Modified starch-light rare earth complex, rubber composite material containing modified starch-light rare earth complex as well as preparation method and application of modified starch-light rare earth complex
Through the preparation method of modified starch-light rare earth complex, the problem of poor dispersion and compatibility of starch in rubber is solved, the vulcanization rate and mechanical properties of rubber composites are improved, and the application form of starch in rubber is expanded.
Patent Information
- Application Number
- CN202510438147.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-09
- Publication Date
- 2025-07-18
AI Technical Summary
The poor dispersion and compatibility of starch in rubber lead to low mechanical properties and processing properties of rubber composites.
By using the preparation method of modified starch-light rare earth complex, the modified starch-light rare earth complex is formed by coordinating the light rare earth compound with modified starch and alkaline silica under alkaline conditions, and mixed with white carbon black to serve as fillers for rubber composites to enhance its dispersion and interface effect.
The vulcanization rate and mechanical properties of rubber materials, such as tensile strength and tear strength, enhance the dispersion of white carbon black and the interface effect of the rubber matrix, and improve the overall performance of the material.
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Abstract
Description
Technical Field
[0001] This application relates to the technical field of rubber composites, and particularly relates to a modified starch-light rare earth complex, a rubber composite containing the same, and a preparation method and application thereof. Background Art
[0002] As a natural, renewable, and low-cost material, starch has broad application prospects in the rubber industry. Starch itself has relatively large particles, high crystallinity, and is prone to agglomeration, and has poor compatibility with rubber. Therefore, it needs to be modified to improve its dispersibility and performance in rubber. Modified starch can be used as a reinforcing agent for rubber to improve the mechanical properties of rubber.
[0003] Common modification methods include gelatinization, esterification, oxidation, and graft modification, etc. For example, by gelatinization pretreatment, single helix structure modification, and ultra-high pressure homogenization treatment, hollow nano-starch with high cavities can be prepared. This modified starch has excellent free radical scavenging ability and dispersibility, and can significantly improve the aging resistance of rubber. Research shows that after adding modified starch, the tensile strength, modulus at a specified elongation, and tear strength of rubber are significantly improved. At the same time, starch can reduce the viscosity of rubber, making it easier to process, and reducing energy consumption during the production process. As a natural and biodegradable material, starch can replace some traditional reinforcing agents such as carbon black or silica, reduce the production cost of rubber products, and reduce the impact on the environment. In addition, after starch is compounded with rubber, a material with a certain network structure can be formed. The starch / rubber composite material prepared by methods such as blending and co-condensation not only retains the elasticity of rubber, but also significantly improves its wear resistance, fatigue resistance, and tear resistance.
[0004] However, starch is a natural polymer material, and there are significant differences in its molecular structure from rubber, resulting in poor compatibility between the two. During the mixing process, starch particles are difficult to be uniformly dispersed in the rubber matrix and are prone to agglomeration, which affects the overall performance of the composite material. Moreover, the interfacial interaction between starch and rubber is weak, and it is difficult to form good chemical bonding or physical entanglement. This makes the starch particles easy to fall off or separate from the rubber matrix during rubber processing and use, resulting in a decline in mechanical properties. In addition, large-sized starch particles are difficult to be fully dispersed in the rubber matrix and are prone to form stress concentration points, reducing the mechanical strength of the material. The dispersion uniformity of starch is difficult to control. Even using methods such as mechanical stirring and grinding, it is difficult to completely eliminate the agglomeration of starch particles, which makes the performance of the rubber composite material vary at different positions, affecting its consistency and reliability. The above defects greatly limit the application of starch in rubber.
[0005] Coordination compounds are also widely used in rubber. Researchers usually select appropriate ligands according to the desired properties, and then combine the ligands with the central principle through coordination reactions to form coordination compounds. In terms of enhancing the mechanical properties of rubber, the formation of coordination bonds between metal ions and functional groups in rubber can significantly improve the tensile strength, modulus, and heat resistance of rubber. Using coordination compounds as interfacial enhancers can improve the compatibility between rubber and fillers (such as lignin), promote the uniform dispersion of fillers, and thus enhance the overall performance of the composite material.
[0006] Based on this, the development of starch-based coordination compounds for enhancing the mechanical and processing properties of rubber is of great significance. Summary of the Invention
[0007] This application provides a modified starch-light rare earth complex, a rubber composite material containing the same, and its preparation method and application, aiming to solve the technical problems of poor dispersion of existing starch additives in rubber and poor compatibility with rubber, resulting in low mechanical and processing properties of starch-rubber composite materials.
[0008] To achieve the above object, this application adopts the following technical solutions.
[0009] In the first aspect of this application, a modified starch-light rare earth complex is provided, which has the chemical structure shown in formula (1):
[0010]
[0011] Wherein, R is La or Ce; x + y - z = 3.
[0012] In the second aspect of this application, a preparation method of the above-mentioned modified starch-light rare earth complex is provided, including:
[0013] Uniformly dispersing a light rare earth compound and a ligand in a solvent, and performing a coordination reaction under alkaline conditions to obtain a modified starch-light rare earth complex;
[0014] The ligand includes modified starch and alkalized silica.
[0015] Preferably, the light rare earth compound includes lanthanum chloride or cerium chloride;
[0016] The solvent is deionized water.
[0017] Preferably, the modified starch is prepared by the following method: dispersing starch in water to obtain a suspension; adding a sodium hydroxide solution to the suspension and stirring evenly to obtain a homogeneous yellow solution; drying the homogeneous yellow solution to obtain the modified starch; wherein, the mass ratio of starch to sodium hydroxide is (4 - 5):1;
[0018] and / or
[0019] The alkalized silica is prepared by reacting precipitated silica with a sodium hydroxide solution; the mass ratio of precipitated silica to sodium hydroxide is 1.5:1.
[0020] Preferably, the mass ratio of the modified starch, alkalized silica and light rare earth compound is (0.44-1.74):(0.16-0.48):1.
[0021] Preferably, the temperature of the coordination reaction is 30°C to 90°C.
[0022] In the third aspect of the present application, there is provided an application of the above-mentioned modified starch-light rare earth complex or the modified starch-light rare earth complex prepared by the above-mentioned preparation method in a rubber composite material.
[0023] In the fourth aspect of the present application, there is provided a rubber composite material, which is prepared by the following method:
[0024] Mix the above-mentioned modified starch-light rare earth complex and precipitated silica evenly to obtain a mixed filler;
[0025] Thin-pass styrene-butadiene rubber on an open mill, then add a vulcanization activator, mixed filler, vulcanization accelerator, antioxidant for mixing, and then press into a raw rubber sheet;
[0026] Vulcanize the raw rubber sheet to obtain a rubber composite material.
[0027] Preferably, the vulcanization activator includes zinc oxide and stearic acid;
[0028] The mass ratio of styrene-butadiene rubber, zinc oxide, stearic acid, vulcanization accelerator, antioxidant, precipitated silica and modified starch-light rare earth complex is 100:5:2:2:2:30:(1-10).
[0029] Preferably, the temperature of the mixing is 20-60°C;
[0030] and / or
[0031] The temperature of the vulcanization treatment is 150-180°C, and the pressure of the vulcanization treatment is 10-20 MPa.
[0032] Compared with the prior art, the beneficial effects of the present application are:
[0033] The modified starch-rare earth complex of the present application can improve the vulcanization rate and vulcanization properties of rubber materials, and can also improve the mechanical properties such as tensile strength and tear strength of rubber materials. Specifically, the modified starch-rare earth complex of the present application is an amphiphilic molecule. Its polar end has a strong interaction with silica, and the non-polar end, after modification and coordination with rare earth atoms, destroys the regularity of starch molecules, thereby reducing the crystallization of starch molecular chains, enabling the non-polar end to be better dispersed in the rubber matrix. Its special molecular structure can bind to a part of silica through the polar end, serving as the "seed" of silica aggregates, or several polar ends are distributed at the two-phase interface of silica aggregates to form a "coat"; the former can reduce the size of silica agglomerates and thus improve the dispersibility of silica, and the latter can enhance the interfacial interaction between silica and the rubber matrix, improving the mechanical properties of rubber composites.
[0034] The present application improves the dispersibility of starch in styrene-butadiene rubber through starch modification and coordination methods, solves the problem of difficult dispersion of starch in the rubber matrix, and expands the application form of starch in rubber. Brief Description of the Drawings
[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for description in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments recorded in the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.
[0036] Figure 1 Infrared spectra of the modified starch-light rare earth complexes prepared for Examples 1-5 and Comparative Example 1;
[0037] Figure 2 Vulcanization curves of the rubber composites of Application Examples 1-5 and Application Comparative Examples 1-4. Detailed Embodiments
[0038] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.
[0039] In the following description of the present embodiment, terms such as "include", "comprise", "have" and "contain" are all open-ended terms, meaning including but not limited to.
[0040] In the following description of this embodiment, the term "and / or" is used to describe the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, B exists alone, and the situation where A and B exist simultaneously. Wherein A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship.
[0041] In the following description of this embodiment, the term "at least one" means one or more, and "a plurality" means two or more. "At least one of the following" or its similar expressions refer to any combination of these items, including any combination of single item(s) or plural item(s). For example, "at least one of a, b, or c", or "at least one of a, b, and c" can both represent: a, b, c, a - b (that is, a and b), a - c, b - c, or a - b - c, where a, b, and c can be single or plural respectively.
[0042] The terms used in the embodiments of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The singular forms "a" and "the" used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.
[0043] Those skilled in the art should understand that in the following description of the embodiments of this application, the sequence numbers do not mean the order of execution. Some or all of the steps can be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of this application.
[0044] Those skilled in the art should understand that the numerical range in the embodiments of this application should be understood as specifically disclosing each intermediate value between the upper and lower limits of the range. The intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or the intermediate value within the stated range, is also included in this application. The upper and lower limits of these smaller ranges can be independently included or excluded from the range.
[0045] Unless otherwise specified, the technical / scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which this application belongs. Although this application only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein can also be used in the implementation or testing of this application. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In case of conflict with any incorporated document, the content of this specification shall prevail.
[0046] In a first aspect, the present application provides a modified starch-light rare earth complex, which has a chemical structure shown in formula (1):
[0047]
[0048] wherein R is La or Ce; x + y - z = 3.
[0049] The preparation method of the modified starch-light rare earth complex includes:
[0050] Uniformly dispersing a light rare earth compound and a ligand in a solvent, and performing a coordination reaction under alkaline conditions to obtain a modified starch-light rare earth complex;
[0051] The ligand includes modified starch and alkalized silica.
[0052] In the present application, the light rare earth compound includes lanthanum chloride or cerium chloride, such as any one of anhydrous lanthanum chloride, lanthanum chloride trihydrate or lanthanum chloride hexahydrate, or any one of anhydrous cerium chloride, cerium chloride hexahydrate or cerium chloride heptahydrate, preferably cerium chloride heptahydrate. The solvent is deionized water.
[0053] In the present application, the coordination reaction can be carried out by uniformly dispersing a light rare earth compound and a ligand in a solvent, or by separately preparing a light rare earth compound solution, a modified starch solution and alkalized silica, and then mixing them for a coordination reaction.
[0054] Specifically, the modified starch is prepared by the following method: dispersing starch in water to obtain a suspension, where the mass-volume ratio of starch to water is 0.21 - 0.44 g / mL; adding a sodium hydroxide solution to the suspension and stirring evenly to obtain a homogeneous yellow solution, i.e., a modified starch solution, where the concentration of the sodium hydroxide solution is 12 - 33 wt%; the mass ratio of starch to sodium hydroxide is (4 - 5):1, preferably 4.05:1. Drying the homogeneous yellow solution gives the modified starch.
[0055] The alkalized silica is prepared by reacting fumed silica with a sodium hydroxide solution, where the mass ratio of fumed silica to sodium hydroxide is 1.5:1 and the concentration of the sodium hydroxide solution is 7 - 20 wt%.
[0056] In the present application, preferably the mass ratio of the modified starch, alkalized silica and light rare earth compound is (0.44 - 1.74):(0.16 - 0.48):1; preferably the temperature of the coordination reaction is 30°C - 90°C and the reaction time is 2 - 120 min.
[0057] In the present application, preferably the solid-phase product of the coordination reaction is washed 2 - 5 times with deionized water and then dried at 30 - 90°C for 12 - 72 h to obtain the modified starch-light rare earth complex.
[0058] This application improves the dispersibility of starch in styrene-butadiene rubber through starch modification and coordination methods, solves the problem of difficult dispersion of starch in the rubber matrix, and expands the application form of starch in rubber.
[0059] The modified starch-light rare earth complex of this application has good reinforcing effect on rubber and can be used as a reinforcing agent to prepare rubber composites. It can improve the vulcanization rate and vulcanization properties of rubber materials, and can also improve the mechanical properties such as tensile strength and tear strength of rubber materials. The mechanism is that on the one hand, the modified starch-light rare earth complex of this application is an amphoteric molecule, and its polar end has strong interaction with silica, while the non-polar end destroys the regularity of starch molecules after modification and coordination with rare earth atoms, thereby reducing the crystallization of starch molecular chains, so that the non-polar end can be better dispersed in the rubber matrix.
[0060] On the other hand, the modified starch-light rare earth complex of this application can bind to a part of silica through its polar end, serving as the "seed" of silica aggregates, or several polar ends are distributed at the two-phase interface of silica aggregates to form an "outer coat"; the former can reduce the size of silica aggregates and thus improve the dispersibility of silica, and the latter can enhance the interfacial interaction between silica and the rubber matrix and improve the mechanical properties of rubber composites.
[0061] This application also provides a rubber composite material, which is prepared by the following method:
[0062] Mix the above-mentioned modified starch-light rare earth complex and silica evenly to obtain a mixed filler;
[0063] Thin-pass styrene-butadiene rubber on an open mill, then add a vulcanization activator, the mixed filler, a vulcanization accelerator, and an antioxidant for mixing, and then press into a raw rubber sheet;
[0064] Vulcanize the raw rubber sheet to obtain a rubber composite material.
[0065] In this application, the vulcanization activator includes zinc oxide and stearic acid; the vulcanization accelerator can be selected from N-cyclohexyl-2-benzothiazole sulfenamide (CZ) or other commercially available vulcanization accelerators; the antioxidant is selected from antioxidant 4020 or other commercially available rubber antioxidants.
[0066] In this application, preferably, the mass ratio of styrene-butadiene rubber, zinc oxide, stearic acid, vulcanization accelerator, antioxidant, silica, and modified starch-light rare earth complex is 100:5:2:2:2:30:(1-10).
[0067] In this application, the temperature of the mixing is 20-60°C; after the raw rubber sheet obtained by mixing is parked for 12-24 hours, vulcanization is carried out. The temperature of the vulcanization treatment is 150-180°C, preferably 160°C; the pressure of the vulcanization treatment is 10-20 MPa, and the vulcanization treatment time is 5-20 minutes.
[0068] The rubber composite material of this application has high tensile strength, tear strength, fast vulcanization rate and good vulcanization performance.
[0069] The following further illustrates this application through examples.
[0070] Example 1
[0071] This application provides a preparation method of a modified starch-light rare earth complex, including:
[0072] S1. At room temperature, add 32.4 g of starch to 150 ml of deionized water, and stir to disperse it into a suspension; dissolve 8 g of sodium hydroxide in 50 ml of deionized water, add this sodium hydroxide solution to the starch suspension and stir to obtain a homogeneous yellow solution, that is, a modified starch solution, denoted as solution A;
[0073] Dissolve 16 g of sodium hydroxide in 100 ml of deionized water, then add 24 g of silica white, heat up to 80°C and react for 15 minutes until the silica white dissolves to obtain a colorless and clear solution, that is, alkalized silica, denoted as solution B;
[0074] Dissolve 74.4 g of cerium chloride heptahydrate in 50 ml of deionized water to obtain a light yellow solution, denoted as solution C;
[0075] S2. Heat solution A to 80°C, add solution B, and keep warm for 5 minutes; then add solution C and react for 5 minutes. Centrifuge to separate the white solid in the reaction solution, and wash it with deionized water until the washing liquid changes from a light white turbid liquid to a clear and transparent liquid. Dry the washed solid at 60°C for 72 hours to obtain a modified starch-light rare earth complex.
[0076] Example 2
[0077] This application provides a preparation method of a modified starch-light rare earth complex, including:
[0078] S1. At room temperature, add 64.8 g of starch to 150 ml of deionized water, and stir to disperse it into a suspension; dissolve 16 g of sodium hydroxide in 50 ml of deionized water, add this sodium hydroxide solution to the starch suspension and stir to obtain a homogeneous yellow solution, that is, a modified starch solution, denoted as solution A;
[0079] Dissolve 8 g of sodium hydroxide in 100 ml of deionized water, then add 12 g of silica white, heat up to 85 °C and react for 10 min until the silica white dissolves to obtain a colorless and clear solution, namely alkalized silica, denoted as solution B;
[0080] Dissolve 74.4 g of cerium chloride heptahydrate in 50 ml of deionized water to obtain a light yellowish solution, denoted as solution C;
[0081] S2. Heat solution A to 80 °C, add solution B, and keep warm for 5 min; then add solution C and react for 10 min. Centrifuge to separate the white solid in the reaction solution, and wash it with deionized water until the washing liquid changes from a faintly white turbid liquid to a clear and transparent liquid. Dry the washed solid at 60 °C for 72 h to obtain the modified starch-light rare earth complex.
[0082] Example 3
[0083] This application provides a preparation method of a modified starch-light rare earth complex, including:
[0084] S1. At room temperature, add 29.35 g of starch to 100 ml of deionized water, and stir to disperse it into a suspension; dissolve 7.25 g of sodium hydroxide in 50 ml of deionized water, add this sodium hydroxide solution to the starch suspension and stir to obtain a homogeneous yellow solution, namely the modified starch solution, denoted as solution A;
[0085] Dissolve 21.74 g of sodium hydroxide in 100 ml of deionized water, then add 32.61 g of silica white, heat up to 80 °C and react for 20 min until the silica white dissolves to obtain a colorless and clear solution, namely alkalized silica, denoted as solution B;
[0086] Dissolve 67.4 g of cerium chloride heptahydrate in 50 ml of deionized water to obtain a light yellowish solution, denoted as solution C;
[0087] S2. Heat solution A to 80 °C, add solution B, and keep warm for 5 min; then add solution C and react for 10 min. Centrifuge to separate the white solid in the reaction solution, and wash it with deionized water until the washing liquid changes from a faintly white turbid liquid to a clear and transparent liquid. Dry the washed solid at 60 °C for 72 h to obtain the modified starch-light rare earth complex.
[0088] Example 4
[0089] This application provides a preparation method of a modified starch-light rare earth complex, including:
[0090] S1. At room temperature, add 64.8 g of starch to 100 ml of deionized water and stir to disperse it into a suspension; dissolve 16 g of sodium hydroxide in 50 ml of deionized water, add this sodium hydroxide solution to the starch suspension and stir to obtain a homogeneous yellow solution, namely the modified starch solution, denoted as solution A;
[0091] Dissolve 24 g of sodium hydroxide in 100 ml of deionized water, then add 16 g of silica white, heat up to 80 °C and react for 20 min until the silica white dissolves to obtain a colorless and clear solution, namely the alkalized silica, denoted as solution B;
[0092] Dissolve 74.4 g of cerium chloride heptahydrate in 50 ml of deionized water to obtain a light yellow solution, denoted as solution C;
[0093] S2. Heat solution A to 80 °C, add solution B, and keep warm for 5 min; then add solution C and react for 15 min. Centrifuge to separate the white solid in the reaction solution and wash it with deionized water until the washing liquid changes from a light white turbid liquid to a clear and transparent liquid. Dry the washed solid at 60 °C for 72 h to obtain the modified starch-light rare earth complex.
[0094] Example 5
[0095] This application provides a preparation method of a modified starch-light rare earth complex, including:
[0096] S1. At room temperature, add 97.2 g of starch to 100 ml of deionized water and stir to disperse it into a suspension; dissolve 24 g of sodium hydroxide in 50 ml of deionized water, add this sodium hydroxide solution to the starch suspension and stir to obtain a homogeneous yellow solution, namely the modified starch solution, denoted as solution A;
[0097] Dissolve 12 g of sodium hydroxide in 100 ml of deionized water, then add 8 g of silica white, heat up to 80 °C and react for 20 min until the silica white dissolves to obtain a colorless and clear solution, namely the alkalized silica, denoted as solution B;
[0098] Dissolve 74.4 g of cerium chloride heptahydrate in 50 ml of deionized water to obtain a light yellow solution, denoted as solution C;
[0099] S2. Heat solution A to 70 °C, add solution B, and keep warm for 5 min; then add solution C and react for 120 min. Centrifuge to separate the white solid in the reaction solution and wash it with deionized water until the washing liquid changes from a light white turbid liquid to a clear and transparent liquid. Dry the washed solid at 60 °C for 72 h to obtain the modified starch-light rare earth complex.
[0100] Comparative Example 1
[0101] S1. At room temperature, add 32.4 g of starch to 150 ml of deionized water, and stir to disperse it into a suspension; dissolve 8 g of sodium hydroxide in 50 ml of deionized water, add this sodium hydroxide solution to the starch suspension and stir to obtain a homogeneous yellow solution, namely the modified starch solution, denoted as solution A;
[0102] Dissolve 74.4 g of cerium chloride heptahydrate in 50 ml of deionized water to obtain a beige solution, denoted as solution C;
[0103] S2. Heat solution A to 80 °C, add solution C, and react for 5 min. Centrifuge to separate the white solid in the reaction solution, and wash it with deionized water until the washing liquid changes from a light white turbid liquid to a clear and transparent liquid. Dry the washed solid at 60 °C for 72 h to obtain the modified starch-light rare earth complex.
[0104] Test the infrared spectra of the modified starch-light rare earth complexes prepared in Examples 1-5 and Comparative Example 1, and compare them with the unmodified starch. The results are as Figure 1 shown. It can be seen from Figure 1 that compared with the unmodified starch, the relevant infrared absorption peaks of the modified starch-light rare earth complex have obvious displacements, and an Si-O absorption peak appears in the infrared spectrum of the modified starch-light rare earth complex, proving that the modified starch-light rare earth complex is successfully prepared.
[0105] Prepare rubber composites from the modified starch-light rare earth complexes prepared in Examples 1-3 as follows:
[0106] Application Example 1
[0107] The raw materials of the rubber composite, by mass, include:
[0108] 100 parts of styrene-butadiene rubber 1502, 5 parts of zinc oxide, 2 parts of stearic acid, 2 parts of N-cyclohexyl-2-benzothiazole sulfenamide, 2 parts of antioxidant 4020, 30 parts of white carbon black, and 1 part of the modified starch-light rare earth complex of Example 1.
[0109] Mix the modified starch-light rare earth complex and white carbon black evenly to obtain a mixed filler; first, thin-pass styrene-butadiene rubber 1502 on a two-roll mill 2-3 times, and then sequentially add zinc oxide and stearic acid, the mixed filler, N-cyclohexyl-2-benzothiazole sulfenamide, and antioxidant 4020. After all the materials are added, make 3 triangular bales and 3 rolls, and finally press into a film. Let the raw film stand for 16 h and carry out vulcanization treatment. The vulcanization treatment temperature is 160 °C, the pressure is 10 MPa, and the time is 10 min; the rubber composite is obtained after vulcanization treatment.
[0110] Application Example 2
[0111] In Application Example 2, compared with Application Example 1, the dosage of the modified starch-light rare earth complex is 5 parts, and the rest are the same as those in Application Example 1.
[0112] Application Example 3
[0113] In Application Example 3, compared with Application Example 1, the dosage of the modified starch-light rare earth complex is 10 parts, and the rest are the same as those in Application Example 1.
[0114] Application Example 4
[0115] In Application Example 4, compared with Application Example 1, the modified starch-light rare earth complex prepared in Example 2 is used, and its dosage is 5 parts, and the rest are the same as those in Application Example 1.
[0116] Application Example 5
[0117] In Application Example 5, compared with Application Example 1, the modified starch-light rare earth complex prepared in Example 3 is used, and its dosage is 5 parts, and the rest are the same as those in Application Example 1.
[0118] Application Comparative Example 1
[0119] In Application Comparative Example 1, compared with Application Example 1, there is no modified starch-light rare earth complex, and the rest are the same as those in Application Example 1.
[0120] Application Comparative Example 2
[0121] In Application Comparative Example 2, compared with Application Example 1, the modified starch-light rare earth complex prepared in Comparative Example 1 is used, and the rest are the same as those in Application Example 1.
[0122] Application Comparative Example 3
[0123] In Application Comparative Example 3, compared with Application Example 1, the modified starch-light rare earth complex prepared in Comparative Example 1 is used, and its dosage is 5 parts, and the rest are the same as those in Application Example 1.
[0124] Application Comparative Example 4
[0125] In Application Comparative Example 4, compared with Application Example 1, the modified starch-light rare earth complex prepared in Comparative Example 1 is used, and its dosage is 10 parts, and the rest are the same as those in Application Example 1.
[0126] The vulcanization curves of the rubber composites of Application Examples 1-5 and Application Comparative Examples 1-4 were tested, and the results are as Figure 2 shown. It can be seen from Figure 2 that compared with Application Comparative Example 1, Application Examples 1-5 show that the modified starch-light rare earth complex can improve the vulcanization rate of rubber and increase the torque of the vulcanizate. Compared with Application Comparative Examples 2-4, the vulcanization performance of the modified starch-light rare earth complex containing alkalized silica is better.
[0127] The mechanical properties of the rubber composites of Test Application Examples 1-5 and Application Comparative Examples 1-4 were tested, and the test results are shown in Table 1.
[0128] Table 1 Mechanical property data of rubber composites
[0129]
[0130]
[0131] As can be seen from Table 1, the modified starch-light rare earth complex of the present application has a better reinforcing effect on rubber. The rubber composite containing the modified starch-light rare earth complex of the present application has better tensile stress, tensile strength and tear strength compared with Application Comparative Example 1.
[0132] From the test results of Test Application Examples 1-5 and Application Comparative Examples 2-4, it can be seen that the modified starch-light rare earth complexes of Application Comparative Examples 2-4 do not contain alkalized silica, and their reinforcing effect on rubber is lower than that of the modified starch-light rare earth complex containing alkalized silica in the present application. The definite elongation stress, tensile strength and tear strength of the rubber composites reinforced by them are all lower than those of the rubber composites reinforced by the modified starch-light rare earth complex of the present application. This is because the modified starch-light rare earth complex without alkalized silica does not contain polar ends, and its combination with silica is not good, making it difficult to improve the dispersion of silica and the interfacial interaction between silica and the rubber matrix, and the improvement effect on the mechanical properties of rubber composites is not good.
[0133] As the dosage of the modified starch-light rare earth complex increases, as shown in Test Application Examples 1-3, the definite elongation stress and tear strength of the rubber composite gradually increase, while the tensile strength and elongation at break first increase and then decrease. When the addition amount of the modified starch-light rare earth complex is 5 parts, the rubber composite has the best comprehensive performance.
[0134] Although the present application has been described in detail with general descriptions and specific implementation examples in this specification, based on the present application, some modifications or improvements can be made, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present application all fall within the scope claimed by the present application.
Claims
1. A modified starch-light rare earth complex, characterized in that, It has the chemical structure shown in formula (1): wherein, R is La or Ce; x + y - z = 3.
2. The preparation method of the modified starch-light rare earth complex according to claim 1, characterized in that, It includes:[[]] Uniformly dispersing a light rare earth compound and a ligand in a solvent, and carrying out a coordination reaction under alkaline conditions to obtain a modified starch-light rare earth complex; The ligand includes modified starch and alkalized silica.
3. The preparation method according to claim 2, characterized in that, The light rare earth compound includes lanthanum chloride or cerium chloride; The solvent is deionized water.
4. The preparation method according to claim 2, wherein: The modified starch is prepared by the following method: dispersing starch in water to obtain a suspension; adding a sodium hydroxide solution to the suspension and stirring evenly to obtain a homogeneous yellow solution; drying the homogeneous yellow solution to obtain the modified starch; wherein, the mass ratio of starch to sodium hydroxide is (4 - 5):1; and / or The alkalized silica is prepared by reacting silica white with a sodium hydroxide solution; the mass ratio of silica white to sodium hydroxide is 1.5:
1.
5. The preparation method according to claim 2, characterized in that, The mass ratio of the modified starch, alkalized silica and light rare earth compound is (0.44 - 1.74):(0.16 - 0.48):
1.
6. The preparation method according to claim 2, wherein The temperature of the coordination reaction is 30°C to 90°C.
7. Use of the modified starch-light rare earth complex according to claim 1 or the modified starch-light rare earth complex prepared by the preparation method according to claim 2 in a rubber composite material.
8. A rubber composite material, characterized in that, It is prepared by the following method: Mixing the modified starch-light rare earth complex according to claim 1 evenly with silica white to obtain a mixed filler; Thin-pass styrene-butadiene rubber on an open mill, then add a vulcanization activator, the mixed filler, a vulcanization accelerator, and an antioxidant for mixing, and then press into a raw rubber sheet; Carrying out vulcanization treatment on the raw rubber sheet to obtain a rubber composite material.
9. The rubber composite material according to claim 8, wherein The vulcanization activator includes zinc oxide and stearic acid; The mass ratio of styrene-butadiene rubber, zinc oxide, stearic acid, vulcanization accelerator, antioxidant, silica white and modified starch-light rare earth complex is 100:5:2:2:2:30:(1 - 10).
10. The rubber composite material according to claim 8, characterized in that, The temperature of the mixing is 20 - 60°C; and / or The temperature of the vulcanization treatment is 150 - 180°C, and the pressure of the vulcanization treatment is 10 - 20 MPa.