阅读说明：本技术 一种二维共价有机骨架/丁苯橡胶复合材料及其制备方法 (Two-dimensional covalent organic framework/styrene butadiene rubber composite material and preparation method thereof ) 是由 杨杰 穆立文 吉远辉 陈仁芳 刘学江 李阳 于 2020-12-28 设计创作，主要内容包括：本发明公开了一种二维共价有机骨架/丁苯橡胶复合材料及其制备方法。所述复合材料包括丁苯橡胶和二维共价有机骨架,所述丁苯橡胶和二维共价有机骨架的质量配比为100:0.1-5；所述二维共价有机骨架包括羧基、氨基、羟基中的一种或两种以上基团。本发明的二维共价有机骨架/丁苯橡胶复合材料的力学性能较好,拉伸强度达到30-45 MPa,断裂伸长率在560-780%。该发明利用二维共价有机骨架的高比表面积、良好的稳定性和分子层上的活性官能团,可以有效地作为丁苯橡胶的补强填料。(The invention discloses a two-dimensional covalent organic framework/styrene butadiene rubber composite material and a preparation method thereof. The composite material comprises styrene butadiene rubber and a two-dimensional covalent organic framework, wherein the mass ratio of the styrene butadiene rubber to the two-dimensional covalent organic framework is 100: 0.1-5; the two-dimensional covalent organic framework comprises one or more than two groups of carboxyl, amino and hydroxyl. The two-dimensional covalent organic framework/styrene butadiene rubber composite material has good mechanical property, the tensile strength reaches 30-45 MPa, and the elongation at break is 560-780%. The invention utilizes the high specific surface area and good stability of the two-dimensional covalent organic framework and the active functional group on the molecular layer, and can be effectively used as the reinforcing filler of the styrene butadiene rubber.)

1. A two-dimensional covalent organic framework/styrene butadiene rubber composite material is characterized in that: the composite material comprises styrene butadiene rubber and a two-dimensional covalent organic framework, wherein the mass ratio of the styrene butadiene rubber to the two-dimensional covalent organic framework is 100: 0.1-5; the two-dimensional covalent organic framework comprises one or more than two groups of carboxyl, amino and hydroxyl.

2. The two-dimensional covalent organic framework/styrene butadiene rubber composite material of claim 1, wherein: the two-dimensional covalent organic skeleton is one or more of COF-1, COF-5, COF-8, COF-14 and COF-43.

3. The two-dimensional covalent organic framework/styrene butadiene rubber composite material of claim 1, wherein: the two-dimensional covalent organic framework/styrene butadiene rubber composite material also comprises an accelerator, wherein the accelerator is one or more of benzothiazole Disulfide (DM), N-cyclohexyl-2-benzothiazole sulfenamide (CZ) and tetramethylthiuram disulfide (TMTD).

4. The two-dimensional covalent organic framework/styrene butadiene rubber composite material of claim 1, wherein: the two-dimensional covalent organic framework/styrene butadiene rubber composite material also comprises a vulcanizing agent, wherein the vulcanizing agent is one or more of sulfur, sulfur monochloride, selenium and tellurium.

5. The two-dimensional covalent organic framework/styrene butadiene rubber composite material of claim 1, wherein: the two-dimensional covalent organic framework/styrene butadiene rubber composite material also comprises a filler, wherein the filler is one or more of carbon black, calcium carbonate, argil and talcum powder.

6. The two-dimensional covalent organic framework/styrene butadiene rubber composite material of claim 1, wherein: the two-dimensional covalent organic framework/styrene butadiene rubber composite material also comprises an active agent, wherein the active agent is one or more of zinc oxide, stearic acid, zinc stearate and ethanolamine.

7. The two-dimensional covalent organic framework/styrene butadiene rubber composite material of claim 1, wherein: the two-dimensional covalent organic framework/styrene-butadiene rubber composite material also comprises an anti-aging agent, wherein the anti-aging agent is one or more of 2,2, 4-trimethyl-1, 2-dihydroquinoline polymer (RD), 6-ethoxy-2, 2, 4-yl-1, 2-dihydroquinoline (AW), N- (1, 3-dimethylbutyl-N '-phenyl-p-phenylenediamine (4020) and N, N' -2-beta-naphthyl-p-phenylenediamine (DNP).

8. The two-dimensional covalent organic framework/styrene butadiene rubber composite material of claim 1, wherein: the two-dimensional covalent organic framework/styrene butadiene rubber composite material also comprises a plasticizer, wherein the plasticizer is one or more of dioctyl phthalate (DOP), dibutyl phthalate (DBP), coumarone resin and vaseline.

9. The method of preparing a two-dimensional covalent organic framework/styrene butadiene rubber composite according to any of claims 1 to 8, comprising the steps of:

adding styrene butadiene rubber into an internal mixer, sequentially adding a filler, a two-dimensional covalent organic framework, zinc oxide and stearic acid, stirring at the temperature of 40-50 ℃ of the internal mixer, and standing after internal mixing is finished to obtain a section of rubber compound;

b, adding the first-stage rubber compound, a vulcanizing agent and an accelerator into the open mill, mixing at the temperature of 40-50 ℃, and standing after mixing to obtain a second-stage rubber compound;

and c, vulcanizing the two-stage rubber compound at the vulcanization temperature of 175-185 ℃ to obtain the two-dimensional covalent organic framework/styrene butadiene rubber composite material.

10. The method for preparing the two-dimensional covalent organic framework/styrene butadiene rubber composite material according to claim 9, wherein the banburying time is 5 min, and the mixing time is 8 min; in the vulcanization process, the vulcanization pressure is 10-20 MPa, and the vulcanization time is 12-15 min.

Technical Field

The invention relates to the technical field of preparation of rubber composite materials. In particular to a two-dimensional covalent organic framework/styrene butadiene rubber composite material and a preparation method thereof.

Background

Rubber is the only material with high elasticity so far, and is an important strategic substance. Rubber products such as tires, rubber tubes, sealing elements, conveyor belts and the like are widely applied to the fields of traffic transportation, irrigation and water conservancy, national defense and military industry, aerospace and the like. Styrene-butadiene rubber (SBR) is a copolymer of butadiene and styrene, 70% used in the tire industry. The wear resistance is better, and the abrasion loss is lower. The performances of heat resistance, oil resistance, aging resistance and the like are also superior to those of natural rubber. However, styrene-butadiene rubber has a large trans-structure and a benzene ring on a side group, so that hysteresis loss is large, heat generation is high, elasticity is low, cold resistance is slightly poor, shrinkage is large, green strength is low, and adhesiveness is poor. Meanwhile, the styrene butadiene rubber is non-self-reinforced rubber, has low strength and can be used after a reinforcing agent is added.

The reinforcing agent can simultaneously and obviously improve the tensile strength, the tearing strength and the wear resistance of the rubber, for example, the carbon black can improve the strength of the synthetic rubber by about 10 times by virtue of the reinforcing elements such as high specific surface area, stable structure, good surface activity and the like, thereby playing an important role in the rubber. In particular, the layered nano structure is used as a reinforcing agent, the composite with the polymer can be completed in the polymer forming process, and the structure of the graphite sheet layer can endow the nano composite structure with excellent mechanical properties, but the structure has three-dimensional characteristics on the layered structure, the surface area is small, the active sites are insufficient, and the using effect is influenced.

Two-dimensional Covalent Organic Frameworks (COFs) are a class of porous polymers with highly crystalline structures and tunable functions, composed of organic monomers that are planarly connected by covalent bonds and then stacked one on top of another in an ordered fashion by non-covalent interactions to form layered structures. COFs, which have the advantages of low density, high surface area, adjustable pore size and ordered pore structure, good thermal and chemical stability, good crystallinity, designability of unit structures, etc., are considered as a new source of layered materials and have received great attention because they can be obtained not only in highly oriented multilayer structures but also in thick layers at the molecular level. The styrene butadiene rubber has high specific surface area, good stability and active functional groups on a molecular layer, and has a special effect when being applied to styrene butadiene rubber.

Disclosure of Invention

The invention aims to solve the problems of poor mechanical property and unstable mechanical strength of styrene butadiene rubber in the prior art and influence on the use effect, and provides a two-dimensional covalent organic framework/styrene butadiene rubber composite material and a preparation method thereof. The two-dimensional covalent organic framework/styrene butadiene rubber composite material provided by the invention has the characteristics of excellent mechanical property and the like.

The object of the invention can be achieved by the following measures:

the invention provides a two-dimensional covalent organic framework/styrene butadiene rubber composite material which comprises the following raw materials in parts by weight: 100 parts of styrene butadiene rubber, 0.1-5 parts of two-dimensional covalent organic framework, 0.5-2 parts of accelerator, 2-5 parts of zinc oxide, 0.5-3 parts of stearic acid, 0.5-3 parts of vulcanizing agent, 0.5-2 parts of anti-aging agent, 0-20 parts of plasticizer and 0-20 parts of filler; the two-dimensional covalent organic framework comprises one or more than two groups of carboxyl, amino and hydroxyl; the mass ratio of the styrene butadiene rubber to the two-dimensional covalent organic framework is 100: 0.1-5.

Furthermore, the two-dimensional covalent organic framework is one or more of COF-1, COF-5, COF-8, COF-14 and COF-43.

The accelerator is one or more of benzothiazole Disulfide (DM), N-cyclohexyl-2-benzothiazole sulfenamide (CZ) and tetramethylthiuram disulfide (TMTD).

Preferably, the vulcanizing agent is one or more of sulfur, sulfur monochloride, selenium and tellurium.

Preferably, the filler is one or more of carbon black, calcium carbonate, pottery clay and talcum powder.

Preferably, the active agent is one or more of zinc oxide, stearic acid, zinc stearate and ethanolamine.

Preferably, the anti-aging agent is one or more of 2,2, 4-trimethyl-1, 2-dihydroquinoline polymer (RD), 6-ethoxy-2, 2, 4-yl-1, 2-dihydroquinoline (AW), N- (1, 3-dimethylbutyl-N '-phenyl-p-phenylenediamine (4020) and N, N' -2-beta-naphthyl-p-phenylenediamine (DNP).

Preferably, the plasticizer is one or more of dioctyl phthalate (DOP), dibutyl phthalate (DBP), coumarone resin and vaseline.

As a particularly preferable scheme of the invention, the two-dimensional covalent organic framework/styrene-butadiene rubber composite material further comprises a silane coupling agent, the two-dimensional covalent organic framework/styrene-butadiene rubber composite material comprises carboxyl, the dosage of the silane coupling agent is 1-1.5 times of that of the carboxyl in the two-dimensional covalent organic framework, experiments prove that the existence of the carboxyl greatly influences the bonding strength of the two-dimensional covalent organic framework and the styrene-butadiene rubber, and the problem can be effectively solved by adding the silane coupling agent.

The preparation method of the two-dimensional covalent organic framework/styrene butadiene rubber composite material comprises the steps of adding styrene butadiene rubber into an internal mixer, sequentially adding filler, the two-dimensional covalent organic framework, zinc oxide and stearic acid, stirring at the temperature of 40-50 ℃ of the internal mixer, and standing after internal mixing is finished to obtain a section of rubber compound; adding the first-stage rubber compound, a vulcanizing agent, an accelerator, an anti-aging agent and a plasticizer into an open mill, mixing at the temperature of 40-50 ℃, and standing after mixing to obtain a second-stage rubber compound; and vulcanizing the two-stage rubber compound at the vulcanization temperature of 175-185 ℃ to obtain the two-dimensional covalent organic framework/styrene butadiene rubber composite material.

The banburying time in the process is 5 min, and the mixing time is 8 min.

In the process of the invention, the vulcanization pressure is 10-20 MPa, and the vulcanization time is 5-20 min.

Furthermore, the two-dimensional covalent organic framework/styrene butadiene rubber composite material prepared by the process has good mechanical property, the tensile strength reaches 30-35 MPa, and the elongation at break is 560-680%.

Compared with the traditional styrene butadiene rubber reinforcing agent, the styrene butadiene rubber reinforcing agent has the advantages and beneficial effects that:

1) the two-dimensional covalent organic framework can regulate and control the specific surface area and the active functional group thereof, so as to prepare the styrene-butadiene rubber composite material with excellent mechanical property;

2) the preparation conditions and the process are simple and easy to control, the raw materials are wide in source, and the large-scale preparation is facilitated.

Detailed Description

The present invention is further illustrated by the following examples, which are intended to be illustrative only and not limiting. The reagents used in the following examples are, unless otherwise specified, conventional reagents available in the art; the methods used, unless otherwise specified, are conventional in the art.

Example 1:

firstly, 100 parts of butadiene styrene rubber is added into an internal mixer, 5 parts of carbon black, 0.5 part of COF-1 containing carboxyl active groups, 2 parts of zinc oxide and 3 parts of stearic acid are sequentially added, the temperature of the internal mixer is kept at 40 ℃, stirring is carried out, and standing is carried out after internal mixing is finished, so as to obtain a section of rubber compound; adding the first-stage rubber compound, 2 parts of sulfur, 1 part of CZ, 1 part of antioxidant 4020 and 3 parts of DOP into an open mill, mixing at the temperature of 50 ℃, and standing after the mixing is finished to obtain a second-stage rubber compound; and (3) standing for 24 h, vulcanizing the second-stage rubber compound at 180 ℃ and 10 MPa, and carrying out flat-plate heat vulcanization for 14 min to obtain the two-dimensional covalent organic framework/styrene butadiene rubber composite material. The material is cut into dumbbell-shaped samples with the length of 115 mm by a special rubber cutter, and the vulcanized rubber is subjected to tensile property test according to the national standard GB/T528-2009, wherein the tensile speed is 500 mm/min. The tensile strength can reach 32 MPa, and the elongation at break is 640 percent.

Example 2:

firstly, 100 parts of butadiene styrene rubber is added into an internal mixer, 10 parts of white carbon black, 5 parts of COF-8 containing carboxyl active groups, 5 parts of zinc oxide and 1 part of stearic acid are sequentially added, the temperature of the internal mixer is kept at 45 ℃, stirring is carried out, and standing is carried out after internal mixing is finished, so as to obtain a section of rubber compound; adding the first-stage rubber compound, 0.5 part of sulfur, 2 parts of TMTD, 1 part of anti-aging agent AW and 10 parts of coumarone resin into an open mill, mixing at the temperature of 50 ℃, and standing after the mixing is finished to obtain a second-stage rubber compound; and (3) after standing for 24 h, vulcanizing the second-stage rubber compound, setting the temperature to be 175 ℃, keeping the pressure to be 15 MPa, and carrying out flat-plate hot vulcanization for 12 min to obtain the two-dimensional covalent organic framework/styrene butadiene rubber composite material. The material is cut into dumbbell-shaped samples with the length of 115 mm by a special rubber cutter, and the vulcanized rubber is subjected to tensile property test according to the national standard GB/T528-2009, wherein the tensile speed is 500 mm/min. The tensile strength can reach 34 MPa, and the elongation at break is 620%.

Example 3

Firstly, 100 parts of styrene butadiene rubber is added into an internal mixer, 5 parts of carbon black, 0.5 part of COF-1 containing carboxyl active groups, 2 parts of zinc oxide, 3 parts of stearic acid and a silane coupling agent KH550 accounting for 1.25 times of carboxyl in the COF-1 are sequentially added, the temperature of the internal mixer is kept at 40 ℃, stirring is carried out, and standing is carried out after internal mixing is finished, so that a section of rubber compound is obtained; adding the first-stage rubber compound, 2 parts of sulfur, 1 part of CZ, 1 part of antioxidant 4020 and 3 parts of DOP into an open mill, mixing at the temperature of 50 ℃, and standing after the mixing is finished to obtain a second-stage rubber compound; and (3) standing for 24 h, vulcanizing the second-stage rubber compound at 180 ℃ and 10 MPa, and carrying out flat-plate heat vulcanization for 14 min to obtain the two-dimensional covalent organic framework/styrene butadiene rubber composite material. The material is cut into dumbbell-shaped samples with the length of 115 mm by a special rubber cutter, and the vulcanized rubber is subjected to tensile property test according to the national standard GB/T528-2009, wherein the tensile speed is 500 mm/min. The tensile strength can reach 45 MPa, and the elongation at break is 780%.

Comparative example 1:

firstly, 100 parts of styrene butadiene rubber is added into an internal mixer, 5 parts of carbon black, 2 parts of zinc oxide and 3 parts of stearic acid are sequentially added, the internal mixer is kept at 40 ℃, stirring and internal mixing are carried out, and after the stirring and internal mixing, a rubber block is kept stand to obtain a rubber compound; adding the first-stage rubber compound, 2 parts of sulfur, 1 part of CZ, 1 part of anti-aging agent 4020 and 3 parts of DOP into an open mill, keeping equipment at 50 ℃ for mixing, and standing after mixing to obtain a second-stage rubber compound; and (3) standing for 24 h, vulcanizing the second-stage rubber compound, setting the vulcanization temperature at 180 ℃ and the pressure at 10 MPa, and carrying out flat-plate hot vulcanization for 17 min to obtain the two-dimensional covalent organic framework/styrene butadiene rubber composite material. The material is cut into dumbbell-shaped samples with the length of 115 mm by a special rubber cutter, and the vulcanized rubber is subjected to tensile property test according to the national standard GB/T528-2009, wherein the tensile speed is 500 mm/min. The tensile strength can reach 26 MPa, and the elongation at break is 520%. After the cutting, the dumbbell-shaped rubber has tiny cracks and is easy to spread, and the mechanical strength of the styrene butadiene rubber is influenced.

Comparative example 2

Firstly, 100 parts of butadiene styrene rubber is added into an internal mixer, 5 parts of carbon black, 0.5 part of COF-1 containing carboxyl active groups, 2 parts of zinc oxide, 3 parts of stearic acid and a titanate coupling agent accounting for 1.25 times of carboxyl in the COF-1 are sequentially added, the temperature of the internal mixer is kept at 40 ℃, stirring is carried out, and standing is carried out after internal mixing is finished, so that a section of rubber compound is obtained; adding the first-stage rubber compound, 2 parts of sulfur, 1 part of CZ, 1 part of antioxidant 4020 and 3 parts of DOP into an open mill, mixing at the temperature of 50 ℃, and standing after the mixing is finished to obtain a second-stage rubber compound; and (3) standing for 24 h, vulcanizing the second-stage rubber compound at 180 ℃ and 10 MPa, and carrying out flat-plate heat vulcanization for 14 min to obtain the two-dimensional covalent organic framework/styrene butadiene rubber composite material. The material is cut into dumbbell-shaped samples with the length of 115 mm by a special rubber cutter, and the vulcanized rubber is subjected to tensile property test according to the national standard GB/T528-2009, wherein the tensile speed is 500 mm/min. The tensile strength can reach 26 MPa, and the elongation at break is 440%.

It can be seen from examples 1-3 and comparative examples 1-2 that the addition of COF two-dimensional framework material can effectively improve the mechanical properties of styrene-butadiene rubber, while the addition of silane coupling agent can further improve the mechanical strength, but it should be noted that other conventional coupling agents such as titanate, aluminate and zirconate can not achieve corresponding effects.