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Developing high‐performance and reusable adhesives from renewable feedstocks is of significance to sustainable development, yet it still remains a formidable task. Herein, castor oil, melevodopa, and iron ions are used as building blocks to construct a novel bio‐based supramolecular adhesive (BSA) with outstanding adhesion performances. It is prepared through partial coordination between melevodopa functionalized castor oil and Fe3+ ions. Noncovalent interactions between adherends and the catechol unit from melevodopa contribute to reinforcing adhesion, and the metal‐ligand coordination between catechol and Fe3+ ions is utilized to strengthen cohesion. By combining strong adhesion and tough cohesion, the prepared BSA achieves an adhesion strength of 14.6 MPa at ambient temperature, a record‐high value among reported bio‐based adhesives as well as supramolecular adhesives to the best of knowledge. It also outperforms those adhesives at cryogenic temperature, realizing another record‐high adhesion strength of 9.5 MPa at −196 °C. In addition, the BSA displays excellent multi‐reusability with more than 87% of the original adhesion strength remaining even after reuse for ten times. It is highly anticipated that this line of research will provide a new insight into designing bio‐based adhesives with outstanding adhesion performances and excellent multi‐reusability. An ultra‐strong and multi‐reusable bio‐based adhesive is successfully constructed by utilizing castor oil, melevodopa, and iron ions as building blocks. By combining strong adhesion with tough cohesion, it achieves record‐high adhesion strengths of 14.6 MPa at ambient temperature and 9.5 MPa at −196 °C. What's more, it exhibits excellent multi‐reusability of ten times with over 87% adhesion strength remaining.

Buildings in cold climates are often exposed to extreme weather events, including heatwaves and prolonged power outages. In this study, three lightweight experimental buildings were instrumented in Québec to assess their thermal resilience. Each building featured a different wall assembly insulated with bio-based materials. The dynamic thermal behavior was analyzed during winter heating interruptions and summer heatwaves, using in situ measurements and specific performance indicators. Although all three wall systems met high thermal resistance levels, results showed that this static property alone was not able to predict thermal resilience. One building, despite having lower static performance, maintained cooler indoor temperatures during a heat wave due to a higher share of bio-based materials. This study emphasizes the importance of moving beyond static indicators and relying on real-world performance assessments to inform sustainable building design in cold regions affected by climate change.

In the present study, an epoxy compound, 1,2‐epoxy‐6‐methyl‐triglycidyl‐3,4,5‐cyclohexanetricarboxylate (EGCHC) synthesized from sorbic acid, maleic anhydride, and allyl alcohol is proposed. Using commodity chemicals, a bio‐based carbon content of 68.4 % for the EGCHC resin is achieved. When cured with amine hardeners, the high oxirane content of EGCHC forms stiff cross‐linked networks with strong mechanical and thermal properties. The characterization of the epoxy specimens showed that EGCHC can compete with conventional epoxy resins such as DGEBA. A maximum stiffness of 3965 MPa, tensile strength of 76 MPa, and T g of 130 °C can be obtained by curing EGCHC with isophorone diamine (IPD). The cured resin showed to be decomposable under mild conditions due to the ester bonds. The solid material properties of EGCHC expose its potential as a promising bisphenol A, and epichlorohydrine free alternative to conventional petroleum‐based epoxies with an overall high bio‐based carbon content.

Summary This study examines the life cycle energy demand and greenhouse gas (GHG) emissions associated with substituting natural cellulose and kenaf in place of glass fibers in automotive components. Specifically, a 30 wt% glass-fiber composite component weighing 3 kilograms (kg) was compared to a 30 wt% cellulose fiber composite component (2.65 kg) and 40 wt% kenaf fiber composite component (2.79 kg) for six cars, crossovers, and sport utility vehicles. The use-phase fuel consumption of the baseline and substitute components, with and without powertrain resizing, were determined using a mass-induced fuel consumption model based on U.S. Environmental Protection Agency test records. For all vehicles, compared to the baseline glass fiber component, using the cellulose composite material reduced life cycle energy demand by 9.2% with powertrain resizing (7.2% without) and reduced life cycle GHG emissions by 18.6% with powertrain resizing (16.3% without), whereas the kenaf composite component reduced energy demand by 6.0% with powertrain resizing (4.8% without) and GHG emissions by 10.7% with powertrain resizing (9.2% without). For both natural fiber components, the majority of the life cycle energy savings is realized in the use-phase fuel consumption as a result of the reduced weight of the component.

Flammability is a significant challenge in polymer‐based electronics. In this regard, triboelectric nanogenerators (TENGs) have enabled a safe means for harvesting mechanical energy for conversion into electrical energy. However, most existing polymers used for TENGs are sourced from petroleum‐based raw materials and are highly flammable, which can further accelerate the spread of fire and harm the ecological environment. In addition, the existing intrinsic flame‐retardant TENGs are not elastic at room temperature, which may potentially damage the flexible equipment and harm firefighters. This study presents an intrinsic flame‐retardant bio‐based elastic phytic acid polyurethane (PUPA) synthesized using a simple and efficient one‐pot polycondensation. The cross‐linked structure and polar phosphorus‐containing segments of PUPA are fabricated into PUPA‐TENG, demonstrating a superior elasticity (elongation up to 660%), flame retardancy (UL94 V‐0), impact resistance (34.71 MJ m−3), and dielectric constant (Dk = 9.57). Consequently, this study provides a simple strategy for tailoring TENGs toward environmentally friendly and secure power generators and electronics, which can effectively reduce fire hazards and potentially be applied to other fire‐risk fields such as personal protection, firefighting, and new energy. This study presents an intrinsic flame‐retardant bio‐based elastic phytic acid polyurethane (PUPA), demonstrating a superior elasticity (elongation up to 660%), flame retardancy (UL94 V‐0), impact resistance (34.71 MJ m−3), and dielectric constant (Dk = 9.57). A simple strategy is provided for tailoring TENGs toward environmentally friendly and secure power generators and electronics, which can effectively reduce fire hazards.

Plastic pollution has emerged as a significant global issue, highlighting the need for sustainable alternatives and effective recycling methods. Concurrently, the cactus plant offers a promising source of bio‐based materials, particularly due to its resilience in harsh environments. This study focused on the performance characterization of cactus powder mixed with recycled high‐density polyethylene (rHDPE) pellets for filament production suitable for 3D printing using the Fused Filament Fabrication method. The physical properties of both cactus and rHDPE were investigated, and composite filaments were prepared from 5%, 10%, and 15% cactus powder alongside rHDPE. Performance evaluation of the composite filaments was conducted using a Universal Testing Machine. Additionally, the chemical composition of cactus powder was analyzed, and the particle size distribution was determined. The combination of HDPE pellets and cactus powder yielded a viable filament, though increasing proportions of cactus reduced the extrusion properties. The tensile strength of pure rHDPE filament was measured at 16.27 MPa, while the tensile strengths for the 5% and 10% cactus composites were 14.97 and 10.74 MPa, respectively. For the printed specimens, the tensile strength was recorded at 13.04 MPa for rHDPE and 8.28 MPa for the 5% cactus composite. The flexural strength results showed 21.77 MPa for rHDPE and 15.64 MPa for the 5% cactus composite. These findings suggest that cactus powder can serve as a valuable additive in developing sustainable 3D printing materials. This study explores the integration of cactus powder with recycled HDPE to develop 3D‐printable bio‐composite filaments. Results show that cactus powder can be incorporated up to 10% to allow better printability while enhancing sustainability. The study provides insights into optimizing material formulations for eco‐friendly additive manufacturing applications.

Advancements in modern engineering design require materials that maintain thermal and mechanical stability under diverse conditions. To promote sustainability and eco‐friendliness, researchers are increasingly exploring natural alternatives to synthetic fibers. Among bio‐fibers, Borassus flabellifer fruit shell (husk), has no other uses than disposal or waste‐to‐energy in Bangladesh. While other parts of the plant, such as, the fruit and leaf stalks, are commonly utilized for fine and coarse fibers, the husk fiber remains underexplored. Hence, this study investigates exclusively the thermal properties of untreated Borassus husk fibers according to ASTM E2550 and ASTM E1269‐11 standards and evaluates their curved specimens' mechanical properties using ASTM D2344 and ASTM D6415 standards. The findings reveal that raw Borassus husk fibers exhibit remarkable thermal stability, characterized by a higher char content and an elevated integral process decomposition temperature compared to the its fine and coarse fibers. During cellulose decomposition, the husk fibers demonstrate a specific heat capacity of 1.6 J/g°C, which surpasses that of coconut fibers. Additionally, mechanical testing indicates that the curved husk possesses competitive inter‐laminar tensile strength and short‐beam strength, comparable to glass fiber‐reinforced polymers, curved woven glass/polyester composites and some bio‐composites. Fracture surface analysis reveals a unique morphology, featuring non‐uniform, cross‐linked, and porous tubular structures, which contribute to the material's distinct thermal and mechanical properties. These results highlight the potential of untreated Borassus husk fibers as a viable material for engineering applications. Utilizing this underexplored resource could promote the cultivation and preservation of B. flabellifer trees, thereby encouraging sustainable development.

Soft robotics has gained significant attention for its potential to deliver safe, adaptable, and biocompatible machines, by embracing the mechanical compliance of soft materials. However, the manufacture of soft robotic devices and machines still largely relies on petroleum‐based polymers. Furthermore, in light‐induced 3D printing, a key technology for fabricating complex 3D monolithic soft robots, non‐sustainable resins remain predominant. This work addresses this issue by developing a photocurable bio‐based resin to monolithically fabricate soft robots. We formulate a resin using soybean oil as a renewable precursor and shape it via Digital Light Processing into an origami‐inspired vacuum‐actuated actuator. The bio‐based material has a Young's modulus of 18.9 MPa and an elongation at break of 19.6%. The origami deformation, based on folding rather than stretching, enables actuator operation, despite the lower elongation range of our material compared to silicone elastomers. We report on the characterization of the bulk material properties and the mechanical performance of the actuator, which performs 2000 cycles without failure before testing ceased. Finally, we design and fabricate a monolithic soft robotic gripper with integrated origami actuation using our bio‐based material. We show the functional operation of the gripper in grasping different objects, as well as in underwater settings. This work develops a photocurable, bio‐based resin from soybean oil for the monolithic fabrication of sustainable soft robots via Digital Light Processing. An origami‐inspired, vacuum‐actuated soft gripper is designed and fabricated, enabling reliable operation despite the material's lower elongation. The origami structure withstands 2000 cycles, and the gripper demonstrates versatile grasping of objects with varying stiffness, including underwater applications.

Formaldehyde-free epoxidized soybean oil-based resin has been prepared under acidic conditions by co-condensation of the epoxidized soybean oil and condensed tannin originating from agricultural and forestry sources as the main raw materials, whereas 1,6-hexanediamine was employed as a cross-linking agent. Fourier transform infrared spectroscopy (FTIR) and electrospray ionization (ESI) corroborated that tannin and epoxidized soybean oil underwent crosslinking under acidic conditions supported by hexamethylenediamine. A bio-based grinding wheel was fabricated by formulation of the developed resin with wood powder as source of grinding particles. The appearance, hardness, compressive strength and wear resistance of the resulting grinding wheel were studied. The results have shown that the grinding wheel possesses a smooth surface with no bubbles or cracks, and its hardness and wear resistance were greater than that of a phenolic resin-based grinding wheel. Interestingly, the grinding wheel incorporates more than 90% of its raw materials as biomass renewable materials; thus, it is generally considered non-toxic. In addition, the future feasibility of this approach to replace some petrochemical resins that are frequently used in the fabrication of grinding wheels is considered.

The refurbishment of the building stock is a key strategy towards the achievement of the climate and energy goals of the European Union. This study aims at evaluating the energy and environmental impacts associated with retrofitting a residential apartment to improve its vertical envelope thermal insulation. Two insulation materials, stone wool and cellulose fibers, are compared. The life cycle assessment methodology is applied assuming 1 m2 of retrofitted vertical envelope as functional unit. Moreover, to estimate the net energy and environmental benefits achievable in the retrofitted scenario compared with the non-retrofitted one, a second analysis is performed in which the system boundaries are expanded to include the building operational phase, and 1 m2 of walkable floor per year is assumed as reference. The results show that the use of cellulose fibers involve lower impacts in most of the assessed categories compared to stone wool, except for abiotic resource depletion. In detail, the use of cellulose fibers allows to reduce the impact on climate change up to 20% and the consumption of primary energy up to 10%. The evaluation of the net energy and environmental benefits shows the effectiveness of the retrofit energy policies.