Polyimide (PI) fiber is a promising and high-performance polymer fiber with high temperature resistance and low density; however, much energy is needed during the thermal imidization process. Here, PI fiber with excellent mechanical properties and high-temperature resistance was fabricated via the dry-jet wet spinning method for polyamic acid (PAA) precursor fiber, followed by stretching and thermal imidization reaction at a lower temperature. With the increase of the stretching ratio, the mechanical properties of the PI fiber increase significantly. When the stretching was twice as long, the tensile strength and initial modulus of the fiber were as high as 6.23 and 114.13 cN·dtex^–1, respectively. Fourier transform infrared results revealed that all samples were completely imidized at 260 °C. The resulting PI fibers exhibit only 5% weight loss at 539.53 °C, and its limiting oxygen index (LOI) can reach up to 32.6%, showing excellent high temperature resistance and flame-retardant properties as well as commendable mechanical performance, which compare favorably with those of other imidization methods.

The environmental and ecological concerns drive researchers to synthesize functional materials using components from natural resources. Nanocellulose (NC), derived from plants, marine animals, or microorganisms, is a green material attracting attention due to its abundance, biocompatibility, and biodegradability. NC’s interstice properties enable the synthesis of functional nanocomposites in forms like aerogels, foams, paper, sheets, or hollow filaments. This review briefly describes NC classification and production while comprehensively presenting its mechanical, rheological, optical, and electrical properties, offering foundational knowledge for future research. Additionally, it highlights recent developments in NC-based products across fields such as papermaking, water treatment, civil engineering, electronics, cosmetics, food, and medicine. For the first time, this paper explores recent advances in NC molecular simulation, providing insights into structure, arrangement, and interactions through molecular dynamic simulation. Finally, future prospects for NC-based applications are discussed to encourage studies addressing current challenges.

Nanomaterials, particularly nanofibers produced through electrospinning, have garnered significant attention due to their unique properties and diverse applications. This research explores the influence of collector design, electrode geometry, and collector speed on the properties of electrospun polyacrylonitrile (PAN) nanofibers. Finite element analysis (FEA) was employed to simulate electric fields, revealing the impact of collector geometry on field intensity. The experimental setup, enclosed in an isolated chamber, employed various collector types and electrode configurations. Scanning electron microscope (SEM) analysis showcased the effect of collector speed on fiber alignment and diameter. Furthermore, FEA simulations elucidated the role of electrode geometry and voltage in shaping the electric field, impacting fiber properties. The study introduces a novel, in-house method for producing highly aligned nanofibers and provides insights into optimizing electrospinning parameters for enhanced fiber properties. A testing protocol is devised to minimize surface damage when conducting mechanical tests on nanofiber films, employing a dynamic mechanical analyzer (DMA). Mechanical testing demonstrated the correlation between alignment and tensile strength. Overall, this research contributes valuable insights for tailoring electrospinning processes for tissue engineering and energy storage.

Zinc complexes have a considerable impact on human health and the environment, especially on aquatic wildlife. One of the primary sources of zinc release to the environment is worn rubber particles from tires. The environmental footprint of zinc oxide (ZnO) during production, use, and landfilling has prompted researchers to reduce its use in rubber formulations due to ecological and economic concerns. In this study, composite ZnO materials where ZnO particles are coated on precipitated calcium carbonate (CaCO₃) are used in styrene butadiene rubber/butadiene rubber (SBR/BR) compounds, and their performance is compared with white seal ZnO and active ZnO. Trial compounds are prepared on a laboratory scale using composite ZnO materials with ZnO:CaCO₃ ratios of 40:60, 60:40, and 90:10, and control compounds with white seal and active ZnO. All compounds are tested to evaluate their curing and physico-mechanical properties. It is observed that the surface area of ZnO plays an essential role in crosslink density and, hence, compound performance. Trial materials have no negative effect on the curing and mechanical properties of the compounds. Thus, it is concluded that composite ZnO materials can be used as alternatives to both white seal ZnO and active ZnO. They have environmental and economic advantages due to their lower ZnO content. The compound recipe has the potential to be used for tire tread compounds.

The rates of in vivo bioresorption of composite monofilaments based on polylactide (PLA) containing chitin nanofibrils of two types (pure chitin (CN) or chitin modified with poly(ethylene glycol) (CN-PEG)) or silver nanoparticles stabilized with poly(N-vinylpyrrolidone) (Poviargol) were studied. The in vivo bioresorption rate and its dependence on the degree of orientational drawing of the samples (which varied from 1 in non-oriented samples to 4 in oriented samples) were investigated up to 12 months after implantation. Bioresorption of the samples was monitored using differential scanning calorimetry, scanning electron microscopy, and mechanical tests. Using the differential scanning calorimetry (DSC) method, it was shown that there is a gradual decrease in molecular weight due to a decrease in the temperatures of phase transitions and changes in peak shapes. It has also been shown that the addition of fillers containing water-soluble polymers accelerates the bioresorption of composite sutures. A thread made from pure PLA lost half its strength by the 9^th month of implantation, whereas for threads with the addition of CNPEG or Poviargol, this happened after 3.5 months. This causes leaching of water-soluble agents and changes in the supramolecular structure of the filament. This study shows the promise of using these composite threads as a suture material.