Preparation method of high-strength rosin elastomer

Abstract

The invention discloses a preparation method of a high-strength rosin elastomer, which is characterized in that pyromellitic acid is used as a ring opening agent, maleated rosin is used as a cross-linking agent, and epoxidized soybean oil is subjected to ring opening polymerization and is cross-linked with the maleated rosin to form a firm three-dimensional network structure, so that the high-strength rosin elastomer is obtained. The method is simple in process and easy to operate, the raw materials are derived from biomass, the cost is low, and the method is green and environment-friendly, and the prepared rosin elastomer is high in elasticity, good in stability, high in mechanical strength, biodegradable, good in water resistance and good in application prospect.

Description

Technical Field

[0001] The invention belongs to the field of natural polymer materials, and in particular relates to a method for preparing a high-strength rosin elastomer. Background Art

[0002] With the extensive use of synthetic polymers and the resulting problems of difficulty in degradation and environmental pollution, the use of natural renewable resources to prepare biodegradable polymer materials has become a hot topic in current basic research and applied research. Compared with traditional synthetic polymers, natural polymer materials have the advantages of low price, good biodegradability, non-toxicity, wide sources and renewable resources. Elastomers are highly praised for their unique elastic properties that can restore their original shape after deformation. Their applications cover various fields such as automobiles, industry, and medicine. However, the current development of elastomers faces multiple challenges, including the demand for sustainability, the necessity of performance improvement, the exploration of functional integration, the balance of cost-effectiveness, processing difficulties and the challenge of recycling and reuse. Therefore, it is necessary to build an elastomer with stable performance, green and environmentally friendly and recyclable. Summary of the invention

[0003] The purpose of the present invention is to provide a method for preparing a high-strength rosin elastomer in view of the shortcomings of the existing elastomer preparation process.

[0004] To achieve the above object, the present invention adopts the following technical solution: A high-strength rosin elastomer, the preparation method of which comprises the following steps: (1) Take maleic rosin and pyromellitic acid and add them to anhydrous ethanol respectively, heat them in a water bath until they are completely dissolved, and prepare maleic rosin solution and pyromellitic acid solution; (2) The maleic rosin solution and the pyromellitic acid solution prepared in step (1) are mixed evenly and then added to the epoxidized soybean oil. After stirring evenly, the mixture is heated in an oil bath to react and form a rosin-based elastomer.

[0005] Furthermore, in step (1), the water bath heating temperature is 50°C-70°C, and the heating time is 5 min-10 min.

[0006] Furthermore, the concentration of the maleic rosin solution obtained in step (1) is 0.05 g / mL-0.2 g / mL, and the concentration of the pyromellitic acid solution is 0.01 g / mL-0.1 g / mL.

[0007] Furthermore, the amounts of the maleic rosin solution and the pyromellitic acid solution in step (2) are converted according to a mass ratio of maleic rosin, pyromellitic acid and epoxidized soybean oil of 1:1:1-1:1:5.

[0008] Furthermore, the reaction temperature in step (2) is 90°C-150°C, and the reaction time is 2h-8h.

[0009] The invention uses maleic rosin, a natural extract, as a crosslinking agent and pyromellitic acid as a ring-opening agent, utilizes multiple carboxyl groups of pyromellitic acid to cause ring-opening polymerization of epoxy soybean oil, and crosslinks with maleic rosin to form a highly crosslinked network structure, thereby giving the elastomer higher strength and stability. Among them, the tricyclic phenanthrene rigid structure of maleic rosin can play the role of the elastomer skeleton, and pyromellitic acid can provide crosslinking stability and water resistance for the elastomer.

[0010] The significant advantages of the present invention are: (1) The process of the present invention is simple, easy to operate, and the raw materials are derived from biomass, which is low in cost and environmentally friendly; (2) The rosin elastomer prepared by the present invention has high mechanical strength, good water resistance and is biodegradable. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is the SEM image of the rosin elastomer obtained in Example 3.

[0012] Figure 2 1. The morphology comparison diagram of the rosin elastomer obtained in Example 3 before compression (a) and after compression (b). DETAILED DESCRIPTION

[0013] A high-strength rosin elastomer, the preparation of which comprises the following steps: (1) adding maleic rosin and pyromellitic acid to anhydrous ethanol respectively, and heating in a water bath at 50°C-70°C for 5 min-10 min until they are completely dissolved, thereby obtaining a maleic rosin solution with a concentration of 0.05 g / mL-0.2 g / mL and a pyromellitic acid solution with a concentration of 0.01 g / mL-0.1 g / mL; (2) The maleic rosin solution and the pyromellitic acid solution prepared in step (1) are mixed evenly in a mass ratio of maleic rosin, pyromellitic acid and epoxidized soybean oil of 1:1:1-1:1:5, and then added to the epoxidized soybean oil. After stirring evenly, the mixture is placed in an oil bath and heated at 90°C-150°C for 2h-8h to form a rosin-based elastomer.

[0014] In order to make the contents of the present invention easier to understand, the technical solution of the present invention is further described below in conjunction with specific implementation methods, but the present invention is not limited thereto.

[0015] Example 1 (1) Add 6 g of maleic rosin to 50 mL of anhydrous ethanol, and heat in a water bath at 60°C for 8 min until the maleic rosin is completely dissolved, to obtain a maleic rosin solution with a concentration of 0.12 g / mL; add 6 g of pyromellitic acid to 150 mL of anhydrous ethanol, and heat in a water bath at 60°C for 8 min until the pyromellitic acid is completely dissolved, to obtain a pyromellitic acid solution with a concentration of 0.04 g / mL; (2) The maleic rosin solution and the pyromellitic acid solution prepared in step (1) were added to 24 g of epoxidized soybean oil and mixed evenly. The mixture was then placed in an oil bath and heated at 100° C. for 3 h to obtain a rosin elastomer.

[0016] Example 2 (1) Add 10 g of maleic rosin to 50 mL of anhydrous ethanol, and heat in a water bath at 70°C for 5 min until the maleic rosin is completely dissolved, thereby obtaining a maleic rosin solution with a concentration of 0.2 g / mL; add 10 g of pyromellitic acid to 100 mL of anhydrous ethanol, and heat in a water bath at 70°C for 5 min until the pyromellitic acid is completely dissolved, thereby obtaining a pyromellitic acid solution with a concentration of 0.1 g / mL; (2) The maleic rosin solution and the pyromellitic acid solution prepared in step (1) are added to 30 g of epoxidized soybean oil and mixed evenly, and then placed in an oil bath and heated at 140° C. for 7 h to obtain a rosin elastomer.

[0017] Example 3 (1) Add 2.5 g of maleic rosin to 50 mL of anhydrous ethanol, and heat in a water bath at 50°C for 10 min until the maleic rosin is completely dissolved, to obtain a maleic rosin solution with a concentration of 0.05 g / mL; add 2.5 g of pyromellitic acid to 50 mL of anhydrous ethanol, and heat in a water bath at 50°C for 10 min until the pyromellitic acid is completely dissolved, to obtain a pyromellitic acid solution with a concentration of 0.05 g / mL; (2) The maleic rosin solution and the pyromellitic acid solution prepared in step (1) are added to 5 g of epoxidized soybean oil and mixed evenly. The mixture is then placed in an oil bath and heated at 120° C. for 5 h to obtain a rosin elastomer.

[0018] Figure 1 The SEM image of the obtained rosin elastomer is shown in Figure 1. As can be seen from the figure, the obtained rosin elastomer has a highly cross-linked network structure, which can give it higher strength and stability.

[0019] Figure 2 The morphology comparison diagram of the obtained rosin elastomer before (a) and after (b) compression at a pressure of 9MPa. As can be seen from the figure, the rosin elastomer bends and deforms after being compressed, and when the load is removed, the elastomer can return to its original shape, indicating that the mechanical properties of the rosin elastomer are good.

[0020] Comparative Example 1 (1) Add 6 g of maleic rosin to 50 mL of anhydrous ethanol and heat in a 60°C water bath for 8 min until the maleic rosin is completely dissolved to obtain a maleic rosin solution with a concentration of 0.12 g / mL; (2) Add the maleic rosin solution prepared in step (1) into 24 g of epoxidized soybean oil and mix well. Then place the mixture in an oil bath and heat at 100° C. for 3 h.

[0021] Comparative Example 2 (1) Add 6 g of rosin acid to 50 mL of anhydrous ethanol, heat in a water bath at 60°C for 8 min until the rosin acid is completely dissolved, and obtain a rosin acid solution with a concentration of 0.12 g / mL; add 6 g of pyromellitic acid to 150 mL of anhydrous ethanol, heat in a water bath at 60°C for 8 min until the pyromellitic acid is completely dissolved, and obtain a pyromellitic acid solution with a concentration of 0.04 g / mL; (2) Add the rosin acid solution and pyromellitic acid solution prepared in step (1) to 24 g of epoxidized soybean oil and mix well. Then place the mixture in an oil bath and heat at 100° C. for 3 h.

[0022] The tensile strength, compressive strength and water absorption rate of the samples prepared in the embodiment and the comparative example were tested respectively. The results are shown in Table 1.

[0023] Table 1 Performance test of different elastomers

[0024] As shown in Table 1, the tensile strength, compressive strength and water resistance of the rosin elastomer obtained in the examples are significantly better than those in the comparative examples, which is mainly because the pyromellitic acid and maleic rosin in the examples act together on the epoxidized soybean oil to synergistically enhance the mechanical properties and water resistance of the elastomer, among which Example 3 has the best effect. In Comparative Example 1, since there is no pyromellitic acid, the epoxidized soybean oil cannot be ring-opened for polymerization, resulting in the inability to form the product. The rosin acid used in Comparative Example 2 has only one carboxyl group in its structure, and its cross-linking effect with the epoxidized soybean oil and pyromellitic acid is weaker than that of maleic rosin, resulting in the mechanical properties and water resistance of the elastomer being worse than those in the examples.

[0025] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made according to the scope of the patent application of the present invention should fall within the scope of the present invention.

Claims

1. A method for preparing a high-strength rosin elastomer, characterized in that: The following steps are involved: (1) Take maleic rosin and pyromellitic acid and add them to anhydrous ethanol respectively, heat them in a water bath until they are completely dissolved, and prepare maleic rosin solution and pyromellitic acid solution; (2) The maleic rosin solution and the pyromellitic acid solution prepared in step (1) are mixed evenly and then added to the epoxidized soybean oil. After stirring evenly, the mixture is heated in an oil bath to react and form a rosin-based elastomer.

2. The method for preparing a high-strength rosin elastomer according to claim 1, characterized in that: The concentration of the maleic rosin solution obtained in step (1) is 0.05 g / mL-0.2 g / mL, and the concentration of the pyromellitic acid solution is 0.01 g / mL-0.1 g / mL.

3. The method for preparing a high-strength rosin elastomer according to claim 1, characterized in that: The amounts of the maleic rosin solution and the pyromellitic acid solution in step (2) are calculated based on the mass ratio of maleic rosin, pyromellitic acid and epoxidized soybean oil being 1:1:1-1:1:

5.

4. The method for preparing a high-strength rosin elastomer according to claim 1, characterized in that: The reaction temperature in step (2) is 90°C-150°C and the reaction time is 2h-8h.

5. A high-strength rosin elastomer obtained by the method according to any one of claims 1 to 4.

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