Lignin-based dual-phase carbon black as well as preparation method and application thereof

Abstract

The invention relates to lignin-based biphase carbon black as well as a preparation method and application thereof, and belongs to the technical field of biomass chemical energy. The preparation method of the lignin-based biphase carbon black comprises the following steps: mixing modified lignin, a silicon source, alcohol and water to obtain a mixed solution, and carrying out acid precipitation on the mixed solution to obtain a lignin / silicon dioxide compound; and carbonizing the lignin / silicon dioxide compound to obtain the lignin / silicon dioxide composite. The lignin-based biphase carbon black prepared by the invention has the advantages of cheap and easily available production materials, simple and low-consumption production process, small particle size, multiple micropores, easy dispersion and the like, has strong binding force with rubber, and is more beneficial to production application and market promotion.

Description

Technical Field

[0001] The present invention belongs to the technical field of biomass chemical energy, and particularly relates to a lignin-based biphasic carbon black, a preparation method thereof, and an application thereof. Background Art

[0002] Lignin is a kind of complex organic polymer with a three-dimensional network structure and various active groups such as hydroxyl groups and carboxyl groups. It has a wide source, is green and renewable, and has a low cost. When lignin is directly used as a rubber filler, its active groups can react with rubber to form a double network structure, thereby enhancing the reinforcement effect on rubber. However, lignin is also a high-molecular filler, which will reduce the rigidity of rubber, and lignin itself is very easy to agglomerate, so it is not conducive to dispersion in rubber when used alone.

[0003] The carbon content of lignin is as high as 50-60%. The active functional groups of lignin can combine with silica. On the one hand, silica can be evenly dispersed with lignin. On the other hand, lignin uses silica as a soft template to form a biphasic composite with a smaller particle size. After the prepared biphasic composite is carbonized, a carbon-silica composite can be obtained. While the particle size is further reduced, the micropores formed by burning off the oxygen-containing functional groups can enable rubber chains to further penetrate therein, enhancing the binding force with rubber. However, the existing carbon-silica composites cannot use lignin to directly mix with a silicon source, and a surfactant needs to be added to prepare a relatively uniform lignin / silica composite, and the addition of the surfactant will reduce the binding strength between lignin and silica. Summary of the Invention

[0004] The first object of the present invention is to provide a preparation method of a lignin-based biphasic carbon black to solve the technical problem that the binding strength between lignin and silica is reduced due to the addition of a surfactant in the preparation process of the existing lignin / silica composite, thereby affecting the structure of the lignin / silica composite.

[0005] The second object of the present invention is to provide a lignin-based biphasic carbon black.

[0006] The third object of the present invention is to provide an application of a lignin-based biphasic carbon black.

[0007] In order to achieve the above objects, the technical solutions adopted by the present invention are as follows:

[0008] A preparation method of a lignin-based biphasic carbon black includes the following steps: mixing modified lignin, a silicon source, an alcohol, and water to obtain a mixed solution, and subjecting the mixed solution to acid precipitation to obtain a lignin / silica composite; carbonizing the lignin / silica composite to obtain the product.

[0009] Further, the modified lignin is quaternized lignin, phosphorylated lignin, sulfonated lignin, hydroxymethylated lignin, aminated lignin, etc.

[0010] Further, the mass ratio of the modified lignin to silicon dioxide in the silicon source is 0.5 - 3:1, the volume ratio of water to alcohol is 2 - 8:1, and 64 - 144 mL of water is added per gram of the modified lignin. If the alcohol content is too high, the yield of the product is likely to decrease significantly. If the content is too low, the product will agglomerate and shrink severely.

[0011] Further, the silicon source is one or more of industrial water glass, sodium metasilicate, tetraethyl orthosilicate, and silicon-containing products after pyrolysis of rice husks; the alcohol is one or more of C1 - C6 alcohols; the silicon source is preferably sodium metasilicate; the alcohol is preferably ethanol.

[0012] Further, the acid precipitation adopts a two-step acid precipitation method, and the substances used for acid precipitation are one or more of hydrochloric acid, sulfuric acid, ammonium chloride, and ammonia water.

[0013] Further, the first acid precipitation is carried out at a pH of 9 - 11, and then the second acid precipitation is carried out at a pH of 2 - 5; the temperature of the first acid precipitation is 20 - 50 °C, the time is 1 - 3 h, the dropping rate of the substance used for the first acid precipitation is 20 - 40 mL / min, and the stirring speed is 300 - 600 r / min; the temperature of the second acid precipitation is 60 - 80 °C, the time is 1 - 3 h, and the dropping rate of the substance used for the second acid precipitation is 3 - 5 mL / min.

[0014] By adopting the two-step acid precipitation method, the silicon source will form a silicon-oxygen-silicon network and precipitate from the solution after the pH is less than 11, forming the core in the modified lignin-based biphasic carbon black core-shell structure. Using the silicon dioxide core as a soft template, when the pH continues to drop to 2 - 5, the modified lignin begins to precipitate from the solution and coat the surface of the silicon dioxide core, thereby forming a modified lignin-silicon dioxide biphasic core-shell composite material. During the first acid precipitation, the dropping rate is controlled at 20 - 40 mL / min, and the stirring speed is controlled at 300 - 600 r / min. Too slow a dropping rate or too low a stirring speed will cause an increase in the particle size of the silicon dioxide core; the dropping rate during the second acid precipitation is 3 - 5 mL / min. Too fast a dropping rate will cause local over-acidity and lead to agglomeration of the modified lignin.

[0015] Further, the carbonization is carried out in one or more mixed gases of nitrogen, carbon dioxide, and argon.

[0016] Further, the temperature of the carbonization is 400 - 1000 °C, the heating rate of the carbonization is 5 - 15 °C / min, and the holding time of the carbonization is 2 - 4 h.

[0017] A lignin-based biphasic carbon black is prepared by using the preparation method of the lignin-based biphasic carbon black described above.

[0018] Application of a lignin-based biphasic carbon black as a filler in styrene-butadiene rubber; the mass ratio of the lignin-based biphasic carbon black to the styrene-butadiene rubber is 10-50:100.

[0019] Advantages of the present invention:

[0020] The lignin-based biphasic carbon black produced by the present invention has cheap and easily available production materials, a simple and low-consumption production process, and has the advantages of small particle size, many micropores, easy dispersion, etc. It has a strong binding force with rubber, which is more conducive to production application and market promotion.

[0021] The present invention uses modified lignin and a silicon source as raw materials, and through a two-step acid precipitation method, a lignin / silica composite with a core-shell structure is precipitated step by step, and then through a carbonization process, a lignin-based biphasic carbon black with a microporous structure is obtained. The lignin / silica composite prepared by the present invention has uniform size, good compounding, and easy dispersion, solving the disadvantage that lignin and silica are prone to self-aggregation themselves. The lignin-based biphasic carbon black with a microporous structure obtained after carbonization has good compatibility with rubber, and the mechanical properties and vulcanization time of the rubber added with the lignin-based biphasic carbon black of the present invention are improved. Brief description of the drawings

[0022] Figure 1 Particle size distribution diagram of the lignin-based biphasic carbon black in Example 1 Detailed implementation manners

[0023] The present invention will be further described below in conjunction with the embodiments of the present invention and the drawings.

[0024] The vulcanizing agent used is sulfur powder.

[0025] Example 1

[0026] The preparation method of the lignin-based biphasic carbon black in Example 1 is as follows:

[0027] Dissolve 5.93 g of sodium metasilicate nonahydrate in 120 mL of deionized water. Subsequently, add 1.25 g of quaternized lignin and maintain the pH of the system at 13. Stir using a semi-moon stirrer, controlling the stirring speed at 500 r / min. Then add 20 mL of absolute ethanol and stir at 20 °C for 30 min to obtain a mixed solution. At 20 °C, add sulfuric acid solution to the mixed solution at a dropping rate of 30 mL / min for the first acid precipitation to rapidly precipitate silica. When the pH is 10.0, stir and react for 1 h with a stirring speed of 300 r / min. After the reaction, raise the temperature of the mixed solution after the first acid precipitation to 70 °C and add sulfuric acid solution at a dropping rate of 4 mL / min for the second acid precipitation until the pH drops to 3, so that the quaternized lignin deposits and coats on the surface of silica. Maintain stirring and reacting at 70 °C for 2 h. After the reaction, use vacuum-assisted filtration to obtain the lignin / silica composite.

[0028] Place the lignin / silica composite dried to constant weight in a clean corundum boat and spread it flat. Under the protection of a nitrogen atmosphere, carry out the carbonization process through a tube furnace. The carbonization conditions are as follows: the heating rate is 10 °C / min. After heating to 500 °C, hold for 3 h, and then naturally cool to obtain lignin-based biphasic carbon black.

[0029] The rubber in Example 1 includes the following raw materials: 40 g of styrene-butadiene rubber, 16 g of lignin-based biphasic carbon black, 0.4 g of stearic acid, 1.2 g of zinc oxide, 0.7 g of vulcanizing agent, 0.4 g of vulcanization accelerator DM, and 0.4 g of vulcanization accelerator CZ.

[0030] The rubber mixing process is as follows:

[0031] Internal mixer process: Set the mixing temperature at 60 °C and the rotation speed of the internal mixer at 50 r / min. Put the styrene-butadiene rubber into the internal mixer and mix for 1 min. Subsequently, add stearic acid and zinc oxide and continue to mix for 2 min. Adjust the rotation speed of the internal mixer to 60 r / min, add the lignin-based biphasic carbon black into the internal mixer, and continue to mix for 2 min until the torque no longer changes and then discharge the rubber.

[0032] Open mill process: Adjust the distance between the front and rear rollers of the open mill to 1 cm and the rotation speed to 10 rpm:12 rpm. Wrap the rubber around the rollers, add the vulcanizing agent, vulcanization accelerator DM, and vulcanization accelerator CZ, carry out cutting, triangular wrapping, and rolling, and discharge the rubber after mixing evenly.

[0033] Example 2

[0034] The preparation method of the lignin-based biphasic carbon black in Example 2 is as follows:

[0035] Dissolve 5.93 g of sodium metasilicate nonahydrate in 120 mL of deionized water, then add 1.25 g of phosphorylated lignin, and maintain the pH of the system at 13. Stir using a semi-moon stirrer, and control the stirring speed at 500 r / min. Then add 20 mL of absolute ethanol, and stir at 20 °C for 30 min to obtain a mixed solution. At 40 °C, add sulfuric acid solution dropwise to the mixed solution at a dropping rate of 30 mL / min for the first acid precipitation to rapidly precipitate silica. When the pH is 10, stir and react for 1 h, and the stirring speed is 400 r / min. After the reaction is completed, raise the temperature of the mixed solution after the first acid precipitation to 70 °C, and add sulfuric acid solution dropwise at a dropping rate of 4 mL / min for the second acid precipitation until the pH drops to 3, so that phosphorylated lignin deposits and coats on the surface of silica. Maintain stirring and reacting at 70 °C for 2 h. After the reaction is completed, use vacuum-assisted suction filtration to obtain a lignin / silica composite.

[0036] Place the lignin / silica composite dried to constant weight in a clean corundum boat and spread it flat. Under the protection of a nitrogen atmosphere, carry out a carbonization process through a tube furnace. The carbonization conditions are as follows: the heating rate is 10 °C / min. After heating to 500 °C, hold for 3 h, and then cool naturally to obtain lignin-based biphasic carbon black.

[0037] The rubber in Example 2 includes the following raw materials: 40 g of styrene-butadiene rubber, 16 g of lignin-based biphasic carbon black, 0.4 g of stearic acid, 1.2 g of zinc oxide, 0.7 g of vulcanizing agent, 0.4 g of vulcanization accelerator DM, and 0.4 g of vulcanization accelerator CZ.

[0038] The rubber mixing process is as follows:

[0039] Internal mixing process: Set the internal mixing temperature at 60 °C and the rotation speed of the internal mixer at 50 r / min. Put the styrene-butadiene rubber into the internal mixer and mix for 1 min, then add stearic acid and zinc oxide and continue to mix for 2 min; adjust the rotation speed of the internal mixer to 60 r / min, add lignin-based biphasic carbon black to the internal mixer, and continue to mix for 2 min until the torque no longer changes and then discharge the rubber.

[0040] Open mill process: Adjust the distance between the front and rear rollers of the open mill to 1 cm and the rotation speed to 10 rpm:12 rpm. Wrap the rubber around the rollers, add the vulcanizing agent, vulcanization accelerator DM, and vulcanization accelerator CZ, carry out cutting, triangular wrapping, and rolling, and discharge the rubber after mixing evenly.

[0041] Example 3

[0042] The preparation method of the lignin-based biphasic carbon black in Example 3 is as follows:

[0043] Dissolve 5.93 g of sodium metasilicate nonahydrate in 80 mL of deionized water, then add 1.25 g of sulfonated lignin, and maintain the pH of the system at 13. Stir using a semi-moon stirrer, and control the stirring speed at 500 r / min. Then add 10 mL of absolute ethanol, and stir at 20 °C for 30 min to obtain a mixed solution. At 20 °C, add sulfuric acid solution to the mixed solution at a dropping rate of 40 mL / min for the first acid precipitation to rapidly precipitate silica. When the pH is 9.0, stir and react for 1 h, and the stirring speed is 500 r / min. After the reaction is completed, raise the temperature of the mixed solution after the first acid precipitation to 60 °C, and add sulfuric acid solution at a dropping rate of 5 mL / min for the second acid precipitation until the pH drops to 2, so that the sulfonated lignin deposits and coats on the surface of silica. Maintain stirring and reacting at 60 °C for 2 h. After the reaction is completed, use vacuum-assisted filtration to obtain the lignin / silica composite.

[0044] Place the lignin / silica composite dried to a constant weight in a clean corundum boat and spread it flat. Under the protection of a nitrogen atmosphere, carry out a carbonization process through a tube furnace. The carbonization conditions are as follows: the heating rate is 10 °C / min. After heating to 500 °C, hold for 3 h, and then naturally cool to obtain lignin-based biphasic carbon black.

[0045] The rubber in Example 3 includes the following raw materials: 40 g of styrene-butadiene rubber, 16 g of lignin-based biphasic carbon black, 0.4 g of stearic acid, 1.2 g of zinc oxide, 0.7 g of vulcanizing agent, 0.4 g of vulcanization accelerator DM, and 0.4 g of vulcanization accelerator CZ.

[0046] The rubber mixing process is as follows:

[0047] Internal mixing process: Set the internal mixing temperature at 60 °C and the rotation speed of the internal mixer at 50 r / min. Put the styrene-butadiene rubber into the internal mixer and mix for 1 min, then add stearic acid and zinc oxide, and continue to mix for 2 min; adjust the rotation speed of the internal mixer to 60 r / min, add the lignin-based biphasic carbon black to the internal mixer, and continue to mix for 2 min until the torque no longer changes and then discharge the rubber.

[0048] Open mill process: Adjust the front and rear roll spacing of the open mill to 1 cm and the rotation speed to 10 rpm:12 rpm. Wrap the rubber around the roll, add the vulcanizing agent, vulcanization accelerator DM, and vulcanization accelerator CZ, carry out cutting, triangular wrapping, and rolling, and discharge the rubber after mixing evenly.

[0049] Example 4

[0050] The preparation method of the lignin-based biphasic carbon black in Example 4 is as follows:

[0051] Dissolve 5.93 g of sodium metasilicate nonahydrate in 180 mL of deionized water, then add 1.25 g of hydroxymethylated lignin, and maintain the pH in the system at 13. Stir using a semi-moon stirrer, and control the stirring speed at 500 r / min. Then add 30 mL of absolute ethanol, and stir at 20 °C for 30 min to obtain a mixed solution. At 40 °C, add sulfuric acid solution dropwise to the mixed solution at a dropping rate of 30 mL / min for the first acid precipitation to rapidly precipitate silicon dioxide. When the pH is 10.0, stir and react for 1 h, and the stirring speed is 600 r / min. After the reaction is completed, raise the temperature of the mixed solution after the first acid precipitation to 70 °C, and add sulfuric acid solution dropwise at a dropping rate of 3 mL / min for the second acid precipitation until the pH drops to 4, so that the hydroxymethylated lignin is deposited and coated on the surface of silicon dioxide. Maintain stirring and reacting at 70 °C for 2 h. After the reaction is completed, use vacuum-assisted filtration to obtain a lignin / silicon dioxide composite.

[0052] Place the lignin / silicon dioxide composite dried to constant weight flat in a clean corundum boat, and carry out a carbonization process through a tubular furnace under the protection of a nitrogen atmosphere. The carbonization conditions are as follows: the heating rate is 10 °C / min. After heating to 500 °C, hold for 3 h, and then naturally cool to obtain lignin-based biphasic carbon black.

[0053] The rubber in Example 4 includes the following raw materials: 40 g of styrene-butadiene rubber, 16 g of lignin-based biphasic carbon black, 0.4 g of stearic acid, 1.2 g of zinc oxide, 0.7 g of vulcanizing agent, 0.4 g of vulcanization accelerator DM, and 0.4 g of vulcanization accelerator CZ.

[0054] The rubber mixing process is as follows:

[0055] Internal mixing process: Set the internal mixing temperature at 60 °C and the rotation speed of the internal mixer at 50 r / min. Put the styrene-butadiene rubber into the internal mixer and mix for 1 min, then add stearic acid and zinc oxide and continue to mix for 2 min; adjust the rotation speed of the internal mixer to 60 r / min, add the lignin-based biphasic carbon black into the internal mixer, and continue to mix for 2 min until the torque no longer changes and then discharge the rubber.

[0056] Open mill process: Adjust the distance between the front and rear rollers of the open mill to 1 cm and the rotation speed to 10 rpm:12 rpm. Wrap the rubber around the rollers, add the vulcanizing agent, vulcanization accelerator DM, and vulcanization accelerator CZ, carry out cutting, triangular wrapping, and rolling, and discharge the rubber after mixing evenly.

[0057] Example 5

[0058] The preparation method of the lignin-based biphasic carbon black in Example 5 is as follows:

[0059] Dissolve 5.93 g of sodium metasilicate nonahydrate in 140 mL of deionized water, then add 1.25 g of aminated lignin, and maintain the pH in the system at 13. Stir using a semi-moon stirrer paddle, and control the stirring speed at 500 r / min. Then add 20 mL of absolute ethanol, and stir at 20 °C for 30 min to obtain a mixed solution. At 20 °C, add sulfuric acid solution dropwise to the mixed solution at a dropping rate of 40 mL / min for the first acid precipitation to rapidly precipitate silicon dioxide. When the pH is 9.0, stir and react for 1 h, and the stirring speed is 300 r / min. After the reaction is completed, raise the temperature of the mixed solution after the first acid precipitation to 60 °C, and add sulfuric acid solution dropwise at a dropping rate of 4 mL / min for the second acid precipitation until the pH drops to 2, so that the aminated lignin deposits and coats on the surface of silicon dioxide. Maintain stirring and reacting at 60 °C for 2 h. After the reaction is completed, use vacuum-assisted filtration to obtain a lignin / silicon dioxide composite.

[0060] Place the lignin / silicon dioxide composite dried to constant weight flat in a clean corundum boat, and carry out a carbonization process through a tube furnace under the protection of a nitrogen atmosphere. The carbonization conditions are as follows: the heating rate is 10 °C / min. After heating to 500 °C, hold for 3 h, and then naturally cool to obtain lignin-based biphasic carbon black.

[0061] The rubber in Example 5 includes the following raw materials: 40 g of styrene-butadiene rubber, 16 g of lignin-based biphasic carbon black, 0.4 g of stearic acid, 1.2 g of zinc oxide, 0.7 g of vulcanizing agent, 0.4 g of vulcanization accelerator DM, and 0.4 g of vulcanization accelerator CZ.

[0062] The rubber mixing process is as follows:

[0063] Internal mixing process: Set the internal mixing temperature at 60 °C and the rotation speed of the internal mixer at 50 r / min. Put the styrene-butadiene rubber into the internal mixer and mix for 1 min, then add stearic acid and zinc oxide, and continue to mix for 2 min; adjust the rotation speed of the internal mixer to 60 r / min, add the lignin-based biphasic carbon black to the internal mixer, and continue to mix for 2 min until the torque no longer changes and then discharge the rubber.

[0064] Open mill process: Adjust the distance between the front and rear rollers of the open mill to 1 cm and the rotation speed to 10 rpm:12 rpm. Wrap the rubber around the rollers, add the vulcanizing agent, vulcanization accelerator DM, and vulcanization accelerator CZ, carry out cutting, triangular wrapping, and rolling, and discharge the rubber after mixing evenly.

[0065] Example 6

[0066] The preparation method of the lignin-based biphasic carbon black in Example 6 is substantially the same as that in Example 1. The difference between the preparation method of the lignin-based biphasic carbon black in Example 6 and that in Example 1 is that the amount of quaternized lignin added in Example 6 is 2.5 g. The carbonization conditions are as follows: the heating rate is 5 °C / min. After heating to 400 °C, it is maintained for 4 h.

[0067] Example 7

[0068] The preparation method of the lignin-based biphasic carbon black in Example 7 is substantially the same as that in Example 1. The difference between the preparation method of the lignin-based biphasic carbon black in Example 7 and that in Example 1 is that the amount of quaternized lignin added in Example 7 is 3.75 g. The carbonization conditions are as follows: the heating rate is 15 °C / min. After heating to 1000 °C, it is maintained for 2 h.

[0069] Comparative Example 1

[0070] The rubber in Comparative Example 1 includes the following raw materials: 40 g of styrene-butadiene rubber, 16 g of carbon black, 0.4 g of stearic acid, 1.2 g of zinc oxide, 0.7 g of vulcanizing agent, 0.4 g of vulcanization accelerator DM, and 0.4 g of vulcanization accelerator CZ.

[0071] The mixing process of the rubber in Comparative Example 1 is as follows:

[0072] Mixing process: Set the mixing temperature to 60 °C and the rotation speed of the internal mixer to 50 r / min. Put the styrene-butadiene rubber into the internal mixer and mix for 1 min. Then add stearic acid and zinc oxide and continue to mix for 2 min. Adjust the rotation speed of the internal mixer to 60 r / min, add carbon black to the internal mixer, and continue to mix for 2 min until the torque no longer changes and then discharge the rubber.

[0073] Open mill process: Adjust the distance between the front and rear rollers of the open mill to 1 cm and the rotation speed to 10 rpm:12 rpm. Wrap the rubber around the rollers, add the vulcanizing agent, vulcanization accelerator DM, and vulcanization accelerator CZ, perform cutting, triangular wrapping, and rolling, and discharge the rubber after mixing evenly.

[0074] Comparative Example 2

[0075] The rubber in Comparative Example 2 includes the following raw materials: 40 g of styrene-butadiene rubber, 16 g of lignin, 0.4 g of stearic acid, 1.2 g of zinc oxide, 0.7 g of vulcanizing agent, 0.4 g of vulcanization accelerator DM, and 0.4 g of vulcanization accelerator CZ.

[0076] The mixing process of the rubber in Comparative Example 2 is as follows:

[0077] Mixing process: Set the mixing temperature at 60°C and the rotational speed of the internal mixer at 50 r / min. Put styrene-butadiene rubber into the internal mixer and mix for 1 min. Then add stearic acid and zinc oxide and continue mixing for 2 min. Adjust the rotational speed of the internal mixer to 60 r / min, add lignin into the internal mixer, and continue mixing for 2 min until the torque no longer changes and then discharge the rubber.

[0078] Open mill process: Adjust the distance between the front and rear rollers of the open mill to 1 cm and the rotational speed to 10 rpm:12 rpm. Wrap the rubber around the rollers, add vulcanizing agent, vulcanization accelerator DM, and vulcanization accelerator CZ, and perform cutting, triangular wrapping, and rolling. After mixing evenly, discharge the rubber.

[0079] Comparative Example 3

[0080] The rubber in Comparative Example 3 includes the following raw materials: 40 g of styrene-butadiene rubber, 16 g of white carbon black, 1.6 g of coupling agent Si69, 0.4 g of stearic acid, 1.2 g of zinc oxide, 0.7 g of vulcanizing agent, 0.4 g of vulcanization accelerator DM, and 0.4 g of vulcanization accelerator CZ.

[0081] The mixing process of the rubber in Comparative Example 3 is as follows:

[0082] Mixing process: Set the mixing temperature at 60°C and the rotational speed of the internal mixer at 50 r / min. Put styrene-butadiene rubber into the internal mixer and mix for 1 min. Then add stearic acid and zinc oxide and continue mixing for 2 min. Adjust the rotational speed of the internal mixer to 60 r / min, add white carbon black and coupling agent Si69 into the internal mixer, and continue mixing for 2 min until the torque no longer changes and then discharge the rubber.

[0083] Open mill process: Adjust the distance between the front and rear rollers of the open mill to 1 cm and the rotational speed to 10 rpm:12 rpm. Wrap the rubber around the rollers, add vulcanizing agent, vulcanization accelerator DM, and vulcanization accelerator CZ, and perform cutting, triangular wrapping, and rolling. After mixing evenly, discharge the rubber.

[0084] The characterization results of the lignin-based dual-phase carbon black in Examples 1-5 are shown in Table 1.

[0085] Table 1 Vulcanization time of the rubbers in Examples 1-5 and Comparative Examples 1-2

[0086]

[0087]

[0088] In Table 1, M H is the maximum torque, M L is the minimum torque, △M is the difference between M H and M L , Tc10 is the pre-vulcanization time, and Tc90 is the optimum vulcanization time.

[0089] As can be seen from Table 1, the vulcanization time T of Example 5 90 is reduced compared to Comparative Example 1 and significantly decreased compared to Comparative Example 2. It can be seen that carbonized lignin can significantly reduce the vulcanization time and increase the vulcanization rate, improving the rubber processability; ΔM reflects the crosslinking density between the filler and the rubber. The higher ΔM is, the closer the crosslinking network formed by the material and the rubber is. ΔM of Examples 1-5 has increased compared to Comparative Example 1, indicating that the grafted functional groups of lignin modification can greatly increase the crosslinking degree with the rubber.

[0090] Table 2 Mechanical property tests of rubbers of Examples 1-5 and Comparative Examples 1-2

[0091]

[0092] Through the comparison of mechanical properties in Table 2, the mechanical properties of Examples 1 to 5 have been significantly improved. The tensile strength of Example 5 is 2.3 MPa higher than that of Comparative Example 1. At the same time, both the 100% modulus and 300% modulus are higher than those of Comparative Example 1. It is obvious that the compatibility and dispersibility of the lignin-based dual-phase carbon black and the rubber have increased, and the mechanical properties of the rubber can be significantly improved.

[0093] The present invention provides a preparation method of lignin-based dual-phase carbon black, which can use a more inexpensive silicon source and green biomass lignin, greatly reducing the production cost. On the other hand, green energy can be used to replace fossil energy, making the production green and sustainable, and there are no environmental problems caused by toxic or other polluting by-products. It has the advantages of simple production, low cost, and remarkable effects.

[0094] The above-described embodiments merely represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the present invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. A method for preparing lignin-based dual-phase carbon black, characterized in that: The following steps are involved: The modified lignin, silicon source, alcohol and water are mixed to obtain a mixed solution, and the mixed solution is subjected to acid precipitation to obtain a lignin / silicon dioxide composite; and the lignin / silicon dioxide composite is carbonized to obtain the composite.

2. The method for preparing lignin-based dual-phase carbon black according to claim 1, characterized in that: The modified lignin includes quaternized lignin, phosphorylated lignin, sulfonated lignin, hydroxymethylated lignin, aminated lignin and the like.

3. The method for preparing lignin-based dual-phase carbon black according to claim 1, characterized in that: The mass ratio of the modified lignin to the silicon dioxide in the silicon source is 0.5-3:1, the volume ratio of the water to the alcohol is 2-8:1, and 64-144 mL of water is added for every gram of the modified lignin.

4. The method for preparing lignin-based dual-phase carbon black according to claim 1, characterized in that: The silicon source is one or more of industrial water glass, sodium metasilicate, ethyl orthosilicate, and silicon-containing products after pyrolysis of rice husks; and the alcohol is one or more of C1-C6 alcohols.

5. The method for preparing lignin-based dual-phase carbon black according to claim 1, characterized in that: The acid precipitation adopts a two-step acid precipitation method, and the substances used in the acid precipitation are one or more of hydrochloric acid, sulfuric acid, ammonium chloride, and ammonia water.

6. The method for preparing lignin-based dual-phase carbon black according to claim 1 or 5, characterized in that: The acid precipitation is first carried out at a pH of 9 to 11, and then a second acid precipitation is carried out at a pH of 2 to 5; the temperature of the first acid precipitation is 20 to 50° C., the time is 1 to 3 hours, the drop rate of the substance used in the first acid precipitation is 20 to 40 mL / min, and the stirring speed is 300 to 600 r / min; the temperature of the second acid precipitation is 60 to 80° C., the time is 1 to 3 hours, and the drop rate of the substance used in the second acid precipitation is 3 to 5 mL / min.

7. The method for preparing lignin-based dual-phase carbon black according to claim 1, characterized in that: The carbonization is carried out in a mixed gas of nitrogen, carbon dioxide, argon or one or more gases.

8. The method for preparing lignin-based dual-phase carbon black according to claim 1, characterized in that: The carbonization temperature is 400-1000° C., the carbonization heating rate is 5-15° C. / min; and the carbonization heat preservation time is 2-4h.

9. A lignin-based dual-phase carbon black, characterized in that: The carbon black is prepared by the method for preparing the lignin-based dual-phase carbon black according to claim 1.

10. Use of the lignin-based dual-phase carbon black as claimed in claim 9 as a filler in styrene-butadiene rubber; the mass ratio of the lignin-based dual-phase carbon black to the styrene-butadiene rubber is 10 to 50:100.

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