Preparation method of bio-based anti-ultraviolet epoxy resin film

Abstract

The invention discloses a novel anti-ultraviolet epoxy resin film prepared by using a bio-based epoxy curing agent, the bio-based epoxy curing agent (AEESN) is derived from bio-based substances eugenol and cysteamine, the molar ratio of an epoxy group of an epoxy monomer to an amino group in the bio-based curing agent AEESN is 1: (1.0-1.5), the epoxy monomer and the bio-based curing agent AEESN can be uniformly mixed at the temperature of 20-50 DEG C, and the anti-ultraviolet epoxy resin film is prepared. And curing under the condition of 60-120 DEG C and preparing a sample. The anti-ultraviolet performance of the resin provided by the invention is derived from the base material, and the resin has excellent mechanical properties and good shape memory ability at the same time.

Description

Technical Field

[0001] The present invention relates to the field of polymer materials, and in particular to a method for preparing a bio-based anti-ultraviolet epoxy resin film. Background Art

[0002] Epoxy resin has outstanding mechanical strength and good chemical stability. It has been widely used in aerospace, coatings, electronic components, construction industry, medical materials and other fields. However, the current market is still dominated by petroleum-based bisphenol A epoxy resin. Long-term exposure to bisphenol A-based resin may cause a series of health risks. At the same time, there is little research on the optical functionality of related bulk chemicals, and most products have long relied on petrochemical resources. Therefore, the development of corresponding optical bio-based functional materials is of great significance for the stability and durability research of materials and the improvement of safety.

[0003] Ultraviolet rays can cause varying degrees of damage to building materials and precision instruments, especially long-term ultraviolet exposure will reduce the corrosion resistance of the instruments. UVA (long-wave ultraviolet rays) of 320-400nm have strong penetrating power and can penetrate into the room through glass, accounting for about 95% of the total ultraviolet rays reaching the earth's surface. They can penetrate into the dermis of the skin and are the main cause of skin tanning, aging, and wrinkles. Isolating UVA can effectively prevent materials from fading and aging and protect human skin. UVB (medium-wave ultraviolet rays) of 280-320nm have higher energy and are the main factor causing skin sunburn, and can also cause certain damage to materials. For polymers, the resin coating will produce free radicals due to ultraviolet radiation in the working environment, which will trigger oxidation reactions, causing discoloration and aging, etc., affecting its working life. Traditional epoxy resins generally achieve relevant performance modifications by adding ultraviolet stabilizers and light scattering agents.

[0004] The main purpose of the present invention is to provide a bio-based anti-ultraviolet epoxy resin film and a preparation method thereof, wherein the resin film has good ultraviolet isolation ability, the transmittance of short-wave ultraviolet (UVC) and medium-wave ultraviolet (UVB) is 0%, the transmittance of long-wave ultraviolet (UVA) is less than 10%, and the blue light blocking rate is greater than 50%. At the same time, the resin film has good mechanical properties and shape memory ability. Summary of the invention

[0005] Purpose of the invention: The technical problem to be solved by the present invention is to provide a bio-based UV-resistant epoxy resin film in view of the deficiencies in the prior art.

[0006] Another technical problem to be solved by the present invention is to provide a method for preparing the above-mentioned bio-based anti-ultraviolet epoxy resin film.

[0007] The technical problem that the present invention needs to solve is to provide the application advantages of the above-mentioned bio-based anti-ultraviolet epoxy resin film.

[0008] In order to solve the above-mentioned first technical problem, the present invention discloses a bio-based anti-ultraviolet epoxy resin film, wherein the polymerization of structural units A and B or A and C constitutes a new binary polymer. The structural units A, B, and C are respectively:

[0009]

[0010] The binary polymer composed of A and B has a repeating structural unit shown in Formula I, and the binary polymer composed of A and C has a repeating structural unit shown in Formula II:

[0011]

[0012] Among them, m 1 、m 2 ≥2, n≥2.

[0013] In order to solve the second technical problem, the present invention discloses a method for preparing the above-mentioned bio-based anti-ultraviolet resin film, which is specifically, epoxy resin monomer and bio-based curing agent AEESN are mixed, stirred and heated until uniform, then molded, and heated and cured to obtain bio-based epoxy resin.

[0014] The epoxy monomers include but are not limited to the following structures:

[0015]

[0016] The molar ratio of the epoxy group of the epoxy monomer to the amino group of the bio-based diamine curing agent is 1:1.0-1.5, preferably 1:1.0-1.2, preferably 1:1.2;

[0017] The mixing temperature is 20-60°C, preferably 50°C; the curing temperature is 60-120°C, preferably 60-110°C.

[0018] The epoxy resin prepared by the method of the present invention has good UV resistance, good mechanical properties, excellent processability and shape memory ability. Therefore, the present invention further proposes the use of the above bio-based resin in the preparation of UV-resistant resin film materials.

[0019] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0020] (1) The curing agent provided by the present invention is derived from biomass, has high biological added value and high biological safety;

[0021] (2) The polymer raw materials provided by the present invention are all liquid at room temperature and are easy to mix. The corresponding polymerization temperature is low, and the preparation process is simple and the conditions are mild.

[0022] (3) The polymer provided in the present invention has good UV resistance;

[0023] (4) The polymer provided in the present invention has good mechanical properties, processability and shape memory ability. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments, and the above and / or other advantages of the present invention will become more clear.

[0025] Figure 1 The infrared test curves of 3EP / AEESN and 4EP / AEESN polymers, wherein a) is the IR curve of 3EP / AEESN system, and b) is the IR curve of 4EP / AEESN system;

[0026] Figure 2 TG test curve of 3EP / AEESN and 4EP / AEESN polymers

[0027] Figure 3 It is the UV-visible light transmittance test curve of 3EP / AEESN and 4EP / AEESN polymers;

[0028] Figure 4 Take pictures of thermal deformation of 3EP / AEESN and 4EP / AEESN polymers DETAILED DESCRIPTION

[0029] 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.

[0030] Example 13 Preparation of EP / AEESN

[0031] Weigh 3EP (2.22 g, 8 mmol) and curing agent AEESN (2.58 g, 7.2 mmol) in a reaction bottle, mix thoroughly at 50°C and inject into the mold, slowly heat up at a rate of 1.5°C / min under a nitrogen atmosphere, store at 60°C for 2 h, 80°C for 1 h, and 100°C for 1 h, then cool naturally to room temperature to obtain polymer 3EP / AEESN.

[0032] Example 24 Preparation of EP / AEESN

[0033] 4EP (3.38 g, 8 mmol) and curing agent AEESN (3.44 g, 9.6 mmol) were weighed into a reaction bottle, mixed thoroughly at 50°C and injected into a mold. The temperature was slowly increased at a rate of 1.5°C / min under a nitrogen atmosphere, and the mixture was kept at 70°C for 2 h, 90°C for 1 h, and 110°C for 1 h. The mixture was then naturally cooled to room temperature to obtain a polymer 4EP / AEESN.

[0034] Judging from infrared data, Figure 1 The infrared absorption peak of the epoxy group in 3EP (910 cm -1 ) disappears, indicating that the epoxy resin is fully polymerized; for the 4EP / AEESN system, the infrared absorption peak of the epoxy group in 4EP (860cm -1 and 910cm -1 ) disappearance indicates that the epoxy resin is fully polymerized, thus proving that the system is fully polymerized.

[0035] Thermogravimetric analysis was performed with a nitrogen flow rate of 40 mL / min, a heating rate of 20 °C / min, and a temperature range of 30 °C to 800 °C. The thermal stability of the samples was analyzed (e.g. Figure 2 ). The initial decomposition temperature of the 3EP / AEESN system is 323.5°C, the decomposition temperature corresponding to 30wt% decomposition is 352.8°C, the maximum decomposition temperature is 345.4°C, and the residual carbon at 800°C is 16.9%; the initial decomposition temperature of the 4EP / AEESN / system is 314.3°C, the decomposition temperature corresponding to 30wt% decomposition is 350.6°C, the maximum decomposition temperature is 338.9°C, and the residual carbon at 800°C is 15.1%.

[0036] The UV-visible transmittance of the prepared film was measured at room temperature using a Shimadzu UV-2550 spectrophotometer (film thickness 0.8 mm). Figure 3 The transmittance of the two systems provided by the present invention for UVC and UVB is 0%; the transmittance of UVA of the 3EP / AEESN system is less than 8.4%, the transmittance for ultraviolet rays with a wavelength of 405nm is 10.59%, and the blue light blocking rate is 60.2%; the transmittance of UVA of the 4EP / AEESN system is less than 8.4%, the transmittance for ultraviolet rays with a wavelength of 405nm is 11.13%, and the blue light blocking rate is 52.8%.

[0037] Mechanical properties were tested using a universal testing machine (manufactured by SUNS Technology Co., Ltd., Shenzhen, China) with a crossbar speed of 5 mm / min for tensile testing and 2 mm / min for bending testing. The average tensile strength of 3EP / AEESN was 83 ± 1.7 MPa and the average bending strength was 129.9 ± 2.4 MPa; the average tensile strength of 4EP / AEESN was 80.5 ± 3.8 MPa and the average bending strength was 125 ± 11.8 MPa.

[0038] The film samples prepared by the present invention are tested for deformation ability under heating conditions. When the polymers are heated to different temperatures, the film (1mm*80mm*10mm) can be deformed into a variety of different shapes (such as Figure 4 ), it can be fixed in this shape after cooling down, and can return to its original shape after being heated again.

[0039] The present invention provides a method for preparing a bio-based anti-ultraviolet epoxy resin film. There are many methods and ways to implement the technical solution. The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention. All components not specified in this embodiment can be implemented by existing technologies.

Claims

1. A method for preparing a bio-based UV-resistant epoxy resin film, characterized in that The curing agent used is a bio-based curing agent based on eugenol, and its structure is as follows: The epoxy monomer structure used is shown below:

2. Preparation of a bio-based UV-resistant epoxy resin film, characterized in that The polymerization of structural units A and B or A and C forms a new type of binary polymer. The structural units A, B, and C are: The binary polymer composed of A and B has a repeating structural unit shown in Formula I, and the binary polymer composed of A and C has a repeating structural unit shown in Formula II: Among them, m1, m2≥2, n≥2.

3. The method for preparing a bio-based anti-ultraviolet resin film according to claim 2, characterized in that The bio-based curing agent AEESN was mixed with epoxy monomers 3EP and 4EP respectively and then cured by injection molding.

4. The method for preparing a bio-based anti-ultraviolet resin film according to claim 2, characterized in that The molar ratio of the epoxy monomers 3EP and 4EP and the epoxy group to the amino group of the bio-based curing agent AEESN is 1:1.0-1.5; the mixing temperature is 20-50°C; and the curing temperature is 60-120°C.

5. The method for preparing a bio-based anti-ultraviolet resin film according to claim 2, characterized in that The initial decomposition temperature is between 310℃ and 340℃, and the maximum decomposition temperature is between 350℃ and 370℃.

6. The method for preparing a bio-based anti-ultraviolet resin film according to claim 2, characterized in that The prepared anti-ultraviolet resin film has a transmittance of 0% to short-wave ultraviolet rays (UVC) and medium-wave ultraviolet rays (UVB), a transmittance of less than 10% to long-wave ultraviolet rays (UVA), and a blue light blocking rate of more than 50%.

7. The method for preparing a bio-based anti-ultraviolet resin film according to claim 2, characterized in that The prepared anti-ultraviolet resin film has good mechanical properties at room temperature, wherein the tensile strength of the polymer composed of structure A and B or C is greater than 75MPa; Its average bending strength is greater than 100MPa.

8. The method for preparing a bio-based anti-ultraviolet resin film according to claim 2, characterized in that The prepared anti-ultraviolet resin film has good shape memory ability.

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