Tokyo Metropolitan University Develops Biobased Poly(ester amide)s with Tensile Properties Beyond Polyolefins
A research team led by Professor Kotohiro Nomura at Tokyo Metropolitan University has achieved a significant breakthrough in sustainable polymer science. Working in cooperation with the Osaka Research Institute of Industrial Science and Technology and the University of Shiga Prefecture, the group has developed biobased poly(ester amide)s derived from inedible biorenewables that not only offer full chemical recyclability but also exhibit tensile properties surpassing those of commodity plastics such as polyethylene and polypropylene.
The development addresses a long-standing challenge in the biobased materials sector: creating polymers from renewable resources that match or exceed the mechanical performance of their fossil-based counterparts. While biobased polymers such as PLA and PHA have found commercial success, few have demonstrated mechanical properties — particularly tensile strength and elongation at break — that surpass conventional polyolefins in film form.
The new materials are synthesised from non-edible vegetable oils, amino acids, and sugars using a catalytic olefin metathesis polymerisation method, specifically acyclic diene metathesis (ADMET) polymerisation. This approach yields high molecular weight polymers with tailored structures. The poly(ester amide) incorporating phenylalanine demonstrates an additional distinctive property: fast self-healing at ambient temperature, opening potential applications in durable coatings and flexible electronics.
Chemical recyclability is engineered into the polymer backbone. The materials can be quantitatively depolymerised to their starting monomers through catalytic transesterification with alcohol, enabling a closed-loop recycling pathway. This feature aligns with circular economy principles by ensuring that end-of-life products can be returned to virgin-quality feedstock without downcycling.
The research was conducted under the Japan Science and Technology Agency (JST) CREST programme, within the research area “Precise Material Science for Degradation and Stability” and the theme “Development of Bio-Based Advanced Polymers and their Depolymerization, Chemical Recycle.” The findings were published in JACS Au on 6 July 2026 under the title “Synthesis of Biobased Aliphatic Poly(ester amide)s and their Thermal, Tensile Properties, and Selective Depolymerization through Transesterification.”
Professor Nomura noted that the combination of high tensile performance, chemical recyclability, and non-edible feedstock sourcing represents a significant step toward sustainable polymers that can compete directly with fossil-based polyolefins in demanding applications. The team is now exploring scale-up pathways and evaluating the materials in specific end-use scenarios, including packaging films and textile fibres.
The use of inedible biorenewables addresses a critical sustainability concern. By avoiding competition with food supply chains, the approach aligns with EU and global policy frameworks that prioritise waste and residue feedstocks for biobased production. The vegetable oil and amino acid building blocks can be sourced from agricultural by-products and non-food crops, enhancing the overall sustainability profile.
Industry observers note that the ADMET polymerisation route, while established in academic research, presents both opportunities and challenges for commercial translation. The molybdenum-alkylidene catalyst system used in the laboratory demonstrates high activity, but catalyst cost and removal at industrial scale will require optimisation. Several chemical companies are reportedly evaluating the technology for potential licensing.
Source: EurekAlert! / Tokyo Metropolitan University press release, July 2026; JACS Au, 6 July 2026.