From Biomass to Performance: Circular Polymers, Coatings, and Bioactives

Amines are valuable products and intermediates for a wide range of industries, from solvents and pharmaceuticals to agrochemicals. Various amines are typically produced from processing petroleum-derived compounds. As oil is a finite resource, more sustainable production of amines would be obtained from lignocellulosic biomass.
Lignocellulosic biomass consists of mainly carbon, hydrogen, and oxygen. Processing of lignocellulose gives a range of compounds containing alcohol and carbonyl functional groups. Primary amines have been produced from metal-catalyzed amination of alcohols at high temperatures and pressure or reductive amination of carbonyls, which lead to a mixture of primary, secondary and tertiary amines.
Enzymatic amination can perform reductive amination of carbonyls selectively to primary amines at room temperature in water. Transaminases (TA) accomplish this by using an amine donor, and amine dehydrogenases (AmDH) accomplish this with ammonia and nicotinamide-based reducing agents such as NADH. TA use leads to stoichiometric byproducts after the amine donor is consumed, increasing process mass intensity (PMI) and raw material costs. For cofactor regeneration, AmDH can be coupled with another enzyme such as formate dehydrogenase (FDH) to ensure that only catalytic NADH is required. AmDH can also be coupled with alcohol dehydrogenase (ADH) for a redox neutral enzyme cascade to make amines from alcohols with only ammonia and the corresponding alcohol as input and water and the amine as the only outputs.
In this work, engineered amine dehydrogenase enzymes are used to produce industrially relevant amine products from alcohols and aldehydes derived from cellulose and hemicellulose with ammonia as nitrogen source. Benefits include room temperature operation in water as solvent, selective production of primary amines, and only water as byproduct.

Cellulose nanomaterials have been prepared from dozens of plant species with specific physical properties such as length, crystallinity and degree of polymerization highly dependent upon the biomass source and method of preparation. However, a comparison of nanofibrils and nanocrystals prepared under identical methods from different origins—even originating from different components of the same plant species—is rarely observed. Herein four byproducts of the cotton plant: cotton gin motes (CGM), cotton gin trash (CGT), cotton seed hulls (CSH) and cotton seed meal (CSM) (Figure 1) where characterized by proximate analysis. Cellulose nanofibrils (CNF) and cellulose nanocrystals (CNC) from each source were prepared (Figure 2) and a physicochemical comparison of the attendant effect of the biomass source on nanomaterial properties is presented. The nanomaterials were characterized for their degree of crystallinity, apparent crystallite size, degree of polymerization and rheological properties of the suspensions.

Cottonseed meals are a protein-rich agricultural byproduct of the cotton industry, yet their utilization remains limited due to poor material performance and low commercial value. This research reports a green and scalable strategy to convert cottonseed meals into high-value and low-impact protein films through a structured pathway consisting of one mild extraction process followed by one of the three complementary reinforcement approaches. A non-destructive aqueous extraction method was developed to obtain cottonseed proteins with high yield and purity while preserving the native protein backbone and cysteine functionality. Controlled dissolution and wet-casting promoted protein unfolding and molecular entanglement, and subsequent solidification enabled recovery of cystine crosslinking, yielding tough and stable films without plasticizers. In-situ mineralization of calcium carbonate nanoparticles within the protein matrix was introduced as a physical reinforcement strategy. Strong interactions between Ca²⁺ ions and protein functional groups enabled uniform nanoparticle dispersion, leading to simultaneous improvements in tensile strength, modulus, and wet-state mechanical properties. Partially aminated chitin nanoparticles were employed as bio-based fillers. Chemical bonding between amino and carboxyl groups provided excellent interfacial compatibility, resulting in composites with enhanced ductility and water resistance at very low filler loadings. Oxidized cellobiose was utilized as a formaldehyde-free aldehyde-crosslinker. Controlled oxidation generated high aldehyde content without formaldehyde formation, enabling efficient low-temperature crosslinking and significant enhancement of both dry and wet mechanical properties of the protein films.

Every disposable paper cup is coated. Paper, an inherently hydro- and oleophilic material, requires a coating to achieve desired water and oil barrier properties. Because commercial coatings rely on fossil-derived polymers (e.g., polyethylene), the end-of-life options for the composite are often restricted to non-circular options (i.e., landfill or incineration). In response to evolving regulations, particularly for single-use packaging, bio-derived polymers and materials have emerged as more sustainable coating alternatives to their petroleum-derived counterparts. DNA stands out as an attractive bio-polymer for coatings due to ample availability from food and agricultural biomass wastes, though it suffers from inherent amphiphilicity and instability. Resolving these pitfalls, we present the novel utility of DNA-cationic lipid self-assemblies as green, circular, multifunctional coatings, finding unrecognized application of a decades old interaction best known for DNA extraction and gene delivery. Coatings based on DNA-cationic lipids result in a material system following green chemistry and engineering principles (e.g., non-hazardous synthesis, energy efficient, excellent atom economy, easy separation, etc.). Coating performance is tunable by varying the cationic lipid structure, yielding a range of hydrophobic and oleophobic properties measured by standardized and industry-accepted methods. Moreover, we demonstrate the coating is recoverable and closed-loop recyclable by multiple methods (i.e. dissolution or salt-triggered dissociation), enabling reuse of both the coating and base material (e.g., paper repulping). Ultimately, we demonstrate how the design of bio-polymer systems can simultaneously support the circular economies of emerging bio-polymers and commodity materials.

Our society has been utilizing synthetic polymers in many aspects of our daily life. The use of synthetic polymers has exponentially expanded over the last 100 years due to its mechanical robustness, lightweight, and manufacturing scalability. However, the functionality of synthetic polymers is typically limited, and is far from the performance and functionality of biological materials, where their interactive adaptation allows a very complex pattern of motions. The interplay between non-equilibrium states in the material can lead to complex collective motion, which is seen in biology but barely accomplished in synthetic materials. Toward mastering such biomimetic non-equilibrium states, we tailored polymers with hydrogen(H)-bonding (bond strength ~10 kJ/mol) or dynamic covalent bonds (covalent adaptive network, bond strength ~50-150 kJ/mol). The incorporation of H-bonding in elastic polymers enables facile self-healing, and the design was expanded to commercially viable primer-less self-healable sealants, that provide longevity through facile healing capability. Furthermore, tuning both H-bonding and dynamic covalent bonds in a tailored network structure enabled self-healing, shape-memory, adaptive rate-dependent mechanical properties as well as high-strength reversible adhesion. Such multi-stage non-equilibrium properties are further tailored via facile multi-layer assembly, providing biomimetic properties of self-healing, puncture resistance, and damage tolerance. This presentation will summarize the polymers with multiple dynamic bonds and their unique non-equilibrium properties, where the basic science design potentially leads to various deployable applications. Our on-going efforts toward mastering multiple non-equilibrium states of dynamic polymers will be discussed.

The persistence of plastics in the environment underscores the need for next-generation polymers that pair high performance with enhanced degradability. However, a broadly applicable framework for designing such materials has remained elusive. In this work, we present a “macroisostere” design strategy in which the carbonyl group (–CO–) of polyurethanes (PUs) is replaced with a sulfonyl group (–SO2–), giving rise to an unexplored class of polymers, polysulfamates. Inspired by bioisosteric principles in drug discovery where small chemical modifications improve overall drug performance, this approach seeks to maintain interchain interactions crucial for thermomechanical properties while introducing enhanced hydrolytic lability. Computational and experimental analyses confirmed that reduced nitrogen-to-sulfonyl donation increases electrophilicity, making –SO2– bonds more labile than –CO– and thereby enables increased degradation. This ‘macroisostere’ therefore enhances the hydrolytic susceptibility of the polymer while maintaining the key interchain interactions responsible for mechanical strength. This work discusses an optimized Sulfur(VI) Fluoride Exchange (SuFEx) polymerization, where we have been able to synthesize ten polysulfamates as structural analogs of common PUs. Subsequently, comparative studies between a PU and its polysulfamate counterpart revealed that this substitution improves thermal stability, slightly decreases the glass transition temperature, and maintains hardness and reduced Young’s modulus, while significantly increasing hydrolytic degradability. These findings establish the “macroisostere” concept as a promising platform for developing high-performance, degradable alternatives to conventional plastics.

Terpenoids and phenylpropanoids constitute the principal components of essential oils (EOs). Owing to their diverse chemical structures, these compounds are of considerable scientific and practical interest, as many exhibit characteristic aromas and pronounced biological activity. Consequently, EOs are widely used in the production of flavors, fragrances, and cosmetics, while highly bioactive EOs are increasingly applied in medicine, plant protection, and as insect and tick repellents. At present, several EO-based biopesticides derived from tea tree, orange, and spearmint are registered on the European Union pesticide market. In the context of the rapidly developing bioeconomy, there is a growing need to develop and implement plant-based preparations, including EO-containing formulations, as environmentally friendly alternatives to synthetic pesticides in sustainable agriculture and horticulture.
The aim of this study was to investigate the chemical composition, stability, and insecticidal activity of oil-in-water emulsions formulated with selected EOs. Essential oils were obtained from seeds of Apiaceae plants, including dill (Anethum graveolens L.), fennel (Foeniculum vulgare Mill.), caraway (Carum carvi L.), and coriander (Coriandrum sativum L.), as well as from biomass of selected conifer species and tansy (Tanacetum vulgare L.). Emulsions were prepared using EOs at concentrations of 0.01–1%, non-ionic surfactants (Tween and saponin), and water. The chemical composition of EOs and their corresponding emulsions was determined by gas chromatography–mass spectrometry (GC–MS). Emulsion stability was evaluated using a turbidimetric method. Insecticidal activity was assessed in laboratory bioassays involving dermal (contact) and inhalation (fumigation) exposure. Larvae of the yellow mealworm (Tenebrio molitor L.) were used as a model test organism.
Monoterpenoids were identified as the dominant constituents in the analyzed essential oils. Emulsions containing EOs from Apiaceae seeds exhibited high insecticidal efficacy in contact toxicity assays, whereas fumigation activity varied among the tested oils, with coriander EO showing the strongest effect. The results indicate that essential oils represent a promising source of bioactive compounds for the development of bioinsecticides. Further research should focus on field validation, environmental risk assessment, and economic feasibility of EO-based pest control strategies.

Essential oils (EOs) are volatile liquid substances of plant origin. They are produced from raw materials or plant waste by steam distillation, hydrodistillation, and, less commonly, by mechanical pressing or organic solvent extraction. In recent years, EOs have attracted increasing scientific interest as potential biopesticides, which is consistent with the principles of the bioeconomy and green chemistry. Their insecticidal and fungicidal properties are well documented, whereas reports on their herbicidal activity remain relatively scarce.
The aim of this study was to determine the chemical composition of EOs obtained from selected plant species and to evaluate their inhibitory effects on seed germination, understood as phytotoxic activity. The research material included essential oils derived from tansy (Tanacetum vulgare L., herb), Canadian goldenrod (Solidago canadensis L., herb), garden dill (Anethum graveolens L., seeds and leaves), caraway (Carum carvi L., seeds), coriander (Coriandrum sativum L., seeds), Scots pine (Pinus sylvestris L.), thuja (Thuja occidentalis L.), and Nordmann fir (Abies nordmanniana (Steven) Spach). Essential oils were obtained by hydrodistillation using a Deryng apparatus with a capacity of 10 L. Their chemical profiles were determined by gas chromatography coupled with mass spectrometry (GC–MS) using a Shimadzu QP-2020NX system. Biological activity was assessed in seed germination inhibition assays conducted on Petri dishes. The tests were performed using aqueous emulsions of EOs at concentrations ranging from 0.01 to 1%, with the addition of Tween 20 as a surfactant.
All analyzed EOs were characterized by a highly complex chemical composition, containing several dozen volatile organic compounds. It was observed that prolonged hydrodistillation resulted in an increased number of detected compounds and higher average molecular weights. The dominant constituents belonged mainly to the groups of monoterpenoids and sesquiterpenoids. The results demonstrated that most of the tested EOs exhibited herbicidal potential by significantly inhibiting seed germination of the test plants. The strongest phytotoxic effects were observed for essential oils obtained from thuja, coriander, dill, and tansy. Further studies should focus on evaluating the effectiveness of these EOs under field conditions and assessing their environmental safety and practical applicability.

Post-harvest losses and mosquito-borne diseases remain major challenges across sub-Saharan Africa, where chemical pesticides are increasingly limited by cost, resistance, and environmental toxicity. To address these constraints, we developed two low-cost, plant-based copper–botanical nanobiopesticides using abundant local biomass: Desert-date (Balanites aegyptiaca) seed oil and Neem (Azadirachta indica) seed oil. Copper (I) oxide (Cu₂O) nanoparticles were synthesized via a green route using neem leaf extract and subsequently hybridized with each oil to yield Cu₂O-NPs@DDO and Cu₂O-NPs@NSO. These hybrid materials were characterized using UV–Vis, FT-IR, XRD, SEM–EDX, and TGA, confirming nanoscale Cu₂O crystallites (6–8 nm), phytochemical capping, and 12–16% oil loading. Performance tests under realistic African use conditions revealed broad-spectrum efficacy. Against Callosobruchus maculatus, Cu₂O-NPs@NSO achieved 100% mortality within 72 h (LC₅₀ = 11.86 µg/mL), while Cu₂O-NPs@DDO caused 100% mortality at 300 µg/mL within 24 h. For Anopheles gambiae larvae, both composites outperformed their individual components, with Cu₂O-NPs@NSO reducing LC₅₀ values from 5021 to 132 µg/mL and Cu₂O-NPs@DDO achieving complete mortality at 400 µg/mL within 24 h. The enhanced activity suggests nanoparticle-enabled controlled release, cuticular penetration, and oxidative stress mechanisms coupled with oil-derived limonoids and fatty acids. Deployment pathways emphasize local manufacturability, low-cost reagents, and alignment with African supply chains (neem and desert-date wastes). The materials are compatible with smallholder storage systems, and suitable for integration into community-level vector-control programs. Ongoing studies focus on safety profiling, scale-up, and regulatory readiness to support adoption across agricultural and public-health contexts.

To remediate the growing global impacts of plastic waste, it is imperative to design sustainable materials that can be used as replacements for current non-renewable and non-biodegradable commercial products. Addressing this issue requires careful selection of both material class and renewable feedstock source to maximize the sustainability of production processes and end-of-life outcomes. This work describes the use of microalgae as a renewable feedstock for preparation of thermoplastic polyester polyurethane (TPU) materials. The sustainable and robust photosynthetic capacity of microalgae paired with cleavable bonds within the polyester TPU backbone result in a material that promotes efficient resource use and reduced ecological impact at the end of its life cycle. High-purity TPU monomers derived from Nannochloropsis salina oil were used to synthesize the first 100% microalgae-sourced TPU material from azelaic acid (AzA), 1,7-heptamethylene diisocyanate (7-HDI), and 1,9-nonanediol (NDO). Thermal and mechanical characterization was used to analyze the structure-function properties of the TPU and assess potential industrial applications. Overall, this work seeks to offer a viable alternative to conventional plastics, supporting the global transition towards sustainable plastic usage.

The transition to a circular plastics economy requires materials that balance robust thermomechanical properties with controlled end-of-life depolymerization. This work targets chemically recyclable spiro-polyacetals by integrating linear acetal units into the polymer backbone to tune degradation rate and product outcomes. The polyacetal VPA–CDVE was synthesized by reacting a vanillin-based spiro acetal monomer (VPA) with cyclohexanedimethanol vinyl ether (CDVE). The spiro acetal monomer was chosen to enhance thermal properties whereas the linear acetal units incorporated into the polymers are expected to accelerate the degradation rate. Thermal analysis confirmed thermal behavior appropriate for applications and processing, with a glass transition temperature of 80 °C and an onset thermal degradation temperature of 252 °C.

To quantify depolymerization behavior, the hydrolysis of VPA–CDVE was monitored in acidic solvent systems using in situ nuclear magnetic resonance (NMR). Kinetic analyses showed that the linear acetal units hydrolyzed rapidly, cleaving the polymer chain into smaller oligomers faster than the spiro-acetal units. Following this initial cleavage, the remaining spiro-fragments degraded at a rate comparable to the VPA monomer. The primary degradation products were identified as vanillin, acetaldehyde, and 1,4-cyclohexanedimethanol, with early-time formation kinetics consistent with a first-order reaction model. Overall, this work establishes a structure–property framework for designing vanillin-derived polyacetals that combine thermal stability imparted by the cyclic units with efficient depolymerization and monomer recovery enabled by incorporation of the linear acetal segments, supporting the development of next-generation circular polymer materials.