Zinc Oxide in Rubber Industry – Formulations & Manufacturing

Zinc-Oxide-in-Rubber-Industry---Formulations-&-Manufacturing-Detail - Citra CakraLogam


Zinc oxide (ZnO) is a compound widely used in the rubber industry due to the excellent properties, it acts as an activator for the vulcanization of rubber. Natural rubber is converted into a more durable material through a chemical process called vulcanization. Therefore, zinc oxide adds strength to rubber compounds and improves their resistance against heat/abrasion and helps guard against ultraviolet degradation.


The high use of zinc oxide in the rubber industry is due to so many optical, physical, and chemical properties it has. Tires, for example, require high loading of zinc oxide for durability and high heat conductivity. It is critical since heat building in tires at high speed plays a big role to keep the vehicle’s safety.


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The Role of Zinc Oxide in Rubber Formulations

1. Activate the entire curing system

When zinc oxide and stearic acid combined, it will produce zinc soap. This will improve the solubility of zinc oxide in the compound and with the accelerator to form a complex. This complex is very lively, reacting with sulfur to produce an extremely strong vulcanizing agent.


2. Improve the cross-linking density

A combination of zinc oxide and stearic acid will produce Zn2++ salt, which is chelated with the sulfur-containing rubber accelerator side-chaining group. Therefore, the weak bond in a stable state change the cracking position of sulfur bonds, so rubber vulcanization can produce shorter cross-linking and add new cross-linking keys to increase the cross-linking density.


3. Improve the anti-aging properties of vulcanized rubber

In the process of vulcanization and use, the polysulfide bond breaks, resulting H2S which will accelerate the rubber cracking. Zinc oxide reacts with it to form new cross-linking bonds, stabilize the vulcanization network, and improve the aging resistance.


Read More: Zinc Oxide in Ceramics – The Secret of a Fine-Finished Selection


In short, the main roles of zinc oxide in rubber formulation are:

  • Take a role as an activator or accelerator.
  • Acts as a sour agent in the rubber vulcanization, it absorbs some of the vulcanization of the production of acidic substances.
  • It can improve the thermal properties of the compound.


Zinc oxide acts as the key ingredient with 50-60% being used in the rubber industry. Since the market is growing each year, as a leading manufacturer and exporter of a comprehensive range of zinc oxide, Citra CakraLogam has been successful in meeting the emerging market demands accurately. Call us on +62343657777 or send us an email to info@citracakralogam.com. Our team will guide you through the whole process.