Views: 0 Author: Sally Lyu Publish Time: 2026-03-20 Origin: Site
When heat resistance is required, the molecular architecture of SEBS is an important factor. However, it should not be oversimplified as “star-shaped SEBS is always better.” In SEBS-based TPEs, the styrene domains mainly act as physical crosslinking points, and different architectures mainly influence flow behavior, hardness, wear resistance, and the balance of mechanical properties. In many practical formulations, a proper combination of linear and radial grades can deliver a better overall balance than relying on only one structure.
Molecular weight is also an important selection parameter. In practice, lower-viscosity grades can improve flow and processing, while overly low molecular cohesion may reduce scratch and wear resistance. For this reason, SEBS should be selected by balancing processability, mechanical performance, and final application requirements, rather than by pursuing only easier processing or only higher viscosity.
A suitable styrene content helps improve hardness, rigidity, and heat resistance, because the styrene phase is the hard segment in SEBS and polystyrene has a glass transition temperature of around 100°C. However, excessively high styrene content may reduce melt flow and worsen compatibility in PP-based systems. Therefore, the right styrene level should be chosen according to the required balance between heat resistance, processing behavior, and overall mechanical properties.
For heat-resistant TPE compounds, a proper stabilization package is essential. Antioxidants such as hindered phenolsand phosphites are commonly used to improve thermal-oxidative stability during processing and long-term service. This is especially important for maintaining color, mechanical performance, and processing consistency.
In formulation design, SEBS can be combined with polypropylene and, when needed, with higher-heat polymer systems through compatibilized blending. Functionalized grades such as SEBS-g-MAH are more accurately described as compatibilizers or performance modifiers, especially in blends involving engineering plastics such as PA or PPO. This kind of design can help improve the overall heat resistance of the compound, while also maintaining a workable processing window.
The addition of inorganic fillers such as talc and silica, and in some cases reinforcing materials such as fibers, can improve stiffness and thermal performance. However, excessive filler loading may reduce elasticity and impact performance. Therefore, filler selection and dosage should be optimized based on the target application.
In SEBS/PP-based TPE systems, the ratio of SEBS to PP and the amount of oil have a strong influence on flowability, mechanical properties, and wear resistance. Excessive oil content may increase surface tackiness and reduce abrasion resistance. For heat-resistant TPE formulations, over-plasticization should be avoided, and the full formulation should be optimized as a system rather than by adjusting a single raw material alone.
When selecting SEBS grades and adjusting the formulation for heat-resistant TPE, the key is not to maximize only one property. The real goal is to achieve the right balance between heat resistance, processing performance, mechanical properties, and end-use requirements.
