Conventional sulfur vulcanization in rubber manufacturing depends on elevated curing temperatures and zinc oxide activators, resulting in high energy consumption and increasing environmental concerns associated with zinc release. To overcome these limitations, a novel graphene oxide (GO)-supported rare-earth-containing accelerator (GO–LZC) was designed by coordinating lanthanum(III) and zinc(II) ions with sodium diethyldithiocarbamate (DC). At the same time, the oxygen-containing groups on GO further participated in ligand coordination. The resulting GO-immobilized complex exhibits a well-defined chelating structure and uniform nanoscale dispersion, which together enhance the accessibility and reactivity of active sulfurating species during curing. When incorporated into solution-polymerized styrene–butadiene rubber (SSBR), GO–LZC markedly promotes crosslink formation at reduced thermal input. Kinetic analysis reveals a substantial decrease in the apparent activation energy, and curing and mechanical tests confirm that efficient vulcanization can be achieved at 130 °C, representing a 20–40 °C reduction relative to typical industrial curing conditions. This work demonstrates a viable strategy for developing low-zinc, energy-efficient, and high-performance vulcanization systems. It highlights the potential of rare-earth/GO hybrid catalysts for sustainable rubber processing.

Hydrogenated acrylonitrile–butadiene rubber (HNBR) is widely used in automotive and sealing applications due to its oil resistance and mechanical durability; however, its long-term performance is significantly influenced by the curing chemistry. Sulfur vulcanization offers superior elasticity but restricted thermal stability, while peroxide curing improves heat resistance at the expense of flexibility. In this study, we investigate hybrid sulfur–peroxide curing to integrate these benefits. The hybrid pathway encompasses competitive and sequential processes, such as partial radical quenching and accelerator oxidation, resulting in a dual crosslink network. Dynamic mechanical, thermal, and temperature scanning stress relaxation (TSSR) evaluations demonstrate that hybrid systems provide precise modulation of the operational temperature–frequency range, broaden the glass-transition relaxation, and control stress dissipation. The coexistence of sulfur and C–C crosslinks results in a heterogeneous structure characterized by diverse crosslink densities and bond energies, leading to numerous relaxation modes and an optimal blend of elasticity, strength, and thermal stability. Microscopy confirms the absence of phase separation, indicating that hybrid vulcanization is a viable approach for producing robust, high-performance HNBR elastomers.

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.

Curcumin (CRC) is a natural active principle with important anti-inflammatory, antioxidant, antibacterial, and antitumor properties but has some limitations, such as poor bioavailability, low water solubility, and rapid metabolism. To preserve CRC’s benefits and eliminate its limitations, novel CRC-loaded core-shell electrospun nanofibers were designed. The nanofibers were prepared by co-axial electrospinning method using poly(vinyl alcohol)/CRC as core and poly(vinyl alcohol)/sodium alginate as shell. Polymer coating protects the CRC, increasing its stability. The swelling degree of CRCloaded nanofibers at pH 5.4 was around 326% higher than at pH 7.4 (297%) due to the repulsions of the anion-anion COO–groups. The release efficiency of CRC at pH 7.4 was 81%, while at pH 5.4 was about 96%. In the first 6 h, there was a slower release of CRC from the nanofibers in both acidic and slightly alkaline environments. Nanofibers showed good hemocompatibility, the values being between 2.36–3.22% after the first 90 min of contact, and after 180 min of treatment, the degree of erythrocyte lysis was between 3.78 and 4.93%. Cell viability assay on V79-4 Chinese hamster fibroblasts demonstrated that treatment with free CRC led to a value of 39% whereas for CRC-loaded nanofibers, the cell viability value increased to 59.66%. The results of the present study indicated that CRC-loaded electrospun nanofibers can have great potential for biomedical applications.