Circular Design of Bio-Based Polymer for Sustainable Bioproducts

Mitigating plastic waste demands high-performance, biodegradable bioplastics to overcome current limitations like brittleness (e.g., PHB, Polyhydroxybutyrate), resistance to degradation at ambient temperature (e.g., PLA, poly lactic acid), and limited functionality. We have developed a new guiding principle for designing multi-functional films with high biodegradability, as demonstrated in two innovative multi-layer film designs. The biomimetic Layered, Ecological, Advanced, multi-Functional film (LEAFF) mimics plant leaf structure to cross-link PLA with cellulose nanofibrils (CNF), significantly enhancing PLA’s mechanical strength while enabling rapid ambient soil biodegradability. The breakthrough transforms PLA utilization as PLA is only compostable and cannot be degraded at ambient temperature. More importantly, LEAFF also offers high transparency, water stability, and superior gas barrier properties to extend food shelf life. The synergistic functionality enables LEAFF to be broadly used for packaging industries. Complementarily, Multifunctional Reinforced Bioplastics (MReB) integrates PHB and CNF cross-linked with TDI to improve mechanical properties, crystallinity, thermal stability, water stability, printability, and air impermeability. MReB enhances biodegradability and avoids microplastic formation. Both LEAFF and MReB represent transformative advances to synergistically enhance mechanical performance, accelerate biodegradability, and introduce essential multifunctionality for broader, sustainable packaging applications while mitigating environmental impact. The guiding principles can be broadly applied to turn compostable and non-degradable plastics into biodegradable plastics while creating value-added properties such as high gas barrier properties to reduce food waste and enhance cost-effectiveness of groceries and food industries.

More than 5 million tons of plastic waste are discharged into our marine ecosystems annually. The Ellen MacArthur Foundation warns that the total weight of plastic waste in the oceans will exceed that of marine life by the year 2050 if plastic waste contamination continues at current rates. Promoting practices such as “reduce, reuse and recycle” are important to ensure a circular economy and minimize marine debris concerns. In this talk, we will present another approach, specifically biodegradation, that can help close the loop and ensure a truly circular use of materials.
Natural polymers such as PHB (polyhydroxybutanoic acid) copolymers and their products are certified to biodegrade in soil, home compost, industrial compost, fresh water and marine environments. Currently, PHB copolymers are the only marine biodegradable polymers available at a reasonable scale to displace many of the single-use and disposable plastic products that tend to pollute our oceans. Further, the PHACT family of PHB copolymers are also biobased – this has the potential to help lower the carbon footprint relative to the use of fossil carbon based polymers.
We will present case studies of applications and products that demonstrate the tremendous value of PHB copolymers in a truly closed loop ecosystem. We will specifically highlight the lower environmental impact of such products from both a carbon footprint and an end-of-life perspective.

The transition toward eco-friendly, paper-based packaging presents significant opportunities as innovative fiber-based materials, barrier coatings, and application processes are developed. At the same time, minimizing waste and byproducts, improving recyclability, and enabling appropriate end-of-life pathways are essential to meeting Extended Producer Responsibility (EPR) goals and ensuring system-level sustainability. This work highlights advanced approaches for developing alternative fiber-based packaging materials through green and sustainable chemical transformations of cellulosic substrates. Key technologies include alternative fibers and (nano)cellulose-based functional materials, supported by real-time, AI-enabled characterization systems. These approaches enable high-performance packaging with enhanced oil and grease resistance, improved water and oxygen barrier properties, and high flexibility, while minimizing environmental impact. Emphasis is placed on replacing single-use plastics with renewable, bio-based alternatives and implementing sustainable manufacturing practices compatible with existing infrastructure. Environmental impacts are evaluated using life-cycle-based metrics, enabling sustainability-informed decision-making. Overall, this work demonstrates how green chemistry principles and AI tools can advance scalable, high-performance fiber-based packaging solutions.

Lightweighting through the creation of porous architectures has been employed extensively in aerogels and foams. The use of two dimensional columnar systems such as honeycombs and their related polygons, has been employed due to the ease of manufacturing 2d structures using modified calendaring systems. More recently the availability of 3d printing led to a resurgence of truss based cellular architectures using struts. Architectures with all plates have shown high performance with some challenges in manufacturability. In this presentation we explore the effect of gradual face insertion into a body centered cubic lattice. We examine a single cell oriented such as that the faces are arranged around the centroid of the cube. A 4x4x4 lattice is then explored to examine stress transfer to the nearest neighbor. Mechanical, thermal and acoustic performance are explored. A modeling approach to material replacement framed in the line of digital twins is employed. The results point to a novel approach of integrating materials selection and design for sustainable high performance multifunctional solutions.

Lignin is a widely available bioresource, yet is underutilized for production of chemicals and polymers. Model compounds derived from lignin depolymerization were investigated as sustainable sources for polymers. Epoxy resins are thermoset polymers widely used in composites, coatings and adhesives, with applications spanning automotive and aerospace industries, structural components, and wind turbine blades, among others. Syringic, vanillic, and 4-hydroxybenzoic acids, products of lignin depolymerization, were investigated as replacements for conventional diglycidyl ether of bisphenol A (DGEBA) in anhydride-cured epoxy resins. The resulting para-phenolic acid-based epoxy resins exhibited high glass transition temperatures (T_g) and similar elongation at tensile behavior as compared to DGEBA-based epoxy resins. Thermomechanical analysis of the resins showed that increasing methoxy groups in the monomer raised the glassy storage modulus (E’) but lowered T_g of the resin. This T_g decrease correlated with reduced crosslink density and rubbery E’. When T_g was plotted against crosslink density, the resin derived from para-phenolic acid followed a consistent linear trend, distinct from that of the petroleum-derived diglycidyl ether of bisphenol A (DGEBA) resin, suggesting a different structure-property relationship. In summary, epoxy monomers derived from para-phenolic acids represent promising biobased alternatives to DGEBA. The number of methoxy groups on the lignin-derivable monomer critically influences crosslink density, T_g and thermomechanical properties of the resulting resins.

Polymer synthesis is dominated by chain growth polymerization and polycondensation, while polyaddition remains comparatively overlooked and underdeveloped. Defined as the stepwise construction of polymer backbones through irreversible bond-forming reactions without the elimination of small molecules, polyaddition represents a fundamentally distinct and underutilized platform for sustainable polymer synthesis. Its intrinsic advantages include excellent atom economy, energy efficiency, direct compatibility with bio-derived monomers, and the ability to encode programmed degradation through precise structural control.
In this contribution, we highlight polyaddition as a viable alternative to conventional polymerization paradigms and present recent advances from our laboratory based on crotonate-derived renewable monomers. Two complementary polyaddition strategies are described: carbon–carbon bond formation via catalytic Michael-type polyaddition of dicrotonates, and carbon–sulfur bond formation through thiol–ene polyaddition, enabling rapid polymer and network formation under mild conditions. More broadly, these results point to polyaddition as a general and adaptable framework for polymer synthesis. Efficient. Modular. Renewable. Designed for performance and end of life.

Building a more resilient, circular, and low-carbon economy is at the core of world’s target in reducing greenhouse gas emissions. At the same time, we are facing harmful environmental effects created by accumulation of plastics. Plastics and composites are inevitable in our modern day-to-day life and their use spans from packaging, auto-parts, electronics, housing structures to sports utility and many more. While plastics found many applications that benefit food preservation and lower the transportation costs, the lack of plastic waste management is creating a pervasive environmental pollution. Today, we consume micro-plastics (<5 mm in size) in our water and as well as it is found in human blood! The questions is, can we harness the benefits that plastic brings to the society, without harmful waste? We desperately need a “Second Age of Plastics” with new materials that can answer the needs of today and not jeopardize tomorrow’s generations. We have been developing plastics with lower carbon footprint that we call “Sustainable Polymers”. Our sustainable materials support Circular Economy and include polymers and their composites from wastes, recycled materials, bio-renewables and their combinations. Two types of materials; (i) biobased, biodegradable, and (ii) biobased non-biodegradable, recyclable polymeric materials can help in creating the circular economy of plastics.

Four key initiatives that can promote better use of sustainable materials in the markets include; (i) Regulatory framework to support bioplastics and sustainable materials; (ii). Carbon tax credits that incentivize industry to lower their carbon footprint, with a clearly defined scientific criterion for life cycle analysis used to determine the carbon footprint for industry; (iii). Consumer education with clear, simple and certified labels that prevent confusion and promote consistency at the consumer level; (iv) Understanding the harm created by not using bioplastics and sustainable materials, in regards to the carbon footprint.

Advancing sustainable technologies in energy and healthcare requires materials that are efficient, affordable, and environmentally responsible. This talk highlights our efforts to addressing critical challenges in clean energy conversion and biomedical applications through the rational design of sustainable polymeric materials having potential for circularity. In the energy domain, we tackle persistent limitations of fuel cells and electrolyzers—such as ion transport inefficiencies, thermal instability, and reliance on costly, unsustainable materials—by rethinking the design of ion-conducting polymers. By repurposing underutilized lignin-rich industrial and agricultural waste, we have synthesized bio-derived ionomers that enhance ion transport across low- and high-temperature regimes while supporting the bioeconomy, circular economy, and sustainability in energy technologies. Beyond energy applications, we demonstrate that lignin-based cationic polymers can effectively kill antibiotic-resistant bacteria while remaining non-cytotoxic to human cells, minimizing environmental and biological impact. Collectively, these works underscore the exceptional potential of lignin as a versatile, renewable feedstock for the circular design of value-added materials for clean energy applications and beyond.

Chitin nanomaterials have emerged as sustainable, high-performance building blocks for advanced functional systems, yet their broader adoption remains constrained by limited control over morphology and scalable processing routes. Here, we examine chitin nanowhiskers and chitin nanofibers as two distinct nanoscale architectures derived from the same abundant biopolymer, highlighting how differences in aspect ratio, surface chemistry, and supramolecular organization govern their performance in encapsulation and composite reinforcement applications.

Chitin nanowhiskers, characterized by rigid, rod-like morphologies and high crystallinity, enable efficient stabilization and encapsulation of active agents through interfacial adsorption and network formation, while chitin nanofibers form flexible, entangled networks well suited for mechanical reinforcement and barrier enhancement in polymer matrices. Emphasis is placed on green and scalable preparation strategies, including ionic-liquid-enabled fractionation and mechanical nanofibrillation, that minimize chemical derivatization, reduce waste, and allow morphology tuning.

By linking nanoscale structure to application-specific functionality and scalable, environmentally responsible processing, this work positions chitin nanowhiskers and nanofibers as versatile platforms for sustainable materials in agricultural and polymer engineering contexts.

Enhancing the biodegradability of existing bio-based polymers expands available options when designing materials for open-environment degradation and composting as end-of-life, particularly for applications where recovery is impractical. Products such as tree guards, agricultural films, and external infrastructure must retain mechanical integrity during use, whilst ideally degrading in a predictable manner once their service life has ended. Achieving this balance; maintaining performance in use whilst enabling degradation only under specific environmental conditions, remains a central challenge in the circular design of biodegradable polymer systems.

We present enzyme-enabled polymers with plastic-degrading enzymes discovered from the natural environment, embedded into solid polymer matrices. Polylactic acid (PLA) is used as a model bio-based polymer to demonstrate this approach, whilst the underlying strategy is applicable to a broader class of degradable plastics. Environmentally derived enzymes were stabilised and nano-dispersed within PLA using previously described encapsulation methods to maintain enzymatic activity. Degradation behaviour was quantified and compared to benchmark systems based on Proteinase K, demonstrating that degradation rates can be modulated through enzyme selection. Enzyme-enabled PLA materials exhibited distinct, enzyme-specific degradation profiles, which were also strongly influenced by pre-processing methods, processing temperature, and environmental conditions. This behaviour highlights the promise of enzyme-enabled polymer nanocomposites as a platform for designing degradation kinetics aligned with realistic end-of-life scenarios.

Importantly, this study includes field trials conducted in the open environment, providing early validation of enzyme-enabled bio-based polymers under real-world conditions. This work presents interdisciplinary strategies combining enzyme discovery, green chemistry principles, and polymer engineering to support the circular design of materials that maintain functional performance during use yet undergo controlled, environmentally triggered degradation in specific conditions.