Isosorbide epoxy resin material and method of preparation

Abstract

The present application relates to the technical fields of epoxy resin, and disclose a kind of isosorbide epoxy resin material and preparation method, the isosorbide epoxy resin material of the present application includes isosorbide polyamine curing agent, and the mass ratio of (60-75) isosorbide epoxy resin, aliphatic epoxy resin, (25-40);Isosorbide epoxy resin and isosorbide polyamine curing agent both contain rigid and heat-resistant double five-membered ring structure, can significantly improve the heat resistance and thermogravimetric loss temperature of epoxy resin, and isosorbide epoxy resin, flexible aliphatic epoxy resin and isosorbide polyamine curing agent all do not contain aromatic ring structure, after light heat treatment, epoxy resin material is not prone to aging yellowing, and the yellowing resistance is good.

Description

Technical Field

[0001] This invention relates to the field of epoxy resin technology, specifically to an isosorbide epoxy resin material and its preparation method. Background Technology

[0002] Epoxy resins mainly include aromatic epoxy resins and aliphatic epoxy resins. Aromatic epoxy resins, such as bisphenol A epoxy resin, have advantages such as high mechanical strength and good heat resistance. However, aromatic epoxy resins have poor toughness and contain benzene rings, making them prone to photo-thermal aging and yellowing, affecting their appearance and properties. Aliphatic epoxy resins have advantages such as high transparency, low viscosity, and high flexibility, but their mechanical strength and heat resistance are relatively poor.

[0003] In recent years, the development of novel epoxy resins possessing properties such as strength, toughness, heat resistance, and resistance to yellowing has become a research hotspot. Bio-based epoxy resins use natural biomass as raw materials, are inexpensive and readily available, and are environmentally friendly. Isosorbide is mainly derived from biomass resources such as corn, wheat, and cassava starch, does not rely on petroleum resources, and contains a rigid double five-membered ring structure, exhibiting advantages such as good heat resistance and high modulus. It can be used to produce high-performance epoxy resins, polyurethanes, polycarbonates, and other materials. Patent CN115895551B discloses a high-reliability underfill adhesive and its preparation method. By preparing an epoxy resin containing POSS and isosorbide segments, the crosslinking points in the system are increased, improving flowability and bonding strength. However, this patent does not solve the problem of poor heat resistance and resistance to yellowing of epoxy resins. Summary of the Invention

[0004] This invention solves the problem that epoxy resins are difficult to have both excellent mechanical strength and toughness, while also improving the heat resistance and yellowing resistance of epoxy resins.

[0005] The technical solution of the present invention is: an isosorbide epoxy resin material, which is composed of isosorbide polyamine curing agent, and isosorbide epoxy resin and aliphatic epoxy resin in a mass ratio of (60-75):(25-40), wherein the molar ratio of the active hydrogen -NH of the isosorbide polyamine curing agent to the total amount of epoxy groups of the isosorbide epoxy resin and the aliphatic epoxy resin is 1:(1-1.08).

[0006] The preparation method of isosorbide epoxy resin material is as follows:

[0007] (1) Add dichloromethane, isosorbide and triethylamine to a flask, add a solution of dichloromethane containing acryloyl chloride dropwise in an ice-water bath, stir and react for 24-30 h, filter, evaporate the filtrate by rotary evaporation, and separate the product by silica gel column to obtain isosorbide acrylate.

[0008] (2) Add solvent, isosorbide acrylate and polyamine compound to a flask equipped with a reflux condenser, heat to 60-70°C, stir to carry out Michael addition reaction for 2-3 hours, evaporate the solution by rotary evaporation, and separate the product by silica gel column to obtain isosorbide polyamine curing agent;

[0009] (3) Add isosorbide and epichlorohydrin to a flask equipped with a reflux condenser, heat to 90-110℃, react for 0.5-1h, then add sodium hydroxide aqueous solution dropwise, stir and react for 2-3h, filter, concentrate the filtrate by rotary evaporation, add water, stir and let stand to separate the layers, remove the water layer, collect the oil layer, dry, and obtain isosorbide epoxy resin.

[0010] (4) Mix isosorbide epoxy resin and aliphatic epoxy resin, then add isosorbide polyamine curing agent, stir and pour into mold, vacuum degas, heat cure at 70-80℃ for 0.5-1h, then heat cure at 110-120℃ for 1-1.5h, cool to room temperature to obtain isosorbide epoxy resin material.

[0011] Preferably, the molar ratio of isosorbide, triethylamine and acryloyl chloride in (1) is 1:(2-2.2):(2-2.3).

[0012] Preferably, in (2), the molar ratio of acrylate isosorbide and polyamine compound is 1:(2.8-3.4).

[0013] Preferably, the polyamine compound in (2) is one or more of ethylenediamine, diethylenetriamine, triethylenetetramine or tetraethylenepentamine.

[0014] Preferably, the solvent in (2) is methanol or ethanol.

[0015] Preferably, in (3), the mass ratio of isosorbide, epichlorohydrin and sodium hydroxide is 100:(580-610):(36-43).

[0016] The beneficial technical effects of this invention are as follows: By compounding rigid isosorbide epoxy resin and flexible aliphatic epoxy resin, the strength and toughness of the epoxy resin material can be controlled. The added isosorbide polyamine curing agent has good compatibility with isosorbide epoxy resin, allowing the isosorbide polyamine curing agent to be uniformly dispersed in the epoxy resin matrix, thereby better facilitating the thermosetting reaction and further improving the mechanical and other properties of the epoxy resin material.

[0017] The isosorbide epoxy resin and isosorbide polyamine curing agent of the present invention both contain a rigid and heat-resistant double five-membered ring structure, which can significantly improve the heat resistance and thermogravimetric loss temperature of epoxy resin. Furthermore, the isosorbide epoxy resin, the flexible aliphatic epoxy resin, and the isosorbide polyamine curing agent do not contain an aromatic ring structure. After photothermal treatment, the epoxy resin material is not prone to aging and yellowing, and has good yellowing resistance. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below.

[0019] The following aliphatic epoxy resin model is Dow XZ92465.

[0020] Example 1:

[0021] (1) Add 800 mL of dichloromethane, 0.4 mol of isosorbide and 0.88 mol of triethylamine to a flask. Add 500 mL of dichloromethane solution containing 0.92 mol of acryloyl chloride dropwise in an ice-water bath. Stir the reaction for 24 h, filter, evaporate the filtrate by rotary evaporation, separate the product by silica gel column chromatography, and elute with ethyl acetate-petroleum ether mixture to obtain isosorbide acrylate.

[0022] (2) Add 300 mL of ethanol, 0.35 mol of isosorbide acrylate, and 0.98 mol of ethylenediamine to a flask equipped with a reflux condenser. Heat to 70 °C and stir for 3 h. Rotary evaporate the solution. Separate the product by silica gel column chromatography and elute with an ethyl acetate-petroleum ether mixture to obtain isosorbide polyamine curing agent. The reaction formula is:

[0023] .

[0024] (3) Add 200g isosorbide and 1200g epichlorohydrin to a flask equipped with a reflux condenser, heat to 110℃ and react for 0.5h, then add 120mL of an aqueous solution containing 80g sodium hydroxide, stir and react for 2h, filter and concentrate the filtrate by rotary evaporation, add water, stir and let stand to separate the layers, remove the water layer, collect the oil layer, dry and obtain isosorbide epoxy resin.

[0025] (4) Mix 300g of isosorbide epoxy resin and 200g of aliphatic epoxy resin, then add isosorbide polyamine curing agent, and control the molar ratio of the active hydrogen-NH of isosorbide polyamine curing agent to the total amount of epoxy groups of isosorbide epoxy resin and aliphatic epoxy resin to be 1:1.04. After stirring, pour into a mold, degas under vacuum, heat cure at 80℃ for 0.5h, then heat cure at 110℃ for 1.5h, and cool to room temperature to obtain isosorbide epoxy resin material.

[0026] Example 2:

[0027] (1) Add 900 mL of dichloromethane, 0.5 mol of isosorbide and 1 mol of triethylamine to a flask. Add 600 mL of dichloromethane solution containing 1.15 mol of acryloyl chloride dropwise in an ice-water bath. Stir the reaction for 30 h, filter, evaporate the filtrate by rotary evaporation, separate the product by silica gel column chromatography, and elute with ethyl acetate-petroleum ether mixture to obtain isosorbide acrylate.

[0028] (2) Add 350 mL of ethanol, 0.45 mol of isosorbide acrylate and 1.44 mol of triethylenetetramine to a flask equipped with a reflux condenser, heat to 70 °C, stir and react for 2 h, evaporate the solution by rotary evaporation, separate the product by silica gel column, and elute with ethyl acetate-petroleum ether mixed solution to obtain isosorbide polyamine curing agent.

[0029] (3) Add 200g isosorbide and 1160g epichlorohydrin to a flask equipped with a reflux condenser, heat to 90°C and react for 1h, then add 130mL of an aqueous solution containing 86g sodium hydroxide, stir and react for 3h, filter and concentrate the filtrate by rotary evaporation, add water, stir and let stand to separate the layers, remove the water layer, collect the oil layer, dry and obtain isosorbide epoxy resin.

[0030] (4) Mix 325g of isosorbide epoxy resin and 175g of aliphatic epoxy resin, then add isosorbide polyamine curing agent, and control the molar ratio of the active hydrogen-NH of isosorbide polyamine curing agent to the total amount of epoxy groups of isosorbide epoxy resin and aliphatic epoxy resin to be 1:1. After stirring, pour into a mold, degas under vacuum, heat cure at 80℃ for 0.5h, then heat cure at 120℃ for 1h, and cool to room temperature to obtain isosorbide epoxy resin material.

[0031] Example 3:

[0032] (1) Add 900 mL of dichloromethane, 0.5 mol of isosorbide and 1.1 mol of triethylamine to a flask. Add 600 mL of dichloromethane solution containing 1.15 mol of acryloyl chloride dropwise in an ice-water bath. Stir the reaction for 24 h, filter, evaporate the filtrate by rotary evaporation, separate the product by silica gel column chromatography, and elute with ethyl acetate-petroleum ether mixture to obtain isosorbide acrylate.

[0033] (2) Add 350 mL of methanol, 0.45 mol of isosorbide acrylate and 1.26 mol of ethylenediamine to a flask equipped with a reflux condenser, heat to 60 °C, stir and react for 3 h, evaporate the solution by rotary evaporation, separate the product by silica gel column, and elute with ethyl acetate-petroleum ether mixed solution to obtain isosorbide polyamine curing agent.

[0034] (3) Add 200g isosorbide and 1200g epichlorohydrin to a flask equipped with a reflux condenser, heat to 100℃ and react for 1h, then add 120mL of an aqueous solution containing 80g sodium hydroxide, stir and react for 2.5h, filter and concentrate the filtrate by rotary evaporation, add water, stir and let stand to separate the layers, remove the water layer, collect the oil layer, dry and obtain isosorbide epoxy resin.

[0035] (4) Mix 350g of isosorbide epoxy resin and 150g of aliphatic epoxy resin, then add isosorbide polyamine curing agent, and control the molar ratio of the active hydrogen-NH of isosorbide polyamine curing agent to the total amount of epoxy groups of isosorbide epoxy resin and aliphatic epoxy resin to be 1:1.08. After stirring, pour into a mold, degas under vacuum, heat cure at 70℃ for 1h, then heat cure at 120℃ for 1h, and cool to room temperature to obtain isosorbide epoxy resin material.

[0036] Example 4:

[0037] (1) Add 750 mL of dichloromethane, 0.4 mol of isosorbide and 0.8 mol of triethylamine to a flask. Add 450 mL of dichloromethane solution containing 0.8 mol of acryloyl chloride dropwise in an ice-water bath. Stir the reaction for 30 h, filter, evaporate the filtrate by rotary evaporation, separate the product by silica gel column chromatography, and elute with ethyl acetate-petroleum ether mixture to obtain isosorbide acrylate.

[0038] (2) Add 300 mL of ethanol, 0.35 mol of isosorbide acrylate and 1.19 mol of diethylenetriamine to a flask equipped with a reflux condenser, heat to 70 °C, stir and react for 2 h, evaporate the solution by rotary evaporation, separate the product by silica gel column, and elute with ethyl acetate-petroleum ether mixed solution to obtain isosorbide polyamine curing agent.

[0039] (3) Add 200g isosorbide and 1220g epichlorohydrin to a flask equipped with a reflux condenser, heat to 110℃ and react for 0.5h, then add 110mL of an aqueous solution containing 72g sodium hydroxide, stir and react for 2h, filter, concentrate the filtrate by rotary evaporation, add water, stir and let stand to separate the layers, remove the water layer, collect the oil layer, dry, and obtain isosorbide epoxy resin.

[0040] (4) Mix 375g of isosorbide epoxy resin and 125g of aliphatic epoxy resin, then add isosorbide polyamine curing agent, and control the molar ratio of the active hydrogen-NH of isosorbide polyamine curing agent to the total amount of epoxy groups of isosorbide epoxy resin and aliphatic epoxy resin to be 1:1.06. After stirring, pour into a mold, degas under vacuum, heat cure at 80℃ for 0.5h, then heat cure at 120℃ for 1h, and cool to room temperature to obtain isosorbide epoxy resin material.

[0041] Comparative Example 1 differs from Example 1 in that it uses ethylenediamine as a curing agent.

[0042] (1) Mix 300g of isosorbide epoxy resin and 200g of aliphatic epoxy resin, then add ethylenediamine, and control the molar ratio of the active hydrogen -NH of ethylenediamine to the total amount of epoxy groups of isosorbide epoxy resin and aliphatic epoxy resin to be 1:1.04. After stirring, pour into a mold, degas under vacuum, heat cure at 80℃ for 0.5h, then heat cure at 110℃ for 1.5h, and cool to room temperature to obtain epoxy resin material.

[0043] Comparative Example 2 differs from Example 1 in that it uses isophorone diamine as a curing agent.

[0044] (1) Mix 300g of isosorbide epoxy resin and 200g of aliphatic epoxy resin, then add isophorone diamine, and control the molar ratio of the active hydrogen -NH of isophorone diamine to the total amount of epoxy groups of isosorbide epoxy resin and aliphatic epoxy resin to be 1:1.04. After stirring, pour into a mold, degas under vacuum, heat cure at 80℃ for 0.5h, then heat cure at 110℃ for 1.5h, and cool to room temperature to obtain epoxy resin material.

[0045] Comparative Example 3 differs from Example 1 in that 4,4'-diaminodiphenylmethane is used as the curing agent.

[0046] (1) Mix 300g of isosorbide epoxy resin and 200g of aliphatic epoxy resin, then add 4,4'-diaminodiphenylmethane, and control the molar ratio of the active hydrogen -NH of 4,4'-diaminodiphenylmethane to the total amount of epoxy groups of isosorbide epoxy resin and aliphatic epoxy resin to be 1:1.04. After stirring, pour into a mold, degas under vacuum, heat cure at 80℃ for 0.5h, then heat cure at 110℃ for 1.5h, and cool to room temperature to obtain epoxy resin material.

[0047] Tensile properties were tested according to GB / T 2567-2021.

[0048] The thermal properties of epoxy resin materials were tested using a thermogravimetric analyzer under a nitrogen atmosphere, with a heating rate of 5℃ / min and a test temperature range of 25-700℃.

[0049] The epoxy resin material was placed in a xenon lamp aging test chamber for 72 hours of photothermal aging. The lamp power was 1.8 kW and the black panel temperature was 80℃. After aging at room temperature for 12 hours, the ΔL, Δa, and Δb values ​​of the epoxy resin material before and after heat treatment were measured using a colorimeter and the method of GB / T 20147.4-2023. The color difference value ΔE was calculated as follows: ΔE = [(ΔL)] 2 +(△a)2 +(△b) 2 ] 1 / 2 The smaller the ΔE, the better the resistance to yellowing. The test results for each embodiment and comparative example obtained through the above test methods are shown in Table 1 below.

[0050] Table 1: Performance test results of epoxy resin materials in each embodiment and comparative example

[0051]

[0052] As shown in Table 1, the epoxy resins of Examples 1-4 exhibit high tensile strength and elongation at break, along with high thermogravimetric temperature (TGA) and low ΔE color difference, demonstrating excellent heat resistance and resistance to yellowing. This is primarily due to the use of a rigid isosorbide epoxy resin and a flexible aliphatic epoxy resin to regulate the strength and toughness of the epoxy resin material. Furthermore, both the isosorbide epoxy resin and the isosorbide polyamine curing agent contain isosorbide structural units, exhibiting good compatibility. This allows the isosorbide polyamine curing agent to be uniformly dispersed within the epoxy resin matrix, facilitating a better thermosetting reaction and further improving the performance of the epoxy resin material. Additionally, both the isosorbide epoxy resin and the isosorbide polyamine curing agent contain a rigid and heat-resistant double five-membered ring structure, which significantly enhances the heat resistance and TGA of the epoxy resin. Isosorbide epoxy resin, flexible aliphatic epoxy resin, and isosorbide polyamine curing agent do not contain aromatic ring structures. After photothermal treatment, epoxy resin materials are not prone to aging and yellowing, have low ΔE color difference values, and good resistance to yellowing.

[0053] In Comparative Example 1, ethylenediamine was used as a curing agent, and the tensile strength and thermogravimetric loss temperature of the epoxy resin material were significantly lower than those in Example 1.

[0054] Comparative Example 2 used isophorone diamine as a curing agent, and the tensile strength, elongation at break, and thermogravimetric loss temperature of the epoxy resin material were lower than those in Example 1.

[0055] Comparative Example 3 used 4,4'-diaminodiphenylmethane as a curing agent. As a solid, it has poor compatibility and solubility in isosorbide epoxy resin and flexible aliphatic epoxy resin, which is not conducive to the thermosetting reaction. The tensile strength and thermogravimetric loss temperature of the prepared epoxy resin material are not much different from those of Example 1, but the elongation at break is low. In addition, it contains multiple benzene ring structures. After photothermal treatment, the epoxy resin material is prone to aging and yellowing, with a large ΔE color difference value and poor resistance to yellowing.

[0056] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An isosorbide epoxy resin material, characterized in that, The isosorbide epoxy resin material includes an isosorbide polyamine curing agent, and isosorbide epoxy resin and aliphatic epoxy resin in a mass ratio of (60-75):(25-40); the molar ratio of the active hydrogen of the isosorbide polyamine curing agent to the total amount of epoxy groups of the isosorbide epoxy resin and the aliphatic epoxy resin is 1:(1-1.08). The isosorbide polyamine curing agent is prepared by the following method: (1) Add dichloromethane, isosorbide and triethylamine to a flask, add a solution of dichloromethane containing acryloyl chloride dropwise in an ice-water bath, stir to carry out the reaction, filter, evaporate the filtrate by rotary evaporation, and separate the product by silica gel column to obtain isosorbide acrylate. (2) Add solvent, isosorbide acrylate and polyamine compound to a flask equipped with a reflux condenser, stir to carry out the reaction, evaporate the solution by rotary evaporation, and separate the product by silica gel column to obtain isosorbide polyamine curing agent; The polyamine compound in (2) is one or more of ethylenediamine, diethylenetriamine, triethylenetetramine, or tetraethylenepentamine.

2. The isosorbide epoxy resin material according to claim 1, characterized in that, The molar ratio of isosorbide, triethylamine and acryloyl chloride in (1) is 1:(2-2.2):(2-2.3).

3. The isosorbide epoxy resin material according to claim 1, characterized in that, The reaction time in (1) is 24-30h.

4. The isosorbide epoxy resin material according to claim 1, characterized in that, The molar ratio of isosorbide acrylate and polyamine compound in (2) is 1:(2.8-3.4).

5. The isosorbide epoxy resin material according to claim 1, characterized in that, The reaction temperature in (2) is 60-70℃ and the reaction time is 2-3h.

6. The isosorbide epoxy resin material according to claim 1, characterized in that, The solvent in (2) is methanol or ethanol.

7. The isosorbide epoxy resin material according to claim 1, characterized in that, The isosorbide epoxy resin is prepared by the following method: isosorbide and epichlorohydrin are added to a flask equipped with a reflux condenser, heated to 90-110℃, and reacted for 0.5-1h. Then, an aqueous solution of sodium hydroxide is added dropwise, and the mixture is stirred for 2-3h. After filtration, the filtrate is concentrated by rotary evaporation, water is added, and the mixture is stirred and allowed to stand to separate into layers. The water layer is removed, the oil layer is collected, and the mixture is dried to obtain the isosorbide epoxy resin.

8. The isosorbide epoxy resin material according to claim 7, characterized in that, The mass ratio of isosorbide, epichlorohydrin, and sodium hydroxide is 100:(580-610):(36-43).

9. A method for preparing an isosorbide epoxy resin material according to any one of claims 1-8, characterized in that, The preparation method is as follows: isosorbide epoxy resin and aliphatic epoxy resin are stirred and mixed, then isosorbide polyamine curing agent is added, stirred and poured into a mold, vacuum degassed, heat cured at 70-80℃ for 0.5-1h, then heat cured at 110-120℃ for 1-1.5h, and cooled to room temperature to obtain isosorbide epoxy resin material.

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