Environment-friendly bio-based epoxy resin composite material and its handicraft

Abstract

The application discloses an environment-friendly bio-based epoxy resin composite material and an artware thereof, and belongs to the technical field of bio-based degradable epoxy resin materials.The composite material is prepared by optimizing a formula and a process with a bio-based epoxy resin as a matrix and a bio-based curing agent.The application solves the problems of insufficient mechanical performance and low controllability of degradation rate of the existing bio-based epoxy resin composite material, has the characteristics of high mechanical strength, controllable biodegradability and good formability, and is suitable for manufacturing various environment-friendly artware.

Description

Technical Field

[0001] This invention relates to the field of bio-based biodegradable epoxy resin materials technology, specifically to an environmentally friendly bio-based epoxy resin composite material and its handicrafts. Background Technology

[0002] Epoxy resins are widely used in the manufacture of handicrafts due to their excellent mechanical properties, chemical resistance, and moldability. However, traditional epoxy resins are prepared from fossil-based raw materials such as bisphenol A, which are non-degradable and easily cause environmental pollution after disposal. With the increasing awareness of environmental protection, bio-based epoxy resins have gradually become a research hotspot. They use renewable resources (such as vegetable oils and natural resins) as raw materials and have good biocompatibility and potential degradability.

[0003] In the existing technology, bio-based epoxy resins have the following shortcomings:

[0004] Insufficient mechanical properties: The tensile strength, impact strength and other properties of pure bio-based epoxy resins are lower than those of traditional fossil-based epoxy resins, making it difficult to meet the structural strength requirements of handicrafts.

[0005] Low controllability of degradation rate: Most bio-based epoxy resins degrade too quickly or too slowly, and their degradation performance cannot be adjusted according to the service life of the crafts.

[0006] The curing system is not environmentally friendly enough: commonly used curing agents (such as ethylenediamine and diethylenetriamine) are mostly fossil-based products, and some of them are toxic, which is contrary to the concept of environmental protection.

[0007] Therefore, it is of great significance to develop an epoxy resin composite material that combines high mechanical properties, controllable degradation and fully bio-based environmental protection characteristics. Summary of the Invention

[0008] To address the shortcomings of existing technologies, this invention provides an environmentally friendly bio-based epoxy resin composite material and its related products, aiming to solve the problems of insufficient mechanical properties, uncontrollable degradation rate, and insufficient environmental friendliness of the curing system of bio-based epoxy resin composite materials, thereby achieving a balance between high performance and fully bio-based environmental friendliness.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] In a first aspect, the present invention provides an environmentally friendly bio-based epoxy resin composite material, comprising the following components by weight: 100 parts of bio-based epoxy resin, 10-30 parts of bio-based curing agent, 0.5-3 parts of curing accelerator, and 0.01-1 parts of initiator.

[0011] Preferably, an environmentally friendly bio-based epoxy resin composite material is prepared by means of the following raw materials by weight: 100 parts of bio-based epoxy resin matrix, 10-20 parts of bio-based curing agent, 1-2 parts of curing accelerator, and 0.1-0.5 parts of initiator.

[0012] The bio-based epoxy resin has the structural formula (Ⅰ):

[0013]

[0014] The preparation method of the bio-based epoxy resin of formula (Ⅰ) is as follows:

[0015] S1: Add ricinoleic acid and resveratrol to toluene, add dicyclohexylcarbodiimide (DCC), heat under reflux at 80-120°C for 3-8 hours, purify, and dry to obtain ricinoleic acid resveratrol ester.

[0016] S2: Add resveratrol ricinoleate and BF3-Et2O to toluene solvent. Under heating conditions of 50-70℃, epichlorohydrin (ECH) is slowly added while stirring. The reaction is carried out at a constant temperature for 3-9 hours. The temperature is then lowered to 30-45℃, and tetramethylammonium chloride catalyst and sodium hydroxide powder are added. The reaction is carried out at a constant temperature and stirred for 1-3 hours. After the reaction is completed, the product is purified, concentrated, and dried to obtain the bio-based epoxy resin of formula (Ⅰ).

[0017] In step S1, the molar ratio of ricinoleic acid to resveratrol is 3:(0.7-1.1); the molar ratio of ricinoleic acid to dicyclohexylcarbodiimide is 1:(0.8-1.3).

[0018] The weight ratio of resveratrol ricinoleate, BF3-Et2O, tetramethylammonium chloride catalyst, and sodium hydroxide in step S2 is 100:(0.1-1):(0.01-1):(0.1-1).

[0019] The bio-based curing agent is selected from at least one of amino acid-amine curing agents, lignin-amine curing agents, and cashew phenol-amine curing agents. Preferably, the amino acid-amine curing agent is cystine.

[0020] The curing accelerator is selected from at least one of imidazole derivatives and organophosphorus compounds; preferably, the imidazole derivative is at least one of 2-methylimidazole and 2-ethyl-4-methylimidazole.

[0021] The initiator is selected from at least one of di-tert-butyl peroxide, dicumyl peroxide, benzoyl peroxide, acetyl peroxide, cumyl hydroperoxide, azobisisobutyronitrile, azobisisoheptanenitrile, benzoyl ether, and benzophenone.

[0022] Secondly, the present invention provides an environmentally friendly biomimetic craft, characterized in that its raw materials include the environmentally friendly bio-based epoxy resin composite material described in the first aspect.

[0023] Preferably, the shape of the handicraft is selected from at least one of plant biomimetic parts, animal biomimetic parts, and traditional patterned decorative parts.

[0024] Thirdly, the present invention provides a method for preparing an environmentally friendly bio-based epoxy resin composite material, as described in the first aspect:

[0025] S1. Preparation of premix: Add the bio-based epoxy resin of formula (Ⅰ) to a high-speed mixer and stir at 500-800 rpm for 10-15 min at 50-70℃; add the bio-based curing agent, curing accelerator and initiator to the premix in sequence, and stir at 1000-1500 rpm for 10-30 min until uniform; ultrasonically disperse for 10-60 min (power 300-500W) to obtain the premix.

[0026] S2. Curing and molding: Pour the premix into a mold preheated to 30-80℃, pre-cur at 50-120℃ for 0.5-3 hours, then cure at 100-200℃ for 1-8 hours. After cooling to room temperature, demold to obtain the final product.

[0027] Compared with the prior art, the present invention has the following superior technical effects:

[0028] This invention provides an environmentally friendly bio-based epoxy resin composite material and its handicrafts, aiming to solve the problems of insufficient mechanical properties, uncontrollable degradation rate and insufficient environmental friendliness of the curing system of bio-based epoxy resin composite materials, and to achieve the unity of high performance and full bio-based environmental protection of the material.

[0029] The environmentally friendly bio-based epoxy resin composite material comprises bio-based epoxy resin of formula (I), a bio-based curing agent, a curing accelerator, and an initiator. This material can form a high-performance material through rigid crosslinking of epoxy-amine and flexible crosslinking of double bonds, possessing both flexibility and rigidity, thus overcoming the previous limitation of epoxy resins only having rigidity. Simultaneously, the disulfide bonds introduced by the curing agent cystine endow the material with self-healing capabilities. Both the bio-based epoxy resin of formula (I) and the bio-based curing agent are naturally derived and readily available, inexpensive, easy to prepare, and have a high biodegradability rate, meeting environmental protection requirements. Attached Figure Description

[0030] Figure 1 This is the chemical structural formula of bio-based epoxy resin (I).

[0031] Figure 2 This is a schematic diagram of the synthesis of bio-based epoxy resin according to formula (Ⅰ).

[0032] Figure 3 The infrared spectrum of bio-based epoxy resin of formula (Ⅰ) is shown. Detailed Implementation

[0033] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. The described embodiments are only some preferred 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.

[0034] The raw materials used in the examples and comparative examples are described below:

[0035] Castor oil-based epoxy resin (12-epoxymethoxy-9-octadecenoic acid triglyceride polymer): purchased from Changzhou Hongyu Chemical Co., Ltd.

[0036] Resveratrol: Purchased from Nanjing Tianyi Chemical Technology Co., Ltd.

[0037] Ricinoleic acid: purchased from Tianjin Xiens Biochemical Technology Co., Ltd.

[0038] Cystine: Purchased from Wuhan Jiye Chemical Co., Ltd.

[0039] Epichlorohydrin: Purchased from Shanghai Yanze Chemical Co., Ltd.

[0040] 1,4-Butanediamine: purchased from Shanghai E. En Chemical Technology Co., Ltd.

[0041] Di-tert-butyl peroxide: Shandong Xinyida Chemical Technology Co., Ltd.

[0042] 2-Ethyl-4-methylimidazole (EMI-24) (curing accelerator): purchased from Tianjin Xiens Biochemical Technology Co., Ltd.

[0043] Unless otherwise specified, the experimental methods used in the examples and comparative examples are conventional or common methods in the art, and the materials and reagents used are commercially available unless otherwise specified.

[0044] Preparation of Formula (I) Bio-based Epoxy Resin (Self-made):

[0045] S1: Ricinoleic acid and resveratrol were added to toluene, followed by dicyclohexylcarbodiimide (DCC). The mixture was heated under reflux at 110°C for 5 hours, purified, and dried to obtain ricinoleic acid resveratrol ester. The molar ratio of ricinoleic acid to resveratrol was 3:0.9; the molar ratio of ricinoleic acid to dicyclohexylcarbodiimide was 1:1.2.

[0046] S2: Castor oil resveratrol ester and BF3-Et2O were added to toluene solvent. Epichlorohydrin (ECH) was slowly added while stirring at 60°C, and the reaction was maintained at this temperature for 5 hours. The temperature was then lowered to 35°C, and tetramethylammonium chloride catalyst and sodium hydroxide powder were subsequently added. The reaction was maintained at this temperature and stirred for 3 hours. After the reaction was completed, the product was purified by chromatographic column chromatography and dried to obtain the bio-based epoxy resin of formula (I). In step S2, the weight ratio of castor oil resveratrol ester, BF3-Et2O, tetramethylammonium chloride catalyst, and sodium hydroxide was 100:0.5:0.6:0.3. The infrared spectrum of formula (I) bio-based epoxy resin is shown below. Figure 3 3000-2800cm -1 A broad peak appears indicating the stretching vibration of long-chain alkyl groups (CH); 1710 cm⁻¹ -1 A strong stretching vibration peak appears at 889 cm⁻¹ on the ester carbonyl group (-C=O); the absorption peak of the epoxy bond (COC) appears at 889 cm⁻¹. -1 Place.

[0047] Example 1

[0048] An environmentally friendly bio-based epoxy resin composite material, by weight, comprises the following raw materials: 100 parts of formula (I) bio-based epoxy resin, 15 parts of cystine, 2 parts of 2-ethyl-4-methylimidazolium (curing accelerator), and 0.5 parts of di-tert-butyl peroxide (initiator). The preparation method is as follows:

[0049] S1. Preparation of premix: Add the bio-based epoxy resin of formula (Ⅰ) to a high-speed mixer and stir at 800 rpm for 10-15 min at 50℃; add the bio-based curing agent, curing accelerator and initiator to the premix in sequence and stir at 1200 rpm for 15 min until uniform; ultrasonically disperse at 400W for 10 min to obtain the premix.

[0050] S2. Curing and molding: Pour the premix into a mold preheated to 70°C, pre-cur at 70°C for 1.5 hours, then cure at 140°C for 7 hours. After cooling to room temperature, demold to obtain the final product.

[0051] Example 2-3

[0052] Compared with Example 1, Examples 2-3 differ only in the amount of raw materials used; the preparation methods and parameters are exactly the same.

[0053] Comparative Example 1

[0054] Comparative Example 1 differs from Example 1 only in that no initiator was added; the preparation method and parameters are exactly the same.

[0055] Comparative Example 2

[0056] Comparative Example 2 differs from Example 1 only in that no curing agent was added; the preparation method and parameters are exactly the same.

[0057] Comparative Example 3

[0058] Comparative Example 3 differs from Example 1 only in that the bio-based epoxy resin of Formula (I) is replaced with commercially available castor oil-based epoxy resin and cystine is replaced with 1,4-butanediamine (curing agent). The preparation methods and parameters are exactly the same.

[0059] Comparative Example 4

[0060] Comparative Example 4 differs from Example 1 in that cystine is replaced with 1,4-butanediamine (curing agent), while the preparation method and parameters are exactly the same.

[0061] Table 1. Raw material composition (parts by weight) for the examples and comparative examples.

[0062]

[0063]

[0064] Performance testing of materials prepared in the examples and comparative examples

[0065] The test was conducted in accordance with GB / T1040.1-2018 "Determination of Tensile Properties of Plastics" to determine the elongation at break.

[0066] The Shore A hardness was determined according to GB / T531.1-2008 "Indentation Hardness Tests for Vulcanized Rubber or Thermoplastic Rubber - Part 1: Shore Hardness Tester Method".

[0067] Test bending strength according to GB / T9341-2008, and test notched impact strength according to GB / T1043.1-2008.

[0068] The sample was buried in humus soil (temperature 25℃, humidity 60%), and the residual mass was measured every 18 months. The degradation rate was calculated as follows: Degradation rate = (initial mass - residual mass) / initial mass × 100%.

[0069] Table 2 Performance Test Results

[0070]

[0071] According to the data in the table above: 1) The elongation at break of the environmentally friendly bio-based epoxy resin composites prepared in Examples 1-3 ranged from 138.39% to 251.41%, and the tensile strength ranged from 98.64 to 123.51 MPa. Compared with Comparative Example 1, the environmentally friendly bio-based epoxy resin composites prepared in Comparative Example 1 only underwent a curing reaction. The epoxy-amine crosslinking network formed by the curing reaction is a rigid connection, so the elongation at break is significantly lower than that of Example 1. Compared with Comparative Example 2, the environmentally friendly bio-based epoxy resin composites prepared in Comparative Example 2 only underwent a free radical polymerization reaction of double bonds. The double bond polymerization introduces flexible carbon chains, forming a tight and partially flexible crosslinking network, thus exhibiting properties similar to rubber materials and greatly improving the elongation at break of the material. The environmentally friendly bio-based epoxy resin composites of Examples 1-3 possess both a rigid epoxy-amine crosslinking network and a flexible crosslinking network formed by double bond polymerization. Therefore, Examples 1-3 combine the rigidity of epoxy resin materials with sufficient flexibility, expanding the application range of the materials. Compared to Example 1, Comparative Example 3 replaced the formula (I) bio-based epoxy resin with commercially available castor oil-based epoxy resin. Although both castor oil-based epoxy resin and formula (I) bio-based epoxy resin belong to the castor oil-based epoxy resin family, formula (I) bio-based epoxy resin has a more complex spatial structure than castor oil-based epoxy resin, which has a relatively linear molecular structure. Therefore, the material prepared in Comparative Example 3 is difficult to form a relatively loose interpenetrating cross-linked network, resulting in insufficient flexibility. Compared to Example 1, Comparative Example 4 replaced cystine with 1,4-butanediamine (curing agent), resulting in a significant decrease in elongation at break. This may be because cystine is a bio-based curing agent with disulfide bonds, which can provide dynamic cross-linking bonds for the cured environmentally friendly bio-based epoxy resin composite material, enabling the material to have self-healing capabilities. 2) The environmentally friendly bio-based epoxy resin composites prepared in Examples 1-3 have a flexural strength ranging from 118.54 to 138.49 MPa and a notched impact strength ranging from 12.43 to 14.38 kJ / m. 2The hardness ranged from 79.1 to 93.5, showing a significant improvement compared to Comparative Examples 1-3. This indicates that the bio-based epoxy resin of Formula (I) and the cystine curing agent in the examples can effectively improve the flexibility and anti-brittleness of the material through rigid crosslinking of epoxy-amine and flexible crosslinking of double bond polymerization. 3) The degradation rate of the environmentally friendly bio-based epoxy resin composites prepared in Examples 1-3 after 18 months ranged from 57.2% to 67.8%, indicating that the environmentally friendly bio-based epoxy resin composites prepared in Examples 1-3 have good degradation performance under natural conditions, meeting the requirements of environmental protection. Although the degradation rate of Example 1 after 18 months decreased compared to Comparative Examples 1 and 2, this is because the environmentally friendly bio-based epoxy resin composites prepared in Example 1 have a higher crosslinking density. Secondly, Comparative Examples 1 and 2 also used the bio-based epoxy resin of Formula (I) provided by this invention, and their high degradation rate also indicates that the bio-based epoxy resin of Formula (I) provided by this invention has excellent degradation performance. The degradation rate of Example 1 was significantly higher than that of Comparative Example 4, indicating that the bio-based curing agent cystine used in Example 1 can significantly improve the degradation rate of the material.

[0072] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. An environmentally friendly bio-based epoxy resin composite material, characterized in that, The preparation materials, by weight, include the following: 100 parts of bio-based epoxy resin, 10-30 parts of bio-based curing agent, 0.5-3 parts of curing accelerator, and 0.01-1 parts of initiator; wherein the bio-based curing agent is cystine; and the curing accelerator is 2-ethyl-4-methylimidazole. The bio-based epoxy resin has structural formula (Ⅰ): （Ⅰ）。 2. The environmentally friendly bio-based epoxy resin composite material according to claim 1, by weight, comprises the following raw materials: 100 parts of bio-based epoxy resin matrix, 10-20 parts of bio-based curing agent, 1-2 parts of curing accelerator, and 0.1-0.5 parts of initiator.

3. The environmentally friendly bio-based epoxy resin composite material according to claim 1, characterized in that, The preparation method of the bio-based epoxy resin of formula (I) is as follows: S1: Add ricinoleic acid and resveratrol to toluene, add dicyclohexylcarbodiimide DCC, heat and reflux at 80-120℃ for 3-8h, purify, dry, and obtain ricinoleic acid resveratrol ester. S2: Add resveratrol ricinoleate and BF3-Et2O to the solvent toluene. Under heating conditions of 50-70℃, slowly add epichlorohydrin (ECH) while stirring, and react at a constant temperature for 3-9 hours. Cool down to 30-45℃, then add tetramethylammonium chloride catalyst and sodium hydroxide powder. Stir at a constant temperature for 1-3 hours. After the reaction is completed, purify, concentrate, and dry to obtain the bio-based epoxy resin of formula (Ⅰ).

4. The environmentally friendly bio-based epoxy resin composite material according to claim 3, characterized in that, The molar ratio of ricinoleic acid to resveratrol in step S1 is 3:(0.7-1.1).

5. The environmentally friendly bio-based epoxy resin composite material according to claim 3, characterized in that, The molar ratio of ricinoleic acid and dicyclohexylcarbodiimide used in step S1 is 1:(0.8-1.3).

6. The environmentally friendly bio-based epoxy resin composite material according to claim 3, characterized in that, The weight ratio of resveratrol ricinoleate, BF3-Et2O, tetramethylammonium chloride catalyst, and sodium hydroxide in step S2 is 100:(0.1-1):(0.01-1):(0.1-1).

7. An environmentally friendly biomimetic handicraft, characterized in that, The raw materials for its preparation include the environmentally friendly bio-based epoxy resin composite material as described in any one of claims 1-6.

8. The environmentally friendly biomimetic handicraft according to claim 7, characterized in that, The design of the handicraft is selected from at least one of plant biomimetic parts and animal biomimetic parts.

Images