Thermoplastic natural rubber (TPNR) is widely used across industries due to its unique blend of elasticity and processability. Thermoplastic vulcanizates (TPVs) based on thermoplastic polyurethane (TPU) offer excellent mechanical properties and flexibility, yet often require enhanced elasticity and durability. Blending TPU with natural rubber (NR) is promising; however, phase incompatibility reduces mechanical strength and thermal stability. To address this, epoxidized NR (ENR) was employed as a compatibilizer in TPU/NR blends. ENR’s hydrocarbon backbone interacts with crosslinked NR, while epoxy groups enhance adhesion with TPU. Incorporating 3 phr of ENR significantly improved crosslinking, increased tensile strength by 41.1%, enhanced stress relaxation, and lowered the glass transition temperatures of both TPU and NR phases in the TPU/NR blends. These effects are attributed to improved chemical bridging between TPU and NR. However, excess ENR disrupts phase compatibility, causing polymer entanglement and reduced strength. Optimizing ENR content is essential for developing high-performance TPU/NR blends. Printability was demonstrated using the material extrusion additive manufacturing (MEx-AM) fused deposition modeling (FDM), showing potential for flexible applications like splints and medical devices.

This is an editorial article. It has no abstract.

Cyclized natural rubber (CNR) was synthesized through the acid-catalyzed reaction of natural rubber (NR) latex using sulfuric acid as a catalyst and stabilized with a non-ionic surfactant. Cyclization was evaluated by iodine numbers under varying reaction times, temperatures, and NR-to-acid ratios. Fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance spectroscopy (¹H-NMR) confirmed the formation of cyclic structures in CNR molecules. Differential scanning calorimetry (DSC) showed that the glass transition temperature (T_g) of CNR increased with cyclization, indicating greater rigidity and less chain flexibility. CNR was then blended with NR and used as a compatibilizer in NR/acrylonitrile butadiene rubber (NBR)blends. It increased blend viscosity, hardness, and dimensional stability but reduced tensile strength and elongation due to its rigid cyclic domains. In NR/NBR blends, CNR outperformed a commercial homogenizer in enhancing interfacial interactions, leading to superior shear flow properties, curing behavior, and mechanical performance. This is attributed to the polar groups in CNR, which enhance intermolecular interactions and phase compatibility, resulting in finer phase morphology. This study highlights the potential of CNR as a versatile material for enhancing the performance of rubber compounds, with promising applications in advanced industrial formulations.

Waste tire rubber poses significant environmental challenges due to its non-biodegradability and complex crosslinkedvstructure. In this sense, this study aims to examine the utilization of deep eutectic solvents (DESs) in the desulfurizationvprocess of ground tire rubber (GTR). A range of hydrogen bond donors (HBDs), including ethylene glycol, malonic acid,vimidazole, toluene sulfonic acid, and urea, were combined with choline chloride, which serves as a hydrogen bond acceptorv(HBA), to synthesize deep eutectic solvents. Subsequently, these DESs are used in the modification of rubber devulcanizationvprocesses. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and Horikx analysis werevused to confirm the occurrence of devulcanization. The studies confirmed that the devulcanization process was selective invnature, effectively reducing random chain scission while maintaining the integrity of the polymer. Furthermore, the vulcanizatesvobtained post-treatment demonstrated enhanced properties, including increased tensile strength, modulus, tear strength, hardness, and durability, with ethylene glycol-based DES (DES-E) exhibiting the most pronounced enhancements.

An antibacterial natural rubber (NR) latex film was successfully prepared in this study. This was done by coating silver (Ag) nanoparticles onto the surface of the NR latex film. The Ag nanoparticles were synthesized using green tea (GT) extract as a bio-reducing agent. The corresponding Ag nanoparticles were then deposited onto the NR latex film. Before synthesis, the phenolic compounds were identified using high-performance liquid chromatography (HPLC). The Ag nanoparticles were found to be smaller than 25 nm in size. Subsequently, an experimental evaluation was conducted to determine the influence of deposition time, namely 1 to 20 min, on the film’s overall performance. Scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (SEM-EDX) confirmed that the Ag content was higher over the deposition time. The surface roughness of the samples was also screened by atomic force microscopy (AFM), where the films became rougher over the deposition time, confirming that Ag nanoparticles dispersed over the surface. As for the antibacterial activities, both qualitative and quantitative tests showed significant outputs. The clear zones of S. aureus and E. coli increased over the deposition time, and a shorter contact time was used to kill the bacteria. This study offers a scientific foundation that supports the development of future rubber products utilizing these findings.