Astemo develops technology to restore strength of degraded plastics to enable reuse Research results published in a leading international journal in the field of composite materials

Tokyo, July 15, 2026 – Astemo, Ltd. (hereafter “Astemo”) has jointly developed a recycling technology with Tohoku University’s Graduate School of Environmental Studies that restores the strength of engineering plastic polybutylene terephthalate (PBT^*1) degraded under high-temperature and high-humidity conditions.

Recycled plastics have conventionally faced challenges for reuse due to performance degradation. The developed technology enables the recovery of PBT’s material properties to levels close to practical implementation, contributing to the realization of a circular economy. This can enable expanded reuse of recycled plastics in applications such as automotive components. The research findings were published on June 23, 2026, in Composites Part A: Applied Science and Manufacturing,^*2 a globally recognized leading academic journal in the field of composite materials.

As resource constraints intensify due to the availability of resources and increasing procurement risks, the transition to a circular economy is becoming essential for achieving carbon neutrality. Resources such as petroleum, which serve as feedstocks for plastics, are finite. Consequently, the importance of plastic recycling and circular use of high-performance materials continues to grow. Reusing waste materials is therefore important not only for reducing raw material consumption and CO₂ emissions, but also for mitigating rising resource costs and procurement risks.
Particularly in the automotive industry, there is growing demand for “closed-loop recycling,” in which resins recovered from end-of-life components are reused for equivalent applications, as well as for higher-quality recycled materials and expanded application opportunities. However, in addition to the challenge of securing sufficient volume of recovered materials, plastics degrade and deteriorate in quality from use. PBT, which is widely used in automotive components and other applications, experiences reductions in mechanical strength due to polymer chain breakdown under operating conditions, making it difficult to ensure material quality when reused. To address these issues, Astemo and Tohoku University conducted research to enable closed-loop recycling of resins recovered from end-of-life vehicles.

In this study, a chain extender^*3 was added to degraded PBT, reconnecting severed polymer chains. The results demonstrated that the molecular weight and reduced tensile strength of degraded materials could be restored to levels close to those of the original material. Furthermore, the study identified effective conditions for property recovery through optimization of additive concentrations and compounding methods. These findings are expected to contribute to improving the quality of recycled materials and expanding the range of applications.

This technology is expected to enable high-value-added recycling of materials recovered from end-of-life vehicles and accelerate resource-circulating material use across a broad range of resin applications, including automotive components.
Going forward, Astemo will apply this technology to expand the use of recycled materials in automotive electronic component housings and other products, promote mass-production applications through improved material quality stability, and advance product designs based on circular materials. Through these initiatives, Astemo aims to both reduce resource constraints and lower CO₂ emissions.

Astemo will continue to advance resource circulation in automotive components through the evolution of materials technologies and the practical implementation of circular materials, contributing to the realization of a sustainable mobility society.