The present study has proposed a straightforward method to improve the reprocessability of modified natural rubber (NR) by blending it with gelatin (GT). The reprocessable characteristics of these blends were evaluated based on their remolding capabilities and mechanical recovery performance. In this method, poly(vinylbenzyl chloride) (PVBC) was first grafted onto NR chains to create graft copolymers known as NR-g-PVBC. The benzyl chloride groups in the graft copolymers were subsequently converted into quaternary ammonium groups, referred to as NR-g-QPVBC. This modification enabled ionic crosslinking when NR-g-QPVBC reacted with ethylenediamine tetraacetic acid. Blends were created by incorporating GT powder into the NR-g-QPVBC latex. The optimal loading level of GT was determined to be 30 wt%, as the resulting film exhibited the highest recovery of tensile properties. Initially, the film's tensile strength was measured at 15 MPa. After being remolded at 160 °C, the tensile strength decreased to 9.3 MPa, resulting in a recovery rate of 60.7% and withstanding a tensile strain of 144%. Although the NR-g-QPVBC/GT films could be remolded, their tensile properties declined with increasing remolding cycles. Therefore, this work demonstrated a practical method for producing NR-based films that could be reshaped through hot-pressing after being formed into products, increasing their reusability.

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.

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.

A nanocomposite of styrene butadiene rubber (SBR) and multi-walled carbon nanotubes (MWCNT) was fabricated using an internal melt mixer. Systematically investigated the role of MWCNT loading on the mechanical, dielectric, electrical and Electromagnetic interference (EMI) shielding characteristics of developed nanocomposites. The fine dispersion of MWCNTs in the SBR matrix was clearly observed from high-resolution transmission electron microscope images. The nanocomposites exhibited outstanding electrical, dielectric and EMI shielding behaviours (~45 dB at 20 phr of MWCNT). A high conductivity of 0.92 S/cm was attained in the nanocomposites and is attributable to the establishment of percolation networks of MWCNT in the SBR matrix. These composites displayed reasonably good mechanical properties because of the reinforcing effect of MWCNT. The economically viable and easy fabrication protocol of this nanocomposite can act as a platform for the synthesis of low-cost and highly effective composite for EMI shielding applications.