Benzocyclobutene-containing diamine monomer as well as preparation method and application thereof

Abstract

The invention relates to a diamine monomer containing benzocyclobutene as well as a preparation method and application thereof, the diamine monomer contains a benzocyclobutene functional group, and Ar1 and Ar2 are independently selected from substituted or unsubstituted arylene groups. The diamine monomer contains a benzocyclobutene functional group and can be used as a functional monomer for self-crosslinking modification of polyimide.

Description

Technical Field

[0001] The invention belongs to the technical field of materials, and in particular relates to a benzocyclobutene diamine-containing monomer and a preparation method and application thereof. Background Art

[0002] Polyimide with a stable imide ring structure is widely used in aerospace, separation and purification, electronic information and other fields as a key polymer material due to its excellent performance and simple and diverse synthesis routes. With the development of the times and technology, conventional polyimide systems are difficult to meet the needs of different application scenarios and are difficult to adapt to some extreme conditions. Cross-linking modification of polyimide is an effective way to improve its performance. Combined with the flexible structural design of polyimide, cross-linkable groups can be combined in the structural design stage of the monomer molecule. After obtaining the polyimide resin material, it can be cross-linked and modified under specific demand conditions, thereby improving the performance of the polyimide in a targeted manner.

[0003] Benzocyclobutene functional groups are a type of self-crosslinkable structure that combines the thermodynamic stability of aromatic compounds with the kinetic reactivity of strained rings. After heating, the four-membered ring structure rapidly opens and forms a highly active polymerizable intermediate. This intermediate with a double bond can not only undergo self-crosslinking to form a polymer, but can also undergo a Diels-Alder reaction to crosslink and polymerize with adjacent double bond structures. Benzocyclobutene polymers have excellent thermal stability, crosslinkable processing, and low dielectric properties, making them active in advanced processing fields such as electronic packaging.

[0004] Combining benzocyclobutene with polyimide structure can make it have the advantages of both. Under the premise of the existing advantageous structure of polyimide, a cross-linked network structure is formed after thermal ring opening. The obtained polymer not only has lower dielectric properties, but also has outstanding performance in the field of gas separation after combing the polymer chain structure. Therefore, it is very necessary to develop polyimide materials containing benzocyclobutene functional groups.

[0005] However, among the monomers containing benzocyclobutene functional groups, there are relatively few functional monomers that can be effectively utilized in polyimide structures. Therefore, it is very important to develop a diamine monomer containing benzocyclobutene functional groups with excellent performance. Summary of the invention

[0006] In view of the deficiencies in the prior art, the object of the present invention is to provide a benzocyclobutene-containing diamine monomer and a preparation method and application thereof, wherein the diamine monomer contains a benzocyclobutene functional group and can be used as a functional monomer for self-crosslinking modification of polyimide and related polymers.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a diamine monomer, the structural formula of the diamine monomer is shown in Formula A:

[0009]

[0010] Wherein, Ar1 and Ar2 are each independently selected from a substituted or unsubstituted arylene group.

[0011] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. Through the following preferred technical solutions, the objectives and beneficial effects of the present invention can be better achieved and realized.

[0012] As a preferred technical solution of the present invention, Ar1 in the diamine monomer is selected from any one of formulas BK, and the structure of formula BK is as follows:

[0013]

[0014] Among them, X 1 -X 64 Each is independently selected from H, amino, dimethylamino, nitro, cyano, hydroxyl, carboxyl, sulfonic acid, sulfonyl, thiol, disulfide bond, methoxy, aldehyde, halogen atom or C1-C12 alkyl.

[0015] The dotted line position indicates the connection position with Ar2; the aromatic ring contained in formula BK is fused with the cyclobutene group at any condensable position thereof.

[0016] In the present invention, C1-C12 can be C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12.

[0017] Preferably, the "C1-C12 alkyl" mentioned in the present invention refers to an alkyl group having 1 to 12 carbon atoms in the main chain, and the C1-C12 alkyl group is selected from any one of methyl, ethyl, propyl and butyl.

[0018] As a preferred technical solution of the present invention, Ar2 in the diamine monomer is selected from any one of formula LU, and the structure of formula LU is as follows:

[0019]

[0020] Among them, X 65 -X 128 Each is independently selected from H, amino, dimethylamino, nitro, cyano, hydroxyl, carboxyl, sulfonic acid, sulfonyl, thiol, disulfide bond, methoxy, aldehyde, halogen atom or C1-C12 alkyl.

[0021] The dotted line position indicates the connection position with Ar1, and in Formula LU, it is connected to the amino group at any connectable position.

[0022] In the present invention, C1-C12 can be C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12.

[0023] Preferably, the "C1-C12 alkyl" mentioned in the present invention refers to an alkyl group having 1 to 12 carbon atoms in the main chain, and the C1-C12 alkyl group is selected from any one of methyl, ethyl, propyl and butyl.

[0024] As a preferred technical solution of the present invention, the diamine monomer includes any one or a combination of at least two of the following compounds:

[0025]

[0026]

[0027]

[0028]

[0029]

[0030]

[0031]

[0032] Among them, Y 1 -Y 459 , Z 1 -Z 519 Each is independently selected from H, amino, hydroxyl, carboxyl or C1-C12 alkyl.

[0033] In the present invention, C1-C12 can be C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12.

[0034] Preferably, the "C1-C12 alkyl" mentioned in the present invention refers to an alkyl group having 1 to 12 carbon atoms in the main chain, and the C1-C12 alkyl group is selected from any one of methyl, ethyl, propyl and butyl.

[0035] In a second aspect, the present invention provides a method for preparing the diamine monomer described in the first aspect, the preparation method comprising the following steps:

[0036] Step a, synthesizing dinitro intermediate III containing benzocyclobutene functional group: monomer I containing boric acid functional group and benzocyclobutene functional group reacts with monomer II containing halogen atom and nitro group to obtain intermediate III;

[0037] Step b, synthesizing diamine monomer IV containing benzocyclobutene functional group: subjecting the intermediate III obtained in step a to reduction reaction to obtain the diamine monomer;

[0038] The reaction formula of the preparation method is as follows:

[0039]

[0040] Wherein, X is -H or -CH 3 .

[0041] The Y is a halogen atom.

[0042] The Ar1 and Ar2 have the same meanings as defined above.

[0043] Preferably, the halogen atom is -F, -Cl, -Br, or -I.

[0044] Preferably, said Y is selected from -Br.

[0045] Preferably, in step a, the molar ratio of the monomer I containing boric acid and benzocyclobutene functional groups to the monomer II containing halogen atoms and nitro groups is 1:(1-1.5), for example, it can be 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, etc.

[0046] Preferably, in step a, the reaction is carried out in a first solvent, and the first solvent includes any one of dimethyl sulfoxide, N,N-dimethylacetamide, N,N-dimethylformamide or N-methylpyrrolidone, or a combination of at least two thereof.

[0047] Preferably, in step a, the reaction is carried out under a first catalyst, and the first catalyst includes any one or a combination of at least two of Pd132, tetrakis(triphenyl)phosphine palladium, potassium carbonate or triethylamine.

[0048] Preferably, in step a, the reaction temperature is 20-200°C, for example, it can be 20°C, 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, etc.

[0049] Preferably, in step a, the reaction time is 2-120 hours, for example, it can be 2h, 5h, 10h, 20h, 30h, 40h, 50h, 60h, 70h, 80h, 90h, 100h, 110h, 120h, etc.

[0050] Preferably, in step a, the reaction further comprises a post-treatment step.

[0051] Preferably, in step a, the post-treatment includes reduced pressure distillation, washing, drying, separation and purification.

[0052] Preferably, in step b, the mass ratio of the intermediate III to the second catalyst is 1:(0.01-0.5), for example, it can be 1:0.05, 1:0.1, 1:0.15, 1:0.2, 1:0.25, 1:0.3, 1:0.35, 1:0.4, 1:0.45, 1:0.5, etc.

[0053] Preferably, in step b, the reaction is carried out in a second solvent, and the second solvent comprises any one of methanol, ethanol, tetrahydrofuran or acetone, or a combination of at least two thereof.

[0054] Preferably, in step b, the reaction is carried out in the presence of a second catalyst, and the second catalyst comprises a Pd / C catalyst.

[0055] Preferably, in step b, the reaction is carried out in the presence of a reducing agent, and the reducing agent comprises hydrazine hydrate.

[0056] Preferably, in step b, the reaction is carried out under reflux conditions.

[0057] Preferably, in step b, the reflux reaction time is 0.5-48 hours, for example, it can be 0.5h, 1h, 2h, 5h, 10h, 15h, 20h, 25h, 30h, 35h, 40h, 45h, 48h, etc.

[0058] Preferably, in step b, the reaction further comprises a post-treatment step.

[0059] Preferably, in step b, the post-treatment includes reduced pressure distillation, washing, drying, separation and purification.

[0060] As a preferred technical solution of the present invention, the preparation method comprises the following steps:

[0061] Step a, synthesizing dinitro intermediate III containing benzocyclobutene functional group: dissolving monomer I containing boric acid functional group and benzocyclobutene functional group and monomer II containing halogen atom and nitro group in a first solvent, adding a first catalyst, reacting at a temperature of 20-200° C. for 2 hours, and then distilling under reduced pressure, washing, drying, separating and purifying to obtain intermediate III.

[0062] Step b, synthesizing diamine monomer IV containing benzocyclobutene functional group: dissolving the intermediate III obtained in step a in a second solvent, adding a second catalyst and a reducing agent, heating to reflux temperature, reflux reaction for 0.5-48 hours, cooling, separating, recrystallizing and drying to obtain the diamine monomer.

[0063] In a third aspect, the present invention provides a polyimide, wherein the reactive monomer of the polyimide comprises the diamine monomer described in the first aspect.

[0064] Compared with the prior art, the present invention has the following beneficial effects:

[0065] The structure of the diamine monomer is designed in the present invention so that it can be used as a functional monomer for self-crosslinking modification of polyimide and related polymers; meanwhile, the preparation method of the diamine monomer of the present invention is simple and easy to operate, and can be completed in only two steps, with a high yield of more than 80%. DETAILED DESCRIPTION

[0066] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0067] Example 1

[0068] This embodiment provides a diamine monomer, and the structural formula of the diamine monomer is as follows:

[0069]

[0070] The preparation method of the above diamine monomer comprises the following steps:

[0071]

[0072] Step a: At room temperature, add 5 mmol of 3-bromo-1,5-dinitrobenzene and 5 mmol of 4-boronic acid benzocyclobutene in a 100 ml dry three-necked flask, add 0.5 mmol of Pd132 and 50 ml of DMF under a nitrogen atmosphere, stir at 70°C for 30 min, heat to 100°C and react for 24 h. After the reaction is completed, pour the solution into deionized water for precipitation, wash repeatedly with water and ethanol for several times, and vacuum dry to obtain a yellow solid benzocyclobutene dinitro intermediate with a yield of 86.7%.

[0073] Step b: weigh 0.5 g of a benzocyclobutene-containing dinitro monomer, add it into a 50 ml dry three-necked flask, stir and add 25 ml of ethanol and 0.05 g of a Pd / C catalyst under a nitrogen atmosphere and mix evenly, heat the solution to reflux, then drop 1 ml of hydrazine hydrate within 10 min, reflux the reaction for 48 h, and filter naturally after the system temperature drops to room temperature. After recrystallization, separate and dry the benzocyclobutene-containing diamine and the monomer diamine, with a yield of 92.1%.

[0074] The structure of the diamine monomer was determined by H NMR ( 1 H-NMR) characterization confirmed the results as follows:

[0075] 1 H-NMR (600 MHz, DMSO-d 6 , δppm): δ7.27(dd,J=7.6,1.5Hz,1H),7.14(s,1H),7.08(d,J=7.6Hz,1H),6 .01(d,J=2.0Hz,2H),5.82(t,J=2.0Hz,1H),4.78(s,4H),3.22–3.11(m,4H).

[0076] Example 2

[0077] This embodiment provides a diamine monomer, and the structural formula of the diamine monomer is as follows:

[0078]

[0079] The preparation method of the above diamine monomer comprises the following steps:

[0080]

[0081] Step a: At room temperature, add 5 mmol of 3-bromo-1,5-dinitrotoluene and 5 mmol of 4-boronic acid benzocyclobutene in a 100 ml dry three-necked flask, add 0.5 mmol of Pd132 and 50 ml of DMF under a nitrogen atmosphere, stir at 70°C for 30 min, heat to 100°C and react for 24 h. After the reaction is completed, pour the solution into deionized water for precipitation, wash repeatedly with water and ethanol for several times, and vacuum dry to obtain a yellow solid benzocyclobutene dinitro intermediate with a yield of 87.4%.

[0082] Step b: weigh 0.5 g of a benzocyclobutene-containing dinitro monomer, add it into a 50 ml dry three-necked flask, stir and add 25 ml of ethanol and 0.05 g of a Pd / C catalyst under a nitrogen atmosphere and mix them evenly, heat the solution to reflux, then drop 1 ml of hydrazine hydrate within 10 min, reflux the reaction for 48 h, and filter naturally after the system temperature drops to room temperature. After recrystallization, separate and dry the benzocyclobutene-containing diamine and the monomer diamine, with a yield of 90.5%.

[0083] The structure of the diamine monomer was determined by H NMR ( 1 H-NMR) characterization confirmed the results as follows:

[0084] 1 H-NMR (600 MHz, DMSO-d 6 , δppm): δ7.30–7.25(m,1H),7.14(d,J=1.7Hz,1H),7.08(d,J=7.6Hz,1H),6.07–5.99 (m,1H),5.81(t,J=1.9Hz,1H),4.79(s,4H),3.14(qd,J=5.7,2.5Hz,4H),2.52(s,3H).

[0085] Example 3

[0086] This embodiment provides a diamine monomer, and the structural formula of the diamine monomer is as follows:

[0087]

[0088] The preparation method of the above diamine monomer comprises the following steps:

[0089]

[0090] Step a: At room temperature, add 5 mmol of 4'-bromo-2-methyl-3,5-dinitro-1,1'-biphenyl and 6 mmol of 4-boronic acid benzocyclobutene in a 100 ml dry three-necked flask, add 0.5 mmol of Pd132 and 50 ml of N,N-dimethylacetamide under a nitrogen atmosphere, stir at 70°C for 30 min, heat to 80°C and react for 30 h. After the reaction is completed, pour the solution into deionized water for precipitation, wash repeatedly with water and ethanol for several times, and vacuum dry to obtain a yellow solid benzocyclobutene dinitro intermediate with a yield of 85.6%.

[0091] Step b: weigh 0.5 g of a benzocyclobutene-containing dinitro monomer, add it into a 50 ml dry three-necked flask, stir and add 25 ml of tetrahydrofuran and 0.05 g of a Pd / C catalyst under a nitrogen atmosphere and mix them evenly, heat the solution to reflux, then drop 1 ml of hydrazine hydrate within 10 min, reflux the reaction for 24 h, and filter naturally after the system temperature drops to room temperature. After recrystallization, separate and dry the benzocyclobutene-containing diamine and the monomer diamine, with a yield of 93.3%.

[0092] The structure of the diamine monomer was determined by H NMR ( 1 H-NMR) characterization confirmed the results as follows:

[0093] 1 H NMR(500MHz,Chloroform-d)δ7.66–7.50(m,4H),7.06(dd,J=7.9,0.8Hz,2H),6.67( d,J=2.0Hz,2H),6.01(d,J=2.2Hz,1H),4.70(s,4H),2.90(m,4H),2.64–2.70(s,3H).

[0094] Example 4

[0095] This embodiment provides a diamine monomer, and the structural formula of the diamine monomer is as follows:

[0096]

[0097] The preparation method of the above diamine monomer comprises the following steps:

[0098]

[0099] Step a: At room temperature, add 5 mmol of 1-(4-bromophenoxy)-3,5-dinitrobenzene and 7.5 mmol of 4-boronic acid benzocyclobutene in a 100 ml dry three-necked flask, add 0.5 mmol of Pd132 and 50 ml of DMF under a nitrogen atmosphere, stir at 70°C for 30 min, heat to 120°C and react for 20 h. After the reaction is completed, pour the solution into deionized water for precipitation, wash repeatedly with water and ethanol for several times, and vacuum dry to obtain a yellow solid benzocyclobutene dinitro intermediate with a yield of 86.1%.

[0100] Step b: weigh 0.5 g of a benzocyclobutene-containing dinitro monomer, add it into a 50 ml dry three-necked flask, stir and add 25 ml of acetone and 0.05 g of a Pd / C catalyst under a nitrogen atmosphere and mix them evenly, heat the solution to reflux, then drop 1 ml of hydrazine hydrate within 10 min, reflux the reaction for 42 h, and filter naturally after the system temperature drops to room temperature. After recrystallization, separate and dry the benzocyclobutene-containing diamine and the monomer diamine, with a yield of 89.2%.

[0101] The structure of the diamine monomer was determined by H NMR ( 1 H-NMR) characterization confirmed the results as follows:

[0102] 1 H NMR(500MHz,Chloroform-d)δ7.64–7.57(m,3H),7.26(d,J=0.9Hz,1H),7.08–7.0 0(m,3H),6.27(d,J=2.2Hz,1H),5.98(t,J=2.2Hz,2H),4.94(s,4H),2.89(s,4H).

[0103] Example 5

[0104] This embodiment provides a diamine monomer, and the structural formula of the diamine monomer is as follows:

[0105]

[0106] The preparation method of the above diamine monomer comprises the following steps:

[0107]

[0108] Step a: At room temperature, add 5 mmol of 4'-(3,5-dinitrophenoxy)-[1,1'-biphenyl]-4-ol and 5 mmol of 4-bromobenzocyclobutene in a 100 ml dry three-necked flask, add 0.5 mmol of Pd132 and 50 ml of dimethyl sulfoxide under a nitrogen atmosphere, stir at 70°C for 30 min, heat to 100°C and react for 24 h. After the reaction is completed, pour the solution into deionized water for precipitation, wash repeatedly with water and ethanol for several times, and vacuum dry to obtain a yellow solid benzocyclobutene dinitro intermediate with a yield of 85.1%.

[0109] Step b: weigh 0.5 g of a benzocyclobutene-containing dinitro monomer, add it into a 50 ml dry three-necked flask, stir and add 25 ml of ethanol and 0.03 g of a Pd / C catalyst under a nitrogen atmosphere and mix them evenly, heat the solution to reflux, then drop 1 ml of hydrazine hydrate within 10 min, reflux the reaction for 36 h, and filter naturally after the system temperature drops to room temperature. After recrystallization, separate and dry the benzocyclobutene-containing diamine and the monomer diamine, with a yield of 92.7%.

[0110] The structure of the diamine monomer was confirmed by nuclear magnetic hydrogen spectrum (1H-NMR), and the results were as follows:

[0111] 1H NMR(500MHz,Chloroform-d)δ7.60–7.51(m,4H),7.11–6.98(m,5H),6.91(dt,J=7.6,0.9Hz,1H),6.71(dp,J=1.8,0.8Hz,1 H), 6.27 (d, J = 2.2Hz, 2H), 5.98 (t, J = 2.2Hz, 1H), 5.07 (d, J = 0.9Hz, 2H), 4.94 (s, 4H), 2.94–2.87 (m, 2H), 2.87–2.80 (m, 2H).

[0112] Application Example 1

[0113] Synthesis of imide-containing diamine monomer A. Add aromatic diamine DPD (12.2571 g, 90 mmol) to a 500 ml three-necked flask under nitrogen protection, then add 240 ml of NMP, and after DPD is completely dissolved, add aromatic dianhydride NTCDA (8.0454 g, 30 mmol), stir and react at room temperature for 24 hours, after the reaction is completed, add 80 ml of water-carrying toluene, continue stirring and heating at 180°C for 24 hours, and obtain a homogeneous imide-containing diamine solution. After the toluene is completely evaporated, stop heating, cool naturally to room temperature, pour the reaction solution into a high-speed stirring mixture of methanol and water (2 L, V: V = 1: 1), obtain a precipitate, dissolve the obtained precipitate in DMF, then precipitate in methanol, filter, dry naturally, and continue drying at 80°C in vacuum for 24 hours to obtain imide-containing diamine monomer A powder.

[0114] Preparation of a self-microporous polyimide C1 containing benzocyclobutene side groups. The preparation process is as follows: 1g of the above-prepared diamine monomer A and 1g of the diamine monomer B1 containing benzocyclobutene are mixed evenly, added to a three-necked flask protected by nitrogen, and then 150ml of trifluoroacetic acid is added. After complete dissolution, 2ml of dimethoxymethane (22.4mmol) is added, stirred at room temperature for 48 hours, and then carefully alkalized with a 2.5% ammonia solution, and the resulting solution is stirred to precipitate a white fibrous precipitate. The solid is filtered out and washed with water and methanol three times each. The obtained fibrous precipitate is dissolved with chloroform, then precipitated in methanol, filtered, and dried naturally, and then continued to dry at 120°C in vacuum for 24 hours to obtain a self-microporous polyimide C1 containing benzocyclobutene side groups.

[0115]

[0116] FTIR spectrum showed that the polymer -1 , 1717cm -1 , 1788cm -1The absorption peak of the imide ring is shown nearby, and the polymer structure is consistent with expectations.

[0117] A cross-linked self-microporous polyimide film containing benzocyclobutene side groups was prepared. Its molecular chain structure is shown in C1.

[0118] Take 3g of the self-microporous polyimide C1 powder containing benzocyclobutene side groups and dissolve it in NMP to prepare a polymer solution with a solid content of 5wt.%, and evenly coat it on a glass plate. Then dry it in a vacuum oven according to the program heating method of 40℃ for 1 to 5 hours, 60℃ for 1 to 5 hours, 80℃ for 1 to 5 hours, 120℃ for 1 to 5 hours, and 150℃ for 1 to 5 hours to remove the solvent. Then perform heat curing and crosslinking according to the heating program of 200℃ for 1 to 5 hours, 250℃ for 1 to 5 hours, and 300℃ for 1 to 2 hours. After cooling, a cross-linked self-microporous polyimide film can be obtained. The film thickness is controlled at 52 microns. The obtained film has a tensile strength of more than 60MPa, an elongation at break of more than 25%, and a T d5％ Above 440℃, T g Above 450℃. The initial temperature of thermal crosslinking is 192℃, the peak temperature is 220℃, and the termination temperature is 262℃. After the crosslinking is completed, the polyimide does not dissolve significantly after being immersed in a conventional solvent for 48 hours. The tensile strength of the crosslinked film is above 75MPa, the elongation at break is above 10%, the tensile modulus is increased from 2.1GPa to 2.5GPa, and T d5％ Above 440℃, T g Above 450℃. The permeability of the six gases of PIs membrane before and after crosslinking follows the trend of He>H 2 >CO 2 >O 2 >N 2 >CH 4 The order is consistent with their kinetic diameters (He <H 2 <CO 2 <O 2 <N 2 <CH 4 ). H of the polymer before cross-linking 2 The permeability is 373 Barrer, CO 2 274 Barrer, H 2 / CO 2 The selectivity is 1.36. After thermal crosslinking, H 2 The permeability is 252 Barrer, CO 2 150 Barrer, H 2 / CO 2 The selectivity is 1.68.

[0119] Application Example 2

[0120] Synthesis of imide-containing diamine monomer A. Add aromatic diamine DPD (12.2571 g, 90 mmol) to a 500 ml three-necked flask under nitrogen protection, then add 240 ml of NMP, and after DPD is completely dissolved, add aromatic dianhydride NTCDA (8.0454 g, 30 mmol), stir and react at room temperature for 24 hours, after the reaction is completed, add 80 ml of water-carrying toluene, continue stirring and heating at 180°C for 24 hours, and obtain a homogeneous imide-containing diamine solution. After the toluene is completely evaporated, stop heating, cool naturally to room temperature, pour the reaction solution into a high-speed stirring mixture of methanol and water (2 L, V: V = 1: 1), obtain a precipitate, dissolve the obtained precipitate in DMF, then precipitate in methanol, filter, dry naturally, and continue drying at 80°C in vacuum for 24 hours to obtain imide-containing diamine monomer A powder.

[0121] Preparation of self-microporous polyimide C2 containing benzocyclobutene side groups. The preparation process is as follows: 1g of the above-prepared diamine monomer A and 1g of the diamine monomer B2 containing benzocyclobutene are mixed evenly, added to a three-necked flask protected by nitrogen, and then 150ml of trifluoroacetic acid is added. After complete dissolution, 2ml of dimethoxymethane (22.4mmol) is added, stirred at room temperature for 48 hours, and then carefully alkalized with 2.5% ammonia solution, and the resulting solution is stirred to precipitate a white fibrous precipitate. The solid is filtered out and washed with water and methanol three times each. The obtained fibrous precipitate is dissolved with chloroform, then precipitated in methanol, filtered, and dried naturally, and then continued to dry at 120°C in vacuum for 24 hours to obtain self-microporous polyimide C2 containing benzocyclobutene side groups.

[0122]

[0123] FTIR spectrum showed that the polymer -1 , 1716cm -1 , 1776cm -1 The absorption peak of the imide ring is shown nearby, and the polymer structure is consistent with expectations.

[0124] A cross-linked self-microporous polyimide film containing benzocyclobutene side groups was prepared. Its molecular chain structure is shown in C2.

[0125] Take 3g of the self-microporous polyimide C2 powder containing benzocyclobutene side groups and dissolve it in NMP to prepare a polymer solution with a solid content of 5wt.%, and evenly coat it on a glass plate. Then dry it in a vacuum oven according to the program heating method of 40℃ for 1 to 5 hours, 60℃ for 1 to 5 hours, 80℃ for 1 to 5 hours, 120℃ for 1 to 5 hours, and 150℃ for 1 to 5 hours to remove the solvent. Then perform heat curing and crosslinking according to the heating program of 200℃ for 1 to 5 hours, 250℃ for 1 to 5 hours, and 300℃ for 1 to 2 hours. After cooling, a cross-linked self-microporous polyimide film can be obtained. The film thickness is controlled at 40 microns. The obtained film has a tensile strength of more than 72MPa, an elongation at break of more than 18%, and a T d5％ Above 450℃, T g Above 450℃. The initial temperature of thermal crosslinking is 188℃, the peak temperature is 232℃, and the termination temperature is 260℃. After the crosslinking is completed, the polyimide does not dissolve significantly after being immersed in a conventional solvent for 48 hours. The tensile strength of the crosslinked film is above 80MPa, the elongation at break is above 10%, the tensile modulus is increased from 2.0GPa to 2.4GPa, and T d5％ Above 450℃, T g Above 450℃. The permeability of the six gases of PIs membrane before and after crosslinking follows the trend of He>H 2 >CO 2 >O 2 >N 2 >CH 4 The order is consistent with their kinetic diameters (He <H 2 <CO 2 <O 2 <N 2 <CH 4 ). H of the polymer before cross-linking 2 The permeability is 404 Barrer, CO 2 312 Barrer, H 2 / CO 2 The selectivity is 1.29. After thermal crosslinking, H 2 The permeability is 314 Barrer, CO 2 160 Barrer, H 2 / CO 2 The selectivity is 1.96.

[0126] Application Example 3

[0127] Synthesis of imide-containing diamine monomer A. Add aromatic diamine DPD (12.2571 g, 90 mmol) to a 500 ml three-necked flask under nitrogen protection, then add 240 ml of NMP, and after DPD is completely dissolved, add aromatic dianhydride NTCDA (8.0454 g, 30 mmol), stir and react at room temperature for 24 hours, after the reaction is completed, add 80 ml of water-carrying toluene, continue stirring and heating at 180°C for 24 hours, and obtain a homogeneous imide-containing diamine solution. After the toluene is completely evaporated, stop heating, cool naturally to room temperature, pour the reaction solution into a high-speed stirring mixture of methanol and water (2 L, V: V = 1: 1), obtain a precipitate, dissolve the obtained precipitate in DMF, then precipitate in methanol, filter, dry naturally, and continue drying at 80°C in vacuum for 24 hours to obtain imide-containing diamine monomer A powder.

[0128] Preparation of self-microporous polyimide C3 containing benzocyclobutene side groups. The preparation process is as follows: 1g of the above-prepared diamine monomer A and 1g of the diamine monomer B3 containing benzocyclobutene are mixed evenly, added to a three-necked flask protected by nitrogen, and then 150ml of trifluoroacetic acid is added. After complete dissolution, 2ml of dimethoxymethane (22.4mmol) is added, stirred at room temperature for 48 hours, and then carefully alkalized with 2.5% ammonia solution, and the resulting solution is stirred to precipitate a white fibrous precipitate. The solid is filtered out and washed with water and methanol three times each. The obtained fibrous precipitate is dissolved with chloroform, then precipitated in methanol, filtered, and dried naturally, and then continued to dry at 120°C in vacuum for 24 hours to obtain self-microporous polyimide C3 containing benzocyclobutene side groups.

[0129]

[0130] FTIR spectrum showed that the polymer -1 , 1716cm -1 , 1776cm -1 The absorption peak of the imide ring is shown nearby, and the polymer structure is consistent with expectations.

[0131] A cross-linked self-microporous polyimide film containing benzocyclobutene side groups was prepared. Its molecular chain structure is shown in C3.

[0132] Take 3g of the self-microporous polyimide C3 powder containing benzocyclobutene side groups and dissolve it in NMP to prepare a polymer solution with a solid content of 5wt.%, and evenly coat it on a glass plate. Then dry it in a vacuum oven according to the program heating method of 40℃ for 1 to 5 hours, 60℃ for 1 to 5 hours, 80℃ for 1 to 5 hours, 120℃ for 1 to 5 hours, and 150℃ for 1 to 5 hours to remove the solvent. Then perform heat curing and crosslinking according to the heating program of 200℃ for 1 to 5 hours, 250℃ for 1 to 5 hours, and 300℃ for 1 to 2 hours. After cooling, a cross-linked self-microporous polyimide film can be obtained. The film thickness is controlled at 52 microns. The obtained film has a tensile strength of more than 60MPa, an elongation at break of more than 30%, and T d5％ Above 440℃, T g Above 450℃. The initial temperature of thermal crosslinking is 195℃, the peak temperature is 217℃, and the termination temperature is 255℃. After the crosslinking is completed, the polyimide does not dissolve significantly after being immersed in a conventional solvent for 48 hours. The tensile strength of the crosslinked film is above 65MPa, the elongation at break is above 12%, the tensile modulus is increased from 1.9GPa to 2.2GPa, T d5％ Above 440℃, T g Above 450℃. The permeability of the six gases of PIs membrane before and after crosslinking follows the trend of He>H 2 >CO 2 >O 2 >N 2 >CH 4 The order is consistent with their kinetic diameters (He <H 2 <CO 2 <O 2 <N 2 <CH 4 ). H of the polymer before cross-linking 2 The permeability is 427 Barrer, CO 2 393Barrer, H 2 / CO 2 The selectivity is 1.08. After thermal crosslinking, H 2 The permeability is 270 Barrer, CO 2 172 Barrer, H 2 / CO 2 The selectivity is 1.57.

[0133] Application Example 4

[0134] Synthesis of imide-containing diamine monomer A. Add aromatic diamine DPD (12.2571 g, 90 mmol) to a 500 ml three-necked flask under nitrogen protection, then add 240 ml of NMP, and after DPD is completely dissolved, add aromatic dianhydride NTCDA (8.0454 g, 30 mmol), stir and react at room temperature for 24 hours, after the reaction is completed, add 80 ml of water-carrying toluene, continue stirring and heating at 180°C for 24 hours, and obtain a homogeneous imide-containing diamine solution. After the toluene is completely evaporated, stop heating, cool naturally to room temperature, pour the reaction solution into a high-speed stirring mixture of methanol and water (2 L, V: V = 1: 1), obtain a precipitate, dissolve the obtained precipitate in DMF, then precipitate in methanol, filter, dry naturally, and continue drying at 80°C in vacuum for 24 hours to obtain imide-containing diamine monomer A powder.

[0135] Preparation of self-microporous polyimide C4 containing benzocyclobutene side groups. Preparation process: 1g of the above-prepared diamine monomer A and 1g of the diamine monomer B4 containing benzocyclobutene are mixed evenly, added to a three-necked flask protected by nitrogen, and then 150ml of trifluoroacetic acid is added. After complete dissolution, 2ml of dimethoxymethane (22.4mmol) is added, stirred at room temperature for 48 hours, and then carefully alkalized with 2.5% ammonia solution, and the resulting solution is stirred to precipitate a white fibrous precipitate. The solid is filtered out and washed with water and methanol three times each. The obtained fibrous precipitate is dissolved in chloroform, then precipitated in methanol, filtered, and dried naturally, and then continued to dry at 120°C in vacuum for 24 hours to obtain self-microporous polyimide C4 containing benzocyclobutene side groups.

[0136]

[0137] FTIR spectrum showed that the polymer -1 , 1717cm -1 , 1780cm -1 The absorption peak of the imide ring is shown nearby, and the polymer structure is consistent with expectations.

[0138] A cross-linked self-microporous polyimide film containing benzocyclobutene side groups was prepared. Its molecular chain structure is shown in C4.

[0139] Take 3g of the self-microporous polyimide C4 powder containing benzocyclobutene side groups and dissolve it in NMP to prepare a polymer solution with a solid content of 5wt.%, and evenly coat it on a glass plate. Then dry it in a vacuum oven according to the program heating method of 40℃ for 1 to 5 hours, 60℃ for 1 to 5 hours, 80℃ for 1 to 5 hours, 120℃ for 1 to 5 hours, and 150℃ for 1 to 5 hours to remove the solvent. Then perform heat curing and crosslinking according to the heating program of 200℃ for 1 to 5 hours, 250℃ for 1 to 5 hours, and 300℃ for 1 to 2 hours. After cooling, a cross-linked self-microporous polyimide film can be obtained. The film thickness is controlled at 60 microns. The obtained film has a tensile strength of more than 70MPa, an elongation at break of more than 20%, and T d5％ Above 440℃, T g Above 450℃. The initial temperature of thermal crosslinking is 197℃, the peak temperature is 230℃, and the termination temperature is 250℃. After the crosslinking is completed, the polyimide does not dissolve significantly after being immersed in a conventional solvent for 48 hours. The tensile strength of the crosslinked film is above 72MPa, the elongation at break is above 12%, the tensile modulus is increased from 1.7GPa to 2.0GPa, T d5％ Above 440℃, T g Above 450℃. The permeability of the six gases of PIs membrane before and after crosslinking follows the trend of He>H 2 >CO 2 >O 2 >N 2 >CH 4 The order is consistent with their kinetic diameters (He <H 2 <CO 2 <O 2 <N 2 <CH 4 ). H of the polymer before cross-linking 2 The permeability is 477 Barrer, CO 2 For 401 Barrer, H 2 / CO 2 The selectivity is 1.19. After thermal crosslinking, H 2 The permeability is 335 Barrer, CO 2 277 Barrer, H 2 / CO 2 The selectivity is 1.21.

[0140] Application Example 5

[0141] Synthesis of imide-containing diamine monomer A. Add aromatic diamine DPD (12.2571 g, 90 mmol) to a 500 ml three-necked flask under nitrogen protection, then add NMP240 ml, and after DPD is completely dissolved, add aromatic dianhydride NTCDA (8.0454 g, 30 mmol), stir and react at room temperature for 24 hours, and after the reaction is completed, add 80 ml of water-carrying toluene, continue stirring and heating at 180°C for 24 hours to obtain a homogeneous imide-containing diamine solution. After the toluene is completely evaporated, stop heating, cool naturally to room temperature, pour the reaction solution into a high-speed stirring mixture of methanol and water (2 L, V: V = 1: 1) to obtain a precipitate, dissolve the obtained precipitate in DMF, then precipitate in methanol, filter, dry naturally, and continue drying at 80°C in vacuum for 24 hours to obtain imide-containing diamine monomer A powder.

[0142] Preparation of self-microporous polyimide C5 containing benzocyclobutene side groups. The preparation process is as follows: 1g of the above-prepared diamine monomer A and 1g of the diamine monomer B5 containing benzocyclobutene are mixed evenly, added to a three-necked flask protected by nitrogen, and then 150ml of trifluoroacetic acid is added. After complete dissolution, 2ml of dimethoxymethane (22.4mmol) is added, stirred at room temperature for 48 hours, and then carefully alkalized with 2.5% ammonia solution, and the resulting solution is stirred to precipitate a white fibrous precipitate. The solid is filtered out and washed with water and methanol three times each. The obtained fibrous precipitate is dissolved with chloroform, then precipitated in methanol, filtered, and dried naturally, and then continued to dry for 24 hours at 120°C in vacuum to obtain self-microporous polyimide C5 containing benzocyclobutene side groups.

[0143]

[0144] FTIR spectrum showed that the polymer -1 , 1717cm -1 , 1780cm -1 The absorption peak of the imide ring is shown nearby, and the polymer structure is consistent with expectations.

[0145] A cross-linked self-microporous polyimide film containing benzocyclobutene side groups was prepared. Its molecular chain structure is shown in C5.

[0146] Take 3g of the self-microporous polyimide C5 powder containing benzocyclobutene side groups and dissolve it in NMP to prepare a polymer solution with a solid content of 5wt.%, and evenly coat it on a glass plate. Then dry it in a vacuum oven according to the program heating method of 40℃ for 1 to 5 hours, 60℃ for 1 to 5 hours, 80℃ for 1 to 5 hours, 120℃ for 1 to 5 hours, and 150℃ for 1 to 5 hours to remove the solvent. Then perform heat curing and crosslinking according to the heating program of 200℃ for 1 to 5 hours, 250℃ for 1 to 5 hours, and 300℃ for 1 to 2 hours. After cooling, a cross-linked self-microporous polyimide film can be obtained. The film thickness is controlled at 44 microns. The obtained film has a tensile strength of more than 65MPa, an elongation at break of more than 30%, and T d5％ Above 440℃, T g Above 450℃. The initial temperature of thermal crosslinking is 190℃, the peak temperature is 227℃, and the termination temperature is 259℃. After the crosslinking is completed, the polyimide does not dissolve significantly after being immersed in a conventional solvent for 48 hours. The tensile strength of the crosslinked film is above 73MPa, the elongation at break is above 14%, the tensile modulus is increased from 1.6GPa to 2.1GPa, and T d5％ Above 440℃, T g Above 450℃. The permeability of the six gases of PIs membrane before and after crosslinking follows the trend of He>H 2 >CO 2 >O 2 >N 2 >CH 4 The order is consistent with their kinetic diameters (He <H 2 <CO 2 <O 2 <N 2 <CH 4 ). H of the polymer before cross-linking 2 The permeability is 295 Barrer, CO 2 241Barrer, H 2 / CO 2 The selectivity is 1.22. After thermal crosslinking, H 2 The permeability is 178 Barrer, CO 2 133 Barrer, H 2 / CO 2 The selectivity is 1.34.

[0147] The applicant declares that the present invention uses the above-mentioned embodiments to illustrate the benzocyclobutene diamine-containing monomer and its preparation method and application, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A diamine monomer, characterized in that The structural formula of the diamine monomer is shown in Formula A: Wherein, Ar1 and Ar2 are each independently selected from a substituted or unsubstituted arylene group.

2. The diamine monomer according to claim 1, characterized in that Ar1 in the diamine monomer is selected from any one of formulas BK, and the structure of formula BK is as follows: Among them, X1-X 64 Each is independently selected from H, amino, dimethylamino, nitro, cyano, hydroxyl, carboxyl, sulfonic acid, sulfonyl, thiol, disulfide bond, methoxy, aldehyde, halogen atom or C1-C12 alkyl; The dotted line position indicates the connection position with Ar2; the aromatic ring contained in formula BK is fused with the cyclobutene group at any condensable position thereof.

3. The diamine monomer according to claim 1 or 2, characterized in that Ar2 in the diamine monomer is selected from any one of formula LU, and the structure of formula LU is as follows: Among them, X 65 -X 128 Each is independently selected from H, amino, dimethylamino, nitro, cyano, hydroxyl, carboxyl, sulfonic acid, sulfonyl, thiol, disulfide bond, methoxy, aldehyde, halogen atom or C1-C12 alkyl; The dotted line position indicates the connection position with Ar1, and in Formula LU, it is connected to the amino group at any connectable position.

4. The diamine monomer according to any one of claims 1 to 3, characterized in that The diamine monomer includes any one or a combination of at least two of the following compounds: Among them, Y1-Y 459 , Z1-Z 519 Each is independently selected from H, amino, hydroxyl, carboxyl or C1-C12 alkyl.

5. A method for preparing the diamine monomer according to any one of claims 1 to 4, characterized in that: The preparation method comprises the following steps: Step a, synthesizing dinitro intermediate III containing benzocyclobutene functional group: monomer I containing boric acid functional group and benzocyclobutene functional group reacts with monomer II containing halogen atom and nitro group to obtain intermediate III; Step b, synthesizing diamine monomer IV containing benzocyclobutene functional group: subjecting the intermediate III obtained in step a to reduction reaction to obtain the diamine monomer; The reaction formula of the preparation method is as follows: Wherein, X is -H or -CH3; Said Y is a halogen atom; The Ar1 and Ar2 each independently have the same definition as in claim 1.

6. The preparation method according to claim 5, characterized in that: Said Y is selected from -Br; Preferably, in step a, the molar ratio of the monomer I containing boric acid and benzocyclobutene functional groups to the monomer II containing halogen atoms and nitro groups is 1:(1-1.5); Preferably, in step a, the reaction is carried out in a first solvent, and the first solvent comprises any one or a combination of at least two of dimethyl sulfoxide, N,N-dimethylacetamide, N,N-dimethylformamide or N-methylpyrrolidone; Preferably, in step a, the reaction is carried out under a first catalyst, and the first catalyst includes any one or a combination of at least two of Pd132, tetrakis(triphenyl)phosphine palladium, potassium carbonate or triethylamine.

7. The preparation method according to claim 5 or 6, characterized in that: In step a, the reaction temperature is 20-200°C; Preferably, in step a, the reaction time is 2-120 hours; Preferably, in step a, the reaction further comprises a post-treatment step; Preferably, in step a, the post-treatment includes reduced pressure distillation, washing, drying, separation and purification.

8. The preparation method according to any one of claims 5 to 7, characterized in that: In step b, the mass ratio of the intermediate III to the second catalyst is 1:(0.01-0.5); Preferably, in step b, the reaction is carried out in a second solvent, and the second solvent comprises any one or a combination of at least two of methanol, ethanol, tetrahydrofuran or acetone; Preferably, in step b, the reaction is carried out under a second catalyst, and the second catalyst comprises a Pd / C catalyst; Preferably, in step b, the reaction is carried out under a reducing agent, and the reducing agent comprises hydrazine hydrate; Preferably, in step b, the reaction is carried out under reflux conditions; Preferably, in step b, the reflux reaction time is 0.5-48 hours; Preferably, in step b, the reaction further comprises a post-treatment step; Preferably, in step b, the post-treatment includes reduced pressure distillation, washing, drying, separation and purification.

9. The preparation method according to any one of claims 5 to 8, characterized in that: The preparation method comprises the following steps: Step a, synthesizing dinitro intermediate III containing benzocyclobutene functional group: dissolving monomer I containing boric acid functional group and benzocyclobutene functional group and monomer II containing halogen atom and nitro group in a first solvent, adding a first catalyst, reacting at a temperature of 20-200° C. for 2 hours, and then distilling under reduced pressure, washing, drying, separating and purifying to obtain intermediate III; Step b, synthesizing diamine monomer IV containing benzocyclobutene functional group: dissolving the intermediate III obtained in step a in a second solvent, adding a second catalyst and a reducing agent, heating to reflux temperature, reflux reaction for 0.5-48 hours, cooling, separating, recrystallizing and drying to obtain the diamine monomer.

10. A polyimide, characterized in that: The reactive monomer of the polyimide comprises the diamine monomer according to any one of claims 1 to 4.

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