A polyphenol-based in-situ surface modifier for carbon black, a method of making the same, and products comprising the same

Abstract

The application discloses a kind of based on polyphenol carbon black in-situ surface modifier and preparation method and the product comprising it, belong to rubber material technical field, the preparation method includes the following steps: polyphenol compound is dissolved in water with the silane coupling agent containing epoxy group, by heating stirring and condensation reflux is carried out hydroxyl-epoxy group ring-opening reaction, to prepare the based on polyphenol carbon black in-situ surface modifier, then the modifier is applied to preparation rubber composite material, carbon black can be with modifier through van der waals force, hydrogen bond, π-π conjugation and covalent bond Multiple interface interaction is formed, realize carbon black surface in-situ modification, significantly improve the dispersion effect of carbon black in rubber matrix and enhance the interface interaction in composite material, to greatly improve the mechanical properties of rubber composite material, reduce energy loss and heat generation under dynamic condition.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of rubber materials, and particularly relates to a polyphenol-based in-situ surface modifier for carbon black, a preparation method thereof and a product containing the same. BACKGROUND

[0002] Carbon black is an irreplaceable reinforcing filler in rubber materials and has played a huge role in promoting the development of the rubber industry. In order to fully exert the reinforcing effect of carbon black in rubber and reduce the hysteresis loss and dynamic heat generation of rubber materials after carbon black filling, improving the dispersion of carbon black in rubber matrix and enhancing the interfacial interaction between carbon black and rubber are the key. The main methods widely reported for improving the dispersion of carbon black in rubber include using surface-modified pre-treated carbon black and directly adding in-situ surface modifiers during rubber processing to modify carbon black in-situ. Although using surface-modified pre-treated carbon black can achieve good results, it usually requires complex pretreatment steps, is high in cost and long in cycle. Therefore, directly adding modifiers to modify carbon black in-situ during rubber processing is increasingly valued.

[0003] However, the method of directly adding modifiers to modify the surface of carbon black in-situ has obvious advantages such as simple and quick operation and low cost, but also has problems to be solved. First, compared with other nanofillers, the content of active functional groups on the surface of carbon black is extremely low, which means that it is difficult for the modifier to establish stable interaction with carbon black. Second, due to the small proportion of the modifier in the rubber formula, the probability of effective collision between the modifier and carbon black particles is low during the short mixing and hot pressing process, resulting in insufficient space and time for in-situ modification, and the effect of in-situ surface modification is often not as good as pretreatment modification.

[0004] Therefore, it is necessary to develop an in-situ surface modifier that can meet the needs of carbon black in-situ surface modification and enhance the interfacial bonding between carbon black and rubber matrix, so as to prepare high-performance rubber / carbon black composites through a more simple and efficient modification method, which is still an important issue in the scientific research and technical development of rubber / carbon black composites. SUMMARY

[0005] In view of the above technical problems, the present application provides a polyphenol-based in-situ surface modifier for carbon black, a preparation method thereof and a product containing the same.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0007] One of the technical solutions is:

[0008] A preparation method of a polyphenol-based in-situ surface modifier for carbon black, comprising the following steps:

[0009] The polyphenol compound and the silane coupling agent containing an epoxy group are dissolved in water, a hydroxyl-epoxy ring-opening reaction is carried out through heating stirring and condensation reflux to prepare the polyphenol-based carbon black in-situ surface modifier.

[0010] The polyphenol compound includes any one of tannic acid, gallic acid, catechin, epicatechin, theaflavin, anthocyanidin, resveratrol, lignan, coumarin, caffeic acid and curcumin.

[0011] The silane coupling agent containing an epoxy group includes any one of gamma-glycidoxypropyltrimethoxysilane, 3-[(2,3)-epoxypropoxy]propylmethyldimethoxysilane, [8-(epoxypropyloxy)-n-octyl]trimethoxysilane and 1,3-bis(3-glycidoxypropyl)-1,1,3,3-tetramethyldisiloxane.

[0012] Preferably, the mass ratio of the polyphenol compound and the silane coupling agent containing an epoxy group is (2-5):(1-4).

[0013] Preferably, the amount of the polyphenol compound is 10-60% of the total mass of the polyphenol compound and the silane coupling agent containing an epoxy group.

[0014] Preferably, the heating temperature in the heating stirring process is 20-80 DEG C.

[0015] The stirring time is 6-48 hours.

[0016] Preferably, after the reaction is completed, a purification step is further included, specifically, the solution obtained in the reaction is centrifuged and washed, and vacuum dried.

[0017] The second technical scheme of the present application is:

[0018] A polyphenol-based carbon black in-situ surface modifier is prepared by the above preparation method.

[0019] The third technical scheme of the present application is:

[0020] A rubber composite material, raw materials of which include carbon black, rubber and the above polyphenol-based carbon black in-situ surface modifier.

[0021] Beneficial effects: The polyphenol-based carbon black in-situ surface modifier provided by the present application is applied in a rubber composite material, carbon black can form multiple interfacial interactions with the modifier through van der Waals force, hydrogen bond, pi-pi conjugation and covalent bond, successfully realizing in-situ modification of the carbon black surface, significantly improving the dispersion effect of carbon black in the rubber matrix and the interfacial interaction in the composite material, thereby greatly improving the mechanical properties of the rubber composite material and reducing the energy loss and heat generation under dynamic conditions.

[0022] Preferably, the adding amount of the polyphenol-based carbon black in-situ surface modifier is 0.5-10 wt.% of the carbon black;

[0023] The adding amount of the carbon black is 10-100 wt.% of the rubber.

[0024] Further, the rubber is one or more of natural rubber, styrene-butadiene rubber and isoprene rubber.

[0025] Preferably, the rubber composite further comprises the following raw materials:

[0026] Antioxidant, zinc oxide, stearic acid, accelerator and sulfur.

[0027] Further, the antioxidant is one or more of antioxidant RD, antioxidant 4010NA, antioxidant 4010 and antioxidant 4020; and / or

[0028] The accelerator is at least one of accelerator CZ, accelerator M, accelerator DM, accelerator TT and accelerator D.

[0029] Optionally, the adding amount of the antioxidant is 1.5 wt.% of the rubber; the adding amount of the zinc oxide is 5 wt.% of the rubber; the adding amount of the stearic acid is 2 wt.% of the rubber; the adding amount of the accelerator is 2 wt.% of the rubber; and the adding amount of the sulfur is 1.6 wt.% of the rubber.

[0030] The fourth technical solution of the present application:

[0031] The preparation method of the above rubber composite comprises the following steps:

[0032] Directly mixing the above raw materials, hot-pressing vulcanization to obtain the rubber composite.

[0033] Preferably, when the mixing is performed by a banbury mixer, the mixing temperature is 60-100℃ and the mixing time is 5-10 minutes; and / or

[0034] When the mixing is performed by an open mill, the mixing temperature is 30-60℃ and the mixing time is 8-10 minutes.

[0035] Compared with the prior art, the present application has the following advantages and technical effects:

[0036] 1) The synthesis process of the in-situ surface modifier of the present application is simple, which can be obtained by only one step reaction, the reaction condition is mild, the cost is low, and it is green and environmentally friendly;

[0037] 2) The in-situ surface modifier of the present application can be applied in rubber composites, carbon black can form multiple interfacial interactions with the modifier through van der Waals force, hydrogen bond, π-π conjugation and covalent bond, successfully realizing the in-situ modification of the surface of carbon black, significantly improving the dispersion effect of carbon black in the rubber matrix and the interfacial interaction in the reinforced composite, thereby greatly improving the mechanical properties of the rubber composite and reducing the energy loss and heat generation under dynamic conditions;

[0038] 3) The in-situ surface modifier of the present application can be directly applied to traditional rubber formulations, showing great commercial application potential, and is of great significance for low-energy, low-pollution and low-cost manufacturing of high-performance and environmentally friendly and energy-saving rubber products. BRIEF DESCRIPTION OF DRAWINGS

[0039] The accompanying drawings, which form a part of this application, are used to provide further understanding of the application and are incorporated in and constitute a part of this specification. The illustrative embodiments of the present application and their description serve to explain the application. In the drawings:

[0040] Figure 1 Scanning electron microscope images of the surface morphology of the rubber composites prepared for Comparative Example 1 (a) and Example 1 (b). DETAILED DESCRIPTION

[0041] Various illustrative embodiments of the present application are described in detail below. The detailed description is not intended to limit the present application, but rather to explain certain aspects, features, and embodiments of the present application.

[0042] It should be understood that the terms used herein are merely descriptive, but are not intended to limit the present application. In addition, for numerical ranges in the present application, it should be understood that each intermediate value between the upper limit and the lower limit of the range is also specifically disclosed. Each smaller range within the range of the stated value or the stated range and any other stated value or intermediate value within the stated range is also included in the present application. The upper limit and the lower limit of these smaller ranges can be independently included or excluded from the range.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application pertains. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present application, the preferred methods and materials are described. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials in connection with which the documents are cited. In the case of conflict between any document incorporated by reference and the present specification, the present specification controls.

[0044] Many modifications and variations to the illustrative embodiments described herein will be apparent to those of ordinary skill in the art from this specification, which is to be regarded in an illustrative manner. Other embodiments will be apparent to those of ordinary skill in the art from consideration of the specification and practice of the subject matter disclosed herein. The specification and examples are illustrative only.

[0045] The term "antioxidant RD" in the embodiments of the present application refers to 2,2,4-trimethyl-1,2-dihydroquinoline polymer, 2,4-trimethyl-1,2-dihydroquinoline polymer, homopolymer of 2-dihydro-2,2,4-trimethylquinoline; 2,2,4-trimethyl-1,2-dihydroquinoline; alias antioxidant TMQ, antioxidant RD, antioxidant 224.

[0046] Antioxidant 4010NA, alias N-isopropyl-N'-phenyl-p-phenylenediamine, is a light red to purple red, brown granular, molecular formula is C 15 H 18 N2.

[0047] Antioxidant 4010, alias: N-cyclohexyl-N'-phenyl-p-phenylenediamine; N-phenyl-N'-cyclohexyl-p-phenylenediamine; antioxidant CPPD belongs to p-phenylenediamine rubber antioxidant.

[0048] Antioxidant 4020, alias: N-(1,3-dimethyl)butyl-N'-phenyl-p-phenylenediamine; antioxidant DMPPD belongs to p-phenylenediamine rubber antioxidant.

[0049] Promoter CZ, molecular formula C 13 H 16 N2S2, chemical name is N-cyclohexyl-2-benzothiazole sulfenamide;

[0050] Promoter M, 2-mercaptobenzothiazole, also known as promoter M, is an organic compound, chemical formula C7H5NS2, is a light yellow crystalline powder, mainly used as a sensitive reagent for detecting gold, bismuth, cadmium, cobalt, mercury, nickel, lead, thallium and zinc and rubber accelerator.

[0051] Promoter DM, rubber accelerator DM is an organic compound, chemical formula C 14 H8N2S4, light yellow needle-like crystal, slightly soluble in benzene, dichloromethane, carbon tetrachloride, acetone, ethanol, diethyl ether at room temperature, insoluble in water, ethyl acetate, gasoline and alkali.

[0052] Promoter TT, Chinese name: tetramethylthiuram disulfide, molecular formula: C6H 12 N2S4, CAS number: 137-26-8;

[0053] Promoter D, molecular formula C 13H 13 N3, English name: accelerator D, Chinese alias: diphenyl guanidine; accelerator DPG; rubber vulcanization accelerator DPG; 1,3-diphenyl guanidine; N,N'-diphenyl guanidine; symmetrical diphenyl guanidine.

[0054] The embodiment of the present application discloses a preparation method of a polyphenol-based carbon black in-situ surface modifier, comprising the following steps:

[0055] The polyphenol compound and the silane coupling agent containing an epoxy group are dissolved in water, and the reaction is stirred for 6-48 hours under the condition of condensation reflux at 20-80 DEG C. After the reaction is completed, the reaction solution is centrifuged and washed, and vacuum dried to obtain the polyphenol-based carbon black in-situ surface modifier;

[0056] The polyphenol compound includes any one of tannic acid, gallic acid, catechin, epicatechin, theaflavin, anthocyanin, resveratrol, lignan, coumarin, coffee acid and curcumin;

[0057] The silane coupling agent containing an epoxy group includes any one of gamma-glycidoxypropyltrimethoxysilane, 3-[(2,3)-epoxypropoxy]propylmethyldimethoxysilane, [8-(epoxypropyloxy)-n-octyl]trimethoxysilane and 1,3-bis(3-glycidoxypropyl)-1,1,3,3-tetramethyldisiloxane;

[0058] In some preferred embodiments, a preparation method of a polyphenol-based carbon black in-situ surface modifier comprises the following steps: 150 mL of deionized water is added into a three-necked flask, then 2 g of tannic acid and 1.5 g of gamma-glycidoxypropyltrimethoxysilane are added, and the reaction is stirred at 80 DEG C under the condition of condensation reflux for 8 hours; the impurities are removed by centrifugal washing with diethyl ether, and finally the purified polyphenol-based carbon black in-situ surface modifier m1 is obtained by vacuum drying, with a yield of 88%.

[0059] In some preferred embodiments, a preparation method of a polyphenol-based carbon black in-situ surface modifier comprises the following steps: 120 mL of deionized water is added into a three-necked flask, then 2.5 g of gallic acid and 1.8 g of 3-[(2,3)-epoxypropoxy]propylmethyldimethoxysilane are added, and the reaction is stirred at 60 DEG C under the condition of condensation reflux for 6 hours; the impurities are removed by centrifugal washing with diethyl ether, and finally the purified polyphenol-based carbon black in-situ surface modifier m2 is obtained by vacuum drying, with a yield of 83%.

[0060] In some preferred embodiments, a preparation method of a polyphenol-based in-situ surface modifier of carbon black comprises the following steps: adding 200 mL of deionized water into a three-necked flask, then adding 4.3 g of curcumin and 3.6 g of 31,3-bis(3-glycidyloxypropyl)-1,1,3,3-tetramethyldisiloxane, heating and stirring at 20°C, condensing reflux, reacting for 48 hours, washing and removing impurities by centrifugation with diethyl ether, and finally vacuum drying to obtain a purified polyphenol-based in-situ surface modifier m3, with a yield of 92%.

[0061] As used herein, "comprise", "comprising", "have", "having", "include", "including", "contain", "containing", "provide", "providing", "carry", "carrying", "comprise" and the like are open-ended terms, i.e., to mean including but not limited to.

[0062] As used herein, "room temperature" means 20-30°C, unless otherwise specified. The vulcanization time mentioned in the following examples is obtained by testing the mixed rubber in a vulcameter.

[0063] As used herein, "parts" means mass parts, unless otherwise specified.

[0064] The raw materials used in the present application are commercially available.

[0065] The technical solutions of the present application are further illustrated by the following examples.

[0066] Example 1

[0067] A preparation method of a rubber / carbon black composite material based on a polyphenol-based in-situ surface modifier of carbon black, the specific steps are as follows:

[0068] 1 g of in-situ surface modifier of carbon black (m1), 20 g of carbon black, 100 g of natural rubber, 5 g of zinc oxide, 2 g of stearic acid, 1.5 g of accelerator CZ, 0.5 g of accelerator DM, 1.5 g of antioxidant 4020 and 1.6 g of sulfur are mixed in an open mill, wherein the mixing temperature is 50°C and the mixing time is 8 min, then hot press vulcanization is carried out at a temperature of 143°C with a vulcanization time of 1 min, to obtain a rubber composite material (rubber / carbon black composite material).

[0069] Example 2

[0070] The difference from Example 1 is only that the in-situ surface modifier of carbon black m2 is used to replace m1 in equal mass. The other conditions are the same as those in Example 1.

[0071] Example 3

[0072] The difference from Example 1 is only that the in-situ surface modifier of carbon black m3 is used to replace m1 in equal mass. The other conditions are the same as those in Example 1.

[0073] Example 4

[0074] The difference from Example 2 is that the amount of carbon black in-situ surface modifier m2 is 1.5 g. Other conditions are the same as Example 2.

[0075] Example 5

[0076] The difference from Example 3 is that the amount of carbon black in-situ surface modifier m3 is 1.5 g. Other conditions are the same as Example 3.

[0077] Example 6

[0078] The difference from Example 1 is that the natural rubber is replaced with butadiene styrene rubber with the same mass, and the hot pressing temperature is 160℃. Other conditions are the same as Example 1.

[0079] Comparative Example 1

[0080] The difference from Example 1 is that no carbon black in-situ surface modifier m1 is added, and other conditions are the same as Example 1.

[0081] Comparative Example 2

[0082] The difference from Example 6 is that no carbon black in-situ surface modifier m1 is added. Other conditions are the same as Example 6.

[0083] The formulations of the rubber / carbon black composite materials prepared in Examples 1-6 and the rubber materials prepared in Comparative Examples 1-2 are shown in Table 1.

[0084] Table 1

[0085]

[0086] Effect verification

[0087] The rubber / carbon black composite materials prepared in Examples 1-6 and the rubber materials prepared in Comparative Examples 1-2 are respectively subjected to performance tests, and the test results are shown in Table 2. The tensile strength, elongation at break and modulus at 300% are measured according to the standard ISO 37-2005, the test temperature is room temperature, and the tensile rate is 500 mm / min; the dynamic temperature rise is measured according to the standard ISO 4666-3:2016; the dynamic energy loss is measured by dynamic mechanical analyzer (DMA), and the test conditions are that the sample is heated from -80℃ to 80℃ at a rate of 3℃ / min in tension mode, and the frequency is 1 Hz (the energy loss is represented by the tan δ peak value).

[0088] Table 2

[0089]

[0090] As can be seen from the properties of the rubber composites obtained in Comparative Example 1 and Examples 1-3 in Table 2, compared with Comparative Example 1 without adding the carbon black in-situ surface modifier, after adding different carbon black in-situ surface modifiers, the tensile strength and 300% modulus of the natural rubber composites are obviously improved, and the fatigue temperature rise (dynamic temperature rise) and energy loss under dynamic strain are obviously reduced. In addition, according to the surface morphology scanning electron microscope images of Comparative Example 1 (a) and Example 1 (b), it can be seen that the unmodified carbon black in Comparative Example 1 forms large-size agglomerates in the rubber, while after modification by the in-situ surface modifier, the carbon black in Example 1 obviously weakens the agglomeration in the rubber matrix and significantly enhances the dispersion effect. Figure 1

[0091] Comparing the properties of the rubber composites in Table 2 between Comparative Example 1 and Examples 2 and 4; or between Comparative Example 1 and Examples 3 and 5, it is found that when the same carbon black in-situ surface modifier is used, as the amount increases, the tensile strength of the natural rubber composite is further improved, and the temperature rise and energy loss under dynamic conditions are further reduced.

[0092] Comparing between Comparative Example 2 and Example 6 in Table 2, it is found that after applying the carbon black in-situ surface modifier to the styrene-butadiene rubber / carbon black composite, the influence on the comprehensive performance of the composite is similar to that in the natural rubber / carbon black composite, and both can significantly improve the comprehensive performance of the rubber composite.

[0093] In summary, the carbon black in-situ surface modifier based on polyphenol prepared by the present application can improve the dispersibility of carbon black in rubber, greatly improve the mechanical strength of the rubber composite, and reduce the energy loss and heat generation of the rubber composite under dynamic strain.

[0094] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any changes or replacements within the technical scope disclosed by the present application can be easily thought of by those skilled in the art, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.​

Claims

1. A rubber composite material, characterized by, The raw materials include carbon black, rubber and polyphenol-based carbon black in-situ surface modifier; The preparation method of the polyphenol-based carbon black in-situ surface modifier comprises the following steps: The polyphenol compound and the silane coupling agent containing epoxy group are dissolved in water, and a hydroxyl-epoxy ring-opening reaction is carried out by heating stirring and condensation reflux to prepare the polyphenol-based carbon black in-situ surface modifier; The polyphenol compound includes any one of tannic acid, gallic acid, catechin, epicatechin, theaflavin, anthocyanin, resveratrol, lignan, coumarin, caffeic acid and curcumin; The silane coupling agent containing epoxy group includes any one of γ-glycidyl ether propyl trimethoxysilane, 3-[(2,3)-epoxypropoxy] propyl methyl dimethoxysilane, [8-(epoxypropyl-oxy)-n-octyl] trimethoxysilane and 1,3-bis(3-glycidyl propyl)-1,1,3,3-tetramethyl disiloxane.

2. A rubber composite according to claim 1, characterized in that The amount of the polyphenol compound is 10-60% of the total mass of the polyphenol compound and the silane coupling agent containing epoxy group.

3. A rubber composite material according to claim 1, wherein The heating temperature in the heating stirring process is 20-80℃; The stirring time is 6-48 hours.

4. A rubber composite material according to claim 1, wherein The addition amount of the polyphenol-based carbon black in-situ surface modifier is 0.5-10wt.% of the amount of the carbon black; The addition amount of the carbon black is 10-100wt.% of the amount of the rubber.

5. A rubber composite material according to claim 1, wherein The rubber composite material further includes the following raw materials: anti-aging agent, zinc oxide, stearic acid, accelerator and sulfur.

6. A method of preparing a rubber composite material, characterized by, The preparation method comprises the following steps: The raw materials of the rubber composite material are directly mixed and hot-pressed to obtain the rubber composite material.

7. The preparation method of the rubber composite material according to claim 6, wherein, When the mixing process uses an internal mixer, the mixing temperature is 60-100℃ and the mixing time is 5-10 minutes; and / or When the mixing process uses an open mill, the mixing temperature is 30-60℃ and the mixing time is 8-10 minutes.

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