Reinventing Cellulose into Sustainable and Versatile Bioplastics via Molecular-Scale Design

This study compares three polyethylene grades—a benchmark PE100 and two high‐temperature resistant polyethylene (PE‐RT) types (Type I and Type II)—to assess their suitability for flexible riser applications. The materials were evaluated for their thermal stability, crystallinity, mechanical performance, and resistance to thermal aging at 110°C for up to 180 days. Differential scanning calorimetry (DSC) and x‐ray diffraction (XRD) indicated that PE‐RT Type II had a higher degree of crystallinity. Thermogravimetric analysis (TGA) showed that PE100 had the highest T onset (457°C), confirming its superior thermal stability. However, PE‐RT Type II was the most promising material, showing a balanced response to thermal and chemical stress with excellent thermo‐oxidative durability, flexibility, and aging resistance. The tensile test results demonstrated that PE‐RT Type II consistently outperformed PE‐RT Type I in mechanical strength and durability. After aging tests performed in synthetic oil at 80°C for 180 days, PE‐RT Type II retained approximately 85% of its original elongation at break and 90% of its initial tensile strength. In contrast, PE‐RT Type I exhibited a significant reduction in performance, retaining only about 42% of its original elongation and 70% of its tensile strength. These results indicate that PE‐RT Type II is more resistant to thermal and oxidative degradation, reinforcing its suitability for long‐term use in high‐temperature flexible riser systems. Fourier‐transform infrared (FTIR) spectroscopy revealed more significant oxidation in Type I, suggesting lower resistance to thermo‐oxidative degradation. Overall, PE‐RT Type II displayed an enhanced balance of properties, making it the most promising candidate among the evaluated materials for application in high‐temperature flexible riser barrier layers.

Synergistically program thermal expansional and mechanical performances in 3D metamaterials: Design-Architecture-Performance

Effects of edge-seal design on the mechanical and thermal performance of vacuum-insulated glazing

Natural fiber composites are often sought after in industries, such as automotive and aerospace, due to their low density compared to traditional synthetic composites. Sisal and jute are renewable and biodegradable resources, making them attractive from a sustainability standpoint. The effect of carbon nanotube (CNT) insertion of a composed sisal and jute fiber composite material on the thermal and mechanical characteristics is investigated in this study. The primary objective of this research is to determine the exceptional mechanical strength and heat resistance that allows the composite-filled filling CNT to perform better than others. The methodical experimental approach was used to evaluate the effect of sisal and jute matrix and different amounts of CNTs’ mechanical and thermal properties. Thermal behavior is found by thermogravimetric analysis, and mechanical performance is used to qualify tensile strength, flexural strength, and impact resistance. The result suggests that CNTs may have reinforcing properties and significant tensile and flexural strength improvement. Impact resistance improved and increased the toughness of the composite material. The 7% CNT composite exhibited improvements in tensile strength of 63.9% and flexural strength of 46.6%, suggesting the synergistic reinforcing effect of CNTs. The high temperature from the use of need resistance shows promise for the composite material based on the tests of its capability for heat absorption and thermal stability. Various technical contexts are potentially useful in focusing on environmentally friendly material creation that exhibits exceptional thermal and mechanical properties.

Given the significant environmental challenges posed by plastic waste, innovative reuse strategies are essential. This study seeks to bridge a gap in prior research by investigating the novel application of polyvinyl chloride drainage pipe waste (PVC) as a partial sand substitute in mortar, aiming to enhance both the thermal behavior and mechanical performance. Previous studies have noted that while integrating plastic waste into construction materials can enhance thermal properties, it frequently results in a reduction of mechanical strength. To address this issue, our study carefully considered the size of PVC aggregates. Seven substitution rates (0%, 5%, 10%, 15%, 20%, 25%, and 30% by weight) were evaluated through laboratory tests, including bulk density, water absorption, compressive and flexural strength, thermal conductivity, volumetric heat capacity, and thermal diffusivity. Additionally, numerical simulations using TRNSYS software on office buildings assessed the energy-saving potential. Furthermore, a multi-objective optimization approach was introduced to identify the optimal mix composition, balancing mechanical strength and thermal performance. Results showed that increasing PVC content improved thermal properties, with an optimal substitution rate also enhancing mechanical characteristics. Notably, a 30% replacement rate demonstrated significant energy savings, which could be further increased by increasing the mortar thickness.

Thin nanocomposite films of thermoplastic starch, chitosan and cellulose nanofibers (bacterial cellulose or nanofibrillated cellulose) were prepared for the first time by solvent casting of water based suspensions of the three polysaccharides. The role of the different bioploymers on the final properties (thermal stability, transparency, mechanical performance and antimicrobial activity) of the films was related with their intrinsic features, contents and synergic effects resulting from the establishment of interactions between them. Thermoplastic starch displays an important role on the thermal stability of the films because it is the most stable polysaccharide; however it has a negative impact on the mechanical performance and transparency of the films. The addition of chitosan improves considerably the transparency (up to 50 % transmittance for 50 % of chitosan, in respect to the amount of starch), mechanical performance and antimicrobial properties (at least 25 % of chitosan and no more than 10 % of cellulose nanofibers are required to observe bacteriostatic or bactericidal activity) but decrease their thermal stability. The incorporation of cellulose nanofibers had the strongest positive impact on the mechanical properties of the materials (increments of up to 15 and 30 MPa on the Young′s modulus and Tensile strength, respectively, for films with 20 % of BC or NFC). Nonetheless, the impact in thermal stability and mechanical performance of the films, promoted by the addition of chitosan and cellulose nanofibres, respectively, was higher than the expected considering their percentage contents certainly because of the establishment of strong and complex interactions between the three polysaccharides.

ABSTRACTTo improve the reactivity and compatibility of lignin, it was first functionalized via the method of epoxidation. The epoxidized lignin (LEP) modified epoxy resin with good mechanical and shape memory performance was fabricated ingeniously by introducing the LEP into the epoxy resin homogeneously with the aid of synergistic dispersion and crosslinking of polyetheramine without using organic solvents. The effect of LEP addition on the curing reaction, thermal, mechanical, and shape memory performance of epoxy resin were intensively evaluated. The epoxy‐diamine curing reaction was promoted by the LEP incorporation, and the thermal stability and mechanical performance of epoxy resin were improved. The tensile strength and modulus of the LEP‐modified epoxy were increased by 14.3% and 32.5%, respectively. Such reinforcing effect of LEP on the thermal and mechanical performance was contributed to the rigid LEP chains which were chemically crosslinked into the network of epoxy resin uniformly. Also, the rigid LEP component in the cured epoxy resin inhibited the movement of chain segments, which could enhance the mechanical stability and slow down the rapid shape recovery rate of the epoxy resin network to some extent.

This study explores fiber-reinforced composites (FRCs) using a 70:30 blend of cardanol-based resin and epoxy resin (EEW 190) with six different hardeners: diethylenetriamine (DETA), triethylenetetramine (TETA), meta-xylylenediamine (MXDA), isophorone diamine (IPDA), polyamide and polyamidoamine. Composites were fabricated using jute fiber mats (eco-friendly, lightweight, suitable for packaging and low-load structural panels), woven glass fabrics (moderate strength and stiffness, ideal for marine and construction applications), and woven carbon fiber fabrics (high strength and thermal stability, applicable in aerospace and automotive structures) as reinforcements and characterized for thermal stability, mechanical performance, morphological properties and chemical resistance. Thermogravimetric analysis (TGA) and differential thermogravimetric analysis (DTGA) demonstrated superior thermal resistance for carbon fiber composites, retaining up to 80% of their weight at 500°C, followed by glass and jute composites. Mechanical testing revealed that carbon fiber composites exhibited the highest tensile (83.3 MPa), flexural (223.5 MPa) and impact strength (9.75 J/cm), significantly outperforming glass and jute composites. Morphological analysis using scanning electron microscopy (SEM) confirmed strong interfacial bonding and minimal voids in composites cured with polyamidoamine, while rigid hardeners (DETA, TETA) led to brittleness and micro-cracks. Chemical resistance testing highlighted carbon fiber composites exceptional stability, maintaining structural integrity across various chemical environments.

Multi-phase metamaterials containing framework structures to program thermal expansion and mechanical performances

Unique Ligand Exchange Dynamics of Metal–Organic Polyhedra for Vitrimer-like Gas Separation Membranes

The growing emphasis on sustainability has spurred interest in natural fibers as renewable and biodegradable alternatives to synthetic materials. This study explores the underutilized pseudostem fibers of Alpinia galanga (A. galanga), a perennial herb of the Zingiberaceae family, widely cultivated for its rhizomes in traditional medicine and culinary practices. Despite its economic and ethnobotanical significance, the pseudostems are often discarded as agricultural waste, contributing to environmental challenges. This research investigates the structural, chemical, and mechanical properties of A. galanga fibers, revealing their high cellulose and lignin content and lightweight nature making them viable for lightweight composite applications. To overcome inherent limitations such as high moisture content and limited mechanical performance, the fibers underwent alkaline and permanganate chemical treatments. Advanced characterization techniques, including Fourier Transform Infrared Spectroscopy (FTIR, Thermogravimetric Analysis (TGA), X-ray Diffraction (XRD), and tensile strength testing, were employed to evaluate the effects of these treatments on thermal stability, crystallinity, and mechanical performance. Results demonstrated significant enhancements in tensile strength, thermal resistance, and structural integrity, underscoring the fibers’ potential as eco-friendly reinforcement agents in composite materials. This pioneering study not only provides the first comprehensive characterization of A. galanga pseudostem fibers but also offers a sustainable solution to agricultural waste management, advancing the development of renewable, high-performance materials and promoting circular economy practices.

The development of porous materials requires a thorough knowledge of their physical properties. When used as thermal insulation, the properties that govern their insulating capacity are thermal conductivity, thermal diffusivity and specific heat. The presence of moisture, some of its origin, in buildings causes damage to walls that extend from the formation of mold in complete impregnation through the degradation of the thermal and mechanical performance. The major objective of this study is to determine the physical properties of a building material lightened by vegetable fiber (concrete pomace olive), used as an insulation bearer. Our goal is to develop and expand the field of use of these materials in construction. A judicious choice of additions proportions and implementation techniques will be considered. A particular interest is the thermal characteristics and mechanical strength, which is a decisive criterion for selecting a material in the construction. We determine the thermal conductivity of the materials studied with experimental equipment that allows us to make measurements of the thermal properties under actual use conditions (temperature and humidity) and also the study of the mechanical compressive strength of the materials studied and the interest in these materials is highlighted.

Epoxy (EP) composites are increasingly employed as thermal interface materials in electronic devices, yet their thermomechanical reliability remains poorly understood at the microscopic level. In particular, the combined influence of cross-linking density and nanofiller reinforcement on thermal stability and mechanical performance has not been systematically clarified. Here, we investigate EP networks reinforced with hexagonal boron nitride (h-BN) nanosheets using atomistic modelling, focusing on composites with varying cross-linking densities (40%, 50%, 60%, and 85%) alongside pure EP systems. Additionally, we investigate the effects of h-BN concentration and aspect ratio on the nanocomposite's thermal and mechanical stability. Key parameters examined include interfacial interaction energy, interfacial adhesion energy, glass transition temperature, mean square displacement, coefficient of thermal expansion, and mechanical response under strain. The results show that higher cross-linking density and h-BN incorporation markedly improve thermal and mechanical stability, while networks cured beyond the gel point maintain robust properties at elevated temperatures. Systems below this threshold exhibit pronounced degradation, underscoring the importance of network connectivity. Uniaxial tensile deformation further reveals that composites with cross-linking density above 55% achieve superior modulus, higher tensile strength, and reduced strain. By establishing clear structure–property correlations and revealing the microscopic mechanisms that govern stability, this work addresses a critical gap in understanding EP nanocomposites and provides essential physical insights for designing thermally stable, low-expansion, and mechanically reliable materials for electronic applications.

Hwangtoh (Korean red clay) and Biochar were used to develop building materials for sustainable and energy-efficient buildings and propose environmentally and thermally superior materials. Rice husk, coconut shell, and bamboo were made of biochar through pyrolysis with complete oxygen limitation. The compressive strength test was carried out to analyze the thermal performance and the mechanical performance, and the thermal conductivity measurement was conducted in order to derive the physical property information for the thermal performance of the material. The microporous structure affecting the thermal conductivity and mechanical performance. Through the dynamic heat transfer experiment, the temperature changes of the biochar mixed specimens in the same heating environment were analyzed. Comprehensive considerations have shown that bamboo biochar is replaced by 10% by weight.

Plastic pollution has become a global concern, demanding urgent attention and concerted efforts to mitigate its environmental impacts. Biodegradable plastics have emerged as a potential solution, offering the prospect of reduced harm through degradation over time. However, the lower mechanical strength and slower degradation process of biodegradable plastics have hindered their widespread adoption. In this study, we investigate the incorporation of New Zealand (NZ) jade (pounamu) particles into poly(lactic acid) (PLA) to enhance the performance of the resulting composite. We aim to improve mechanical strength, flame retardation, and degradability. The material properties and compatibility with 3D printing technology were examined through a series of characterization techniques, including X-ray diffraction, dispersive X-ray fluorescence spectrometry, scanning electron microscopy, energy-dispersive X-ray spectroscopy, thermogravimetric analysis, 3D printing, compression molding, pycnometry, rheometry, tensile tests, three-point bending, and flammability testing. Our findings demonstrate that the addition of NZ jade particles significantly affects the density, thermal stability, and mechanical properties of the composites. Compounding NZ jade shows two different changes in thermal stability. It reduces flammability suggesting potential flame-retardant properties, and it accelerates the thermal degradation process as observed from the thermogravimetric analysis and the inferred decrease in molecular weight through rheometry. Thus, the presence of jade particles can also have the potential to enhance biodegradation, although further research is needed to assess its impact. The mechanical properties differ between compression-molded and 3D-printed samples, with compression-molded composites exhibiting higher strength and stiffness. Increasing jade content in composites further enhances their mechanical performance. Th results of this study contribute to the development of sustainable solutions for plastic pollution, paving the way for innovative applications and a cleaner environment.