阅读说明：本技术 一种改性橡胶粉的制备方法 (Preparation method of modified rubber powder ) 是由 谭金和 于 2021-01-08 设计创作，主要内容包括：本发明涉及橡胶技术领域,具体涉及一种改性橡胶粉的制备方法,所述改性橡胶粉的制备方法,包括如下步骤：(1)将废旧橡胶粗碎,去除杂质,再粉碎,去除杂质,得到橡胶粉；(2)橡胶粉在微波作用下得到物质A；(3)将物质A加入有机溶剂中,与引发剂、改性剂混合,即得；所述引发剂为过氧化苯甲酰-N,N-二甲基苯胺体系与偶氮二异丁酸二甲酯的混合物。本发明具有工艺简单、生产成本低、制备得到的橡胶制品力学性能优异的优点。(The invention relates to the technical field of rubber, in particular to a preparation method of modified rubber powder, which comprises the following steps: (1) coarsely crushing waste rubber, removing impurities, crushing again, and removing impurities to obtain rubber powder; (2) obtaining a substance A from the rubber powder under the action of microwave; (3) adding the substance A into an organic solvent, and mixing with an initiator and a modifier to obtain the product; the initiator is a mixture of a benzoyl peroxide-N, N-dimethylaniline system and dimethyl azodiisobutyrate. The invention has the advantages of simple process, low production cost and excellent mechanical property of the prepared rubber product.)

1. The preparation method of the modified rubber powder is characterized by comprising the following steps:

(1) coarsely crushing waste rubber, removing impurities, crushing again, and removing impurities to obtain rubber powder;

(2) obtaining a substance A from the rubber powder under the action of microwave;

(3) adding the substance A into an organic solvent, and mixing with an initiator and a modifier to obtain the product; the initiator is a mixture of a benzoyl peroxide-N, N-dimethylaniline system and dimethyl azodiisobutyrate.

2. The method according to claim 1, wherein the rubber in the step (1) is at least one of natural rubber, styrene-butadiene rubber, SBS rubber and nitrile-butadiene rubber.

3. The method according to claim 1, wherein the rubber powder in step (1) has a particle size of 20 to 150 mesh, preferably 20 to 50 mesh: 50-100 meshes: 100-150 meshes is 1:2-4: 1-3.

4. The method as claimed in claim 1, wherein the power of the microwave in step (2) is 200-400W, and the action time of the microwave is 15-30 min.

5. The method according to claim 1, wherein the organic solvent in step (3) is at least one of dichloromethane, chloroform, cyclohexane, toluene and tetrahydrofuran.

6. The method according to claim 1, wherein the ratio of the volume of the organic solvent to the mass of the rubber powder in the step (3) is 5 to 10 mL/g.

7. The method according to claim 1, wherein the mass of the benzoyl peroxide-N, N-dimethylaniline system in the step (3) is 0.05-0.1% of the mass of the rubber powder, the mass ratio of benzoyl peroxide to N, N-dimethylaniline is 2-4:1, and the mass of the dimethyl azodiisobutyrate is 0.01-0.04% of the mass of the rubber powder.

8. The production method according to claim 1, wherein the modifier in the step (3) is at least one of maleic anhydride, polypropylene-grafted maleic anhydride, styrene, methyl methacrylate and acrylonitrile; the mass of the modifier is 10-20% of the mass of the rubber powder.

9. The preparation method of claim 8, wherein the modifier is a mixture of maleic anhydride and polypropylene grafted maleic anhydride, and the mass ratio of the maleic anhydride to the polypropylene grafted maleic anhydride is 3-8: 1.

10. A modified rubber crumb prepared by the process of any one of claims 1 to 9.

Technical Field

The invention relates to the technical field of rubber, in particular to a preparation method of modified rubber powder.

Background

The waste rubber mainly refers to industrial products such as waste tires, rubber shoes, adhesive tapes, sealing rubber plates and the like, wherein the waste tires are mainly used. The waste tire is difficult to degrade due to the specific three-dimensional cross-linked network structure of the waste rubber, and the environment is greatly polluted because the waste tire is piled for a long time and is not treated in time. Therefore, the problem of recycling a series of industrial waste rubber products represented by waste tires has been a great problem. The waste rubber is effectively and reasonably recycled, so that the corresponding environmental pollution problem can be solved, the development of the industrial field can be promoted, the quality of life is improved, and the development of the industrial level is indirectly promoted.

The recycling method of the waste rubber comprises direct utilization and indirect utilization. The direct utilization is that the material is used in the original shape or similar shape, including retreading, decorating material, buffering material, material for sports equipment, etc. The waste rubber can be directly utilized without too many treatment processes, the resource reutilization can be realized, the method is simple to operate and has low requirement on equipment, but the method has the advantages of obvious defects, low utilization rate and difficulty in producing products with high added values.

The indirect utilization of the waste rubber refers to the utilization of the waste rubber after processing by physical and chemical methods, such as regenerated rubber, waste rubber powder preparation, thermal cracking, combustion power generation, landfill and the like. The reclaimed rubber is rubber which is capable of being re-vulcanized, wherein cross-linking bonds such as disulfide and polysulfide formed in the vulcanization process are cut off by means of heat, machinery, physical chemistry and the like, so that the high elasticity of the rubber is eliminated, and the rubber is plastic and viscous. The mixing of the reclaimed rubber in the rubber product is beneficial to the mixing processing of the rubber, but the production of the reclaimed rubber has the problems of high working strength, complex production process, high energy consumption, high production cost, great environmental pollution and the like. The thermal cracking product of the waste tire rubber can be used for producing products with high added values such as oil products, chemicals, fuels and the like, but the method has large investment, high recovery cost and secondary pollution to the environment, so the application is limited. The methods of combustion power generation, landfill and the like occupy land resources, have low degradation speed and are easy to pollute the environment.

At present, the waste rubber is recycled by producing coarse rubber particles or fine, fine and hyperfine waste rubber powder, which is a clean and effective resource recycling mode, and the waste rubber powder becomes one of the most promising methods for treating the waste rubber at present. At present, the preparation of the waste rubber powder from the waste tire is the main direction of waste tire treatment, has the advantages of relatively low production cost, high added value of products, large-scale production, small environmental pollution and the like, and can be applied to the fields of rubber industry, plastic industry, road asphalt, building materials and the like.

The waste rubber powder has a compact three-dimensional cross-linked network structure, the surface is inert, the chemical reaction activity is low, the surface property of the waste rubber powder is different from that of a polymer matrix, the compatibility of the waste rubber powder and the polymer matrix is poor, if the waste rubber powder is directly added into a high polymer material, a better bonding interface is difficult to form, and the performance of the waste rubber powder modified high polymer material is not ideal along with the increase of the addition amount of the waste rubber powder. Therefore, the waste rubber powder needs to be modified by degradation, surface activation and the like to improve the interface bonding between the waste rubber powder and the polymer material, so that the consumption of the waste rubber powder and the comprehensive performance of the blending material can be increased simultaneously. At present, the main modification methods include mechanochemical method, physical method, chemical method, biological method and the like.

Chinese patent application CN109774016A discloses a production method for producing fine rubber powder by using waste tires. The conventional process for producing the rubber powder at normal temperature is optimized, and the multi-stage screening module is added in the coarse crushing and fine crushing processes, so that the high-efficiency utilization of the raw materials is ensured, and the utilization rate of the raw materials and the generation rate of the fine rubber powder are improved; the calcium carbonate powder and the circuit board powder are added in the preparation of the grinding material, so that the flowability and the dispersibility of the rubber powder in the grinding process are effectively promoted, the rubber powder is not easy to agglomerate, and the later geometrical properties of the rubber powder are not influenced. The production method for decomposing the waste tires into the fine rubber powder is simple and practical, has high safety, and has the advantages of low energy consumption, high yield, good finished product dispersibility, low metal impurities and the like. However, the method does not modify the surface of the rubber powder, and the prepared rubber powder is used for preparing rubber products, so that the performance of the rubber powder is required to be further improved.

Chinese patent application CN1974621A discloses a modified rubber powder and its preparation method and use, the modified rubber powder has the chemical structure: the side chain of the rubber powder contains alkyl, alkenyl, hydroxyl, carboxyl, nitrile group or amido, or the side chain of the rubber powder is connected with one of the following compounds through double bond reaction: butadiene, polystyrene, vinyl acetate, acrylates, acrylonitrile, vinyl chloride, styrene or maleic anhydride. The modified rubber powder of the invention keeps the structural characteristics of corresponding rubber, thereby having good mechanical property, chemical and physical properties, processing property and the like of the rubber. And functional groups are introduced on the side chain of the rubber, so that the compatibility of the original rubber and other high polymers such as rubber, plastic, polyurethane and the like is obviously improved, and the rubber has the characteristics of easy grafting reaction and functional group chemical reaction, and is beneficial to the bonding and chemical modification of other compounds. However, the rubber powder obtained after modification is used for preparing rubber products, and the performance of the rubber powder needs to be further improved.

Therefore, it is necessary to develop a method for preparing a modified rubber powder which can solve the above-mentioned problems.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide the preparation method of the modified rubber powder with simple process, low production cost and excellent mechanical property of the prepared rubber product.

The invention is realized by the following technical scheme:

a preparation method of modified rubber powder comprises the following steps:

(1) coarsely crushing waste rubber, removing impurities, crushing again, and removing impurities to obtain rubber powder;

(2) obtaining a substance A from the rubber powder under the action of microwave;

(3) adding the substance A into an organic solvent, and mixing with an initiator and a modifier to obtain the product; the initiator is a mixture of a benzoyl peroxide-N, N-dimethylaniline system and dimethyl azodiisobutyrate.

Preferably, the rubber in the step (1) is at least one of natural rubber, styrene-butadiene rubber, SBS rubber and nitrile rubber.

Preferably, the particle size of the rubber powder in the step (1) is 20-150 meshes.

More preferably, the particle size of the rubber powder in the step (1) is 20-50 mesh: 50-100 meshes: 100-150 meshes is 1:2-4: 1-3.

Preferably, the power of the microwave in the step (2) is 200-400W, and the acting time of the microwave is 15-30 min.

Preferably, the organic solvent in step (3) is at least one of dichloromethane, chloroform, cyclohexane, toluene and tetrahydrofuran.

Preferably, the ratio of the volume of the organic solvent to the mass of the rubber powder in the step (3) is 5-10 mL/g.

Preferably, the mass of the benzoyl peroxide-N, N-dimethylaniline system in the step (3) is 0.05-0.1% of the mass of the rubber powder.

Preferably, the mass ratio of the benzoyl peroxide to the N, N-dimethylaniline in the step (3) is 2-4: 1.

Preferably, the mass of the dimethyl azodiisobutyrate in the step (3) is 0.01 to 0.04% of the mass of the rubber powder.

Preferably, the modifier in step (3) is at least one of maleic anhydride, polypropylene grafted maleic anhydride, styrene, methyl methacrylate and acrylonitrile.

Preferably, the mass of the modifier is 10-20% of the mass of the rubber powder.

More preferably, the modifier is a mixture of maleic anhydride and polypropylene grafted maleic anhydride, and the mass ratio of the maleic anhydride to the polypropylene grafted maleic anhydride is 3-8: 1.

Preferably, the substance A in the step (3) is added into an organic solvent, heated to 25-100 ℃, mixed with an initiator and a modifier, filtered after 1-2h, and dried in vacuum to obtain the compound.

More preferably, the preparation method of the modified rubber powder comprises the following steps:

(1) coarsely crushing the waste rubber, removing impurities, crushing again, and removing impurities to obtain rubber powder of 20-150 meshes;

(2) obtaining a substance A from the rubber powder under the action of microwave; the power of the microwave is 200-400W, and the action time of the microwave is 15-30 min;

(3) adding the substance A into an organic solvent, heating to 25-100 ℃, mixing with an initiator and a modifier, filtering after 1-2h, and drying in vacuum to obtain the product; the initiator is a mixture of a benzoyl peroxide-N, N-dimethylaniline system and dimethyl azodiisobutyrate.

The invention also relates to the modified rubber powder prepared by the preparation method.

The invention has the beneficial effects that:

the invention optimizes the particle size composition of the rubber powder, is beneficial to heat diffusion among rubber particles with different particle sizes, and simultaneously avoids the phenomenon that the rubber particles are fused and agglomerated because of locally absorbing excessive heat, thereby being not beneficial to rubber modification.

The invention optimizes the power and action time of the microwave, is beneficial to breaking as many cross-linking bonds as possible under the action of the microwave, and simultaneously avoids consuming residual double bonds or causing internal agglomeration for too long time, which is not beneficial to modification.

The invention optimizes the composition of the initiator, is beneficial to the modification of rubber, and obviously improves the mechanical property of the modified rubber powder.

The invention optimizes the composition of the modifier, and particularly when the modifier is a mixture of maleic anhydride and polypropylene grafted maleic anhydride, the mechanical property after modification is further improved.

The modified rubber powder is used for preparing tires, and the wear resistance and mechanical property of the tires are obviously improved.

Detailed Description

The invention will be further described with reference to specific embodiments, and the advantages and features of the invention will become apparent as the description proceeds. These examples are illustrative only and do not limit the scope of the present invention in any way. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention, and that such changes and modifications may be made without departing from the spirit and scope of the invention.

The polypropylene grafted maleic anhydride used in the examples and comparative examples of the present application was obtained from ancient sea plastics chemical Co., Ltd, Dongguan city.

Example 1

A preparation method of modified rubber powder comprises the following steps:

(1) coarsely crushing the waste natural rubber, removing impurities, crushing again, and further removing the impurities to obtain 20-mesh rubber powder;

(2) obtaining a substance A from the rubber powder under the action of microwave; the microwave power is 200W, and the microwave action time is 15 min;

(3) adding the substance A into dichloromethane, heating to 30 ℃, mixing the dichloromethane with 5mL/g of the ratio of the volume of the dichloromethane to the mass of the rubber powder, an initiator and a modifier, filtering after 2h, and drying in vacuum to obtain the rubber powder;

the initiator is a mixture of a benzoyl peroxide-N, N-dimethylaniline system and dimethyl azodiisobutyrate, the mass of the benzoyl peroxide-N, N-dimethylaniline system (the mass ratio of benzoyl peroxide to N, N-dimethylaniline is 2:1) is 0.05 percent of the mass of the rubber powder, and the mass of the dimethyl azodiisobutyrate is 0.01 percent of the mass of the rubber powder;

the modifier is a mixture of maleic anhydride and polypropylene grafted maleic anhydride, the mass ratio of the maleic anhydride to the polypropylene grafted maleic anhydride is 3:1, and the mass of the modifier is 10% of that of the rubber powder.

Example 2

A preparation method of modified rubber powder comprises the following steps:

(1) coarsely crushing the waste butadiene styrene rubber, removing impurities, crushing again, and further removing the impurities to obtain 150-mesh rubber powder;

(2) obtaining a substance A from the rubber powder under the action of microwave; the microwave power is 400W, and the microwave action time is 30 min;

(3) adding the substance A into cyclohexane, heating to 70 ℃, mixing the substance A with an initiator and a modifier at a ratio of the volume of the cyclohexane to the mass of the rubber powder of 10mL/g, filtering after 1h, and drying in vacuum to obtain the rubber powder;

the initiator is a mixture of a benzoyl peroxide-N, N-dimethylaniline system and dimethyl azodiisobutyrate, the mass of the benzoyl peroxide-N, N-dimethylaniline system (the mass ratio of benzoyl peroxide to N, N-dimethylaniline is 4:1) is 0.1% of the mass of the rubber powder, and the mass of the dimethyl azodiisobutyrate is 0.04% of the mass of the rubber powder;

the modifier is a mixture of maleic anhydride and polypropylene grafted maleic anhydride, the mass ratio of the maleic anhydride to the polypropylene grafted maleic anhydride is 8:1, and the mass of the modifier is 20% of that of the rubber powder.

Example 3

A preparation method of modified rubber powder comprises the following steps:

(1) coarsely crushing the waste natural rubber, removing impurities, crushing again, and further removing the impurities to obtain 100-mesh rubber powder;

(2) obtaining a substance A from the rubber powder under the action of microwave; the power of the microwave is 300W, and the acting time of the microwave is 20 min;

(3) adding the substance A into toluene, heating to 100 ℃, mixing the toluene with the rubber powder at a ratio of the volume of the toluene to the mass of the rubber powder of 8mL/g, filtering after 1.5h, and drying in vacuum to obtain the rubber powder;

the initiator is a mixture of a benzoyl peroxide-N, N-dimethylaniline system and dimethyl azodiisobutyrate, the mass of the benzoyl peroxide-N, N-dimethylaniline system (the mass ratio of benzoyl peroxide to N, N-dimethylaniline is 3:1) is 0.08% of the mass of the rubber powder, and the mass of the dimethyl azodiisobutyrate is 0.02% of the mass of the rubber powder;

the modifier is a mixture of maleic anhydride and polypropylene grafted maleic anhydride, the mass ratio of the maleic anhydride to the polypropylene grafted maleic anhydride is 5:1, and the mass of the modifier is 15% of that of the rubber powder.

Example 4

The difference from the example 3 is only that the particle size of the rubber powder in the step (1) is different, specifically 20-50 meshes: 50-100 meshes: 100-150 mesh is 1:2:1, and the rest conditions are the same.

Example 5

The difference from the example 3 is only that the particle size of the rubber powder in the step (1) is different, specifically 20-50 meshes: 50-100 meshes: 100-150 mesh is 1:4:3, and the rest conditions are the same.

Example 3-1

The difference from example 3 is only that the microwave exposure time in step (2) is 10min, and the rest conditions are the same.

Examples 3 to 2

The difference from example 3 is only that the microwave exposure time in step (2) is 40min, and the rest conditions are the same.

Examples 3 to 3

The only difference from example 3 is the type of initiator in step (3), the mixture of benzoyl peroxide-N, N-dimethylaniline system and dimethyl azodiisobutyrate is replaced by a benzoyl peroxide-N, N-dimethylaniline system, the remaining conditions being the same and being as follows:

the initiator is a benzoyl peroxide-N, N-dimethylaniline system, and the mass of the benzoyl peroxide-N, N-dimethylaniline system (the mass ratio of benzoyl peroxide to N, N-dimethylaniline is 3:1) is 0.1% of the mass of the rubber powder.

Examples 3 to 4

The only difference from example 3 is the type of initiator in step (3), the mixture of benzoyl peroxide-N, N-dimethylaniline system and dimethyl azodiisobutyrate was replaced by dimethyl azodiisobutyrate, and the remaining conditions were the same, as follows:

the initiator is dimethyl azodiisobutyrate, and the mass of the dimethyl azodiisobutyrate is 0.1% of that of the rubber powder.

Examples 3 to 5

The difference from example 3 is only in the kind of modifier in step (3), and the rest conditions are the same, specifically as follows:

the modifier is maleic anhydride, and the mass of the maleic anhydride is 15% of that of the rubber powder.

Examples 3 to 6

The difference from example 3 is only in the kind of modifier in step (3), and the rest conditions are the same, specifically as follows:

the modifier is a mixture of maleic anhydride and polypropylene, the mass ratio of the maleic anhydride to the polypropylene is 5:1, and the mass of the modifier is 15% of that of the rubber powder.

Test example 1

The modified rubber powder prepared in each example is used for preparing vulcanized rubber, and the modified rubber powder comprises the following raw materials in parts by weight: 80 parts of natural rubber, 20 parts of modified rubber powder, 5 parts of zinc oxide, 2 parts of stearic acid SA, 50 parts of carbon black N33050, 1.2 parts of anti-aging agent 40202, 1.8 parts of accelerator CZ and 1.8 parts of sulfur.

Firstly, thinly passing natural rubber on a double-roller open mill for 5 times, then mixing the above-mentioned components by using domestic Haake internal mixer, feeding temp. is 100 deg.C, main machine temp. is 150 deg.C, and its initial rotation speed is 60 rpm, firstly, thinly passing throughAnd putting the natural rubber and the modified rubber powder into an internal mixer, and then sequentially adding carbon black N330, zinc oxide, stearic acid SA, an anti-aging agent 4020, an accelerator CZ and sulfur every 1 minute. Then carrying out rubber vulcanization on a flat vulcanizing machine under the vulcanization condition of 143 ℃ x t₉₀。

The prepared vulcanized rubber is tested for physical and mechanical properties and wear resistance,

physical and mechanical properties: testing the hardness of the rubber by using a Shore A type durometer, wherein the test standard refers to GB/T531-1999; the tensile property test is referred to GB/T528-1998, and the shape of a sample is a 1-type dumbbell-shaped sample; the tear properties are tested with reference to GB/T529-1999, square specimen, tensile speed 500 mm/min.

Wear resistance: refer to national standard GB/T1689-1998.

The results are shown in Table 1.

TABLE 1 vulcanized rubber physical and mechanical Properties and abrasion resistance test

The above detailed description is specific to one possible embodiment of the present invention, and the embodiment is not intended to limit the scope of the present invention, and all equivalent implementations or modifications without departing from the scope of the present invention should be included in the technical scope of the present invention.