A bio-based composite reinforcing agent, and a preparation method and application thereof

Abstract

This invention discloses a bio-based composite reinforcing agent, comprising, by weight, the following raw materials: 4-8 parts of silica, 1-4 parts of lignin, and 1-4 parts of modified glass fiber powder. The lignin is any one or a combination of enzymatically hydrolyzed lignin, alkali lignin, lignin sulfate, lignin sulfonate, and etherified lignin. The silica is any one or a combination of JS180, JS185, 2115MP, 1165MP, V15, and V43. The modified glass fiber powder is obtained by modifying glass fiber powder with dopamine. This invention also discloses a method for preparing this bio-based composite reinforcing agent and its application in shoe sole materials. The prepared bio-based composite reinforcing agent has a good reinforcing effect on the rubber matrix and can improve the overall performance of the shoe sole.

Description

Technical Field

[0001] This invention relates to the field of rubber shoe sole materials technology, specifically to a bio-based composite reinforcing agent, its preparation method, and its application. Background Technology

[0002] In recent years, with the trend of greening and lightweighting of rubber shoe outsoles, lignin, as a natural polymer, has received increasing attention in the field of rubber shoe soles due to its high surface activity, excellent anti-aging properties and thermal stability.

[0003] Lignin, the second largest biomass resource, is mainly derived from the paper industry as a byproduct. However, its industrial utilization rate is extremely low, with the vast majority being directly discharged or incinerated, causing environmental pollution. Lignin is composed of rigid phenyl units and contains active groups such as hydroxyl, carbonyl, and conjugated double bonds. It not only produces less dust pollution but is also inexpensive, making it a promising candidate for reinforcing rubber and shoe materials. However, during the extraction and drying process from waste, lignin easily agglomerates into large particles due to strong intermolecular hydrogen bonding, making it difficult to disperse in rubber. Current technologies can improve its dispersibility and reinforcing effect on rubber through chemical modification, including hydroxymethylation, sulfonation, and esterification. However, chemical modification methods are not only costly but also do not significantly improve reinforcing performance. Therefore, new modification methods need to be developed to further improve the dispersibility and reinforcing properties of lignin in rubber. Summary of the Invention

[0004] One of the objectives of this invention is to provide a bio-based composite reinforcing agent that can effectively improve the dispersibility of lignin in a rubber matrix and enhance its reinforcing effect on the rubber matrix.

[0005] The second objective of this invention is to provide a method for preparing the above-mentioned bio-based composite reinforcing agent, wherein the prepared bio-based composite reinforcing agent has a good reinforcing effect on the rubber matrix.

[0006] The third objective of this invention is to provide the application of the above-mentioned bio-based composite reinforcing agent in shoe sole materials, which can improve the overall performance of shoe soles.

[0007] To achieve the above objectives, the solution of the present invention is: A bio-based composite reinforcing agent, by weight, comprises the following raw materials in the following amounts: 4-8 parts of silica, 1-4 parts of lignin, and 1-4 parts of modified glass fiber powder, wherein the lignin is any one or more of enzymatically hydrolyzed lignin, alkali lignin, lignin sulfate, lignin sulfonate, and etherified lignin; the silica is any one or more of JS180, JS185, 2115MP, 1165MP, V15, and V43; and the modified glass fiber powder is obtained by modifying glass fiber powder with dopamine.

[0008] A bio-based composite reinforcing agent, by weight, comprises the following raw materials in the following amounts: 4-6 parts of fumed silica, 2-3 parts of lignin, and 2-3 parts of modified glass fiber powder.

[0009] The BET specific surface area of ​​the silica is 120~180 m². 2 / g, with an average particle size of 10~20 nm and a relative density of 2.10 g / cm³. 3 DBP oil absorption value is 1~2 cm. 3 / g, pH value is 3.5~4.0.

[0010] The modified glass fiber powder is prepared by first adding glass fiber powder to a beaker containing deionized water, then ultrasonically dispersing it while stirring to obtain a glass fiber powder dispersion. Then, dopamine aqueous solution is added to the above glass fiber powder dispersion, and alkali is added to obtain a reaction solution with pH=8~9. Ultrasonication is stopped and stirring is continued. Finally, the above glass fiber powder dispersion is filtered and washed multiple times, and then vacuum dried to obtain the modified glass fiber powder.

[0011] The concentration of the dopamine aqueous solution is 1~5 g / L, the mass ratio of dopamine to glass fiber powder is 1:10~20, the total stirring time is not less than 5 h, the length of the glass fiber powder is 0.5~2 mm, and the diameter of the glass fiber powder is 5~8 μm.

[0012] A method for preparing a bio-based composite reinforcing agent involves adding 4-8 parts of silica, 1-4 parts of lignin, and 1-4 parts of modified glass fiber powder to a premixing device, adjusting the process parameters of the premixing device to ensure uniform mixing of the raw materials, and obtaining the bio-based composite reinforcing agent. The premixing device can be any one of a ball mill, a twin-spiral high-speed mixer, and an air jet mill.

[0013] A method for preparing a bio-based composite reinforcing agent involves adding 4-8 parts of silica, 1-4 parts of lignin, and 1-4 parts of modified glass fiber powder into a twin-screw high-speed mixer, adjusting the screw spacing to 1-3 μm, the rotation speed to 50-200 rpm / min, and the mixing time to 1-3 h to ensure uniform mixing of the raw materials, thereby obtaining the bio-based composite reinforcing agent.

[0014] A method for preparing a bio-based composite reinforcing agent involves adding 4-8 parts of silica, 1-4 parts of lignin, and 1-4 parts of modified glass fiber powder into an air jet mill. The mill disc rotation speed is adjusted to 1000-2500 rpm / min, the motor frequency is 30-60 Hz, and the pressure is 5-10 bar to ensure uniform mixing of the raw materials, thereby obtaining the bio-based composite reinforcing agent.

[0015] A method for preparing a bio-based composite reinforcing agent involves adding 4-8 parts of silica, 1-4 parts of lignin, and 1-4 parts of modified glass fiber powder into a ball mill. The mass ratio of the grinding balls to the total raw materials is 1-2.5:1. The ball mill rotates at a speed of 200-650 rpm / min and simultaneously revolves and rotates on its own axis, alternating between forward and reverse rotation 3-5 times, each time for 45 minutes, to ensure uniform mixing of the raw materials and obtain the bio-based composite reinforcing agent.

[0016] Application of a bio-based composite reinforcing agent in shoe sole materials, wherein the shoe sole material comprises the following raw materials in parts by weight: 100 parts raw rubber, 30-60 parts the bio-based composite reinforcing agent, 16-39 parts activator, 1-2 parts accelerator, and 1-14 parts additives. The activator comprises 3-8 parts zinc oxide, 1-3 parts stearic acid, 3-6 parts polybutadiene, 2-6 parts coordination crosslinking agent, 3-6 parts softening oil 4006, 2-5 parts PEG4000, and 1-3 parts vulcanizing agent, wherein the vulcanizing agent is sulfur or peroxide. The accelerator comprises any one or more combinations of accelerator DM-80, accelerator D, and accelerator TS. The coordination crosslinking agent comprises zinc acrylate, zinc methacrylate, magnesium acrylate, zinc chloride, etc. The material contains at least one of zinc acetate and magnesium chloride. The additives include any one or more combinations of 1-2 parts anti-frost agent, 1-2 parts antioxidant, and 0.5-1 part anti-aging agent. The antioxidants include any one or two combinations of UV-327 and UV-1020. The anti-aging agents include any one or more combinations of anti-aging agent SP, anti-aging agent 264, and anti-aging agent RD. The preparation method of the sole material is as follows: first, raw rubber is placed in a two-roll mill and passed through a roller to obtain plasticized rubber. Then, the obtained plasticized rubber, bio-based composite reinforcing agent, activator, accelerator, and additives are added to a mixer for mixing to obtain compound rubber. Finally, the obtained compound rubber is repeatedly passed through a two-roll mill, cooled, and then placed in a mold for hot pressing to obtain the rubber sole.

[0017] By adopting the above technical solution, the bio-based composite reinforcing agent, its preparation method, and its application of the present invention have the following beneficial effects: 1. In the preparation process of modified glass fiber powder, the present invention modifies the glass fiber powder by adding dopamine. Under weakly alkaline conditions, the self-polymerization property of dopamine forms a deposition film on the surface of the glass fiber powder, thereby improving the micro-interfacial bonding force between the glass fiber powder and the rubber matrix. The modified glass fiber powder can significantly improve the physical properties of the rubber matrix and broaden the application prospects of the glass fiber powder. 2. In the preparation process of this bio-based composite reinforcing agent, by selecting appropriate mechanical grinding equipment, the composite reinforcing agent formed by lignin-fumed silica-modified glass fiber powder achieves a finer particle size and better dispersion, preventing the aggregation and precipitation of lignin, fumed silica and modified glass fiber powder, thereby improving the comprehensive performance of rubber shoe sole composite materials. Moreover, no chemical modification of lignin is required, making it green and environmentally friendly. 3. This invention effectively improves the dispersibility of lignin, silica, and glass fiber powder in rubber through pre-dispersion treatment of the reinforcing agent and metal ion coordination crosslinking technology. The rubber matrix and lignin filler form reversible and recoverable dynamic ionic bonds through metal ion coordination, thereby absorbing and dissipating a large amount of mechanical energy caused by external forces and enhancing the network strength of the rubber. The addition of modified glass fiber powder can enhance the fatigue life of rubber and improve the wear resistance and anti-slip properties of rubber composites. In summary, the composite reinforcing agent made by pre-dispersion treatment of the three fillers can effectively improve the comprehensive performance of rubber. Detailed Implementation

[0018] To further explain the technical solution of the present invention, the present invention will be described in detail below through specific embodiments.

[0019] Example 1 A method for preparing a bio-based composite reinforcing agent involves first placing 24 g of silica, 8 g of modified glass fiber powder, and 8 g of alkali lignin into a twin-screw high-speed mixer, adjusting the screw spacing to 1.5 μm, and the rotation speed to 160 rpm / min. After mixing for 2 hours, the bio-based composite reinforcing agent is obtained.

[0020] The specific type of silica is JS180, with a BET specific surface area of ​​120~180 m². 2 / g, with an average particle size of 10~20 nm and a relative density of 2.10 g / cm³. 3 DBP oil absorption value is 1~2 cm. 3 / g, pH value is 3.5~4.0.

[0021] Furthermore, the modified glass fiber powder is prepared by first adding 8 g of glass fiber powder with a length of 0.5~2 mm and a diameter of 5~8 μm to a beaker containing 320 mL of deionized water and ultrasonically dispersing it. During ultrasonic dispersion, the mixture is stirred at a speed of 200 r / min for 0.5 h to obtain a glass fiber powder dispersion. Then, 320 mL of a dopamine aqueous solution with a concentration of 2 g / L is added to the above glass fiber powder dispersion. Sodium carbonate is added to adjust the pH of the reaction solution to 9. Ultrasonic dispersion is stopped and stirred for 3 h. Finally, the above glass fiber powder dispersion is filtered and washed multiple times and then vacuum dried at 90 °C to obtain the modified glass fiber powder.

[0022] Example 2 The difference from Example 1 is that in Example 2, the preparation method of the bio-based composite reinforcing agent is to first add 24g of silica, 8g of modified glass fiber powder and 8g of alkali lignin into an air jet mill, adjust the speed of the grinding disc to 2000rpm / min, the frequency of the motor to 50Hz and the pressure to 8 bar, so that the raw materials are uniformly mixed to obtain the bio-based composite reinforcing agent.

[0023] Example 3 The difference from Example 1 is that in Example 3, the preparation method of the bio-based composite reinforcing agent is to first add 24g of silica, 8g of modified glass fiber powder and 8g of alkali lignin into a ball mill. The mass ratio of grinding balls to the total mass of each raw material is 1.2:1. The ball mill rotates at 500 rpm / min and simultaneously rotates on its own axis and revolves around the sun. The rotation alternates between forward and reverse directions 4 times, each time for 45 minutes, so that the raw materials are uniformly mixed to obtain the bio-based composite reinforcing agent.

[0024] Comparative Example 1 Silica, modified glass fiber powder, and alkali lignin are not premixed and can be added directly during the preparation of the shoe sole.

[0025] Comparative Example 2 The difference from Example 1 is that in Comparative Example 2, the modified glass fiber powder was replaced with an equal amount of ordinary glass fiber powder to obtain the bio-based composite reinforcing agent.

[0026] Comparative Example 3 The difference from Example 2 is that in Comparative Example 3, the modified glass fiber powder was replaced with an equal amount of ordinary glass fiber powder to obtain the bio-based composite reinforcing agent.

[0027] Comparative Example 4 The difference from Example 3 is that in Comparative Example 4, the modified glass fiber powder was replaced with an equal amount of ordinary glass fiber powder to obtain the bio-based composite reinforcing agent.

[0028] Application examples The bio-based composite reinforcing agents prepared in the various embodiments and comparative examples were applied to the preparation of shoe sole materials. The preparation method of the shoe sole materials is as follows: First, 75 parts of rare earth butadiene rubber, 15 parts of hydrogenated nitrile butadiene rubber, 5 parts of isoprene rubber, and 5 parts of ethylene propylene diene monomer (EPDM) rubber were fed into an open mill and passed through a thin mill for 2 minutes at a 3mm roller gap. After cooling to room temperature, the rubber components were added to an internal mixer and pressed into a ball. The mixture was then stirred at 70 rpm / min and 70°C, with the ball being lifted and pressed into a ball every 30 seconds. After 1 minute, 40 parts of bio-based composite reinforcing agent, 1 part of anti-frost agent 1956, 0.5 parts of antioxidant SP, 2 parts of PEG4000, 1 part of antioxidant UV-327, 3.5 parts of zinc oxide, 1 part of stearic acid, 5 parts of polybutadiene, and 3.5 parts of zinc methacrylate were added, and the mixture was pressed into a ball and held in place. 60s; after lifting the compaction block, add 3 parts of softening oil 4006 and press the compaction block down. Control the temperature to reach 135℃ and maintain it for 1 minute before discharging the rubber and cleaning. Finally, put the above rubber compound into the internal mixer and mix at a speed of 30 rpm. Lift and press the compaction block every 30 seconds. After 1 minute, add 1 part of accelerator DM-80, 0.5 parts of accelerator D, 0.1 parts of accelerator TS and 2.4 parts of sulfur. When the rubber compound temperature reaches 95℃, discharge the rubber and sheet it. After cooling, cut the obtained rubber composition into the size required by the mold and put it into the mold. Vulcanize at 160℃ for the positive vulcanization time (T90+20s) and then take it out to obtain the rubber shoe sole.

[0029] The raw materials used in the above embodiments, comparative examples, and application examples are all commercially available products, specifically sourced as follows: rare earth butadiene rubber was purchased from Xinjiang Dushanzi Petrochemical Co., Ltd.; hydrogenated nitrile butadiene rubber and ethylene propylene diene monomer (EPDM) rubber were purchased from Arlanx Newtech Changzhou Co., Ltd.; isoprene rubber and polybutadiene were purchased from Sinopec Corporation; silica was purchased from Fujian Shaxian Jinsha Silica Manufacturing Co., Ltd.; glass fiber powder was purchased from Shandong Futai Fiber Co., Ltd.; alkali lignin was purchased from Hangzhou Shishi Technology Development Co., Ltd.; dopamine and zinc methacrylate were purchased from Nanjing Shouqianshou Chemical Co., Ltd.; PEG4000, anti-frost agent, antioxidant, and softening oil 4006 were purchased from Ningbo Shenghan Chemical Co., Ltd.; zinc oxide and stearic acid were purchased from Changzhou Qixiang Chemical Co., Ltd.; and accelerators and sulfur were purchased from Shandong Shangshun Chemical Co., Ltd.

[0030] Performance testing The corresponding rubber soles prepared using the bio-based composite reinforcing agents of each embodiment and comparative example were subjected to corresponding physical property tests, and the results are shown in Table 1.

[0031] Table 1. Processing and physical property data of rubber soles in embodiments and comparative examples of the present invention.

[0032] The physical property comparison data from Examples 1-3 and Comparative Example 1 show that the rubber shoe soles prepared with the premixed composite reinforcing agent exhibit higher wear resistance, slip resistance, and tensile strength compared to rubber composites filled with the same amount of unpremixed composite reinforcing agent. This is because the modified glass fiber powder, silica, and lignin, after premixing, can be better dispersed within the rubber matrix during mixing. This facilitates the formation of more binding adhesives between the modified glass fiber powder and silica fillers and the rubber, and also helps lignin form more zinc ion coordination crosslinks with the rubber through zinc salt bridging. Furthermore, it can be seen that ball milling has a better premixing effect than twin-screw high-speed mixing and air jet milling. This is because, in addition to the differences in premixing process and strength, the ball milling process also involves premixing media such as grinding balls, which facilitates high-intensity collisions between fillers, resulting in a composite reinforcing agent with smaller particle size and better dispersion, thus improving the reinforcing effect on the rubber composite.

[0033] The physical property comparison data from Examples 1-3 and Comparative Examples 2-4 show that the rubber soles prepared by adding the composite reinforcing agent composed of unmodified glass fiber powder to the rubber composite material exhibit lower wear resistance, slip resistance, and tensile strength compared to the rubber composite material filled with the same amount of modified glass fiber powder. This is because the unmodified glass fiber powder has low chemical activity and poor interfacial affinity with the rubber matrix, leading to a decrease in its performance. Modification of the glass fiber powder improves its affinity and adhesion to the rubber, resulting in improved performance. Furthermore, it can be seen that the rubber composite material filled with the composite reinforcing agent composed of modified glass fiber powder, lignin, and silica exhibits a greater torque difference compared to the unmodified glass fiber powder. Generally, the maximum torque (M) is significantly higher. H The elasticity of a reactive rubber compound is generally related to the hardness of the rubber composite material, and the minimum torque (M) L The viscosity of reactive rubber is correlated with its Mooney viscosity, and the difference between the maximum and minimum torque (M) is related to this. H-L The degree of cross-linking of the rubber composite material can be seen, which further proves that the modified glass fiber powder can improve the interfacial force between the glass fiber powder and the rubber matrix.

[0034] The above embodiments are not intended to limit the product form and style of the present invention. Any appropriate changes or modifications made by those skilled in the art should be considered as not departing from the patent scope of the present invention.

Claims

1. A bio-based composite reinforcing agent, characterized in that: The raw materials, by weight, include the following amounts: 4-8 parts silica, 1-4 parts lignin, and 1-4 parts modified glass fiber powder. The lignin is any one or a combination of enzymatically hydrolyzed lignin, alkali lignin, lignin sulfate, lignin sulfonate, and etherified lignin. The silica is any one or a combination of JS180, JS185, 2115MP, 1165MP, V15, and V43. The modified glass fiber powder is obtained by modifying glass fiber powder with dopamine.

2. The bio-based composite reinforcing agent according to claim 1, characterized in that: By weight, it includes the following raw materials in the following amounts: 4-6 parts silica, 2-3 parts lignin and 2-3 parts modified glass fiber powder.

3. The bio-based composite reinforcing agent according to claim 1, characterized in that: The BET specific surface area of ​​the silica is 120~180 m². 2 / g, with an average particle size of 10~20 nm and a relative density of 2.10 g / cm³. 3 DBP oil absorption value is 1~2cm 3 / g, pH value is 3.5~4.

0.

4. The bio-based composite reinforcing agent according to claim 1, characterized in that: The modified glass fiber powder is prepared by first adding glass fiber powder to a beaker containing deionized water, then ultrasonically dispersing it while stirring to obtain a glass fiber powder dispersion. Then, dopamine aqueous solution is added to the above glass fiber powder dispersion, and alkali is added to obtain a reaction solution with pH=8~9. Ultrasonication is stopped and stirring is continued. Finally, the above glass fiber powder dispersion is filtered and washed multiple times, and then vacuum dried to obtain the modified glass fiber powder.

5. The bio-based composite reinforcing agent according to claim 4, characterized in that: The concentration of the dopamine aqueous solution is 1~5 g / L, the mass ratio of dopamine to glass fiber powder is 1:10~20, the total stirring time is not less than 5 h, the length of the glass fiber powder is 0.5~2 mm, and the diameter of the glass fiber powder is 5~8 μm.

6. A method for preparing the bio-based composite reinforcing agent as described in claim 1, characterized in that: The process involves adding 4-8 parts of silica, 1-4 parts of lignin, and 1-4 parts of modified glass fiber powder to a premixing device, adjusting the process parameters of the premixing device to ensure uniform mixing of the raw materials, and obtaining the bio-based composite reinforcing agent. The premixing device can be any one of a ball mill, a twin-screw high-speed mixer, or an air jet mill.

7. The method for preparing a bio-based composite reinforcing agent according to claim 6, characterized in that: The raw materials are mixed uniformly by adding 4-8 parts of silica, 1-4 parts of lignin and 1-4 parts of modified glass fiber powder into a twin-screw high-speed mixer, adjusting the screw spacing to 1-3 μm, the rotation speed to 50-200 rpm / min, and the mixing time to 1-3 h, so that the raw materials are uniformly mixed to obtain the bio-based composite reinforcing agent.

8. The method for preparing a bio-based composite reinforcing agent according to claim 6, characterized in that: The raw materials are mixed uniformly by adding 4-8 parts of silica, 1-4 parts of lignin and 1-4 parts of modified glass fiber powder into an air jet mill, adjusting the speed of the grinding disc to 1000-2500 rpm / min, the frequency of the motor to 30-60 Hz and the pressure to 5-10 bar, so as to obtain the bio-based composite reinforcing agent.

9. The method for preparing a bio-based composite reinforcing agent according to claim 6, characterized in that: The process involves adding 4-8 parts of silica, 1-4 parts of lignin, and 1-4 parts of modified glass fiber powder into a ball mill. The mass ratio of the grinding balls to the total raw materials is 1-2.5:

1. The ball mill rotates at 200-650 rpm / min and simultaneously revolves and rotates on its own axis, alternating between forward and reverse rotation 3-5 times, each time for 45 minutes, to ensure uniform mixing of the raw materials and obtain the bio-based composite reinforcing agent.

10. The application of a bio-based composite reinforcing agent in a shoe sole material, the shoe sole material comprising the following raw materials in parts by weight: 100 parts raw rubber, 30-60 parts the bio-based composite reinforcing agent as described in claim 1, 16-39 parts activator, 1-2 parts accelerator, and 1-14 parts additives, wherein the activator comprises 3-8 parts zinc oxide, 1-3 parts stearic acid, 3-6 parts polybutadiene, 2-6 parts coordination crosslinking agent, 3-6 parts softening oil 4006, 2-5 parts PEG4000, and 1-3 parts vulcanizing agent, wherein the vulcanizing agent is sulfur or peroxide, the accelerator comprises any one or more combinations of accelerator DM-80, accelerator D, and accelerator TS, and the coordination crosslinking agent comprises zinc acrylate, zinc methacrylate, and magnesium acrylate. The material comprises at least one of zinc chloride, zinc acetate, and magnesium chloride. The additives include any one or more combinations of 1-2 parts anti-frost agent, 1-2 parts antioxidant, and 0.5-1 part anti-aging agent. The antioxidants include any one or two combinations of UV-327 and UV-1020. The anti-aging agents include any one or more combinations of anti-aging agent SP, anti-aging agent 264, and anti-aging agent RD. The preparation method of the sole material is as follows: first, raw rubber is placed in a two-roll mill for thin-pass rolling to obtain plasticized rubber. Then, the obtained plasticized rubber, bio-based composite reinforcing agent, activator, accelerator, and additives are added to a mixer for mixing to obtain compound rubber. Finally, the obtained compound rubber is repeatedly thin-passed in a two-roll mill, cooled, and then placed in a mold for hot pressing to obtain the rubber sole.

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