How to optimize the elastic properties of styrene-butadiene rubber (SBR)?

Styrene-butadiene Rubber (Styrene-butadiene rubber, SBR) is a common synthetic rubber, because of its excellent elasticity, wear resistance and processing performance, is widely used in tires, soles, seals and other fields. In practical applications, the elastic performance of SBR still has room for improvement. This paper will analyze how to optimize the elastic properties of SBR from the aspects of chemical composition, microstructure control and processing technology.

1. Key factors affecting the elastic performance of SBR

before discussing how to optimize the elastic performance of SBR, we need to clarify the main factors that affect its elasticity.

1.1 chemical composition

the chemical composition of SBR is mainly composed of styrene and butadiene. Styrene provides a rigid structure that imparts heat resistance and aging resistance to rubber, while butadiene imparts excellent elasticity and abrasion resistance to rubber. To optimize the elastic properties of SBR, it is first necessary to reasonably adjust the ratio of styrene and butadiene to achieve the best state of rigid-flexible bonding. Generally speaking, when the styrene content of SBR is between 20% and 30%, its elastic performance is the best.

1.2 microstructure control

the microstructure of SBR plays a key role in its elastic properties. By adjusting the polymerization process (such as solution polymerization or emulsion polymerization), the length of the rubber molecular chain, the crosslinking density and the microstructure can be controlled. For example, increasing the crosslink density can improve the elongation stress and fatigue resistance of SBR, but may sacrifice some elasticity. Therefore, when optimizing the elastic properties of SBR, it is necessary to find a balance between crosslinking density and elasticity.

Selection of 1.3 fillers and auxiliaries

fillers are an integral part of the SBR formulation. Carbon black, white carbon black, clay and other fillers can not only enhance the rigidity and strength of rubber, but also improve its elastic properties. For example, the use of high structure carbon black can significantly increase the elastic modulus and tensile strength of SBR. The rational use of additives (such as plasticizers, anti-aging agents, etc.) can also effectively improve the processing performance and use performance of SBR.

2. Strategies to optimize the elastic performance of SBR

2.1 Optimized Rubber Formulation

by adjusting the rubber formula, the elastic properties of SBR can be significantly improved. For example:

• monomer ratio optimization: Appropriately increasing the content of butadiene can improve the elastic recovery rate and anti-fatigue performance of SBR.
• Selection and dosage of crosslinking agent: The type and amount of crosslinking agent directly affect the crosslinking density of SBR. Dynamic Vulcanization (dynamic vulcanization) technology can prepare highly crosslinked SBR by in-situ polymerization without adding crosslinking agents, thereby significantly improving its elastic properties.

2.2 improved processing technology

the processing technology has an important influence on the elastic properties of SBR. For example:

• mixing process: A reasonable mixing process can ensure that the fillers and additives are evenly dispersed in the rubber matrix, thereby improving the tensile strength and elastic modulus of SBR.
• vulcanization process: Vulcanization is a key step in SBR processing. By controlling the curing temperature, time and the amount of curing agent, the curing degree of SBR can be optimized, thereby improving its elasticity and flex resistance.

2.3 Structure Design and Innovation

in recent years, researchers have further improved the elastic properties of SBR by introducing new materials and structural designs. For example:

• nano material modification: The introduction of nano-materials (such as CNTs and nano-SiO₂) into SBR can significantly improve its elasticity, strength and aging resistance.
• porous structure design: By controlling the foaming process, the porous SBR material can be prepared, which can give it excellent cushioning performance and energy absorption performance.

3. Elastic performance optimization in practical applications

in practical applications, the elastic performance optimization of SBR needs to be adjusted in combination with specific application scenarios. For example:

• tire industry: By optimizing the elastic properties of SBR, the wear resistance, wet skid resistance and comfort of tires can be improved.
• sole material: By improving the elastic recovery rate and anti-fatigue performance of SBR, lighter and more comfortable sole materials can be prepared.
• Seals and Gaskets: By optimizing the elasticity and aging resistance of SBR, more durable seals and gaskets can be prepared.

4. Future development trend

with the in-depth research on the elastic performance of SBR, the future development trend will focus on the following aspects:

• green process green SBR materials are prepared by developing environment-friendly monomers and additives.
• Intelligent rubber material: Develop SBR materials with intelligent response performance by introducing sensors and self-repair technology.
• multi-functional composite material: By combining SBR with other functional materials, composite materials with multiple functions such as elasticity, conductivity and antibacterial properties are prepared.

The elastic properties of styrene-butadiene rubber (SBR) can be significantly improved by reasonable chemical composition design, microstructure control and processing technology optimization. This can not only meet the market demand for high-performance rubber materials, but also promote technological progress and product upgrades in related industries. In the future, with the continuous emergence of new materials and new technologies, the elastic performance optimization of SBR will move to a higher level.