Terpyridyl modified epoxy resin, metal organic polymer material as well as preparation method and application of terpyridyl modified epoxy resin and metal organic polymer material

Abstract

The invention belongs to the technical field of metal organic high-molecular polymers, and particularly relates to terpyridyl modified epoxy resin, a metal organic high-molecular material as well as a preparation method and application of the metal organic high-molecular material. The terpyridyl modified epoxy resin has a structure as shown in a formula (1): # imgabs0 #; the metal organic polymer material obtained by coordination of the terpyridyl modified epoxy resin and transition metal ions has a chain structure, the structure is stable, the formed metal terpyridyl structure has the characteristics of large conjugation and large electron density, and the catalytic performance of the metal organic polymer material can be effectively improved. The metal organic polymer material has good catalytic performance and shows huge potential in an experiment for reducing the curing temperature of the electrophoretic paint.

Description

Technical Field

[0001] The invention belongs to the technical field of metal organic macromolecular polymers, and particularly relates to a terpyridine modified epoxy resin, a metal organic macromolecular material, and a preparation method and application thereof. Background Art

[0002] Epoxy resin is a high molecular polymer with the molecular formula (C11H 12 Epoxy resin (O3)n is a general term for a class of polymers containing more than two epoxy groups in the molecule. It is a condensation product of epichlorohydrin and bisphenol A or polyols. Due to the chemical activity of the epoxy group, it can be opened with a variety of compounds containing active hydrogen, cured and cross-linked to form a network structure, so it is a thermosetting resin. The excellent physical, mechanical and electrical insulation properties of epoxy resin, the bonding properties with various materials, and the flexibility of its use process are not possessed by other thermosetting plastics. Therefore, it can be made into coatings, composite materials, casting materials, adhesives, molding materials and injection molding materials, and is widely used in various fields of the national economy. However, the curing temperature of epoxy resin is relatively high, which is not conducive to its application in some coatings. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the above-mentioned prior art. To this end, the present invention provides a terpyridine-modified epoxy resin, a metal organic polymer material and a preparation method and application thereof. The terpyridine-modified epoxy resin of the present invention is coordinated with transition metal ions to form a metal organic polymer material, and the metal organic polymer material has a stable structure and has the advantage of reducing the curing temperature of the electrophoretic paint.

[0004] A first aspect of the present invention provides a terpyridine-modified epoxy resin.

[0005] Specifically, a terpyridine-modified epoxy resin has a structure shown in formula (1):

[0006]

[0007] Wherein, R represents a hydrogen atom, a long alkyl chain, a long alkoxy chain, a polypeptide chain, a polyethersulfone chain or a polyaromatic hydrocarbon ring chain;

[0008] n is a positive integer.

[0009] Preferably, the carbon number of the alkyl long chain is 1-10, further 1-8.

[0010] Preferably, the carbon number of the alkoxy long chain is 1-10, further 1-8.

[0011] Preferably, the carbon number of the polyaromatic hydrocarbon ring chain is 6-60, further 6-30.

[0012] Preferably, n is 1-3.

[0013] Preferably, said R is hydrogen.

[0014] A second aspect of the present invention provides a method for preparing a terpyridine-modified epoxy resin.

[0015] Specifically, a method for preparing a terpyridine-modified epoxy resin comprises the following steps:

[0016] Mixing compound 2 with epoxy resin and reacting them to obtain the terpyridine-modified epoxy resin;

[0017] The structure of compound 2 is

[0018] The structure of the epoxy resin is

[0019]

[0020] Preferably, the mass ratio of the compound 2 to the epoxy resin is 30:(40-70), and more preferably 30:(58.5-60).

[0021] Preferably, the reaction temperature is 110-125°C, more preferably 115-125°C.

[0022] Preferably, the reaction time is 20-40 minutes, more preferably 30-40 minutes.

[0023] Preferably, the preparation process of the compound 2 comprises: adding boron tribromide to the compound 1 under ice bath conditions, then stirring at room temperature, and after stirring, quenching with water under ice bath conditions to separate and obtain the compound 2;

[0024] The structural formula of the compound 1 is

[0025] Preferably, the preparation process of the compound 1 comprises: mixing sodium hydroxide or potassium hydroxide and ethanol, then adding p-methoxybenzaldehyde and 2-acetylpyridine, stirring and mixing, then adding ammonia water, reacting, filtering, washing, and obtaining the compound 1.

[0026] Preferably, during the preparation of compound 1, the reaction temperature is 70-80° C. and the reaction time is 12-20 hours.

[0027] A third aspect of the present invention provides a metal organic polymer material.

[0028] A metal organic polymer material having a structure shown in formula (1):

[0029]

[0030] Wherein, R represents a hydrogen atom, a long alkyl chain, a long alkoxy chain, a polypeptide chain, a polyethersulfone chain or a polyaromatic hydrocarbon ring chain;

[0031] M 2+ represents transition metal ions;

[0032] n is a positive integer.

[0033] Preferably, M 2+ Selected from Cr 2+ , Mn 2+ , Fe 2+ 、Co 2+ 、Ni 2+ 、Zn 2+ , Cu 2+ 、Cd 2+ 、Ru 2+ At least one of the above.

[0034] The divalent metal ion M2+ can react with the terpyridine organic ligand compound to form tpy-M(II)-tpy with a pseudo-octahedron, and can also form tpy-M(II).

[0035] The R group is mainly a chain structure for modifying metal organic polymer materials, which is usually beneficial to improve the solubility and conductivity of metal organic polymer materials, as well as the performance of combining with metal oxides or graphene surfaces, so that metal organic polymer materials can be involved in more fields. In theory, hydrogen atoms, alkyl long chains, alkoxy long chains, polypeptide chains, polyethersulfone chains, polyaromatic hydrocarbon ring chains and other functional chain structures modified at their ends can be selected, and hydrogen atoms are preferred in the present invention.

[0036] A fourth aspect of the present invention provides a method for preparing a metal organic polymer material.

[0037] The method for preparing a metal organic polymer material comprises the following steps:

[0038] Adding a transition metal salt to a terpyridine-modified epoxy resin and heating the resin to react, thereby obtaining the metal organic polymer material;

[0039] The mass ratio of the terpyridine modified epoxy resin to the transition metal salt is less than 88.5g:13.37.

[0040] Preferably, the mass ratio of the terpyridine-modified epoxy resin to the transition metal salt is 88.5::(13.5-30), and more preferably 88.5:(15-26.73).

[0041] Preferably, the heating reaction temperature is 60-80° C., and the heating reaction time is 3-4 hours.

[0042] Preferably, the transition metal salt is an aqueous solution of a transition metal salt.

[0043] Preferably, the cation in the transition metal salt is M 2+ Optionally, the anion in the transition metal salt is a nitrate ion, a sulfate ion or a chloride ion.

[0044] Preferably, the terpyridine modified epoxy resin is dissolved in methanol and methyl isobutyl ketone (MIBK), and then a transition metal salt solution is added to carry out a heating reaction.

[0045] Preferably, the volume ratio of methanol to methyl isobutyl ketone is 1-2:1.

[0046] The methanol and MIBK mixed solvent used in the present invention plays an important role in the generation of metal organic polymer materials. The methanol and MIBK mixed solvent can well dissolve the terpyridine modified epoxy resin and metal ions to carry out homogeneous reaction.

[0047] A fifth aspect of the present invention provides a paint.

[0048] A paint comprises the above metal organic polymer material.

[0049] Preferably, the paint comprises electrophoretic paint, which has the characteristic of low curing temperature.

[0050] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0051] (1) The metal organic polymer material provided by the present invention has a chain structure, which is constructed by self-assembly guided by coordination bonds of terpyridine-modified epoxy resin and transition metal ions. Its structure is stable, and the metal terpyridine structure formed has the characteristics of large conjugation and high electron density, which can effectively improve its catalytic performance. The metal organic polymer material has good catalytic performance and shows great potential in the experiment of reducing the curing temperature of electrophoretic paint.

[0052] (2) The metal organic polymer material provided by the present invention has extensive basic research value and extensive potential application research value in water-based industrial topcoats, electrophoretic paints, special functional coatings, engineering plastics, etc.

[0053] (3) The metal organic polymer material provided by the present invention has a simple preparation method and mild reaction conditions, which is conducive to large-scale industrial production. DETAILED DESCRIPTION

[0054] In order to make the technical scheme of the present invention more clearly understood by those skilled in the art, the following embodiments are listed for illustration. It should be pointed out that the following embodiments do not limit the protection scope of the present invention.

[0055] Unless otherwise specified, the raw materials, reagents or devices used in the following examples can be obtained from conventional commercial sources or by existing known methods.

[0056] Example 1: Preparation of terpyridine-modified epoxy resin and metal organic polymer materials

[0057] The preparation method of terpyridine modified epoxy resin and metal organic polymer material comprises the following steps:

[0058] (1) Sodium hydroxide solid (9.6 g) was added to 200 ml of ethanol solution to obtain a mixed solution, p-anisaldehyde (5.45 g) and 2-acetylpyridine (9.8 mL) were added to the mixed solution under ice bath conditions, the obtained mixture was stirred at room temperature for 20 h, 150 mL of ammonia water was added, the mixture was refluxed at 80° C. for 20 h, and a yellow solid was obtained by filtration. The mixture was heated under reflux and washed with isopropanol to finally obtain a light yellow solid as compound 1 (11.05 g). The structural formula of compound 1 is

[0059]

[0060] The NMR characterization results of compound 1 are: 1 H NMR (400MHz, DMSO-d6, 298K, ppm): δ8.60 (2H, tpy-H 6,6” ),8.58(2H,tpy-H 3,3” ),8.73(s,2H,tpy-H 3’,5’ ),8.25(2H,tpy-H 4,4” ),7.61(2H,Ph-H a ),7.72(m,2H,tpy-H 5,5” ),6.93(4H,Ph-H b ),3.81(s,2H,H c );

[0061] (2) Boron tribromide (1M, 1.5mmol, 1.5mL) was slowly added dropwise to a solution of compound 1 (339.4mg) in anhydrous dichloromethane (200mL) under 0°C ice bath conditions. After the addition was completed, the mixture was stirred at room temperature for 5h. After 5h, the mixture was quenched with water (100mL) under 0°C ice bath conditions, and concentrated under reduced pressure to remove dichloromethane. The mixed solution was extracted with ethyl acetate (EA) to obtain an organic phase, which was dried over anhydrous sodium sulfate and passed through a silica gel column at room temperature with ethyl acetate as the eluent. The mixture was concentrated under reduced pressure at room temperature to obtain compound 2 (330mg). The structural formula of compound 2 is

[0062] The NMR characterization results of compound 2 are: 1 H NMR (400MHz, DMSO-d6, 298K, ppm): δ8.95 (2H, tpy-H 6,6” ),8.89(2H,tpy-H 3,3” ),8.84(s,2H,tpy-H 3’,5’ ),8.35(2H,tpy-H 4,4” ),7.95(2H,Ph-H a ),7.83–7.76(m,2H,tpy-H 5,5” ),7.44(4H,Ph-H b ),9.67(s,2H,H c );

[0063] (3) Epoxy resin prepolymer 100g and bisphenol A (17g) were added into a 6ml MIBK reactor, stirred at 115°C for 20min, 0.15g of chain extender (N,N-dimethylbenzylamine) was added, stirred at 115°C for 1h, and the epoxy value was tested to be 0.303, to obtain epoxy resin 1, the structural formula of epoxy resin 1 is:

[0064] (4) Compound 2 (30 g, the amount of raw materials in step (2) was proportionally increased to obtain a sufficient amount of compound 2) was added to 58.5 g of epoxy resin 1, and stirred in a reactor at 120° C. for 40 min. The epoxy value was tested to be 0.1025, and a terpyridine-modified epoxy resin was obtained, the structural formula of which is:

[0065]

[0066] (5) 88.5 g of terpyridine-modified epoxy resin was weighed and added to a reactor. 30 ml of a solution of MIBK and methanol (the volume ratio of MIBK to methanol was 2:1) was added thereto. Zinc nitrate hexahydrate (26.73 g) was dissolved in 30 mL of methanol and added to the reactor. The reactor was covered with a stopper and reacted at 60° C. for 4 hours to obtain 100 g of a metal organic polymer material, which was a light yellow resin with a yield of 88%.

[0067] Comparative Example 1

[0068] Compared with Example 1, the difference of Comparative Example 1 is that the amount of zinc nitrate hexahydrate used is 13.365 g, and the rest of the process is the same as Example 1.

[0069] Product effect testing

[0070] Experiment to lower the curing temperature of electrophoretic paint: Take the S series electrophoretic paint emulsion and color paste of Kede Environmental Protection Co., Ltd. with a curing temperature of 180°C, and prepare 1 kg of electrophoretic paint bath according to the ratio of color paste: emulsion: pure water = 1:3:4. Connect the anode and cathode, connect the metal plate to be coated with the cathode, adjust the rectifier cabinet to the 3min constant voltage mode, turn on the rectifier cabinet and slowly increase the voltage to 120V. After 3 minutes, take out the metal plate and wash off the floating paint on the surface with pure water. Place it at room temperature for 8 minutes, and then put it in an oven with a set temperature and bake it for 20 minutes. Wait for the sample to cool completely and wipe it with alcohol, MIBK, and acetone respectively. After wiping 3 times, there is no gloss loss or powdering on the board surface, and the paint film has no discoloration, which means it is completely cured. Use this test condition to verify the change in curing temperature of the paint film before and after the addition of the bath liquid to the metal organic polymer material prepared in Example 1.

[0071] The metal organic polymer material prepared in Example 1 was diluted with MIBK before being added to the bath solution, and the dilution ratio was metal organic polymer material: MIBK = 1:10 (mass ratio), and the amount added after dilution was one thousandth of the bath solution (mass ratio). Under the same conditions, the electrophoretic paint sample was baked at 180°C, and the metal organic polymer material prepared in Example 1 and the original bath sample were wiped with alcohol, MIBK, and acetone respectively, and no loss of gloss, differentiation, or fading occurred on the board surface, proving that the paint film can be completely cured under the baking condition of 180°C.

[0072] Under the same conditions, the electrophoretic paint sample was baked at 160°C, and the metal organic polymer material prepared in Example 1 and the original tank sample were wiped with alcohol, MIBK and acetone respectively. The original tank sample showed gloss loss, powdering and fading, while the plate surface added with the metal organic polymer material prepared in Example 1 did not show gloss loss, powdering and fading, proving that the paint film was completely cured under the baking condition of 160°C after adding the metal organic polymer material prepared in Example 1, while the original tank liquid only reached surface dryness.

[0073] In order to further verify the effect of the metal organic polymer material prepared in Example 1 on the curing temperature of the electrophoretic paint, the baking temperature was set to 140°C and 150°C to test the dryness of the board surface. The experimental results show that the sample board surface with the metal organic polymer material prepared in Example 1 can be completely cured under the baking condition of 150°C, but slight paint peeling will occur when wiping with acetone and MIBK under the baking condition of 140°C, proving that the paint film cannot be completely cured under this condition. That is, after adding the metal organic polymer material prepared in Example 1 to the electrophoretic paint, the original curing temperature of the paint of 180°C can be reduced to 150°C, or even close to 140°C, which has the effect of reducing the curing temperature.

[0074] To achieve the reduction of the curing temperature of electrophoretic paint, the metal active sites formed by the terpyridine on the metal organic polymer material and the transition metal ion mono-matching have strong catalytic performance. In order to verify this, on the basis of Example 1, the amount of zinc nitrate hexahydrate added was reduced by half to obtain a metal organic polymer material (recorded as Comparative Example 1), which was added to the electrophoretic paint tank liquid under the same conditions, and the drying performance of the paint film was tested. The experimental results showed that when the curing temperature was 180°C, the paint film could be completely cured, but when the curing temperature was 160°C, the paint film surface was wiped with three solvents and slight paint peeling occurred, proving that the paint film did not achieve complete curing at 160°C. In order to further prove the effect of the addition on the curing temperature, when the curing temperature was 170°C, the paint film surface was wiped with solvents and it was found that the paint film did not show obvious paint peeling, proving that the paint film could be completely cured at 170°C. This experiment proved that when the amount of zinc nitrate hexahydrate added was reduced to half of that in Example 1, the curing temperature of the metal organic polymer material was slightly lower than that of the original bath solution, but compared with Example 1, the curing temperature was significantly increased. The reason may be that the double coordination structure, i.e., tpy-M(II)-tpy, appeared in the reaction and was the main product, and the reduction of empty orbitals led to a decrease in catalytic performance. It proved that the ratio of metal ions to organic ligands is crucial to the system.

[0075] In summary, the metal organic polymer material provided by the present invention has the performance of reducing the curing temperature of electrophoretic paint to 150°C, or even close to 140°C.

[0076] It should be pointed out that, within the scope of the present invention, by changing the dosage of each substance, a metal organic polymer material having a similar effect to that of Example 1 can also be prepared.

Claims

1. A terpyridine modified epoxy resin, characterized in that: It has the structure shown in formula (1): Wherein, R represents a hydrogen atom, a long alkyl chain, a long alkoxy chain, a polypeptide chain, a polyethersulfone chain or a polyaromatic hydrocarbon ring chain; n is a positive integer.

2. The method for preparing a terpyridine-modified epoxy resin according to claim 1, wherein: The following steps are involved: Mixing compound 2 with epoxy resin and reacting them to obtain the terpyridine-modified epoxy resin; The structure of compound 2 is The structure of the epoxy resin is 3. The preparation method according to claim 2, characterized in that: The mass ratio of the compound 2 to the epoxy resin is 30:(40-70); and / or the reaction temperature is 110-125° C.; and / or the reaction time is 20-40 minutes.

4. The preparation method according to claim 2, characterized in that: The preparation process of the compound 2 comprises: adding boron tribromide to the compound 1 under ice bath conditions, and then stirring at room temperature, and after stirring, quenching with water under ice bath conditions to separate and obtain the compound 2; The structural formula of the compound 1 is 5. The preparation method according to claim 4, characterized in that: The preparation process of the compound 1 includes: mixing sodium hydroxide or potassium hydroxide and ethanol, then adding p-methoxybenzaldehyde and 2-acetylpyridine, stirring and mixing, then adding ammonia water, reacting, filtering, washing, and obtaining the compound 1.

6. Metal organic polymer material, characterized in that: It has the structure shown in formula (1): Wherein, R represents a hydrogen atom, a long alkyl chain, a long alkoxy chain, a polypeptide chain, a polyethersulfone chain or a polyaromatic hydrocarbon ring chain; M 2+ represents transition metal ions; n is a positive integer.

7. The metal organic polymer material according to claim 6, characterized in that: M 2+ Selected from Cr 2+ , Mn 2+ , Fe 2+ 、Co 2 + 、Ni 2+ 、Zn 2+ , Cu 2+ 、Cd 2+ 、Ru 2+ At least one of .

8. The method for preparing the metal organic polymer material according to claim 6 or 7, characterized in that: The following steps are involved: Adding a transition metal salt to a terpyridine-modified epoxy resin and heating the resin to react, thereby obtaining the metal organic polymer material; The mass ratio of the terpyridine modified epoxy resin to the transition metal salt is less than 88.5g:13.

37.

9. The preparation method according to claim 8, characterized in that: The heating reaction temperature is 60-80° C., and the heating reaction time is 3-4 hours; and / or, the terpyridine-modified epoxy resin is dissolved in methanol and methyl isobutyl ketone, and then a transition metal salt is added to carry out a heating reaction.

10. A paint, characterized in that: The metal organic polymer material comprises the metal organic polymer material according to claim 6 or 7.

Images