The Circularity Gap in High Performance Polymers
Automotive electrification depends on high performance polymers that can withstand heat, voltage, and mechanical stress. Materials such as Radel® PPSU are widely used in electric motor components because of their durability and thermal stability.
That durability, however, presents a challenge. These specialty polymers are difficult to recycle at end of life. As vehicle platforms shift toward hybrid and electric systems, the industry faces mounting pressure to reduce carbon intensity while maintaining strict safety and performance standards.
Closing this gap required a new approach that combined material science, certification, and cross value chain collaboration.
Introducing the ECHO Framework
Syensqo created ECHO as an internal brand dedicated to circular and sustainable polymer solutions. Under this framework, the company developed specific grades incorporating certified circular and renewable feedstocks through a mass balance approach verified under the ISCC PLUS regime.
One of the first commercial outcomes is Radel® PPSU ECHO, engineered for slot liner applications in hybrid and electric motors. Certified circular feedstock is attributed via mass balance, with full traceability from source to finished product.
This marked the first time a PPSU material for automotive electric motor applications achieved this level of certified circular integration.
Collaboration Across the Automotive Value Chain
The ECHO project extended beyond material development. Syensqo worked closely with automotive OEMs developing hybrid electric platforms, Tier 1 suppliers, and electric motor manufacturers specialized in 400V systems.
Joint validation programs confirmed that the ECHO grade matched the technical performance of conventional PPSU while meeting new sustainability criteria. The slot liners were successfully integrated into hybrid and electric motor production, establishing an operational model for circular specialty polymers.
Performance Gains Through Design Innovation
The project delivered measurable efficiency improvements.
Radel® PPSU ECHO enabled thinner slot liner designs, achieving up to 42 percent reduction in material thickness compared to legacy solutions. Thinner designs contribute directly to improved electric motor efficiency.
In addition, traditional manufacturing steps such as moisture management and dedusting processes were eliminated. This streamlined production and reduced energy use during component manufacturing.
Certified Circular Content with Verified Impact
Radel® PPSU ECHO offers fossil feedstock substitution of up to 38 percent, with a Product Carbon Footprint reduction of up to 7 percent compared to conventional grades. Commercial launch of certified circular slot liners began in early 2025.
The result is a material that maintains identical performance standards while integrating traceable circular and renewable content.
Creating a Blueprint for Circular Specialty Polymers
ECHO demonstrates that advanced polymers can move beyond linear use models. By combining certification, mass balance accounting, collaborative validation, and performance driven redesign, Syensqo has created a working example of circular integration in automotive electrification.
If widely adopted across Europe, this approach can help establish a functional circular value chain for specialty polymers, directly supporting EU sustainability objectives and accelerating progress toward lower carbon mobility.
As the Syensqo team states:
“With the ECHO portfolio, we are proving that advanced polymers can be part of the solution for circular manufacturing, delivering sustainability without sacrificing technical excellence.”