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 need to recycle elastomeric waste requires studying its viability in industrial applications. This study investigates the feasibility of recycling elastomeric waste by analyzing whether virgin ethylene-propylene-diene monomer (EPDM) can be replaced by blends of virgin EPDM and thermomechanically and microwave devulcanized EPDM (EPDMd) in industrial applications from the perspective of environmental degradation. Two types of samples were examined: conventional EPDM used to roof membranes, and EPDM blended with different amounts (20, 40, and 50 phr) of EPDMd. Samples were subjected to natural aging in coastal and mountainous environments. Results show that mechanical properties decline with higher EPDMd content and, to a lesser degree, with prolonged outdoor exposure. The coastal climate proved more aggressive than the mountainous one when EPDMd content exceeded 40 phr. Zinc stearate (ZnSt₂), a byproduct of vulcanization, was found to influence the evolution of the mechanical behavior. The combined analysis of scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), abrasion tests, and thermogravimetric analysis (TGA) provided insights into the degradation processes of these elastomeric blends.

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 study investigates a sustainable hybrid-filler strategy for natural rubber (NR) compound by partially replacing petroleum-based carbon black (CB) with talc and introducing a silane coupling agent to mitigate interfacial incompatibility. Compounds containing CB, CB+talc and CB+talc+increasing silane were produced via two-stage mixing and characterized for morphology (dispersion/mapping), curing and flow behavior (differential scanning calorimetry DSC/moving die rheometer, MDR/Mooney), crosslink density (Flory–Rehner), physical–mechanical properties, dynamic performance (Payne effect/heat build-up/tension–fatigue), and thermal stability (aging/thermogravimetric analysis,TGA). Talc reduced the compound viscosity, offering processing benefits. The swelling test indicated that talc decreased crosslink density, but silane recovered it, forming covalent linkages. Tensile strength and elongation at break were improved without altering hardness. Dynamically, talc increased heat build-up, whereas silane inverted the trend and reduced the temperature rise gradually from 41.5 to 29.4°C at 2 phr. Fatigue life was improved with talc (~10%), and further with silane (up to 36% at 2 phr), highlighting a favorable stiffness–fatigue balance with compatibilization. Overall, partial CB replacement by talc, in combination with silane, delivers meaningful sustainability gains with improved dynamic performance while preserving key mechanical properties of NR compounds.