mixture), 0.130 g DABCO (1,4- Diazabicyclo[2.2.2]octane), 19.27 g HEMA (Hydroxyethyl methacrylate), 0.092 g BQ (benzoquinone) and 171.599g DMPr (N,N-Dimethylpropionamide, CAS 758-96-3), heated to65C and mixed for 1 hr. After cooling to room temperature, 36.23 g 4-Dimethylamino pyridine and 10.80 g DMPr followed by 14.53 g ODA (Oxydianiline, CAS 101-80-4) in 124.17 g DMPr and mixed for 30 minutes. Over 10 minutes, 141.53 g T3P (Propylphosphonic anhydride 50% in DMF) followed by 38.33 g DMPr. The reaction exothermed to 41.4oC and was allowed to proceed for 5 hrs at room temperature during which time the viscosity increased to 25.75 cPs. The reaction was quenched with acetic acid and then precipitated in 70% IPA / water. The washed and dried powder had a Mw by GPC of 35,366 with 1.571 polydispersity. % Ester by NMR was 78.9% based on integration of HEMA =CH2 peaks at 5.5 to 6.5 ppm and Aromatic C-H peaks at 7 – 9 ppm. Sample E.

[0043] A 1-L Reaction Kettle was equipped with mechanical stirrer, nitrogen purge, and heating mantle with thermocouple and PID temperature controller. The reactor was loaded with 21.73 g TAHQ (p-phenylenebis(trimellitate anhydride), CAS# 2770-49-2 which is 0.294 mole / L at initial concentration in the initial reaction mixture), 0.088 g DABCO (1,4- Diazabicyclo[2.2.2]octane), 19.27 g HEMA (Hydroxyethyl methacrylate), 0.066 g BQ (benzoquinone) and 148.14 g DMPr (N,N-Dimethylpropionamide, CAS 758-96-3), heated to 65C and mixed for 1 hr. After cooling to room temperature, 23.17 g 4-Dimethylamino pyridine and 8.90 g DMPr followed by 15.98 g BisP diamine (Bisaniline-P; 4,4'-[1,4- Phenylenebis(1-Methyl-ethylidene)]Bisaniline, CAS 2716-10-1) in 157.64 g DMPr and mixed for 30 minutes. Over 10 minutes, 90.43 g T3P (Propylphosphonic anhydride 50% in DMF) followed by 24.42 g DMPr. The reaction exothermed to 41.4oC and was allowed to proceed for 5 hrs at room temperature during which time the viscosity increased to 22.20 cPs. The reaction was quenched with acetic acid and then precipitated in 70% IPA / water. The washed and dried powder had a Mw by GPC of 35,366 with 1.784 polydispersity. % Ester by NMR was 75.0% based on integration of HEMA =CH2 peaks at 5.5 to 6.5 ppm and Aromatic C-H peaks at 7 – 9 ppm. Sample F.

[0044] A 1-L Reaction Kettle was equipped with mechanical stirrer, nitrogen purge, and heating mantle with thermocouple and PID temperature controller. The reactor was loaded with 16.49 g HPMDA (1,2,4,5-Cyclohexanetetracarboxylic Dianhydride, CAS 2754-41-8 which is 0.668 mole / L at initial concentration in the initial reaction mixture), 0.051 g DABCO (1,4-Diazabicyclo[2.2.2]octane), 19.14 g HEMA (Hydroxyethyl methacrylate), 0.043 g BQ (benzoquinone) and 101.32 g DMPr (N,N-Dimethylpropionamide, CAS 758-96- 3), heated to 65oC and mixed for 1 hr. After cooling to room temperature, 38.89 g 4- Dimethylamino pyridine and 10.68 g DMPr followed by 14.43 g ODA (Oxydianiline, CAS 101-80-4) in 123.94 g DMPr and mixed for 30 minutes. Over 10 minutes, 140.26 g T3P (Propylphosphonic anhydride 50% in DMF) followed by 37.94 g DMPr. The reaction exothermed to 43.1oC and was allowed to proceed for 3.5 hrs at room temperature during which time the viscosity increased to 20.6 cPs. The reaction was quenched with acetic acid and then precipitated in 70% IPA / water. The washed and dried powder had a Mw by GPC of 33,992 with 2.003 polydispersity. % Ester by NMR was 83.42% based on integration of HEMA =CH2 peaks at 5.5 to 6.5 ppm and Aromatic C-H peaks at 7 – 9 ppm. Sample G.

[0045] A 1-L Reaction Kettle was equipped with mechanical stirrer, nitrogen purge, and heating mantle with thermocouple and PID temperature controller. The reactor was loaded with 15.06 g HPMDA (1,2,4,5-Cyclohexanetetracarboxylic Dianhydride, CAS 2754- 41-8 which is 0.668 mole / L at initial concentration in the initial reaction mixture), 0.050g DABCO (1,4-Diazabicyclo[2.2.2]octane), 17.51 g HEMA (Hydroxyethyl methacrylate), 0.043 g BQ (benzoquinone) and 92.56 g DMPr (N,N-Dimethylpropionamide, CAS 758-96- 3), heated to 65C and mixed for 1 hr. After cooling to room temperature, 32.79 g 4- Dimethylamino pyridine and 9.72 g DMPr followed by 17.53 g PIDA (1-(4-Aminophenyl)- 1,3,3-trimethyl-2H-inden-5-amine, CAS 54628-89-6) in 152.30 g DMPr and mixed for 30 minutes. Over 1 minutes, 128.09 g T3P (Propylphosphonic anhydride 50% in DMF) followed by 34.70 g DMPr. The reaction exothermed to 43.2oC and was allowed to proceed for 3 hrs at room temperature during which time the viscosity increased to 9.70 cPs. The reaction was quenched with acetic acid and then precipitated in 70% IPA / water. The washed and dried powder had a Mw by GPC of 22,530 with 1.587 polydispersity. % Ester by NMR was 84.87% based on integration of HEMA =CH2 peaks at 5.5 to 6.5 ppm and Aromatic C-H peaks at 7 – 9 ppm. Sample H.

[0046] An oven-dried 1000 ml 4-necked round-bottom flask was equipped with overhead stirrer and flushed with nitrogen for 1 hour. To the flask was charged with 50 g DMPr (N,N-Dimethylpropanamide, CAS 758-96-3) and tuned the agitation to 150 rpm. Followed by the addition of 16.112 g BTDA (50 mmol, Benzophenone tetracarboxylic dianhydride, CAS 2421-28-5 which is 0.613 mole / L at initial concentration in the initial reaction mixture) and 13.014 g HEMA (100 mmol, (Hydroxyethyl)methacrylate, CAS 868- 77-9) and rinsed with 15 g DMPr. Then, to the flask were charged with 0.027 g BQ (0.25 mmol, 1,4-Benzoquinone, CAS 106-54-2) and 0.084 g DABCO (0.75 mmol, 1,4- Diazabicyclo[2.2.2]octane, CAS 280-57-9) and rinsed with 10 g DMPr. The resulting reaction was stirred at 35 ˚C for 2 hours then cooled to rt and stirred at rt for 1 more hour.50 g of DMPr was added to the reaction and the agitation was tuned to 250 rpm. To the reaction flask was added 20.239 g TEA (200 mmol, Triethylamine, CAS 121-44-8) and rinsed with 5 g DMPr. The reaction temperature rose to 27 ˚C. After stirring at rt for 15 min, a pre- dissolved solution of 5.139 g 1,4-tCHDA (45 mmol, trans-1,4-Diaminocyclohexane, CAS 2615-25-0) in 50 g DMPr was loaded to the reaction and rinsed with 5 g DMPr. The reaction became cloudy. After stirring at rt for 15 min, the agitation was tuned to 300 rpm, followed by adding 95.455 g T3P® (150 mmol, Propylphosphonic anhydride, 50 wt% in DMF, CAS 68957-94-8) through additional funnel. The addition was finished in 10 min and reaction temperature rose to 38 ˚ C. After stirring at rt for 30 min, a wet DMPr solution (10.8 g DI water and 100 g DMPr) was added, followed by addition of 25 g Oxalic acid dihydrate (CAS 6153-56-6). The resulting mixture was stirred at rt for 30 min then precipitated into 2.5 L DI water. The washed and dried powder had a Mw by GPC of 11,856 with 1.23 polydispersity. % Ester by NMR was 88.4% based on integration of two vinyl proton peaks of HEMA at 5.5 to 6.2 ppm and aromatic C-H peaks at 7.5 to 8.2 ppm. Example 2 - Evaluation of varying esterifying agent, solvents, order of addition, or phosphonic acid anhydride

[0047] For the same dianhydride, the same diamine, and using 4-dmap as the coreagent, samples were prepared with varying different esterifying agents, order of addition, solvents, or phosphonic acid anhydrides as shown in Table 2. The molecular weight, polydispersity and percent esterification were determined as described in Example 1. Table 2Sample Esterifying Solven Phosphonic acid % Agent t anhydride GPC Mw PD Ester % % % % % heNMP = N-methyl-2-pyrrolidone EA = ethyl acetate Example 3 – Evaluation of varying coreagent

[0048] For the same dianhydride, the same diamine, using HEMA as the esterifying agent, DMPr as the solvent, and T3P as the phosphonic acid anhydride, various coreagents were tried as shown in Table 3. The molecular weight, polydispersity and percent esterification were determined as described in Example 1.Table 3 Phosphonic acid Coreagent GPC Mw PD % Ester*For this sample,T3P was added before addition of the diamine. For the other samples the diamine was added before addition of the T3P. DABCO = 1,4-Diazabicyclo[2.2.2]octane EMP=5-Ethyl-2-methylpyridine

[0049] This disclosure further encompasses the following aspects.

[0050] Aspect 1: A method of forming a functionalized polyimide precursor comprising reacting a dianhydride with a hydroxyl-functional molecule in a solvent in the presence of a basic catalyst to form an esterified product, and reacting the esterified product with a diamine in the presence of a phosphonic acid anhydride and a coreagent that facilitates amide formation at a temperature less than 45, preferably less than 40℃ to form the functionalized polyimide precursor.

[0051] Aspect 2: The method of Aspect 1 wherein the hydroxyl-functional molecule includes ethylenically unsaturation.

[0052] Aspect 3: The method of Aspect 1 wherein the hydroxyl-functional molecule is a hydroxyalkyl (meth)acrylate or an ethylenically unsaturated alcohol.

[0053] Aspect 4: The method of Aspect 3 wherein the hydroxy-functional molecule comprises hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxypropyl methacrylate, hydroxypropyl acrylate, hydroxybutyl methacrylate, hydroxybutyl acrylate, allyl alcohol, 3- butene-1-ol, 4-pentene-1-ol, 3-(acryloyloxy)-2-hydroxypropyl methacrylate, glycerol dimethacrylate, ethylene glycol vinyl ether, or di(ethylene glycol) vinyl ether.

[0054] Aspect 5: The method of any one of the preceding Aspects further comprising isolating the photopolymerizable precursor.

[0055] Aspect 6: The method of any one of the preceding Aspects wherein the diamine and the coreagent are added before the phosphonic acid anhydride.

[0056] Aspect 7: The method of any one of the previous Aspects wherein the diamine and the coreagent are fully dissolved in the solvent before the addition of the phosphonic acid anhydride.

[0057] Aspect 8: The method of any one of the previous Aspects wherein the solvent is a polar aprotic solvent.

[0058] Aspect 9: The method of any one of the previous Aspects wherein the reacting step (a) occurs at a temperature of 10 to 100℃, preferably 15 to 50℃, more preferably room temperature for a time of from 10 minutes to 5 hours, preferably for a time of 30 minutes to 4 hours, and more preferably, at room temperature for a time of 1 hour to 3 hours.

[0059] Aspect 10: The method of any one of the previous Aspects where the reacting of step (b) is from 15 to 120 minutes, preferably from 30 to 50 minutes.

[0060] Aspect 11: The method of any one of the previous Aspects wherein an initial mole ratio of the dianhydride to the hydroxy-functional molecule is from 1:3 to 4:1.

[0061] Aspect 12: The method of any one of the previous Aspects where an initial concentration of the dianhydride in the solvent is from 0.05 to 1, preferably 0.07 to 0.8, preferably from 0.1 to 0.6, more preferably from 0.1 to 0.5, more preferably 0.15 to 0.4, and yet more preferably, 0.2 to 0.3 moles per liter.

[0062] Aspect 13: The method of any one of the previous Aspects wherein the dianhydride comprises pyromellitic dianhydride (PMDA), 3,3',4,4'- benzophenonetetracarboxylic dianhydride (BTDA), 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA), 3,3',4,4'- diphenylsulfonetetracarboxylic dianhydride (DSDA), 1,2,4,5-benzenetetracarboxylic dianhydride (BTDA), faphthalene-1,4,5,8-tetracarboxylic dianhydride (NTDA), 1,2,3,4- cyclopentanetetracarboxylic dianhydride (CPDA), 4,4'-oxydiphthalic anhydride (ODPA), 1,4,5,8-naphthalenetetracarboxylic dianhydride (NDPA), 1,2,3,4-cyclohexanetetracarboxylic dianhydride (CHDA), 2,3,3',4'-Biphenyltetracarboxylic dianhydride (HBPDA), 1,2,3,4,5,6- Hexaphthalenetetracarboxylic dianhydride (HPTDA), 1,2,3,4-Cycloheptanetetracarboxylic dianhydride (CyC7DA), 1,3,6,8-pyrenetetracarboxylic dianhydride (PTCDA), 4,4'-diphenyl ether dianhydride (DPEDA), 1,2,3,4-cyclooctanetetracarboxylic dianhydride (COTDA), 1,4,5,8-anthracyclotetracarboxylic dianhydride (ANTCDA), 4,4'-diphenylenedianhydride (DPD), 1,3-bis(3-aminophenoxy)benzene dianhydride (3-BAPBDA), 3,4,9,10- perylenetetracarboxylic dianhydride (PTCDA), 2,3,6,7-Naphthalenetetracarboxylic dianhydride (NTCDA), 1,2,3,4,5,6-hexaphthalenehexacarboxylic dianhydride (HHPCDA), 1,2,3,4-cyclooctene-1,3,4,6-tetracarboxylic dianhydride (CODA), 1,3,5,7-cyclooctatetraene tetracarboxylic dianhydride (COTCDA), 4,4'-Oxybis(2,6-dimethylphthalic anhydride) (ODMDPA), 1,3,6,8-Pyrenetetracarboxylic dianhydride (PyreneDA), 1,2,3,4- Cyclohexanetetracarboxylic dianhydride (Cy6DA), p-phenylenebis(trimellitate anhydride (TMHQ), 4,4'-Bisphenol A dianhydride (BPADA), Hydroquinone diphthalic anhydride (HQDEA), 2,2'-Bis-(3,4-Dicarboxyphenyl) hexafluoropropane dianhydride (6-FDA), Tetrahydro-1H-5,9-methanopyrano[3,4-d]oxepine-1,3,6,8(4H)-tetraone (TCA), 1,2,3,4- Butanetetracarboxylic dianhyride (BDA), or a mixture or two or more thereof

[0063] Aspect 14: The method of any one of the previous Aspects wherein the basic catalyst is an organic base.

[0064] Aspect 15: The method of any of any one of the previous Aspects wherein the mole ratio of the diamine to the dianhydride is from 0.7:1 to 1:0.7.

[0065] Aspect 16: The method of any one of the previous Aspects wherein a mole ratio of the coreagent to the dianhydride is 2:1 to 8:1, preferably 3:1 to 6:1.

[0066] Aspect 17: The method of any one of the previous Aspects wherein a mole ratio of phosphnic acid anhydride to dianhydride is from 2:1 to 4:1.

[0067] Aspect 18: The method of any one of the previous Aspects wherein the diamine comprises 4,4'-diaminodiphenyl ether (ODA), 4,4'-diaminodiphenylmethane (DDM), 4,4'-diaminodiphenylsulfone (DDS), 4,4'-methylenedianiline (MDA), 3,3'-diaminobenzidine (DAB), 4,4'-diaminostilbene (DAS), p-phenylenediamine (PPD), 1,3,5- Tris(aminophenoxy)benzene (TAPB), 1,3-Bis(3-aminophenoxy)benzene (3,3'-BAPB), 2,2’- Dimethylbenzidine) (DMAP), 9,9'-Bis (4-aminophenyl) fluorene (FDA), 1-(4-Aminophenyl)- 1,3,3-trimethyl-2H-inden-5-amine (PIDA), diamine (4,4′-(1,4- Phenylenediisopropylidene)bisaniline (BisP), 2,2-bis(4-(4-aminephenoxy)phenyl)propane (BAPP), 3,3'-Diaminodiphenyl sulfone (3,3’-DDS), Bis[4-(4-aminophenoxy)phenyl] Sulfone (BAPS), trans-1,4-Diaminocyclohexane (1,4-CHDA), 1,3-Bis(3-aminophenoxy) Benzene (133-APB), Isophorone diamine, 4,4’-Diaminobenzanilide (DABA), Bis(aminomethyl)norbornane, 2,2-Bis(3-amino-4-hydroxyphenyl)hexafluoropropane (6FAP), 3,3'-Diamino-4,4'-dihydroxydiphenyl Sulfone (DAHPS), 3,3’-Dihydroxy- 4,4’Diamino-biphenyl (HAB), 2,2-Bis(3-amino-4-hydroxylphenyl)propane (BHAPP); or a mixture of two or more thereof

[0068] Aspect 19: The method of any one of the previous Aspects wherein the coreagent comprises isoquinoline, quinoline, pyridine, alkyl pyridine, alkyoxy pyridine, alkylamino pyridines, N,N-diisopropylethylamine, triethylamine, or a cycloaliphatic amine.

[0069] Aspect 20: The method of any one of the previous Aspects wherein the phosphonic acid anhydride is ethylphosphonic acid anhydride, propylphosphonic acid anhydride or butylphosphonic acid anhydride.

[0070] Aspect 21: The method of any one of the previous Aspects wherein the polyimide precursor has a weight average molecular weight of from 10,000 to 130,000, preferably least 15,000 to 100,000, more preferably 20,000 to 80,000 grams per mole as determined by gel permeation chromatography (GPC) using a polystyrene standard.

[0071] Aspect 22: The method of any one of the previous Aspects wherein the polyimide precursor has a polydispersity of less than 3, preferably no greater than 2.5, and more preferably of no greater than 2.0.

[0072] Aspect 23: The method of any one of the previous Aspects wherein the polyimide precursor has a percent esterification of at least 70%, preferably 75 to 90%, based on total number of acid and ester groups.

[0073] All ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other (e.g., ranges of “up to 25 wt.%, or, more specifically, 5 wt.% to 20 wt.%”, is inclusive of the endpoints and all intermediate values of the ranges of “5 wt.% to 25 wt.%,” etc.). Moreover, stated upper and lower limits can be combined to form ranges (e.g. “at least 1 or at least 2 weight percent” and “up to 10 or 5 weight percent” can be combined as the ranges “1 to 10 weight percent”, or “1 to 5 weight percent” or “2 to 10 weight percent” or “2 to 5 weight percent”).

[0074] The disclosure may alternately comprise, consist of, or consist essentially of, any appropriate components herein disclosed. The disclosure may additionally, or alternatively, be formulated so as to be devoid, or substantially free, of any components, materials, ingredients, adjuvants or species used in the prior art compositions or that are otherwise not necessary to the achievement of the function and / or objectives of the present disclosure.

[0075] All cited patents, patent applications, and other references are incorporated herein by reference in their entirety. However, if a term in the present application contradicts or conflicts with a term in the incorporated reference, the term from the present application takes precedence over the conflicting term from the incorporated reference.

[0076] Unless specified to the contrary herein, all test standards are the most recent standard in effect as of the filing date of this application, or, if priority is claimed, the filing date of the earliest priority application in which the test standard appears.

Claims

CLAIMS What is claimed is:

1. A method of forming a functionalized polyimide precursor comprising (a) reacting a dianhydride with a hydroxyl-functional molecule in a solvent in the presence of a basic catalyst to form an esterified product, (b) reacting the esterified product with a diamine in the presence of a phosphonic acid anhydride and a coreagent that facilitates amide formation at a temperature less than 45℃ to form the functionalized polyimide precursor.

2. The method of claim 1 wherein the hydroxyl-functional molecule includes ethylenically unsaturation.

3. The method of claim 1 wherein the hydroxyl-functional molecule is a hydroxyalkyl (meth)acrylate or an ethylenically unsaturated alcohol.

4. The method of claim 3 wherein the hydroxy-functional molecule comprises hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxypropyl methacrylate, hydroxypropyl acrylate, hydroxybutyl methacrylate, hydroxybutyl acrylate, 3- (acryloyloxy)-2-hydroxypropyl methacrylate, glycerol dimethacrylate, allyl alcohol, 3-butene-1-ol, 4-pentene-1-ol, ethylene glycol vinyl ether, or di(ethylene glycol) vinyl ether.

5. The method of claim 1 further comprising isolating the photopolymerizable precursor.

6. The method of claim 1 wherein the solvent is a polar aprotic solvent.

7. The method of claim 1 wherein the reacting step (a) occurs at a temperature of 10 to 100℃, for a time of from 10 minutes to 5 hours.

8. The method of claim 1 where the reacting of step (b) is from 15 to 120 minutes.

9. The method of claim 1 wherein an initial mole ratio of the dianhydride to the hydroxy-functional molecule is from 1:3 to 4:

1.

10. The method of claim 1 where an initial concentration of the dianhydride in the solvent is from 0.1 to 0.5 moles per liter.

11. The method of claim 1 wherein the dianhydride comprises pyromellitic dianhydride (PMDA), 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA), 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), 1,2,3,4- cyclobutanetetracarboxylic dianhydride (CBDA), 3,3',4,4'- diphenylsulfonetetracarboxylic dianhydride (DSDA), 1,2,4,5- benzenetetracarboxylic dianhydride (BTDA), faphthalene-1,4,5,8-tetracarboxylicdianhydride (NTDA), 1,2,3,4-cyclopentanetetracarboxylic dianhydride (CPDA), 4,4'-oxydiphthalic anhydride (ODPA), 1,4,5,8-naphthalenetetracarboxylic dianhydride (NDPA), 1,2,3,4-cyclohexanetetracarboxylic dianhydride (CHDA), 2,3,3',4'-Biphenyltetracarboxylic dianhydride (HBPDA), 1,2,3,4,5,6- Hexaphthalenetetracarboxylic dianhydride (HPTDA), 1,2,3,4- Cycloheptanetetracarboxylic dianhydride (CyC7DA), 1,3,6,8- pyrenetetracarboxylic dianhydride (PTCDA), 4,4'-diphenyl ether dianhydride (DPEDA), 1,2,3,4-cyclooctanetetracarboxylic dianhydride (COTDA), 1,4,5,8- anthracyclotetracarboxylic dianhydride (ANTCDA), 4,4'-diphenylenedianhydride (DPD), 1,3-bis(3-aminophenoxy)benzene dianhydride (3-BAPBDA), 3,4,9,10- perylenetetracarboxylic dianhydride (PTCDA), 2,3,6,7- Naphthalenetetracarboxylic dianhydride (NTCDA), 1,2,3,4,5,6- hexaphthalenehexacarboxylic dianhydride (HHPCDA), 1,2,3,4-cyclooctene- 1,3,4,6-tetracarboxylic dianhydride (CODA), 1,3,5,7-cyclooctatetraene tetracarboxylic dianhydride (COTCDA), 4,4'-Oxybis(2,6-dimethylphthalic anhydride) (ODMDPA), 1,3,6,8-Pyrenetetracarboxylic dianhydride (PyreneDA), 1,2,3,4-Cyclohexanetetracarboxylic dianhydride (Cy6DA), p- phenylenebis(trimellitate anhydride (TMHQ), 4,4'-Bisphenol A dianhydride (BPADA), Hydroquinone diphthalic anhydride (HQDEA), 2,2'-Bis-(3,4- Dicarboxyphenyl) hexafluoropropane dianhydride (6-FDA), Tetrahydro-1H-5,9- methanopyrano[3,4-d]oxepine-1,3,6,8(4H)-tetraone (TCA), 1,2,3,4- Butanetetracarboxylic dianhyride (BDA), or a mixture or two or more thereof 12. The method of any claim 1 wherein the basic catalyst is an organic base.

13. The method of claim 1 wherein the mole ratio of the diamine to the dianhydride is from 0.7:1 to 1:0.

7.

14. The method of claim 1 wherein a mole ratio of the coreagent to the dianhydride is 2:1 to 8:

1.

15. The method of claim 1 wherein a mole ratio of phosphnic acid anhydride to dianhydride is from 2:1 to 4:

1.

16. The method of claim 1 wherein the diamine comprises 4,4'-diaminodiphenyl ether (ODA), 4,4'-diaminodiphenylmethane (DDM), 4,4'-diaminodiphenylsulfone (DDS), 4,4'-methylenedianiline (MDA), 3,3'-diaminobenzidine (DAB), 4,4'- diaminostilbene (DAS), p-phenylenediamine (PPD), 1,3,5- Tris(aminophenoxy)benzene (TAPB), 1,3-Bis(3-aminophenoxy)benzene (3,3'-BAPB), 2,2’-Dimethylbenzidine) (DMAP), 9,9'-Bis (4-aminophenyl) fluorene (FDA), 1-(4-Aminophenyl)-1,3,3-trimethyl-2H-inden-5-amine (PIDA), diamine (4,4′-(1,4-Phenylenediisopropylidene)bisaniline (BisP), 2,2-bis(4-(4- aminephenoxy)phenyl)propane (BAPP), 3,3'-Diaminodiphenyl sulfone (3,3’- DDS), Bis[4-(4-aminophenoxy)phenyl] Sulfone (BAPS), trans-1,4- Diaminocyclohexane (1,4-CHDA), 1,3-Bis(3-aminophenoxy) Benzene (133- APB), Isophorone diamine, 4,4’-Diaminobenzanilide (DABA), Bis(aminomethyl)norbornane, 2,2-Bis(3-amino-4- hydroxyphenyl)hexafluoropropane (6FAP), 3,3'-Diamino-4,4'- dihydroxydiphenyl Sulfone (DAHPS), 3,3’-Dihydroxy-4,4’Diamino-biphenyl (HAB), 2,2-Bis(3-amino-4-hydroxylphenyl)propane (BHAPP); or a mixture of two or more thereof 17. The method of claim 1 wherein the coreagent comprises isoquinoline, quinoline, pyridine, alkyl pyridine, alkyoxy pyridine, alkylamino pyridines, N,N- diisopropylethylamine, triethylamine, or a cycloaliphatic amine.

18. The method of claim 1 wherein the phosphonic acid anhydride is ethylphosphonic acid anhydride, propylphosphonic acid anhydride or butylphosphonic acid anhydride.

19. The method of claim 1 wherein the polyimide precursor has a weight average molecular weight of from 10,000 to 130,000 grams per mole as determined by gel permeation chromatography (GPC) using a polystyrene standard and a polydispersity of less than 3.

20. The method of claim 1 wherein the polyimide precursor has a percent esterification of at least 70% based on total number of acid and ester groups.

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