Table of Contents
Overview
Styrene-butadiene rubber is a copolymer of styrene and butadiene. Based on the polymerization method, it can be classified into emulsion-polymerized SBR and solution-polymerized SBR.
Styrene-Butadiene Rubber was the first synthetic rubber to be industrialized. In the 1920s, the German company I.G. Farben, while working to improve the physical properties of emulsion-polymerized polybutadiene, used styrene as a second monomer to copolymerize with butadiene, leading to the development of emulsion-polymerized SBR. In 1933, the company published the first patent for synthesizing emulsion-polymerized SBR via the acetylene route and began industrial production in 1937 under the trade name Buna S.
After the outbreak of World War II, the demand for rubber as a strategic material surged. The United States rapidly developed the production of emulsion-polymerized SBR and produced GR-S SBR in 1942. The Soviet Union also began SBR production in 1949. These early SBR products were copolymerized at 50°C and are referred to as high-temperature SBR.
In the early 1950s, low-temperature Styrene-Butadiene Rubber, polymerized at around 5°C with excellent performance, emerged. Currently, low-temperature emulsion-polymerized SBR accounts for about 90% of all emulsion-polymerized SBR. High-temperature emulsion polymerization offers a simple formula and easy process control, making it still suitable for certain rubber products with lower performance requirements, hence it remains in limited production.
In the mid-1960s, with the development of anionic polymerization technology, solution-polymerized styrene-butadiene rubber was introduced. Due to its lower rolling resistance, higher wet skid resistance, and better overall performance, it developed rapidly. Currently, solution-polymerized SBR accounts for over 15% of total SBR production.
With the continuous development of synthetic rubber technology, oil-extended SBR masterbatch emerged in 1951, followed by carbon black-filled SBR masterbatch, oil and carbon black co-extended SBR masterbatch, high-styrene SBR, carboxylated SBR, and liquid SBR, among other varieties.
Styrene-butadiene rubber is the most produced synthetic rubber, accounting for about 55% of total synthetic rubber production (including latex) and about 34% of all rubber. It is primarily used in the tire industry. Styrene-Butadiene Rubber is widely used in passenger car tires, small tractor tires, and motorcycle tires, but less so in truck tires and radial tires. It also finds extensive applications in belts, hoses, and various industrial products, such as conveyor belt covers, water hoses, shoe soles, rollers, waterproof rubber products, and rubberized fabrics.
Structure and Chemical Formula
Emulsion-polymerized Styrene-Butadiene Rubber is a copolymer of butadiene and styrene monomers in emulsion, with the following structural formula (-(C₄H₆)-(C₈H₈)-):
The butadiene and styrene units in the copolymer are randomly distributed. About 80% of butadiene addition occurs at the 1,4 position, and 20% at the 1,2 position. The 1,4-position units further consist of cis-1,4 and trans-1,4 configurations. Additionally, there are minor branched and cross-linked structures. The relative content of 1,2 structures and cis-/trans-1,4 structures in the copolymer depends on the polymerization temperature. The effect of polymerization temperature on the microstructure of emulsion-polymerized SBR is shown in the following table.
| Polymerization Temperature / °C | cis-1,4 Structure Content / % | trans-1,4 Structure Content / % | 1,2 Structure Content / % |
|---|---|---|---|
| -33 | 5.4 | 80.4 | 12.7 |
| 5 | 12.3 | 71.8 | 15.8 |
| 50 | 18.3 | 65.3 | 16.3 |
| 70 | 20 | 63 | 17.3 |
| 100 | 22.5 | 60.1 | 17.3 |
Types
As Styrene-Butadiene Rubber is primarily used in tire production, it has a large consumption volume and numerous varieties. Based on the production method, styrene-butadiene rubber can be classified as follows:
| Styrene-Butadiene Rubber (SBR) | Emulsion Polymerization | High Temperature SBR |
| Low Temperature SBR | ||
| Low Temperature SBR Carbon Black Masterbatch | ||
| Low Temperature Oil-Extended SBR | ||
| Low Temperature Oil and Carbon Black Extended SBR | ||
| High Styrene SBR | ||
| Liquid SBR | ||
| Carboxylated SBR | ||
| Solution Polymerization | Alkyl Lithium Solution-Polymerized SBR | |
| Alfin Solution-Polymerized SBR | ||
| Tin-Coupled Solution-Polymerized SBR | ||
| High Trans-1,4 SBR |
① High-Temperature SBR: Polymerized at 50°C, it is the earliest type of SBR. The polymerization process achieves high monomer conversion but results in high gel content, more branched chains, and a high content of low-molecular-weight polymers, leading to inferior physical and mechanical properties. Currently, its production accounts for less than 10% of total SBR output.
② Low-Temperature SBR: Polymerized at around 5°C, it has a narrower molecular weight distribution, fewer branched chains, and a more regular structure. Its physical and mechanical properties are superior to those of high-temperature SBR, making it one of the most produced synthetic rubbers.
③ Low-Temperature SBR Carbon Black Masterbatch: A certain amount of carbon black is added to the SBR latex before coagulation, ensuring uniform dispersion. After coagulation, a carbon black-filled SBR masterbatch is obtained. The pre-dispersion of carbon black in the compound ensures stable physical and mechanical properties and good processing performance.
④ Low-Temperature Oil-Extended SBR: Mineral oils (naphthenic, aromatic, etc.) are added to the latex during polymerization. After coagulation, the latex absorbs a large amount of mineral oil, forming an oil-extended SBR masterbatch. Compared to non-oil-extended SBR, it offers better processing performance, lower shrinkage, a smooth surface, no scorching during processing, lower heat generation during deformation, and lower cost. However, oil extension may slightly compromise the physical and mechanical properties.
⑤ Low-Temperature Oil and Carbon Black Extended SBR: Oil and carbon black are added to the latex during polymerization. After coagulation, an oil and carbon black co-extended SBR masterbatch is obtained. This rubber significantly simplifies processing operations, improves the production environment, shortens mixing time, requires lower temperatures, and reduces scorching risk. Due to the uniform dispersion of carbon black and oil, the compound exhibits good reinforcement, excellent extrusion performance, superior overall vulcanizate properties, and low heat generation under dynamic loading.
⑥ High-Styrene SBR: With a styrene content of 40%–85%, its modulus is close to that of plastics. It can be used as a reinforcing agent for SBR, natural rubber, and other diene rubbers.
⑦ Liquid SBR: Derived from both high-temperature and low-temperature copolymerized SBR latex, it can be used to produce foam rubber, process paper, and manufacture cement and coatings.
⑧ Carboxylated SBR: Produced by copolymerizing 1%–3% of acrylic acid monomers during SBR polymerization. Its physical and mechanical properties are generally better than those of conventional SBR. However, this rubber tends to undergo premature vulcanization after water absorption and is challenging to process.
⑨ Alkyl Lithium Solution-Polymerized SBR: A copolymer produced via solution polymerization of butadiene and styrene using anionic (alkyl lithium) catalysts. Depending on polymerization conditions and catalysts used, it can be random or block-type, with the latter further divided into linear and star-shaped blocks. Random solution-polymerized SBR is similar to emulsion-polymerized SBR, while linear and star-shaped block SBR exhibit thermoplastic properties.
⑩ Alfin Solution-Polymerized SBR: Can be classified into Alfin butadiene-styrene rubber and Alfin butadiene-isoprene rubber. It is produced by copolymerization using an Alfin complex as catalyst, with varying ratios of butadiene and styrene or butadiene and isoprene.
⑪ Tin-Coupled Solution-Polymerized SBR: Butadiene is added for end-capping during the later stages of solution polymerization, followed by the addition of tin tetrachloride as a coupling agent to convert linear polymer chains into branched structures. This compound offers good strength, low rolling resistance, and high wet skid resistance, making it suitable for energy-saving tires.
⑫ High Trans-1,4 SBR: Produced by copolymerizing butadiene and styrene using a di-tert-butanol barium hydroxide-organic lithium catalyst system.
Properties of Raw Rubber
The macro- and microstructures of macromolecules in different types of emulsion-polymerized styrene-butadiene copolymers vary. Macrostructure includes monomer ratio, average molecular weight, molecular weight distribution, branching degree, non-rubber hydrocarbon content, gel content, etc. Microstructure includes the ratio of cis-/trans-1,4 and 1,2 structures in butadiene segments, monomer sequence, etc.
Theoretically, styrene and butadiene can copolymerize in any ratio. The glass transition temperature (Tg) of the copolymer primarily depends on the styrene content. The Tg of 100% polystyrene is 90°C, while that of 100% cis- or trans-polybutadiene is -100°C. The Tg of SBR falls between these values based on the monomer ratio. As styrene content increases, the copolymer transitions from rubber to resin. Higher styrene content reduces elasticity, cold resistance, hysteresis loss, adhesion, and processing performance. The widely used low-temperature emulsion-polymerized SBR has a styrene mass fraction of 23.5%, at which SBR exhibits balanced overall properties.
The number-average molecular weight of styrene-butadiene rubber ranges from 80,000 to 110,000. SBR with a molecular weight below this range is prone to cold flow during storage, while higher molecular weights make processing difficult. For highly filled oil-extended SBR, a higher molecular weight is required. For example, SBR filled with 37.5 phr oil has a molecular weight about 30% higher than conventional SBR. Emulsion-polymerized SBR has a broad molecular weight distribution, with a distribution index between 4 and 6. This facilitates processing. Higher branching also aids processing but reduces physical and mechanical properties. Low-temperature emulsion-polymerized SBR has lower branching than high-temperature SBR, resulting in better physical and mechanical properties. SBR contains non-rubber hydrocarbon components, particularly in emulsion-polymerized SBR, where they can reach up to 10%. These include rosin acid, rosin soap, antioxidants, ash, and volatiles. These components affect SBR properties. For example, residual rosin acid slows the vulcanization rate of SBR compounds, making SBR vulcanize slower than natural rubber.
The butadiene segments in SBR polymers have three linkage types: cis-1,4, trans-1,4, and 1,2 structures. Among these, the 1,2 structure content significantly affects compound properties. Lower 1,2 structure content results in a lower glass transition temperature. The cis-1,4 structure content affects the elasticity of the vulcanizate—higher content improves elasticity. In emulsion-polymerized SBR, the butadiene segments are predominantly trans-1,4 structures. Combined with the steric effect of phenyl groups on the molecular chain, this reduces chain flexibility, negatively impacting the physical and mechanical properties of the vulcanizate, such as lower elasticity and higher heat generation. The internal friction heat generation during fatigue in emulsion-polymerized SBR is related to trans-structure content—higher trans-content increases heat generation, typically twice that of natural rubber. Cold resistance is optimal at around 10% styrene content. At 30% styrene, cold resistance is poorer than natural rubber, and rebound elasticity is also inferior. The random arrangement of monomers in emulsion-polymerized SBR, along with the presence of phenyl groups disrupting chain regularity, prevents crystallization.
Solution-polymerized SBR employs anionic living polymerization, allowing control over the styrene-butadiene ratio, microstructure of butadiene units, macrostructure of the polymer, monomer sequence, molecular weight, and molecular weight distribution. This enables an optimal balance among rolling resistance, wet skid resistance, and wear resistance. The structural differences between solution-polymerized and emulsion-polymerized SBR are shown in the following table.
| Polymerization Method | Emulsion Polymerized SBR | Solution Polymerized SBR |
|---|---|---|
| Styrene Content/% | 23.5 | Controllable |
| Butadiene cis-1,4 Content/% | 7.0~12.3 | Controllable |
| Butadiene trans-1,4 Content/% | 71.8~72 | Controllable |
| Vinyl Content/% | 15.8~21 | Controllable |
| Rubber Hydrocarbon Content/% | 92~95 | 98 |
| Molecular Weight Distribution Index | 4~6 | 1.5~2 |
| Degree of Branching | High | Low |
To further improve wet skid resistance and reduce rolling resistance in solution-polymerized SBR, recent research has focused on end-group modifications, including tin coupling, aminobenzophenone modification, isocyanate modification, etc.
Modifying the polymer chain ends aims to enhance interaction between macromolecule ends and carbon black, improve carbon black dispersion stability, reduce free chain ends, decrease elastic hysteresis loss, and reduce heat generation.
Among these modification techniques, tin-coupled solution-polymerized SBR has developed rapidly due to its simple production process and significant modification effects. Tin coupling improves processing performance, enhances compound-carbon black interaction and dispersion, boosts physical and mechanical properties, and reduces hysteresis. This results in a 25% reduction in rolling resistance, 3%–4% fuel savings, approximately 5% improvement in wet skid resistance, and about 10% increase in wear resistance.
Styrene-Butadiene Rubber is primarily used in tire tread compounds. The wet skid resistance and rolling resistance of tread compounds are crucial and are characterized by the tanδ of the vulcanizate at 0°C and 50°C (or 60°C), respectively. A higher tanδ at 0°C indicates better wet skid resistance, while a lower tanδ at 50°C indicates lower rolling resistance. To achieve good overall performance, maximize tanδ at 0°C and minimize it at 50°C. The above figure shows the relationship between tanδ and temperature for emulsion-polymerized and solution-polymerized SBR.
Tests show that solution-polymerized SBR offers the best balance between wet skid resistance and rolling resistance. Its tanδ at 0°C is similar to that of emulsion-polymerized SBR, but tanδ at 50°C is significantly lower. Although polybutadiene rubber (BR) has low tanδ at 50°C, its tanδ at 0°C is also low, failing to achieve a comprehensive balance. The properties of end-modified solution-polymerized SBR are shown in the following table.
| Property | Tin-Coupled Solution SBR Vulcanizate | Non-coupled Solution SBR Vulcanizate | Tin-Coupled Emulsion SBR Vulcanizate |
|---|---|---|---|
| Mooney Viscosity [ML(1+4)100℃] | 72 | 87 | 65 |
| Tensile Strength / MPa | 23 | 20.1 | 23.5 |
| 100% Modulus / MPa | 3.8 | 3.9 | 4.1 |
| Rolling Resistance (tan δ, 60℃) | 0.185 | 0.14 | 0.102 |
| Wet Skid Resistance Index | 100 | 103 | 104 |
| Wear Resistance Index | 100 | 95 | 115 |
Note: Test formulation: Raw rubber 100 phr, HAF 50 phr, ZnO 3 phr, Stearic acid 2 phr, Antioxidant 4010NA 1 phr, Accelerator 2.6 phr, Sulfur 1.5 phr.
Tin-coupled solution-polymerized SBR outperforms emulsion-polymerized SBR in all comparative indicators, particularly with lower tanδ at 60°C and a higher wet skid resistance index. This gives tin-coupled SBR low rolling resistance and high wet skid resistance. Additionally, it has lower Mooney viscosity, easier processing, better wear resistance, and excellent strength properties.
During the polymerization of solution-polymerized SBR, end groups can be controlled by the sequence of adding styrene or butadiene. The properties of various modified solution-polymerized SBRs with different coupling agents are compared in the following table.
| Coupling Agent | Raw Rubber Mooney Viscosity [ML(1+4)100℃] | Compound Mooney Viscosity [ML(1+4)100℃] | Tensile Strength /MPa | Elongation at Break /% | Loss Tangent tanδ (50℃) | Loss Tangent tanδ (0℃) |
|---|---|---|---|---|---|---|
| None | 54 | 93 | 22.3 | 400 | 0.121 | 0.235 |
| Divinylbenzene | 51 | 70 | 22.5 | 400 | 0.125 | 0.241 |
| Diethyl Adipate | 47 | 74 | 21.6 | 410 | 0.126 | 0.237 |
| SiCl₄ | 57 | 89 | 23.5 | 400 | 0.126 | 0.24 |
| SnCl₄ (Sn-BD) | 57 | 76 | 25 | 400 | 0.096 | 0.239 |
| SnCl₄ (Sn-ST) | 56 | 78 | 23.8 | 400 | 0.105 | 0.238 |
| Emulsion SBR | 53 | 70 | 27 | 490 | 0.157 | 0.234 |
Note: Test formulation: Raw rubber 100 phr, HAF 50 phr, ZnO 3 phr, Stearic acid 2 phr, Antioxidant 1.8 phr, Vulcanization accelerator 1.8 phr, Sulfur 1.5 phr.
From the table, SnCl₄ shows the best coupling effect. Compounds with butadiene end-capping (Sn-BD) exhibit better strength and hysteresis properties than those with styrene end-capping (Sn-ST). Coupling efficiency also affects the viscoelastic and physical-mechanical properties of the vulcanizate. Higher coupling efficiency increases coupled content, reduces tanδ at 50°C, and improves tensile strength, but has no effect on tanδ at 0°C.
Increasing the content of styrene and 1,2 structures in butadiene segments raises the glass transition temperature (T_g) of the raw rubber, improves wet traction and aging resistance, but reduces rebound elasticity and wear resistance. When styrene content exceeds 18%, wear resistance decreases. Solution-polymerized SBR with 18%–21% styrene content offers the best overall performance in processing, wear resistance, and traction on wet surfaces.
Increasing the cis-1,4 structure content in the butadiene segments of solution-polymerized SBR lowers the polymer’s T_g, improves wear resistance, impact elasticity, cold resistance, heat resistance, and resistance to permanent set. Conversely, higher trans-1,4 content reduces macromolecular flexibility, impact elasticity, and wear resistance. Crystallinity increases vulcanizate strength.
The molecular weight of solution-polymerized SBR is around 200,000. As with conventional rubber, increasing molecular weight improves vulcanizate properties such as tensile strength, modulus, elasticity, and wear resistance, but worsens processing performance, extrusion behavior, and scorch safety. Solution-polymerized SBR has a narrow molecular weight distribution, with a distribution index around 1.5. After SnCl₄ coupling, the molecular weight shows a bimodal distribution. After mastication, Sn-C bonds break, restoring the unimodal distribution of uncoupled SBR. Reducing the low-molecular-weight fraction improves tensile strength, wear resistance, rebound elasticity, and oil/carbon black filling capacity of the vulcanizate. Fewer molecules below 100,000 result in lower tanδ at 50°C. Compared to emulsion-polymerized SBR, solution-polymerized SBR has far fewer low-molecular-weight fractions, giving it better wet skid resistance.
Physical and Mechanical Properties of Vulcanizates
Compared to natural rubber, Styrene-Butadiene Rubber offers better heat resistance, aging resistance, and wear resistance. However, it has inferior elasticity, cold resistance, flex crack resistance, and tear resistance. Higher styrene content further reduces elasticity, cold resistance, hysteresis loss, adhesion, and processing performance. Styrene-Butadiene Rubber products generate more heat under repeated deformation, increasing with higher trans-structure content. Light aging is not significant, but Styrene-Butadiene Rubber is more sensitive to ozone than natural rubber, with poorer ozone resistance. Conventional emulsion-polymerized SBR has poor low-temperature performance, with a brittle temperature around -45°C. However, SBR with less than 10% styrene or with methylstyrene replacing styrene can effectively prevent crystallization, achieving a brittle temperature of -76°C. The electrical properties of SBR are mainly influenced by compounding ingredients.
Processing Technology
Compared to natural rubber, styrene-butadiene rubber offers better heat resistance, aging resistance, and wear resistance. However, it has inferior elasticity, cold resistance, flex crack resistance, and tear resistance. Higher styrene content further reduces elasticity, cold resistance, hysteresis loss, adhesion, and processing performance. Styrene-Butadiene Rubber products generate more heat under repeated deformation, increasing with higher trans-structure content. Light aging is not significant, but Styrene-Butadiene Rubber is more sensitive to ozone than natural rubber, with poorer ozone resistance. Conventional emulsion-polymerized SBR has poor low-temperature performance, with a brittle temperature around -45°C. However, SBR with less than 10% styrene or with methylstyrene replacing styrene can effectively prevent crystallization, achieving a brittle temperature of -76°C. The electrical properties of SBR are mainly influenced by compounding ingredients.
Ⅰ Compounding Techniques for Styrene-Butadiene Rubber Compounds
Styrene-Butadiene Rubber has a slower vulcanization rate, requiring more accelerators, but its vulcanization curve is flat, reducing scorch and over-cure risks. Styrene-butadiene rubber has poor mixing processing performance, with little plasticity change during milling, high calender/extrusion deformation, and poor tack. Thus, proper selection of fillers, softeners, and tackifiers is essential.
Styrene-Butadiene Rubber compounding is similar to natural rubber, divided into vulcanization system, reinforcement and filling system, protection system, plasticizers, processing aids, and other additives.
1. Vulcanization System
Generally classified into sulfur vulcanization systems, efficient and semi-efficient vulcanization systems, and organic peroxide vulcanization systems.
(1) Sulfur Vulcanization System: Emulsion-polymerized SBR contains residual fatty acids, soaps, etc., leading to a slower vulcanization rate than natural rubber. Due to lower unsaturation, sulfur dosage is lower, typically 1.0–2.5 phr. Increasing sulfur shortens vulcanization time, increases crosslink density, hardness, modulus, tensile strength, and rebound resilience, but reduces elongation, permanent set, and heat generation. Heat aging and flex resistance worsen. Accelerator selection should consider carbon black type, focusing on compound scorch characteristics and product performance. Common accelerators include thiazoles (e.g., M, DM), sulfenamides (e.g., CZ, NS, NOBS), and thiurams. Practice shows that delayed-action sulfenamide accelerators are most suitable for Styrene-Butadiene Rubber (SBR), offering long Mooney scorch time at processing temperatures and fast curing at vulcanization temperatures. Secondary accelerators like aldehydes or guanidines are less effective alone in styrene-butadiene rubber.
(2) Efficient and Semi-Efficient Vulcanization Systems: Sulfur systems produce polysulfide crosslinks with residual free sulfur, reducing heat resistance and compression set. To improve these, reduce sulfur and increase accelerators so sulfur only participates in efficient crosslinking—this is the efficient vulcanization system. Replacing part of sulfur with sulfur donors gives a semi-efficient system.
(3) Organic Peroxide Vulcanization System: Using organic peroxides like dicumyl peroxide improves heat aging resistance but results in low elongation and tear strength in the vulcanizate.
2. Reinforcement and Filling System
Carbon black is the best reinforcing agent for styrene-butadiene rubber. Key properties affecting vulcanizate performance are particle size (specific surface area), structure, and surface nature. Smaller carbon black particles increase tensile strength, hardness, and wear resistance. However, smaller particles increase heat generation and cracking tendency while reducing rebound resilience. Higher carbon black structure increases modulus, reduces elongation, and improves wear resistance, but also raises cracking tendency and heat generation. Smaller particle size and higher structure increase Mooney viscosity and shorten scorch time. High structure also improves extrusion speed, surface smoothness, and reduces die swell.
Additionally, white fillers like silica, clay, calcium carbonate, magnesium carbonate, and barium sulfate can be used. They improve compound plasticity, tack, and reduce deformation, while enhancing vulcanizate properties such as tensile strength, hardness, wear resistance, tear, elasticity, heat resistance, and electrical properties. They also lower costs and reduce dynamic heat generation.
3. Protection System
Styrene-Butadiene Rubber may harden and become brittle after long-term use. Depending on product requirements, protection is needed. Common protectors include antioxidants, antiozonants, anti-sun cracking agents, flex crack inhibitors, and harmful metal inhibitors. When using protection systems, consider the effects of antioxidants on compound plasticity and vulcanization rate, as well as staining, blooming, toxicity, volatility, and interactions with other additives.
4. Plasticizers
Plasticizers for styrene-butadiene rubber include petroleum-based, coal tar-based, pine tar-based, and fat-based types, as well as palmitic acid, stearic acid, oleic acid, calcium stearate, magnesium stearate, and zinc stearate.
Ⅱ Processing of Styrene-Butadiene Rubber Compounds
Styrene-Butadiene Rubber processing includes mixing, molding, calendering, shaping, and vulcanization. SBR vulcanizes slowly but with a flat curve, reducing scorch and over-cure risks. It has poor mixing performance, with little plasticity change, poor mill banding, and high calender/extrusion deformation.
During processing, note the following: avoid contamination with other rubber scraps during re-milling and preforming; re-mill compounds before use, and use preformed blanks within 48 hours; for high-hardness compounds, molding pressure should exceed 10 MPa per unit area. For vulcanized products thicker than 6 mm, add 5 minutes curing time for every 2 mm increase. For products with metal skeletons, extend curing time based on the adhesive’s curing speed.
Applications
Emulsion-polymerized Styrene-Butadiene Rubber is widely used, except for parts requiring special properties like oil resistance, heat resistance, or resistance to specific media. It is suitable for rubber parts and sheets working in air or ethanol-glycerol mixtures at -60°C to 100°C.
In the tire industry, Styrene-Butadiene Rubber is widely used in passenger car tires, small tractor tires, and motorcycle tires, but less in truck and radial tires. To improve tread wear resistance and groove cracking, oil-extended SBR is often blended with BR; bias ply passenger tire sidewalls use natural rubber blended with SBR. SBR is also widely used in belts and hoses, such as conveyor belt covers, water hoses, shoe soles, rollers, waterproof rubber products, and rubberized fabrics.
Styrene-Butadiene Rubber could also be used in the sealing products industry due to its good elasticity and cost-effectiveness. It is commonly employed in manufacturing gaskets, o-rings, and other static or dynamic sealing components resistant to mineral oil-based hydraulic fluids.