Polyamide 6 and thermoplastic polyurethane recycled hybrid Fibres via twin-screw melt extrusion

The Effect of Polyamide 11 on the Thermal Stability and Light Transmittance of Silicone-Based Thermoplastic Vulcanizates

The effect of polyamide 11 (PA11) on the thermal stability and light transmittance properties of silicone-based thermoplastic vulcanizates (TPVs) has been investigated. The blends were prepared through a dynamic vulcanization process by adding 15, 30, and 45 wt% PA11 to the silicon-based TPVs, respectively. The effect of PA11 on the dispersion of silicone rubber in the TPVs after dynamic vulcanization was characterized by a scanning electron microscope (SEM), the thermal stability of the compounds was evaluated through the changes in mechanical performance in the thermo-oxidative aging process, and the light transmittance of TPVs was measured by a haze meter. The results showed that adding PA11 to silicone-based TPVs caused a decrease in the size of the silicone rubber particles after dynamic vulcanization, resulting in improved dispersion. Due to this, by increasing the compatibility between the segments through silicone's effective dispersion, the amount of light absorption was reduced, and the amount of light transmittance was increased. Finally, according to the results of the thermal aging test, it was found that TPVs with 30 and 45 wt% PA11, respectively, showed outstanding thermal resistance after aging at 160 °C and 168 h and did not melt down.

Rapid In Situ Thermal Decontamination of Wearable Composite Textile Materials

Pandemics stress supply lines and generate shortages of personal protective equipment (PPE), in part because most PPE is single-use and disposable, resulting in a need for constant replenishment to cope with high-volume usage. To better prepare for the next pandemic and to reduce waste associated with disposable PPE, we present a composite textile material capable of thermally decontaminating its surface via Joule heating. This material can achieve high surface temperatures (>100 °C) and inactivate viruses quickly (<5 s of heating), as evidenced experimentally with the surrogate virus HCoV-OC43 and in agreement with analytical modeling for both HCoV-OC43 and SARS-CoV-2. Furthermore, it does not require doffing because it remains relatively cool near the skin (<40 °C). The material can be easily integrated into clothing and provides a rapid, reusable, in situ decontamination method capable of reducing PPE waste and mitigating the risk of supply line disruptions in times of need.

Thermal properties of wood flour reinforced polyamide 6 biocomposites by twin screw extrusion

The use of waste wood flour as polymer reinforcements has recently gained popularity because of its environmental benefits. The goal of this research is to determine the thermal properties of a waste wood flour/polyamide 6 composite made via extrusion. The fillers were melt compounded with polyamide 6 at filler concentrations of 5%, 10%, and 15% using a twin screw extruder, followed by compression molding. The processability of waste wood flour/polyamide 6 composite was evaluated using thermogravimetric analysis (TGA), differential scanning calorimeter (DSC), and dynamic thermomechanical analysis (DMA). According to the TGA analysis, the thermal stability of the composites decreases as the natural fiber content increases. The onset temperature of rapid thermal deterioration was reduced somewhat from 425 °C (neat PA6) to 405 °C (15 wt% wood flour). According to the DSC results, the addition of natural fibers resulted in quantify changes in the glass transition (T g), melting (T m), and crystallization temperature (T c) of the PA6 composites. The storage modulus from the DMA study increased from 1177 MPa (neat PA6) to 1531 MPa due to the reinforcing effects of wood flour (15 wt%). Waste wood flour/polyamide 6 composites offer advantageous thermal properties, enabling us to profit from the strengthening potential of such cellulosic reinforcements while remaining recyclable and generally renewable.

Porous Fiber Processing and Manufacturing for Energy Storage Applications

The objective of this article is to provide an overview on the current development of micro- and nanoporous fiber processing and manufacturing technologies. Various methods for making micro- and nanoporous fibers including co-electrospinning, melt spinning, dry jet-wet quenching spinning, vapor deposition, template assisted deposition, electrochemical oxidization, and hydrothermal oxidization are presented. Comparison is made in terms of advantages and disadvantages of different routes for porous fiber processing. Characterization of the pore size, porosity, and specific area is introduced as well. Applications of porous fibers in various fields are discussed. The emphasis is put on their uses for energy storage components and devices including rechargeable batteries and supercapacitors.

Research of TPU Materials for 3D Printing Aiming at Non-Pneumatic Tires by FDM Method

3D printing technology has been widely used in various fields, such as biomedicine, clothing design, and aerospace, due to its personalized customization, rapid prototyping of complex structures, and low cost. However, the application of 3D printing technology in the field of non-pneumatic tires has not been systematically studied. In this study, we evaluated the application of potential thermoplastic polyurethanes (TPU) materials based on FDM technology in the field of non-pneumatic tires. First, the printing process of TPU material based on fused deposition modeling (FDM) technology was studied through tensile testing and SEM observation. The results show that the optimal 3D printing temperature of the selected TPU material is 210 °C. FDM technology was successfully applied to 3D printed non-pneumatic tires based on TPU material. The study showed that the three-dimensional stiffness of 3D printed non-pneumatic tires is basically 50% of that obtained by simulation. To guarantee the prediction of the performance of 3D printed non-pneumatic tires, we suggest that the performance of these materials should be moderately reduced during the structural design for performance simulation.