A method for the preparation of a high molecular weight epoxy resin

Abstract

The application provides a preparation method of a high molecular weight epoxy resin, comprising the following steps: reacting epichlorohydrin and a cyclic anhydride under the action of an initiator and a catalyst to obtain a high molecular weight epoxy resin; the initiator is selected from organic salts; and the catalyst is selected from one or more of ionic salts, metal oxides, Lewis bases, Lewis acids, Lewis acid-base pairs, metal complexes and double metal cyanides. The method has mild reaction conditions and simple steps, and can synthesize the high molecular weight epoxy resin in one step. The preparation method provided by the application can adjust the molecular weight and the molecular weight distribution of the product by changing the catalyst and reaction conditions such as reaction temperature, reaction time and feed ratio, and can also design epoxy resin materials with various structures and properties by changing other monomers copolymerized with the epichlorohydrin.

Description

Technical Field

[0001] This invention belongs to the field of epoxy resin technology, and specifically relates to a method for preparing high molecular weight epoxy resin. Background Technology

[0002] Epoxy resins are polymers containing two or more epoxy groups. Epoxy resins, represented by DGEBA, possess excellent mechanical properties, high adhesive strength, good heat resistance, and high electrical resistance, and are widely used in the preparation of coatings, electronic materials, adhesives, and matrices for fiber-reinforced composites. High molecular weight epoxy resins (Mn > 800 g / mol) are a very important class of epoxy resins, commonly used in the preparation of epoxy powder coatings. Epoxy powder coatings, while possessing the aforementioned superior properties of epoxy resins, also exhibit strong adhesion to metal surfaces and high coating efficiency, thus having significant applications in the field of metal corrosion protection.

[0003] Polymerization and epoxidation are two essential steps in the preparation of high molecular weight epoxy resins. High molecular weight DGEBA is obtained by melt polycondensation of pre-prepared DGEBA oligomers and bisphenol A at a high temperature of approximately 180°C, a method involving epoxidation followed by polymerization. Conversely, preparing high molecular weight epoxy resins by converting hydroxyl-terminated polymers into epoxy-terminated polymers through a series of reactions involves polymerization followed by epoxidation. However, these strategies cannot obtain high molecular weight epoxy resins in a single step from a monomer mixture and suffer from high energy consumption, large solvent usage, and cumbersome procedures. Therefore, developing a mild and simple method for preparing high molecular weight epoxy resins is of great significance. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a method for preparing high molecular weight epoxy resin, which has mild conditions and simple preparation steps.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows:

[0006] This application provides a method for preparing a high molecular weight epoxy resin, comprising: reacting epichlorohydrin and cyclic anhydride under the action of an initiator and a catalyst to obtain a high molecular weight epoxy resin; wherein the initiator is selected from organic salts; and the catalyst is selected from one or more of ionic salts, metal oxides, Lewis bases, Lewis acids, Lewis acid-base pairs, metal oxides, and bimetallic cyanides.

[0007] Preferably, the cyclic anhydride is selected from one or more of monocyclic anhydrides, bicyclic anhydrides, and polycyclic anhydrides.

[0008] Preferably, the monocyclic anhydride is selected from one or more of succinic anhydride, maleic anhydride, glutaric anhydride, and pimelic anhydride; the bicyclic anhydride is selected from one or more of phthalic anhydride, cyclohexenoic anhydride, cyclohexane anhydride, cyclopentane anhydride, and camphor anhydride; and the polycyclic anhydride is selected from one or more of norbornene and its derivatives.

[0009] Preferably, the molar ratio of epichlorohydrin, cyclic anhydride, initiator and catalyst is 1-100000:1-100000:1-100000:1.

[0010] Preferably, the organic salt is selected from one or more of alkoxides, phenolic salts, amine salts, and carboxylates.

[0011] Preferably, the structural formula of the carboxylate is shown in formula (1):

[0012]

[0013] The structural formula of the alkoxide is shown in formula (2):

[0014]

[0015] In formula (1) or formula (2), R is selected from alkylene or phenylene, and M is selected from lithium, sodium, potassium, rubidium or cesium.

[0016] Preferably, the organic salt is selected from potassium methoxide, sodium methoxide, potassium ethoxide, sodium ethoxide, sodium phenolate, potassium phenolate, lithium bis(trimethylsilyl)amino, zinc bis(bis(trimethylsilyl)amino), stannous octoate, potassium acetate, or disodium terephthalate.

[0017] Preferably, the structural formula of the ionic salt is shown in formula (3) or formula (4):

[0018]

[0019] X - Selected from Cl - ,Br - CF3COO - N3 - Or NO3 - ;

[0020]

[0021] R1, R2, R3, and R4 are independently selected from -Et, - n Bu4、- n One or more of Hept4, where Y is selected from Cl - ,Br - Or I - ;

[0022] Preferably, the Lewis base is selected from 1-tert-butyl-4,4,4-tris(dimethylamino)-2,2-bis[tris(dimethylamino)-n-phosphine-imino]-2λ 5 ,4λ 5 -Bis(phosphorus nitrogen compounds) t Bu-P4), 1-tert-butyl-2,2,4,4,4-penta(dimethylamino)-2λ 5 ,4λ 5 -Bis(phosphorus nitrogen compounds) t Bu-P2), 1,8-diazabicycloundec-7-ene (DBU), 4-dimethylaminopyridine (DMAP), 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (MTBD) or N-methylimidazolium (N-MeIm).

[0023] Preferably, the Lewis acid is selected from dibutyldimethoxytinane Bu2Sn(OMe)2, tetrabutyl titanate [Ti(OBu)4], boron trifluoride BF3, organoborane, tris(pentafluorophenyl)aluminum, acetic acid, or trifluoroacetic anhydride.

[0024] Preferably, in the Lewis acid-base pair, the Lewis acid is the Lewis acid described above, the Lewis base is the Lewis base described above, and the molar ratio of the Lewis acid to the Lewis base is 1:0.01-100.

[0025] Preferably, the metal complex is selected from one or more of TPP metal complexes and their homologues, BDI metal complexes and their homologues, and NNO ligand metal complexes and their homologues;

[0026] Preferably, the bimetallic cyanide has the structure shown in formula (5):

[0027] M Π 3[M Ⅲ (CN)6]2·x M Π X m ·y L·z H2O formula (5)

[0028] Wherein, the M Π It is a divalent metal ion; the M Ⅲ The molecule is a transition metal ion; X is F, Cl, Br, I, OH, CO3, or NO3; L is an oxygen-containing organic ligand; x, y, and z are M in the catalyst, respectively. Π X m The relative contents of L and H2O; m is 1 or 2.

[0029] Preferably, the reaction is carried out in an inert gas atmosphere, the reaction temperature is 0–200°C, and the reaction time is 1–100 h.

[0030] Preferably, the reaction is bulk polymerization or solution polymerization.

[0031] Preferably, the solvent used in the solution polymerization is selected from toluene, xylene, DMF, n-hexane, or propylene carbonate.

[0032] This application provides a method for preparing high molecular weight epoxy resin, comprising the following steps: epichlorohydrin and cyclic anhydride react under the action of an initiator and a catalyst to obtain high molecular weight epoxy resin; the initiator is selected from one or more of alkali metal carboxylates and alkali metal alkoxides; the catalyst is selected from one or more of ionic salts, metal oxides, Lewis bases, Lewis acids, Lewis acid-base pairs, and bimetallic cyanides. This method has mild reaction conditions and simple steps, and can synthesize high molecular weight epoxy resin in one step. The preparation method provided in this application can adjust the molecular weight and molecular weight distribution of the product by changing the catalyst and reaction conditions such as reaction temperature, reaction time, and feed ratio. Furthermore, by changing other monomers copolymerized with epichlorohydrin, epoxy resin materials with various structures and properties can be designed. Experimental results show that the molecular weight of the epoxy resin prepared by the method provided in this invention can range from 0.5 to 8 kg mol. -1 The molecular weight distribution of the epoxy resin can be adjusted arbitrarily between 1.01 and 1.5, and the epoxy value can be adjusted arbitrarily between 0.025 and 0.4 mol / 100g. Attached Figure Description

[0033] Figure 1 The high molecular weight epoxy resin prepared in Example 1 1 H NMR spectrum;

[0034] Figure 2 The high molecular weight epoxy resin prepared in Example 1 1 C NMR spectrum;

[0035] Figure 3 The matrix-assisted laser desorption / ionization time-of-flight mass spectrum of the high molecular weight epoxy resin prepared in Example 1;

[0036] Figure 4 GPC curve of the high molecular weight epoxy resin prepared in Example 1;

[0037] Figure 5 GPC curve of the high molecular weight epoxy resin prepared in Example 7;

[0038] Figure 6 The high molecular weight epoxy resin prepared in Example 81 H NMR spectrum. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] This invention provides a method for preparing high molecular weight epoxy resin, comprising: reacting epichlorohydrin and cyclic anhydride under the action of an initiator and a catalyst to obtain high molecular weight epoxy resin; wherein the initiator is selected from organic salts; and the catalyst is selected from one or more of ionic salts, metal oxides, Lewis bases, Lewis acids, Lewis acid-base pairs, metal oxides, and bimetallic cyanides. The reaction equation is shown below:

[0041]

[0042] Specifically, epichlorohydrin, cyclic anhydride, initiator, and catalyst are mixed and reacted. The molar ratio of epichlorohydrin, cyclic anhydride, initiator, and catalyst is 1–100,000:1–100,000:1–100,000:1, preferably 200:20:2:1 or 200:20:1:1. The cyclic anhydride is selected from one or more of monocyclic anhydride, bicyclic anhydride, and polycyclic anhydride, preferably bicyclic anhydride. The monocyclic anhydride is selected from one or more of succinic anhydride, maleic anhydride, glutaric anhydride, and pimelic anhydride, preferably glutaric anhydride. The bicyclic anhydride is selected from one or more of phthalic anhydride, cyclohexenoic anhydride, cyclohexane anhydride, cyclopentane anhydride, and camphor anhydride, preferably phthalic anhydride or 1,2-cyclohexanediacetic anhydride. The polycyclic anhydride is selected from one or more of norbornene and its derivatives, preferably diethylene glycol anhydride.

[0043] The initiator is an organic salt, including but not limited to one or more of alkoxides, phenolates, amines, and carboxylates. For example, the structural formula of a carboxylate is shown in formula (1):

[0044]

[0045] Wherein, R is selected from alkylene or phenylene, and M is selected from lithium, sodium, potassium, rubidium, or cesium.

[0046] For example, the structural formula of the alkoxide is shown in formula (2):

[0047]

[0048] Wherein, R is selected from alkylene or phenylene, and M is selected from lithium, sodium, potassium, rubidium, or cesium.

[0049] In some specific implementations, the organic salt is selected from potassium methoxide, sodium methoxide, potassium ethoxide, sodium ethoxide, sodium phenolate, potassium phenolate, lithium bis(trimethylsilyl)amino, zinc bis(bis(trimethylsilyl)amino), stannous octoate, potassium acetate, or disodium terephthalate.

[0050] The catalyst is selected from one or more of ionic salts, metal oxides, Lewis bases, Lewis acids, Lewis acid-base pairs, and bimetallic cyanides, preferably ionic salts, Lewis bases, or bimetallic cyanides; the ionic salt is selected from PPN. + X - Or quaternary ammonium salt R4N + Y - Among them, PPN + X - The structural formula is shown in equation (3):

[0051]

[0052] X - Selected from Cl - ,Br - CF3COO - N3 - Or NO3 - PPN + X - PPNCl is preferred;

[0053] The quaternary ammonium salt R4N + Y - The structural formula is shown in equation (4):

[0054]

[0055] R1, R2, R3, and R4 are independently selected from -Et, - n Bu4、- n One or more of Hept4, where Y is selected from Cl - ,Br - Or I - .

[0056] The Lewis base is selected from 1-tert-butyl-4,4,4-tris(dimethylamino)-2,2-di[tris(dimethylamino)-phosphine-2λ]-2λ 5 ,4λ 5 -Bis(phosphorus nitrogen compounds) t Bu-P4), 1-tert-butyl-2,2,4,4,4-penta(dimethylamino)-2λ 5 ,4λ5 -Bis(phosphorus nitrogen compounds) t The Lewis acid is selected from dibutyldimethoxystanane Bu2Sn(OMe)2, tetrabutyl titanate [Ti(OBu)4], boron trifluoride BF3, organoboranes, tris(pentafluorophenyl)aluminum, acetic acid, or trifluoroacetic anhydride. In the Lewis acid-base pair, the Lewis acid is one of the above-mentioned Lewis acids, the Lewis base is one of the above-mentioned Lewis bases, and the molar ratio of the Lewis acid to the Lewis base is 1:0.01-100.

[0057] The bimetallic cyanide has the structure shown in formula (5):

[0058] M Π 3[M Ⅲ (CN)6]2·x M Π X m ·y L·z H2O formula (5)

[0059] Wherein, the M Π It is a divalent metal ion; the M Ⅲ The molecule is a transition metal ion; X is F, Cl, Br, I, OH, CO3, or NO3; L is an oxygen-containing organic ligand; x, y, and z are M in the catalyst, respectively. Π X m The relative contents of L and H2O; m is 1 or 2. In formula (5), M Π Including but not limited to Zn 2+ Co 2+ Fe 2+ Ni 2+ etc.; M Ⅲ Including but not limited to Fe 2+ Fe 3+ Co 2+ Co 3+ Ni 2+ The term L includes, but is not limited to, small molecule alcohols, oligomeric alcohols, aldehydes, ketones, esters, cyclic ethers, etc. This invention does not impose any special restrictions on the bimetallic cyanide; it can be prepared according to methods disclosed in the literature or purchased from other sources.

[0060] Epichlorohydrin, cyclic anhydride, initiator, and catalyst are mixed in the above molar ratio and then reacted. The reaction is either bulk polymerization or solution polymerization. When the reaction is solution polymerization, epichlorohydrin, cyclic anhydride, initiator, and catalyst are mixed with a solvent and reacted. The solvent is selected from toluene, xylene, DMF, n-hexane, or propylene carbonate, preferably toluene. The above reaction is carried out in an inert gas atmosphere, wherein the inert gas is selected from argon, helium, nitrogen, or carbon dioxide; the reaction temperature is 0–200°C, preferably 70–180°C, for example, 90°C or 110°C; the reaction time is 1–100 h, preferably 1–48 h, for example, 4 h or 12 h. After the reaction is completed, cold methanol is added dropwise to the reactants and filtered. After filtration, a high molecular weight epoxy resin is obtained.

[0061] This application provides a method for preparing high molecular weight epoxy resin, comprising: reacting epichlorohydrin and cyclic anhydrides under the action of an initiator and a catalyst to obtain high molecular weight epoxy resin; wherein the initiator is selected from one or more of alkali metal carboxylates and alkali metal alkoxides; and the catalyst is selected from one or more of ionic salts, metal oxides, Lewis bases, Lewis acids, Lewis acid-base pairs, and bimetallic cyanides. This method features mild reaction conditions and simple steps, enabling the one-step synthesis of high molecular weight epoxy resin. The preparation method provided in this application allows for the adjustment of the molecular weight and molecular weight distribution of the product by changing the catalyst and reaction conditions such as reaction temperature, reaction time, and feed ratio. Furthermore, by changing other monomers copolymerized with epichlorohydrin, epoxy resin materials with various structures and properties can be designed, thus providing a simple, efficient, and controllable novel preparation method for high molecular weight epoxy resin.

[0062] Example 1:

[0063] A 25 mL pressure-resistant reaction tube was heated at 300 °C and evacuated three times in an argon atmosphere. While still hot, it was transferred to a glove box, where PPNCl catalyst (28.8 mg, 0.5 mmol), disodium terephthalate (210 mg, 1 mmol), phthalic anhydride PA (1.48 g, 0.01 mol), and epichlorohydrin (7.8 mL, 0.1 mol) were added sequentially. The pressure-resistant reaction tube was then sealed and transferred to a 90 °C oil bath. After reacting for 4 hours, the reaction solution was added dropwise to cold methanol and filtered to obtain a high molecular weight epoxy resin with a yield of 92%. The obtained epoxy resin had a molecular weight of 1.8 kg / mol and an epoxy value of 0.11.

[0064] Example 2:

[0065] A 25 mL pressure-resistant reaction tube was heated at 300 °C and evacuated three times in an argon atmosphere. While still hot, it was transferred to a glove box, where PPNCl catalyst (28.8 mg, 0.5 mmol), disodium terephthalate (210 mg, 1 mmol), phthalic anhydride PA (1.48 g, 0.01 mol), and epichlorohydrin (7.8 mL, 0.1 mol) were added sequentially. The pressure-resistant reaction tube was then sealed and transferred to a 90 °C oil bath. After reacting for 12 h, the reaction solution was added dropwise to cold methanol and filtered to obtain a high molecular weight epoxy resin with a yield of 95%. The obtained epoxy resin had a molecular weight of 1.9 kg / mol and an epoxy value of 0.11.

[0066] Example 3:

[0067] A 25 mL pressure-resistant reaction tube was heated at 300 °C and evacuated three times in an argon atmosphere. While still hot, it was transferred to a glove box, where PPNCl catalyst (28.8 mg, 0.5 mmol), disodium terephthalate (210 mg, 1 mmol), phthalic anhydride PA (1.48 g, 0.01 mol), and epichlorohydrin (7.8 mL, 0.1 mol) were added sequentially. The pressure-resistant reaction tube was then sealed and transferred to an oil bath at 110 °C. After reacting for 4 hours, the reaction solution was added dropwise to cold methanol and filtered to obtain a high molecular weight epoxy resin with a yield of 93%. The obtained epoxy resin had a molecular weight of 1.8 kg / mol and an epoxy value of 0.11.

[0068] Example 4:

[0069] A 25 mL pressure-resistant reaction tube was heated at 300 °C and evacuated three times in an argon atmosphere. While still hot, it was transferred to a glove box, where DMAP catalyst (61 mg, 0.5 mmol), disodium terephthalate (210 mg, 1 mmol), phthalic anhydride PA (1.48 g, 0.01 mol), and epichlorohydrin (7.8 mL, 0.1 mol) were added sequentially. The pressure-resistant reaction tube was then sealed and transferred to a 90 °C oil bath. After reacting for 4 hours, the reaction solution was added dropwise to cold methanol and filtered to obtain a high molecular weight epoxy resin with a yield of 91%. The obtained epoxy resin had a molecular weight of 1.8 kg / mol and an epoxy value of 0.11.

[0070] Example 5:

[0071] A 25 mL pressure-resistant reaction tube was heated at 300 °C and evacuated three times in an argon atmosphere. While still hot, it was transferred to a glove box, where Zn-Co-DMC catalyst (3.0 mg, 0.05 mmol), disodium terephthalate (210 mg, 1 mmol), phthalic anhydride PA (1.48 g, 0.01 mol), and epichlorohydrin (7.8 mL, 0.1 mol) were added sequentially. The pressure-resistant reaction tube was then sealed and transferred to a 90 °C oil bath. After reacting for 4 hours, the reaction solution was added dropwise to cold methanol and filtered to obtain a high molecular weight epoxy resin with a yield of 91%. The obtained epoxy resin had a molecular weight of 1.8 kg / mol and an epoxy value of 0.11.

[0072] Example 6:

[0073] A 25 mL pressure-resistant reaction tube was heated at 300 °C and evacuated three times in an argon atmosphere. While still hot, it was transferred to a glove box, where PPNCl catalyst (28.8 mg, 0.5 mmol), disodium terephthalate (210 mg, 1 mmol), phthalic anhydride PA (1.48 g, 0.01 mol), epichlorohydrin (3.9 mL, 0.05 mol), and toluene (3.9 mL) were added sequentially. The pressure-resistant reaction tube was then sealed and transferred to a 90 °C oil bath. After reacting for 12 h, the reaction solution was added dropwise to cold methanol and filtered to obtain a high molecular weight epoxy resin with a yield of 94%. The obtained epoxy resin had a molecular weight of 1.8 kg / mol and an epoxy value of 0.11.

[0074] Example 7:

[0075] A 25 mL pressure-resistant reaction tube was heated at 300 °C and evacuated three times in an argon atmosphere. While still hot, it was transferred to a glove box, where PPNCl catalyst (28.8 mg, 0.5 mmol), disodium terephthalate (105 mg, 0.5 mmol), phthalic anhydride PA (1.48 g, 0.01 mol), and epichlorohydrin (7.8 mL, 0.1 mol) were added sequentially. The pressure-resistant reaction tube was then sealed and transferred to a 90 °C oil bath. After reacting for 4 hours, the reaction solution was added dropwise to cold methanol and filtered to obtain a high molecular weight epoxy resin with a yield of 90%. The obtained epoxy resin had a molecular weight of 4.1 kg / mol and an epoxy value of 0.05.

[0076] Example 8:

[0077] A 25 mL pressure-resistant reaction tube was heated at 300 °C and evacuated three times in an argon atmosphere. While still hot, it was transferred to a glove box, where PPNCl catalyst (28.8 mg, 0.5 mmol), disodium terephthalate (210 mg, 1 mmol), glutaric anhydride GA (1.14 g, 0.01 mol), and epichlorohydrin (7.8 mL, 0.1 mol) were added sequentially. The pressure-resistant reaction tube was then sealed and transferred to a 90 °C oil bath. After reacting for 4 hours, the reaction solution was added dropwise to cold methanol and filtered to obtain a high molecular weight epoxy resin with a yield of 86%. The obtained epoxy resin had a molecular weight of 1.6 kg / mol and an epoxy value of 0.13.

[0078] Example 9:

[0079] A 25 mL pressure-resistant reaction tube was heated at 300 °C and evacuated three times in an argon atmosphere. While still hot, it was transferred to a glove box, where PPNCl catalyst (28.8 mg, 0.5 mmol), disodium terephthalate (210 mg, 1 mmol), diethylene glycol anhydride (DGA) (1.16 g, 0.01 mol), and epichlorohydrin (7.8 mL, 0.1 mol) were added sequentially. The pressure-resistant reaction tube was then sealed and transferred to a 90 °C oil bath. After reacting for 4 hours, the reaction solution was added dropwise to cold methanol and filtered to obtain a high molecular weight epoxy resin with a yield of 83%. The obtained epoxy resin had a molecular weight of 1.5 kg / mol and an epoxy value of 0.13.

[0080] Example 10:

[0081] A 25 mL pressure-resistant reaction tube was heated at 300 °C and evacuated three times in an argon atmosphere. While still hot, it was transferred to a glove box, where PPNCl catalyst (28.8 mg, 0.5 mmol), disodium terephthalate (210 mg, 1 mmol), 1,2-cyclohexanediacetic anhydride (CHA) (1.54 g, 10 mol), and epichlorohydrin (7.8 mL, 0.1 mol) were added sequentially. The pressure-resistant reaction tube was then sealed and transferred to a 90 °C oil bath. After reacting for 4 hours, the reaction solution was added dropwise to cold methanol and filtered to obtain a high molecular weight epoxy resin with a yield of 88%. The obtained epoxy resin had a molecular weight of 2.3 kg / mol and an epoxy value of 0.09.

[0082] The high molecular weight epoxy resin prepared in Example 1 was characterized by nuclear magnetic resonance (NMR), and the characterization results are as follows: Figure 1 and Figure 2 As shown, Figure 1 yes 1 1H NMR spectrum (500MHz, CDCl3), by 1The 1H NMR spectrum shows that the high molecular weight epoxy resin prepared in Example 1 is a polyester structure with completely alternating epichlorohydrin and phthalic anhydride. The peaks with the same integral size at ppm 3.26, 2.83 and 2.65 are the signal peaks of epoxy groups in the polymer. Figure 2 yes 1 C10 NMR spectrum (100MHz, CDCl3), by 1 The C10 NMR spectrum shows that the high molecular weight epoxy resin prepared in Example 1 has a polyester structure with completely alternating epichlorohydrin and phthalic anhydride. The peaks with the same integral size at ppm 66.35, 49.24, and 44.68 are signal peaks of epoxy groups in the polymer. Examples 2-6 have the same structure as Example 1. 1 H NMR spectrum and 1 CNMR spectrum.

[0083] The high molecular weight epoxy resin matrix prepared in Example 1 was analyzed by laser desorption / ionization time-of-flight mass spectrometry. The time-of-flight mass spectra and the molecular formula structures represented are as follows: Figure 3 As shown, Figure 3 (a) Matrix-assisted laser desorption / ionization time-of-flight mass spectrometry of the epoxy resin prepared in Example 1. Figure 3 (b) is Figure 3 (a) Enlarged view of the boxed portion. (From...) Figure 3 It can be seen that the difference between adjacent peaks is 240.6, which is consistent with the relative molar mass of epichlorohydrin and phthalic anhydride, indicating that the high molecular weight epoxy resin prepared in Example 1 has a completely alternating structure, and it can be determined that the polymer end groups are epoxy groups. The molecular formula in the table is the polymer structural formula shown in this spectrum. Examples 2-6 have the same matrix-assisted laser desorption / ionization time-of-flight mass spectra as Example 1.

[0084] The GPC curve of the high molecular weight epoxy resin prepared in Example 1 was tested, and the results are as follows: Figure 4 As shown, by Figure 4 It can be seen that the high molecular weight epoxy resin prepared in Example 1 has a molecular weight of 2.0 kg / mol and a molecular weight distribution of 1.50. Examples 2-6 have GPC curves similar to those of Example 1.

[0085] The GPC curve of the high molecular weight epoxy resin prepared in Example 7 was tested, and the results are as follows: Figure 5 As shown, by Figure 5 It can be seen that the high molecular weight epoxy resin prepared in Example 7 has a molecular weight of 4.1 kg / mol and a molecular weight distribution of 1.52.

[0086] The high molecular weight epoxy resin prepared in Example 8 was characterized by nuclear magnetic resonance (NMR), and the characterization results are as follows: Figure 6 As shown, Figure 6 for1 H NMR spectrum, by Figure 6 It can be seen that the high molecular weight epoxy resin prepared in Example 8 is a polyester structure with completely alternating epichlorohydrin and 1,2-cyclohexanediacetic anhydride.

[0087] The above description of the embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A method for preparing a high molecular weight epoxy resin, characterized in that, include: Epichlorohydrin and cyclic anhydrides react under the action of an initiator and a catalyst to obtain high molecular weight epoxy resin; The initiator is disodium terephthalate; The catalyst is selected from PPNCl, 4-dimethylaminopyridine, or Zn-Co-DMC; The molar ratio of epichlorohydrin, cyclic anhydride, initiator and catalyst is 100:10:1:0.5, 50:10:1:0.5 or 100:10:0.5:0.5; The reaction is carried out in an inert gas atmosphere, at a temperature of 70~180℃, and for a time of 1~48 h.

2. The preparation method according to claim 1, characterized in that, The cyclic anhydride is selected from one or more of monocyclic anhydrides, bicyclic anhydrides, and polycyclic anhydrides.

3. The preparation method according to claim 2, characterized in that, The monocyclic anhydride is selected from one or more of succinic anhydride, maleic anhydride, glutaric anhydride, and pimelic anhydride; The bicyclic anhydride is selected from one or more of phthalic anhydride, cyclohexenoic anhydride, cyclohexane anhydride, cyclopentane anhydride and camphor anhydride; The polycyclic anhydride is selected from one or more of norbornene and its derivatives.

4. The preparation method according to claim 1, characterized in that, The reaction is either bulk polymerization or solution polymerization.

5. The preparation method according to claim 4, characterized in that, The solvent used in the solution polymerization is selected from toluene, xylene, DMF, n-hexane, or propylene carbonate.

Images