Top 10 Elastomers for Sustainability - JSR entry

Company: JSR Elastomer Europe GmbH

Location: Dusseldorf, Germany

Project: New hydrogenated styrene-butadiene rubber (SBR) for ultra-high strength

Main materials technologies involved
Combination of unique polymerization and hydrogenation technology

Main goal or objective of the development project
The main goal of this project is to achieve a “50%" improvement of wear resistance compared to our conventional grade while keeping a good balance between the rolling resistance and wet grip indicator, like functionalized S-SBR.

Technical challenges addressed by the project team
Seeking continuously for inventions that contribute to society and the environment, JSR identified the need to improve wear resistance properties of tire treads. The consideration is to increase the durability of tires, and at the same time to reduce road-wear particles.

In general, wear resistance can be improved by increasing the molecular weight of the polymer. However, rolling resistance is deteriorated because of the decreasing number of functional groups at the polymer chain-end. 

A high amount of filler is another way to improve wear resistance, but rolling resistance is deteriorated. Besides, the improvement level on wear resistance is not enough (<10%) with both approaches.

To solve this trade-off relationship, JSR has developed a newly hydrogenated polymer with a unique polymerization technology.

Hydrogenated polymer can control the number of crosslinking points to achieve a uniform cross-linked structure. The uniform crosslinked structure can suppress the material break by stress minimization and can improve wear resistance. 

And the single bond after hydrogenation allows free rotation leading to high polymer entanglement, which can contribute to high modulus and better wear resistance. That is, the uniform cross-linked structure and high polymer entanglement by the hydrogenated polymer can achieve a significant improvement in wear resistance.

As for the rolling resistance, our polymerization technology shows a 30% improvement compared to E-SBR. Accordingly, the combination of unique polymerization and hydrogenation technology could overcome the trade-off relationship between wear resistance and rolling resistance.

In practice, we found that JSR hydrogenated S-SBR could improve wear resistance by 50% on the internal tire test while maintaining a good level of rolling resistance.

As far as we know, this would be the first time to apply hydrogenated S-SBR into tire treads as the main rubber ingredient.

What is the commercial status of the technology or product?
A new hydrogenated polymer was introduced a few years ago and getting positive results from many customers. Under this situation, JSR has decided to start its commercialization, and JSR hydrogenated S-SBR has been successfully commercialized in 2020. 

We expect that the new durable polymer could be used for various applications (PCR/OTR/motor cycle/racing, etc.).

Please describe the contribution of the technology or product to sustainability
JSR hydrogenated S-SBR can contribute to not only the reduction of fuel efficiency but also the reduction of microplastic and extension of the product cycle. Since the tire with JSR hydrogenated S-SBR showed 50% improvement on wear resistance, the shelf life for the tire expects to be 1.5 times compared to the conventional tire.

Scope for further enhancements to the technology or product
The next scope is to achieve a 20% improvement of rolling resistance and better processability while maintaining an excellent wear resistance level compared to the current hydrogenated polymer.

Any further comments to further highlight the contribution of this development project to environmental sustainability?
The excellent wear resistance caused by JSR hydrogenated S-SBR can reduce the thickness of tire tread, which contributes to a good rolling resistance, weight reduction of a tire, and saving the material used.