Revisiting the sulfur vulcanisation of rubber

Sulfenamide accelerators in combination with zinc oxide activator are used extensively in the sulfur cure systems of a wide range of industrial rubber articles. However, the excessive use of these chemicals has raised major concerns regarding their adverse effect on marine life and human health as well as the environment. Zinc oxide was functionalised with a sulfenamide accelerator in an organic solvent to provide a convenient single material to use as an additive. The effect of the additive on the cure properties of natural rubber was then measured. The aim was to minimize the use of these two chemicals in the cure system and enhance the efficiency of the sulfur vulcanisation of the rubber. Functionalising zinc oxide with the accelerator reduced the excessive use of these chemicals in the cure system. When the cure properties were compared with those of a sulfur cure-based natural rubber compound used to make tyres, the optimum cure time was noticeably shorter and the rate of cure significantly faster despite reducing the use of these two curatives by almost 77 %. All the indications are that the cure efficiency improves considerably when the chemicals in the cure system are reduced

The perfect cure

I n the processing of raw rubber, sulfur is added for shape retention. To enhance the efficiency of curing and the vulcanization process, chemical curatives known as accelerators and activators are frequently used. However, excessive use of chemical curatives has raised major concerns about their adverse impact on human and animal health as well as on the environment. In most tire compounds, sulfenamide accelerators and zinc oxide are used in combination with sulfur to achieve efficient vulcanization. Since these chemicals are essential to improve the curing process, it is likely that their use in tire compounds will continue for some time. Therefore, their use must be lowered without compromising the cure properties and adversely affecting the cure cycle of tire compounds. ...

Schwefelvernetzung von Kautschuk auf dem Prufstand

Sulfenamidbeschleuniger in Kombination mit Zinkoxid finden in Schwefelvulkanisationssystemen für eine Vielzahl industrieller Kautschukprodukte breite Anwendung. Allerdings gibt der exzessive Einsatz dieser Materialien Grund zu Besorgnis, was ihren negativen Einfluss auf Meeresflora und -fauna, die Gesundheit und die Umwelt angeht. In dieser Arbeit wurde Zinkoxid in einem organischen Lösemittel mit einem Sulfenamidbeschleuniger funktionalisiert, um ein einfach anzuwendendes Additiv aus nur einem Material herzustellen. Dann wurde der Einfluss auf die Vulkanisationseigenschaften von Naturkautschuk untersucht. Ziel war es, den Einsatz dieser beiden Chemikalien im Vulkanisationssystem zu verringern und die Effizienz der Schwefelvulkanisation des Kautschuks zu erhö- hen. Die Funktionalisierung des Zinkoxids mit dem Beschleuniger verringerte den exzessiven Einsatz dieser Chemikalien im Vulkanisationssystem. Ein Vergleich mit den Vulkanisationseigenschaften eines schwefelvulkanisierten Naturkautschuks für Reifen zeigte, dass die optimale Vulkanisationszeit deutlich kürzer und die Vulkanisationsgeschwindigkeit bedeutend höher war, obwohl die Verwendung der beiden Vernetzer um fast 77 % reduziert worden war. Alles deutet darauf hin, dass sich die Vernetzungseffizienz deutlich verbessert, obwohl die Menge der Chemikalien im Vulkanisationssystem reduziert wird. Sulphenamide accelerators in combination with zinc oxide activator are used extensively in the sulphur cure systems of a wide range of industrial rubber articles. However, the excessive use of these chemicals has raised major concern regarding their adverse effect on marine life and human health as well as the environment. Zinc oxide was functionalized with a sulphenamide accelerator in an organic solvent to provide a convenient single material to use as an additive. The effect of the additive on the cure properties of natural rubber was then measured. The aim was to minimize the use of these two chemicals in the cure system and enhance the efficiency of the sulphur vulcanisation of the rubber. Functionalising zinc oxide with the accelerator reduced the excessive use of these chemicals in the cure system. When the cure properties were compared with those of a sulphur cure-based natural rubber compound used to make tyres, the optimum cure time was noticeably shorter and the rate of cure significantly faster despite reducing the use of these two curatives by by almost 77 %. All the indications are that the cure efficiency improves considerably when the chemicals in the cure system are reduced