A polymer rubber stabilizer and preparation method thereof

Abstract

The invention discloses a polymer rubber stabilizer in the technical field of synthetic rubber and a preparation method thereof. The polymer rubber stabilizer is added in a rubber matrix in an amount of 5-7% by mass. The rubber stabilizer of the invention uses a fatty amine as a monomer compound, forms a polyamine compound, and is then compounded with silicon dioxide nanoparticles to form a rubber stabilizer. The macromolecular polyamine stabilizer is compounded with the silicon dioxide nanoparticles to improve the heat-oxidative aging resistance of the rubber, effectively alleviate the problem of rubber blooming, and improve the mechanical properties of the rubber. The stabilizer has a macromolecular structure, improves the compatibility of the stabilizer in the rubber, reduces the precipitation of the stabilizer in the rubber, and improves the aging resistance of the rubber composition.

Description

Technical Field

[0001] The invention belongs to the technical field of synthetic rubber, and specifically refers to a polymer rubber stabilizer and a preparation method thereof. Background Art

[0002] Rubber material is a renewable resource, widely used in aerospace, national defense science and technology, medical materials, automobile tires, daily products and other technical fields. In the process of production, transportation, storage and practical use, due to the influence of internal and external lunar calendar and its surrounding environment, the mechanical properties become unstable, such as cracking, hardening, etc., which belongs to the aging phenomenon of rubber. This is because the molecular chain of rubber contains more isolated C=C bonds and structures such as allylic hydrogen. Due to the presence of unsaturated groups, the material is easily affected by external effects such as heat, oxygen, light, stress and ozone, and ages. At the microscopic level, the rubber molecular chain undergoes physical or chemical changes, including molecular conformational changes, molecular chain slippage, molecular chain oxidation, molecular chain cross-linking or molecular chain degradation, which causes the performance of rubber products to change at the macro level, resulting in permanent deformation of the rubber; in rubber Adding additives during the synthesis process can effectively prevent rubber aging. There are many types of rubber antioxidants, which can play different roles in different stages of rubber aging, thereby slowing down the aging of rubber. Common rubber antioxidants include amine antioxidants and phenolic antioxidants, which can combine with peroxy radicals through the active hydrogen in the functional group, thereby destroying the chain growth process in the aging reaction and delaying the aging process; rubber has a high molecular network, and antioxidants generally have small molecules. Therefore, antioxidants have poor compatibility in rubber, resulting in high mobility of small molecule antioxidants in the rubber network, enrichment on the rubber surface, resulting in a "frost spraying" phenomenon, and reducing the anti-aging effect, but the migration of antioxidants in the rubber network is slow or does not occur, causing the antioxidants to stay inside the rubber molecules for a long time and aging of the rubber outer layer. Summary of the invention

[0003] In view of the above situation, in order to overcome the defects of the prior art, the present invention provides a polymer rubber stabilizer and a preparation method thereof. In order to solve the problem of rubber stability precipitation in rubber, the present invention uses fatty amine as a monomer compound to form a polyamine compound, which is then compounded with silica nanoparticles to form a rubber stabilizer, so that the stabilizer has a macromolecular structure, improves the compatibility of the stabilizer in rubber, reduces the precipitation of the stabilizer in rubber, and improves the aging resistance of the rubber composition.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is as follows: The present invention proposes a method for preparing a polymer rubber stabilizer, which specifically comprises the following steps:

[0005] S1. Dissolve succinic anhydride in DMF, mix well, add silane coupling agent KH550, stir and react for 3-4 hours, add silica nanoparticles, ultrasonically treat for 1-2 hours, increase the temperature to 60-80°C, stir and react for 5-7 hours, wash, and dry to obtain carboxylated nano-silica;

[0006] S2, dissolving the fatty amine monomer in deionized water, placing in a cold water bath for full stirring, adding epichlorohydrin, stirring evenly, raising the reaction temperature to 70-80°C, reacting for 3-4 hours, filtering, removing the filtrate, and drying to obtain a polyamine compound;

[0007] S3, adding the polyamine compound prepared in step S2 to deionized water for dissolution, and after being fully dispersed, adding the carboxylated nano-silica prepared in step S1, raising the reaction temperature to 50-60° C., stirring the reaction for 1-2 hours, filtering, washing, and freeze-drying to obtain a polymer rubber stabilizer;

[0008] Preferably, in step S1, the mass fraction of succinic anhydride in DMF is 4%-6%;

[0009] Preferably, in step S1, the mass ratio between the silane coupling agent and the silica nanoparticles is 1-2:10;

[0010] Preferably, in step S1, the mass ratio between the succinic anhydride and the silane coupling agent is 2-3:1;

[0011] Preferably, in step S2, the fatty amine monomer includes at least one of diethylenetriamine, triethylenetetramine and tetraethylenepentamine; the volume fraction of the fatty amine monomer in deionized water is 30%-50%;

[0012] Preferably, in step S2, the molar ratio of the fatty amine monomer to epichlorohydrin is 1:2-4;

[0013] Preferably, in step S3, the mass ratio between the polyamine compound and the carboxylated nano-silica is 2-3:1.

[0014] The present invention also provides a polymer rubber stabilizer prepared according to the method, wherein the polymer rubber stabilizer is added to the rubber matrix in an amount of 5-7%.

[0015] The beneficial effects achieved by the present invention are as follows:

[0016] The invention provides a high molecular rubber stabilizer and a preparation method thereof. The invention uses a fatty amine as a monomer compound to form a polyamine compound, which is then compounded with silicon dioxide nanoparticles to form a rubber stabilizer, so that the stabilizer has a macromolecular structure, improves the compatibility of the stabilizer in rubber, reduces the precipitation of the stabilizer in rubber, and improves the aging resistance of the rubber composition. In the invention, the surface of the silicon dioxide nanoparticles is carboxylated and modified, and a carboxyl group is introduced into the silicon dioxide surface, so that the reaction activity of the silicon dioxide surface can be improved. The fatty amine monomer is subjected to a condensation polymerization reaction by epichlorohydrin to form a high molecular polyamine compound, and the polymer molecule contains a large number of hydroxyl groups, which can be chemically combined with the carboxyl groups on the surface of the carboxylated silicon dioxide. The invention compounds the macromolecular polyamine stabilizer with the silicon dioxide nanoparticles, so that the heat-oxidative aging resistance of the rubber can be improved, the blooming problem of the rubber can be effectively alleviated, and the mechanical properties of the rubber can also be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The microstructure of the polymer rubber stabilizer prepared in Example 1 at different magnifications;

[0018] Figure 2 A comparison of the cross-sectional morphologies of the rubber materials to which the stabilizers described in Example 1 and Comparative Example 2 are applied;

[0019] Figure 3 This is a graph showing the change of sulfur and nitrogen elements in the rubber material to which the stabilizer described in Examples 1-3 and Comparative Examples 1-2 varies with extraction time.

[0020] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0022] Unless otherwise defined, all professional and scientific terms used herein have the same meanings as those familiar to those skilled in the art. In addition, any methods and materials similar or equivalent to those described herein may be applied to the present invention. The preferred implementation methods and materials described herein are for demonstration purposes only and are not intended to limit the content of this application.

[0023] The experimental methods in the following examples are conventional methods unless otherwise specified; the experimental materials and test strains used in the following examples are purchased from commercial channels unless otherwise specified.

[0024] The silicon dioxide nanoparticles used in the present invention are purchased from Ningbo Jinlei Nanomaterial Technology Co., Ltd. The product brand is JL-SiO2-Y300, and the average particle size is 300 nm.

[0025] Example 1

[0026] A method for preparing a polymer rubber stabilizer specifically comprises the following steps:

[0027] S1. Weigh 2 g of succinic anhydride and place it in a beaker, add 50 mL of DMF, stir and disperse thoroughly, accurately weigh 1 g of silane coupling reagent KH550, place it on a magnetic stirrer, stir at 200 rpm for 3 h, add 10 g of silica nanoparticles, place it in a 400 W ultrasonic device for ultrasonic treatment for 1 h, heat it to 70 ° C, continue stirring and reacting for 5 h, filter, remove the filtrate, wash it three times with anhydrous ethanol and deionized water respectively, and dry it in a vacuum oven at 50 ° C to obtain carboxylated silica nanoparticles;

[0028] S2. Accurately weigh 10 mL of diethylenetriamine and place it in a beaker, add 20 mL of deionized water, place the beaker in an ice water bath to fully dissolve the diethylenetriamine, stir to form a uniform solution, add 14.6 mL of epichlorohydrin to the diethylenetriamine solution in batches, place it on a magnetic stirrer and stir vigorously at 400 rpm for 1 hour, heat the reaction system to 70°C, stir and react for 4 hours, filter, remove the filtrate, wash with deionized water, and dry to obtain a polyamine compound;

[0029] S3, dissolving the polyamine compound prepared in step S2 in 100 mL of deionized water, stirring to fully disperse it, adding the carboxylated nano-silica prepared in step S1, raising the reaction temperature to 50° C., stirring the reaction for 1 hour, filtering, washing with deionized water and anhydrous ethanol, and freeze-drying to obtain a polymer rubber stabilizer.

[0030] This embodiment also provides a polymer rubber stabilizer prepared according to the above method.

[0031] Example 2

[0032] A method for preparing a polymer rubber stabilizer specifically comprises the following steps:

[0033] S1. Weigh 2.5 g of succinic anhydride and place it in a beaker, add 50 mL of DMF, stir and disperse thoroughly, accurately weigh 1 g of silane coupling reagent KH550, place it on a magnetic stirrer, stir at 200 rpm for 4 h, add 15 g of silica nanoparticles, place it in a 400 W ultrasonic device for ultrasonic treatment for 2 h, heat it to 60 ° C, continue stirring and reacting for 7 h, filter, remove the filtrate, wash it three times with anhydrous ethanol and deionized water respectively, and dry it in a vacuum oven at 50 ° C to obtain carboxylated silica nanoparticles;

[0034] S2. Accurately weigh 10 mL of triethylenetetramine and place it in a beaker, add 25 mL of deionized water, place the beaker in an ice water bath to fully dissolve the triethylenetetramine, stir to form a uniform solution, add 18.6 mL of epichlorohydrin to the triethylenetetramine solution in batches, place it on a magnetic stirrer and continue to stir vigorously at 400 rpm for 1 hour, heat the reaction system to 80° C., stir and react for 3 hours, filter, remove the filtrate, wash with deionized water, and dry to obtain a polyamine compound;

[0035] S3, dissolving the polyamine compound prepared in step S2 in 100 mL of deionized water, stirring to fully disperse it, adding the carboxylated nano-silica prepared in step S1, raising the reaction temperature to 60° C., stirring the reaction for 2 h, filtering, washing with deionized water and anhydrous ethanol, and freeze-drying to obtain a polymer rubber stabilizer.

[0036] This embodiment also provides a polymer rubber stabilizer prepared according to the above method.

[0037] Example 3

[0038] A method for preparing a polymer rubber stabilizer specifically comprises the following steps:

[0039] S1. Weigh 3 g of succinic anhydride and place it in a beaker, add 50 mL of DMF, stir and disperse thoroughly, accurately weigh 1 g of silane coupling reagent KH550, place it on a magnetic stirrer, stir at 200 rpm for 4 h, add 15 g of silica nanoparticles, place it in a 400 W ultrasonic device for ultrasonic treatment for 2 h, heat it to 80 ° C, continue stirring and reacting for 6 h, filter, remove the filtrate, wash it three times with anhydrous ethanol and deionized water respectively, and dry it in a vacuum oven at 50 ° C to obtain carboxylated silica nanoparticles;

[0040] S2. Accurately weigh 10 mL of tetraethylene pentamine and place it in a beaker, add 30 mL of deionized water, place the beaker in an ice water bath to fully dissolve the tetraethylene pentamine, stir to form a uniform solution, add 19.5 mL of epichlorohydrin to the tetraethylene pentamine solution in batches, place it on a magnetic stirrer and stir vigorously at 400 rpm for 1 hour, heat the reaction system to 80° C., stir and react for 4 hours, filter, remove the filtrate, wash with deionized water, and dry to obtain a polyamine compound;

[0041] S3, dissolving the polyamine compound prepared in step S2 in 100 mL of deionized water, stirring to fully disperse it, adding the carboxylated nano-silica prepared in step S1, raising the reaction temperature to 55° C., stirring the reaction for 2 h, filtering, washing with deionized water and anhydrous ethanol, and freeze-drying to obtain a polymer rubber stabilizer.

[0042] This embodiment also provides a polymer rubber stabilizer prepared according to the above method.

[0043] Comparative Example 1

[0044] The rubber stabilizer provided in this comparative example is specifically a common commercially available antioxidant PPD, purchased from Tianyuan Aerospace Materials (Yingkou) Technology Co., Ltd., with an active ingredient content of 95% and a powdery appearance.

[0045] Comparative Example 2

[0046] This comparative example provides a rubber stabilizer and a preparation method thereof, which differs from Example 1 only in that the preparation method does not include step S1, that is, compounding the uncarboxylated silica with the polyamine compound, and the remaining components and component contents are the same as those in Example 1.

[0047] Experimental Example 1

[0048] In this experimental example, the microstructure of the polymer rubber stabilizer prepared in Example 1 was observed. The microstructure of Example 1 was observed at different magnifications using a MIRA3 scanning electron microscope. Figure 1 The microstructure of the polymer rubber stabilizer prepared in Example 1 at different magnifications is shown in the figure. The silicon dioxide nanoparticles and the polyamine compound form a complex.

[0049] Example 2

[0050] In this experimental example, the stabilizers described in Examples 1-3 and Comparative Examples 1-2 were made into rubber according to the following formula:

[0051] 40 parts of natural rubber, 60 parts of butadiene rubber, 45 parts of carbon black, 3 parts of zinc oxide, 1 part of stearic acid, 5 parts of stabilizer, 1.5 parts of sulfur, and 0.5 parts of accelerator.

[0052] Set the initial temperature of the internal mixer to 80°C and the rotor speed to 60rpm, add natural rubber and butadiene rubber to the internal mixer and plasticize for 2min, add stabilizer, zinc oxide and stearic acid in turn and mix for 1min, add carbon black twice and continue mixing for 3min. After cooling, turn on the cooling water of the internal mixer, set the speed ratio of the two rollers to 1.1-1.2, add sulfur and vulcanization accelerator, continue mixing, adjust the roller spacing to 0.1mm to make three triangular packages, make two rolls, adjust the roller spacing to 2mm to produce sheets, leave at room temperature for 12h, place in a mold, and process at 150°C and 150Mpa for 15min to obtain a rubber material.

[0053] In this experimental example, the cross-sectional morphology of the rubber material to which the stabilizer described in Example 1 and Comparative Example 2 is applied is analyzed. The rubber material is frozen and brittle fractured under liquid nitrogen, the cross section is sprayed with gold, the screen is fixed with conductive glue, the electron beam acceleration voltage is set to 5 kV, and a Zeiss Merlin high-resolution emission scanning electron microscope is used. Figure 2 The cross-sectional morphology comparison diagram of the rubber material to which the stabilizer described in Example 1 and Comparative Example 2 is applied, Figure A is the cross-sectional morphology of the rubber material to which the stabilizer described in Example 1 is applied, and Figure B is the cross-sectional morphology of the rubber material to which the stabilizer described in Comparative Example 2 is applied. It can be seen that there is less aggregation of SiO2 in the cross-sectional surface of the rubber material described in Example 1, while there are a large number of SiO2 aggregates in the cross-sectional surface of the rubber material described in Comparative Example 2. In the stabilizer described in the present application, the polyamine compound is connected to the carboxylated silica through chemical bonds, and a large number of hydrogen bonds are formed with SiO2, which weakens the hydrogen bonding force between the SiO2 particles, thereby reducing the secondary aggregation of SiO2.

[0054] Experimental Example 3

[0055] In this experimental example, the migration resistance of the rubber material to which the stabilizer described in Examples 1-3 and Comparative Examples 1-2 was applied was tested. The rubber materials corresponding to Examples 1-3 and Comparative Examples 1-2 were cut into strips, and the rubber material strips were immersed in an acetone solution (volume ratio, acetone / methanol = 1:2) at room temperature. The acetone solution was replaced every 12 hours, and elemental analysis was performed on the strips.

[0056] Figure 3 The figure is a graph showing the variation of sulfur and nitrogen elements in the rubber materials to which the stabilizers described in Examples 1-3 and Comparative Examples 1-2 are applied with extraction time. As shown in the figure, with the extension of extraction time, the contents of sulfur and nitrogen elements in the rubber samples in the treatment groups of Examples 1-3 and Comparative Examples 1-2 both show a decreasing trend, indicating that the stabilizer prepared by the present invention can increase the molecular size of the stabilizer through hyperbranched polymerization, increase the compatibility of the stabilizer in the rubber macromolecular network structure, and reduce the blooming phenomenon that causes rubber aging.

[0057] While the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that many changes, modifications, substitutions and variations can be made to the embodiments without departing from the principles and spirit of the invention.

[0058] The present invention and its implementation methods are described above, which is not restrictive. The drawings are only one of the implementation methods of the present invention, and the actual application is not limited thereto. In short, if ordinary technicians in the field are inspired by it and design methods and embodiments similar to the technical solution without creativity without departing from the purpose of the invention, they should all fall within the protection scope of the present invention.

Claims

1. A method for preparing a polymer rubber stabilizer, characterized in that: The specific steps include: S1. Dissolve succinic anhydride in DMF, mix well, add silane coupling agent KH550, stir and react for 3-4 hours, add silica nanoparticles, ultrasonically treat for 1-2 hours, increase the temperature to 60-80°C, stir and react for 5-7 hours, wash, and dry to obtain carboxylated nano-silica; S2, dissolving the fatty amine monomer in deionized water, placing in a cold water bath for full stirring, adding epichlorohydrin, stirring evenly, raising the reaction temperature to 70-80°C, reacting for 3-4 hours, filtering, removing the filtrate, and drying to obtain a polyamine compound; In step S2, the fatty amine monomer includes at least one of diethylenetriamine, triethylenetetramine, and tetraethylenepentamine; the volume fraction of the fatty amine monomer in deionized water is 30%-50%; S3, dissolving the polyamine compound prepared in step S2 in deionized water, and after fully dispersing, adding the carboxylated nano-silica prepared in step S1, raising the reaction temperature to 50-60° C., fully stirring the reaction for 1-2 hours, filtering, washing, and freeze-drying to obtain a polymer rubber stabilizer.

2. The method for preparing a polymer rubber stabilizer according to claim 1, characterized in that: In step S1, the mass fraction of succinic anhydride in DMF is 4%-6%.

3. The method for preparing a polymer rubber stabilizer according to claim 2, characterized in that: In step S1, the mass ratio between the silane coupling agent and the silicon dioxide nanoparticles is 1-2:

10.

4. The method for preparing a polymer rubber stabilizer according to claim 3, characterized in that: In step S1, the mass ratio between the succinic anhydride and the silane coupling agent is 2-3:

1.

5. The method for preparing a polymer rubber stabilizer according to claim 4, characterized in that: In step S2, the molar ratio of the fatty amine monomer to epichlorohydrin is 1:2-4.

6. The method for preparing a polymer rubber stabilizer according to claim 5, characterized in that: In step S3, the mass ratio between the polyamine compound and the carboxylated nano-silica is 2-3:

1.

7. A polymer rubber stabilizer, characterized in that: The polymer rubber stabilizer is prepared according to the preparation method according to any one of claims 1-6.

8. The polymer rubber stabilizer according to claim 7, characterized in that: The added mass of the polymer rubber stabilizer in the rubber matrix is ​​5-7%.

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