Bio-based epoxy resin and preparation method thereof

Abstract

The invention discloses bio-based epoxy resin and a preparation method thereof, and belongs to the field of chemical engineering. The preparation method comprises the following steps: by taking dimethyl succinylsuccinate and epoxy chloropropane which are sourced from organisms as raw materials, carrying out aromatization reaction to prepare a compound 2, 5-dihydroxy dimethyl terephthalate containing bisphenol hydroxyl groups, then reacting with epoxy chloropropane to prepare an epoxy resin monomer, and curing the monomer. The bio-based epoxy resin is obtained by reacting the 2, 5-dihydroxy dimethyl terephthalate with epichlorohydrin to obtain a bio-based epoxy resin monomer and reacting the bio-based epoxy resin monomer with a curing agent, and the bio-based epoxy resin is novel in structure and excellent in performance, has the advantages of being green, environmentally friendly and the like, and has the dual effects of saving petroleum resources and protecting the environment.

Description

Technical Field

[0001] The invention belongs to the field of chemical industry and fine chemicals, and relates to a method for synthesizing an epoxy resin containing a 2,5-dihydroxydimethyl terephthalate structure. Technical Background

[0002] Epoxy resin is a very popular polymer. Due to its excellent mechanical properties, high bonding strength, excellent thermal stability, low cost and good processing performance, it is widely used in aerospace, protective coatings, electronic communications and building materials. According to the "China Epoxy Resin Industry Production, Sales, Demand and Investment Forecast Analysis Report", the global epoxy resin production capacity in 2019 was 4.96 million tons / year. China is the world's largest producer of epoxy resin and also the world's largest consumer of epoxy resin.

[0003] Bisphenol A diglycidyl ether (DGEBA) is the main commercial epoxy resin with excellent chemical and mechanical properties. However, this epoxy resin is mainly prepared by fossil resources, and its raw material bisphenol A (BPA) has been shown to have an impact on human health and the environment (Biotechnol Adv. 2018; 36(1): 311-327). Its preparation route is as follows:

[0004]

[0005] In recent years, the use of renewable resources to synthesize new polymer materials to replace polymer materials derived from petroleum resources has become a rapidly developing field, alleviating the rapid consumption of petroleum resources (Science.2017,358(6365):868-870). Lignin is the most abundant natural aromatic polymer on earth, composed of three phenylpropane units, namely guaiacyl (G-type lignin), syringyl (S-type lignin) and p-hydroxyphenyl (H-type lignin). Using lignin derivatives linalool and diethyl phosphate as raw materials, diamines are used as coupling agents to first react with phosphine addition and then with epichlorohydrin to prepare two resin monomers (Macromolecules.2017,50(5):1892-1901). The limiting oxygen index of the cured bio-based epoxy resin is 31.4% and 32.8%, the glass transition temperature is 214°C, the tensile strength is 30.8 MPa, and the tensile modulus is 2709 MPa, which are much higher than those of the bisphenol A diglycidyl ether (DGEBA) system.

[0006] Chinese patent CN102206324A introduces a kind of all-bio-based epoxy resin and its preparation method. The resin has good mechanical properties, good UV resistance and excellent aging resistance, and is particularly suitable for preparing bio-based composite material matrix resin and outdoor electrical insulation materials. Chinese patent CN102796063A introduces a preparation method of a new type of monohydroxyl bio-based epoxy resin. The new epoxy resin has the characteristics of green and renewable raw materials, simple synthesis process, good stability, good heat resistance and electrical insulation after curing, and the bio-based content is greater than 90%, and the epoxy value reaches 0.28-0.51eq / 100g. It is suitable for coatings, composite materials, castings, electronic and electrical materials, adhesives and anti-corrosion agents. Chinese patent CN107556459A introduces a preparation method of a new type of bio-based epoxy resin containing pyridazinone structure. The resin has good thermal stability and has broad application prospects in coatings, adhesives and aerospace fields.

[0007] World patent WO2016172353A, US patent US2024301125A and US patent US2009275674A all introduce bio-based epoxy resins that can be used in coatings. US patent US10745515B introduces a bio-based epoxy resin with excellent thermal properties and modulus.

[0008] Dimethyl succinosuccinate (DMSS) is an important intermediate for the preparation of dyes, fluorescent dyes and coating materials. It can be prepared by esterification and Clasien ester condensation reaction of biologically derived succinic acid. Its structure contains one or two C=O and an ester group. Using DMSS as a raw material, a series of organic pigments containing quinacridone structure can be prepared. The structural formula of organic pigments is as follows:

[0009]

[0010] Chinese patents CN106831763A and CN105348127A both introduce the synthesis of organic pigments containing quinacridone structure using DMSS as raw material; Chinese patent CN107200736A introduces a synthesis process of organic pigment 1 with good water solubility, surface activity and emulsification and dispersion ability; Chinese patent CN107057054A introduces the synthesis process of organic pigment 2.

[0011] Chinese patent CN101709034B introduces a synthesis process for synthesizing bicyclo[2.2.2]octane 1,4-dicarboxylic acid monomethyl ester using DMSS as raw material, and its structural formula is as follows:

[0012]

[0013] Chinese patent CN101844996B introduces a series of intermediates of advanced organic pigments containing quinacridone structure, the structural formula is as follows:

[0014]

[0015] 2,5-Dihydroxyterephthalic acid dimethyl ester (DDHT) is an intermediate for pharmaceutical, chemical synthesis and synthetic materials, and its application field is broad. The compound can be obtained through aromatization of bio-based succinylsuccinate dimethyl ester (Polymer Chemistry. 2018, 9: 4113-4119), and its preparation route is as follows. There are two phenolic hydroxyl groups in the structure of 2,5-dihydroxyterephthalic acid dimethyl ester, which can be used as the connection site of epichlorohydrin, and the compound has never been used as a synthetic epoxy resin monomer. For this reason, this patent aims to use 2,5-dihydroxyterephthalic acid dimethyl ester as a raw material to synthesize the corresponding epoxy resin monomer and cure it.

[0016]

[0017] Different from the bisphenol A epoxy resin with potential physiological toxicity, the present invention uses bio-based dimethyl succinylsuccinate as raw material, obtains a compound with a bisphenol structure through aromatization, prepares the compound into an epoxy resin monomer, and obtains a novel bio-based epoxy resin through curing. The resin has the characteristics of being green and non-toxic, and the raw material price is cheap. Summary of the invention

[0018] In order to find a substitute for bisphenol epoxy resin, the purpose of the present invention is to provide a new type of bio-based epoxy resin monomer method containing 2,5-dihydroxyterephthalate dimethyl ester structure. The raw material can be dimethyl succinylsuccinate, which has the advantages of being cheap, easily available and having low potential toxicity.

[0019] The present invention provides a bio-based epoxy resin monomer containing dimethyl 2,5-dihydroxyterephthalate (DDHT-ECH), as shown in formula (I):

[0020]

[0021] The specific preparation method of the bio-based epoxy resin monomer of formula (I) prepared by the present invention is: dimethyl succinylsuccinate and N-chlorosuccinimide (NCS) are subjected to aromatization reaction in the presence of an acid as a solvent, and then the reaction solution is allowed to stand and cool, solids are precipitated, the solids are filtered out, and washed with acid, water and ether respectively, to finally obtain the product DDHT. DDHT is then reacted with epichlorohydrin (ECH) in the presence of a catalyst, the reaction solution is cooled in an ice bath, an alkaline aqueous solution is added dropwise, an organic solvent is used for extraction, and finally sand is made and passed through a column. The reaction equation is as follows:

[0022]

[0023] The acid is acetic acid.

[0024] The molar ratio of dimethyl succinylsuccinate to NCS is 1:0.9-1:1.2, preferably 1:1.

[0025] The ether is diethyl ether or dibutyl ether, preferably diethyl ether.

[0026] The catalyst can be tetrabutylammonium bromide (TBAB), Na2CO3, K2CO3, preferably TBAB.

[0027] The molar ratio of dimethyl 2,5-dihydroxyterephthalate to tetrabutylammonium bromide is 1:0.8-1:1.2, preferably 1:1.

[0028] The molar ratio of dimethyl 2,5-dihydroxyterephthalate to epichlorohydrin is 1:4-1:12, preferably 1:10.

[0029] The alkaline solution can be a NaOH aqueous solution, a Na2CO3 aqueous solution, or a K2CO3 aqueous solution, preferably a NaOH aqueous solution, with a concentration of 50 wt%.

[0030] The extraction organic solvent can be dichloromethane or ethyl acetate, preferably dichloromethane.

[0031] The specific preparation method of the bio-based epoxy resin of formula (II) prepared by the present invention is as follows: weigh (I) in a sample bottle, stir, heat and melt. After (I) is melted, add a curing agent. After the two are evenly mixed, pour into a mold and put into a high-temperature oven for curing.

[0032]

[0033] Wherein, R is an alkyl group, a polyether segment, an aromatic group, or an alicyclic group, and m and n are natural numbers.

[0034] The curing agent is diamine 1074 (Croda), polyetheramine D400 (Huntsman), pentamethylenediamine (Kaisai), isophoronediamine (Annaiji), 4,4'-diaminodiphenylmethane (Annaiji), meta-phenylenediamine (Annaiji), and para-phenylenediamine (Annaiji).

[0035] The molar ratio of (I) to the curing agent is 1.8:1-2.2:1, preferably 2:1.

[0036] The curing temperature is 100°C-160°C, preferably 120°C.

[0037] Beneficial effects:

[0038] (1) The raw material used in the present invention is dimethyl succinylsuccinate of biological origin, which has the advantages of being cheap, readily available, green and non-toxic. The bio-based epoxy resin monomer having the structure of formula (I) is obtained through aromatization reaction and epoxidation reaction.

[0039] (2) By curing the bio-based epoxy resin monomer having the structure of formula (I) with the curing agent diamine 1074, pentamethylenediamine, polyetheramine D400, isophoronediamine, and 4,4'-diaminobenzene methane, a bio-based epoxy resin having the structure of formula (II) can be prepared. The synthesis steps of the resin are simple and the reaction yield is high. In addition, the prepared bio-based epoxy resin having the structure of formula (II) has a novel structure that has not been reported before. It is a bio-based, green, and environmentally friendly product that has the dual effects of saving petroleum resources and protecting the environment. It is of great significance to promote the sustainable development of the field of bio-based epoxy resins. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The embodiments of the present invention are described in detail with reference to the accompanying drawings, wherein

[0041] Figure 1 Example 2: Dimethyl 2,5-dihydroxyterephthalate (DDHT) 1 H NMR diagram

[0042] Figure 2 Example 7 Bio-based epoxy resin monomer (DDHT-ECH) 1 H NMR diagram

[0043] Figure 3 : IR graph of Example 17 bio-based epoxy resin (diamine 1074 as curing agent)

[0044] Figure 4 : IR graph of Example 22 bio-based epoxy resin (polyetheramine D400 as curing agent) DETAILED DESCRIPTION

[0045] The experimental methods described in the following examples are conventional methods unless otherwise specified; the reagents and materials described are commercially available unless otherwise specified.

[0046] The nuclear magnetic resonance hydrogen spectra involved in the embodiments were measured using a Bruker Ascend TM-400 nuclear magnetic resonance hydrogen spectrometer of Bruker, the deuterated reagent used was deuterated chloroform (Chloroform-d), and the infrared spectra involved were measured using a Nicolet is10 Fourier transform infrared spectrometer of Thermo Fisher Scientific, USA.

[0047] Example 1

[0048] Preparation of dimethyl 2,5-dihydroxyterephthalate (DDHT): Add dimethyl succinosuccinate (11.4 g, 0.05 mol, 1 eq.), N-chlorosuccinimide (6.0075 g, 0.045 mol, 0.9 eq.), and 50 mL of acetic acid into a 250 mL eggplant-shaped bottle. Stir at 80 ° C for 1 h under argon. After the reaction is completed, cool to room temperature, and after the solid is completely precipitated, vacuum filter to obtain the solid. Wash the solid with acetic acid first, then wash the solid with water, and finally wash the solid with ether, and vacuum dry the solid to obtain a yellow solid.

[0049] Example 2

[0050] Preparation of dimethyl 2,5-dihydroxyterephthalate (DDHT): Add dimethyl succinosuccinate (11.4 g, 0.05 mol, 1 eq), N-chlorosuccinimide (6.675 g, 0.05 mol, 1 eq), and 50 mL of acetic acid into a 250 mL eggplant-shaped bottle. Stir at 80 ° C for 1 h under argon. After the reaction is completed, cool to room temperature, and after the solid is completely precipitated, vacuum filter to obtain the solid. Wash the solid with acetic acid first, then wash the solid with water, and finally wash the solid with ether. The solid is vacuum dried to finally obtain a yellow solid with a yield of 89.4%. 1 H NMR (400MHz, Chloroform-d) δ10.05 (s, 2H), 7.46 (s, 2H), 3.97 (s, 6H).

[0051] Example 3

[0052] Preparation of dimethyl 2,5-dihydroxyterephthalate (DDHT): Add dimethyl succinylsuccinate (11.4 g, 0.05 mol, 1 eq), N-chlorosuccinimide (7.98 g, 0.06 mol, 1.2 eq), and 50 mL of acetic acid into a 250 mL eggplant-shaped bottle. Stir at 80 ° C for 1 h under argon. After the reaction is completed, cool to room temperature, and after the solid is completely precipitated, vacuum filter to obtain the solid. Wash the solid with acetic acid first, then wash the solid with water, and finally wash the solid with ether, and vacuum dry the solid to obtain a yellow solid.

[0053] Example 4

[0054] Preparation of dimethyl 2,5-dihydroxyterephthalate (DDHT): Add dimethyl succinylsuccinate (11.4 g, 0.05 mol, 1 eq), N-chlorosuccinimide (6.675 g, 0.05 mol, 1 eq), and 50 mL of acetic acid into a 250 mL eggplant-shaped bottle. Stir at 80 ° C for 1 h under argon. After the reaction is completed, cool to room temperature, and after the solid is completely precipitated, vacuum filter to obtain the solid. Wash the solid with acetic acid first, then wash the solid with water, and finally wash the solid with dibutyl ether, and vacuum dry the solid to obtain a yellow solid.

[0055] Example 5

[0056] Preparation of dimethyl 2,5-dihydroxyterephthalate (DDHT): Add dimethyl succinylsuccinate (11.4 g, 0.05 mol, 1 eq), N-chlorosuccinimide (7.98 g, 0.05 mol, 1 eq), and 50 mL of acetic acid into a 250 mL eggplant-shaped bottle. Stir at 80 ° C for 1 h under argon. After the reaction is completed, cool to room temperature, and after the solid is completely precipitated, vacuum filter to obtain the solid. Wash the solid with acetic acid first, then wash the solid with water, and finally wash the solid with dibutyl ether, and vacuum dry the solid to finally obtain a yellow solid.

[0057] Example 6

[0058] Preparation of bio-based epoxy resin monomer (DDHT-ECH): Add dimethyl 2,5-dihydroxyterephthalate (DDHT) (11.3g, 0.05mol, 1eq), epichlorohydrin (18.4g, 0.2mol, 4eq), and tetrabutylammonium bromide (16.1g, 0.05mol, 1eq) to a 250mL eggplant-shaped bottle. Build a reflux device and stir and reflux at 80°C for 3h. After the reaction, cool the reaction solution to room temperature in an ice bath, and dissolve sodium hydroxide (10g, 0.25mol, 5eq) in 20mL of water and slowly add it to the eggplant-shaped bottle. Use dichloromethane / water system for extraction, collect the organic phase, and dry it with anhydrous sodium sulfate. Remove dichloromethane by rotary evaporation, and pass sand through a column to obtain a white solid.

[0059] Example 7

[0060] Preparation of bio-based epoxy resin monomer (DDHT-ECH): Add dimethyl 2,5-dihydroxyterephthalate (DDHT) (11.3g, 0.05mol, 1eq), epichlorohydrin (46g, 0.5mol, 10eq), and tetrabutylammonium bromide (16.1g, 0.05mol, 1eq) to a 250mL eggplant-shaped bottle. Build a reflux device and stir and reflux at 80°C for 3h. After the reaction is completed, cool the reaction solution to room temperature in an ice bath, and dissolve sodium hydroxide (10g, 0.25mol, 5eq) in 20mL of water and slowly add it to the eggplant-shaped bottle. Use dichloromethane / water system for extraction, collect the organic phase, and dry it with anhydrous sodium sulfate. Remove dichloromethane by rotary evaporation, and pass sand through a column to obtain a white solid with a yield of 60%. 1 H NMR (400MHz, Chloroform-d) δ7.43 (s, 2H), 4.32 (dd, J=11.1, 2.8Hz, 2H), 4.05 (dd, J= 11.1, 5.1Hz, 2H), 3.91 (s, 6H), 3.37 (ddt, J=5.2, 4.0, 2.7Hz, 2H), 2.94-2.83 (m, 4H).

[0061] Example 8

[0062] Preparation of bio-based epoxy resin monomer (DDHT-ECH): Add dimethyl 2,5-dihydroxyterephthalate (DDHT) (11.3g, 0.05mol, 1eq), epichlorohydrin (55.2g, 0.6mol, 12eq), and tetrabutylammonium bromide (16.1g, 0.05mol, 1eq) to a 250mL eggplant-shaped bottle. Build a reflux device and stir and reflux at 80°C for 3h. After the reaction is completed, cool the reaction solution to room temperature in an ice bath, and dissolve sodium hydroxide (10g, 0.25mol, 5eq) in 20mL of water and slowly add it to the eggplant-shaped bottle. Use dichloromethane / water system for extraction, collect the organic phase, and dry it with anhydrous sodium sulfate. Remove dichloromethane by rotary evaporation, and pass sand through a column to obtain a white solid.

[0063] Example 9

[0064] Preparation of bio-based epoxy resin monomer (DDHT-ECH): Add dimethyl 2,5-dihydroxyterephthalate (DDHT) (11.3g, 0.05mol, 1eq), epichlorohydrin (46g, 0.5mol, 10eq), and tetrabutylammonium bromide (12.88g, 0.04mol, 1eq) to a 250mL eggplant-shaped bottle. Build a reflux device and stir and reflux at 80°C for 3h. After the reaction, cool the reaction solution to room temperature in an ice bath, and dissolve sodium hydroxide (10g, 0.25mol, 5eq) in 20mL of water and slowly add it to the eggplant-shaped bottle. Use dichloromethane / water system for extraction, collect the organic phase, and dry it with anhydrous sodium sulfate. Remove dichloromethane by rotary evaporation, and pass sand through a column to obtain a white solid.

[0065] Example 10

[0066] Preparation of bio-based epoxy resin monomer (DDHT-ECH): Add dimethyl 2,5-dihydroxyterephthalate (DDHT) (11.3g, 0.05mol, 1eq), epichlorohydrin (46g, 0.5mol, 10eq), and tetrabutylammonium bromide (19.32g, 0.06mol, 1.2eq) to a 250mL eggplant-shaped bottle. Build a reflux device and stir and reflux at 80°C for 3h. After the reaction is completed, cool the reaction solution to room temperature in an ice bath, and dissolve sodium hydroxide (10g, 0.25mol, 5eq) in 20mL of water and slowly add it to the eggplant-shaped bottle. Use dichloromethane / water system for extraction, collect the organic phase, and dry it with anhydrous sodium sulfate. Remove dichloromethane by rotary evaporation, and pass sand through a column to obtain a white solid.

[0067] Embodiment 11

[0068] Preparation of bio-based epoxy resin monomer (DDHT-ECH): Add dimethyl 2,5-dihydroxyterephthalate (DDHT) (11.3 g, 0.05 mol, 1 eq), epichlorohydrin (46 g, 0.2 mol, 4 eq), and Na2CO3 (5.3 g, 0.05 mol, 1 eq) to a 250 mL eggplant-shaped bottle. Build a reflux device and stir and reflux at 80 ° C for 3 h. After the reaction is completed, the reaction solution is cooled to room temperature in an ice bath, and sodium hydroxide (10 g, 0.25 mol, 5 eq) is dissolved in 20 mL of water and slowly added to the eggplant-shaped bottle. Extraction is carried out using a dichloromethane / water system, and the organic phase is collected and dried with anhydrous sodium sulfate. Dichloromethane is removed by rotary evaporation, and sand is passed through a column to obtain a white solid.

[0069] Example 12

[0070] Preparation of bio-based epoxy resin monomer (DDHT-ECH): Add dimethyl 2,5-dihydroxyterephthalate (DDHT) (11.3g, 0.05mol, 1eq), epichlorohydrin (46g, 0.2mol, 4eq), and K2CO3 (6.9g, 0.05mol, 1eq) to a 250mL eggplant-shaped bottle. Build a reflux device and stir and reflux at 80°C for 3h. After the reaction, cool the reaction solution to room temperature in an ice bath, and dissolve sodium hydroxide (10g, 0.25mol, 5eq) in 20mL of water and slowly add it to the eggplant-shaped bottle. Use dichloromethane / water system for extraction, collect the organic phase, and dry it with anhydrous sodium sulfate. Remove dichloromethane by rotary evaporation, and pass sand through a column to obtain a white solid.

[0071] Embodiment 13

[0072] Preparation of bio-based epoxy resin monomer (DDHT-ECH): Add dimethyl 2,5-dihydroxyterephthalate (DDHT) (11.3g, 0.05mol, 1eq), epichlorohydrin (46g, 0.2mol, 4eq), and K2CO3 (6.9g, 0.05mol, 1eq) to a 250mL eggplant-shaped bottle. Build a reflux device and stir and reflux at 80°C for 3h. After the reaction, cool the reaction solution to room temperature in an ice bath, and dissolve sodium hydroxide (10g, 0.25mol, 5eq) in 20mL of water and slowly add it to the eggplant-shaped bottle. Use dichloromethane / water system for extraction, collect the organic phase, and dry it with anhydrous sodium sulfate. Remove dichloromethane by rotary evaporation, and pass sand through a column to obtain a white solid.

[0073] Embodiment 14

[0074] Preparation of bio-based epoxy resin monomer (DDHT-ECH): Add dimethyl 2,5-dihydroxyterephthalate (DDHT) (11.3g, 0.05mol, 1eq), epichlorohydrin (46g, 0.5mol, 10eq), and tetrabutylammonium bromide (16.1g, 0.05mol, 1eq) to a 250mL eggplant-shaped bottle. Build a reflux device and stir and reflux at 80°C for 3h. After the reaction, cool the reaction solution to room temperature in an ice bath, and dissolve sodium carbonate (10g, 0.25mol, 5eq) in 20mL of water and slowly add it to the eggplant-shaped bottle. Use dichloromethane / water system for extraction, collect the organic phase, and dry it with anhydrous sodium sulfate. Remove dichloromethane by rotary evaporation, and pass sand through a column to obtain a white solid.

[0075] Embodiment 15

[0076] Preparation of bio-based epoxy resin monomer (DDHT-ECH): Add dimethyl 2,5-dihydroxyterephthalate (DDHT) (11.3g, 0.05mol, 1eq), epichlorohydrin (46g, 0.5mol, 10eq), and tetrabutylammonium bromide (16.1g, 0.05mol, 1eq) to a 250mL eggplant-shaped bottle. Build a reflux device and stir and reflux at 80°C for 3h. After the reaction, cool the reaction solution to room temperature in an ice bath, and dissolve potassium carbonate (10g, 0.25mol, 5eq) in 20mL of water and slowly add it to the eggplant-shaped bottle. Use dichloromethane / water system for extraction, collect the organic phase, and dry it with anhydrous sodium sulfate. Remove dichloromethane by rotary evaporation, and pass sand through a column to obtain a white solid.

[0077] Example 16

[0078] Preparation of bio-based epoxy resin monomer (DDHT-ECH): Add dimethyl 2,5-dihydroxyterephthalate (DDHT) (11.3g, 0.05mol, 1eq), epichlorohydrin (46g, 0.5mol, 10eq), and tetrabutylammonium bromide (16.1g, 0.05mol, 1eq) to a 250mL eggplant-shaped bottle. Build a reflux device and stir and reflux at 80°C for 3h. After the reaction, cool the reaction solution to room temperature in an ice bath, and dissolve sodium hydroxide (10g, 0.25mol, 5eq) in 20mL of water and slowly add it to the eggplant-shaped bottle. Use ethyl acetate / water system for extraction, collect the organic phase, and dry it with anhydrous sodium sulfate. Remove dichloromethane by rotary evaporation, and pass sand through a column to obtain a white solid.

[0079] Embodiment 17

[0080] Preparation of bio-based epoxy resin (diamine 1074 as curing agent (Heda)): Bio-based epoxy resin monomer (DDHT-ECH) (1.2168 g, 0.0036 mol, 1.8 eq) was added to a 20 mL sample bottle and heated to 110 ° C under vacuum conditions. After it melted, diamine 1074 (0.54 g, 0.002 mol, 1 eq) was added to the sample bottle. After mixing evenly, it was poured into a mold and cured in an oven at 120 ° C.

[0081] Embodiment 18

[0082] Preparation of bio-based epoxy resin (diamine 1074 as curing agent (Heda)): Bio-based epoxy resin monomer (DDHT-ECH) (1.352 g, 0.004 mol, 2 eq) was added to a 20 mL sample bottle and heated to 110 ° C under vacuum conditions. After it melted, diamine 1074 (0.54 g, 0.002 mol, 1 eq) was added to the sample bottle. After mixing evenly, it was poured into a mold and cured in an oven at 120 ° C.

[0083] Embodiment 19

[0084] Preparation of bio-based epoxy resin (diamine 1074 as curing agent (Heda)): Bio-based epoxy resin monomer (DDHT-ECH) (1.4872 g, 0.0044 mol, 2.2 eq) was added to a 20 mL sample bottle and heated to 110 ° C under vacuum conditions. After it melted, diamine 1074 (0.54 g, 0.002 mol, 1 eq) was added to the sample bottle. After mixing evenly, it was poured into a mold and cured in an oven at 120 ° C.

[0085] Embodiment 20

[0086] Preparation of bio-based epoxy resin (diamine 1074 as curing agent (Heda)): Bio-based epoxy resin monomer (DDHT-ECH) (1.352 g, 0.004 mol, 2 eq) was added to a 20 mL sample bottle and heated to 110 ° C under vacuum conditions. After it melted, diamine 1074 (0.54 g, 0.002 mol, 1 eq) was added to the sample bottle. After mixing evenly, it was poured into a mold and cured in an oven at 100 ° C.

[0087] Embodiment 21

[0088] Preparation of bio-based epoxy resin (diamine 1074 as curing agent (Heda)): Bio-based epoxy resin monomer (DDHT-ECH) (1.352 g, 0.004 mol, 2 eq) was added to a 20 mL sample bottle and heated to 110 ° C under vacuum conditions. After it melted, diamine 1074 (0.54 g, 0.002 mol, 1 eq) was added to the sample bottle. After mixing evenly, it was poured into a mold and cured in an oven at 160 ° C.

[0089] Embodiment 22

[0090] Preparation of bio-based epoxy resin (polyetheramine D400 as curing agent (Huntsman)): Bio-based epoxy resin monomer (DDHT-ECH) (1.352 g, 0.004 mol, 2 eq) was added to a 20 mL sample bottle and heated to 110 ° C under vacuum conditions. After it melted, polyetheramine D400 (0.8 g, 0.002 mol, 1 eq) was added to the sample bottle. After mixing evenly, it was poured into a mold and cured in an oven at 120 ° C.

[0091] Embodiment 23

[0092] Preparation of bio-based epoxy resin (pentamethylenediamine as curing agent (Kaisai)): Add bio-based epoxy resin monomer (DDHT-ECH) (1.352 g, 0.004 mol, 2 eq) into a 20 mL sample bottle and heat to 110 ° C under vacuum conditions. After it melts, add pentamethylenediamine (0.204 g, 0.002 mol, 1 eq) into the sample bottle. After mixing evenly, pour it into a mold and cure it in a 120 ° C oven.

[0093] Embodiment 24

[0094] Preparation of bio-based epoxy resin (isophorone diamine as curing agent (Annaiji)): Add bio-based epoxy resin monomer (DDHT-ECH) (1.352 g, 0.004 mol, 2 eq) into a 20 mL sample bottle and heat to 110 ° C under vacuum conditions. After it melts, add isophorone diamine (0.34 g, 0.002 mol, 1 eq) into the sample bottle. After mixing evenly, pour it into a mold and cure it in an oven at 120 ° C.

[0095] Embodiment 25

[0096] Preparation of bio-based epoxy resin (4,4'-diaminodiphenylmethane as curing agent (Annaiji)): Add bio-based epoxy resin monomer (DDHT-ECH) (1.352 g, 0.004 mol, 2 eq) into a 20 mL sample bottle and heat to 110 ° C under vacuum conditions. After it melts, add 4,4'-diaminodiphenylmethane (0.396 g, 0.002 mol, 1 eq) into the sample bottle, mix it evenly after it melts, pour it into a mold, and cure it in an oven at 120 ° C.

[0097] Embodiment 26

[0098] Preparation of bio-based epoxy resin (meta-phenylenediamine as curing agent (Annaiji)): Add bio-based epoxy resin monomer (DDHT-ECH) (1.352 g, 0.004 mol, 2 eq) into a 20 mL sample bottle and heat to 110 ° C under vacuum conditions. After it melts, add meta-phenylenediamine (0.216 g, 0.002 mol, 1 eq) into the sample bottle, mix it evenly after it melts, pour it into a mold, and cure it in a 120 ° C oven.

[0099] Embodiment 27

[0100] Preparation of bio-based epoxy resin (with p-phenylenediamine as curing agent (Annaiji)): Add bio-based epoxy resin monomer (DDHT-ECH) (1.352 g, 0.004 mol, 2 eq) into a 20 mL sample bottle and heat to 110 ° C under vacuum conditions. After it melts, add p-phenylenediamine (0.216 g, 0.002 mol, 1 eq) into the sample bottle, mix it evenly after it melts, pour it into a mold, and cure it in an oven at 120 ° C.

Claims

1. A bio-based epoxy resin monomer (DDHT-ECH), characterized in that Having a structure as shown in formula (I):

2. The preparation method of the bio-based epoxy resin monomer as described in formula (I) of claim 1 is: reacting dimethyl 2,5-dihydroxyterephthalate with epichlorohydrin in the presence of a catalyst to obtain a bio-based epoxy resin monomer (DDHT-ECH) containing dimethyl 2,5-dihydroxyterephthalate.

3. The catalyst as claimed in claim 2 is tetrabutylammonium bromide.

4. The molar ratio of dimethyl 2,5-dihydroxyterephthalate to epichlorohydrin as claimed in claim 2 is 1:4-1:

12.

5. The molar ratio of dimethyl 2,5-dihydroxyterephthalate to tetrabutylammonium bromide as claimed in claim 2 is 1:0.8-1:1.

2.

6. A bio-based epoxy resin, characterized in that It has a structure as shown in formula (II): Wherein, R is an alkyl group, a polyether segment, an aromatic group, an alicyclic group, and m and n are natural numbers.

7. The preparation method of the bio-based epoxy resin described in formula (II) as claimed in claim 6 is: heating and melting the bio-based epoxy resin monomer described in formula (I), adding a curing agent, mixing well and pouring into a mold for molding.

8. The molar ratio of the bio-based epoxy resin monomer containing dimethyl 2,5-dihydroxyterephthalate (DDHT-ECH) as claimed in claim 7 to the curing agent is 1.8:1-2.2:

1.

9. The curing agent as claimed in claim 7 and claim 8 is diamine 1074, polyetheramine D400, pentamethylenediamine, isophoronediamine, 4,4'-diaminodiphenylmethane, m-phenylenediamine, p-phenylenediamine.

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