Editorial: From macromolecular design to sustainable polymer systems: reflections for 2026

The year 2025 marked the 60th anniversary of the passing of Hermann Staudinger, whose macromolecular concept established the very foundations of polymer science. As we enter 2026, this milestone invites not only historical reflection but renewed commitment to the chemical principles that continue to shape sustainable materials research.When Staudinger introduced the concept of covalently bonded macromolecules, he did more than define polymers – he provided a molecular framework that enabled chemists to rationally connect structure, reactivity, architecture, and properties. This molecular perspective remains at the heart of contemporary polymer science. Today, however, the central question is no longer solely how to design high-performance materials, but how to design polymer systems that reconcile performance with environmental compatibility, resource efficiency, and long-term societal needs.Over the past two decades, sustainability has become a primary driver of innovation in polymer chemistry. Significant advances have emerged in biobased monomers, renewable feedstocks, green synthetic methodologies, degradable and recyclable polymer architectures, and safer additive systems. The focus has progressively shifted from incremental substitution to systemic redesign – rethinking monomer sourcing, polymerisation pathways, network reversibility, and end-of-life scenarios at the molecular level.Yet recent global disruptions have revealed that sustainability cannot rely exclusively on feedstock origin or recyclability claims. A broader concept is required – one that integrates resilience at the molecular and materials levels. Sustainable polymer systems must maintain functionality across multiple life cycles, withstand variable environmental conditions, and remain compatible with circular economy strategies. Achieving this goal demands deeper integration of macromolecular design, structure–property relationships, and lifetime prediction.In this context, Green Materials plays a distinctive role. The journal emphasises chemistry-driven innovation: the rational design of renewable monomers, functional macromolecules, hybrid systems, and sustainable processing strategies grounded in molecular understanding. The contributions gathered in this issue exemplify how contemporary polymer science continues to evolve along the trajectory initiated by Staudinger – linking molecular insight to responsible material solutions.The contributions in this issue illustrate how molecular insight informs sustainable solutions. Natural fibre-reinforced composites are explored through their mechanical and tribological behaviour1 and additive manufacturing potential,2 showing how interfacial chemistry and polymer–fibre interactions govern performance. Biopolymer films3 and lignin-derived polymers4 demonstrate how renewable macromolecules can be processed and functionalised for practical applications. Bio-based adsorption materials5 and molecular inclusion systems6 reveal the role of surface chemistry and supramolecular interactions in environmental and bioactive contexts. Finally, studies on cryolite regeneration7 underscore the importance of chemical insight for resource circularity. Together, these works exemplify how polymer chemistry, molecular design, and sustainable material strategies intersect.Collectively, the articles in this issue illustrate that sustainable materials research is most impactful when rooted in rigorous chemical understanding. From renewable monomer design and biopolymer processing to interfacial engineering, supramolecular systems, and resource regeneration, each contribution reflects the enduring relevance of macromolecular science.As we move further into 2026, the lesson inherited from Staudinger remains clear: progress in materials sustainability begins with chemistry. By strengthening the molecular foundations of polymer design, and by integrating circularity and resilience into macromolecular architectures, the community continues to build a future in which green materials are not merely alternatives – but standards.