Latex Rubber Encyclopedia

The role and application of zinc oxide in latex recycled rubber products

Create Date:2020-03-24 09:46:49Click volume:385
The role and application of zinc oxide in latex recycled rubber products

As a zinc oxide, zinc oxide is a chemical auxiliary commonly used in the production of natural rubber products. Latex recycled rubber inherits the basic molecular structure and performance characteristics of natural rubber. The main component is rubber hydrocarbons. Substituting natural rubber can significantly reduce raw material costs. The general formula of rubber products containing latex recycled rubber requires the coordination of zinc oxide. Is the role of zinc oxide in the production of latex recycled rubber products the same as the role of zinc oxide in natural rubber products? What should I pay attention to?

1. The main role of zinc oxide in rubber products

Zinc oxide is often used as an activator (inorganic active agent) or accelerator in the formulation of rubber products to strengthen the vulcanization process; active zinc oxide can be used as a reinforcing agent to improve the tear resistance and wear resistance of rubber products; zinc oxide can also When rubber is vulcanized, it absorbs acidic substances such as HCI produced in the vulcanization reaction as a dilute acid agent; zinc oxide can also be used as a colorant in the production of rubber products.

Due to the dispersion of ordinary zinc oxide in rubber products, the rubber product industry uses active zinc oxide or nano zinc oxide.

2. The specific role of zinc oxide in latex recycled rubber products

In general, zinc oxide can promote rubber vulcanization, activation, and reinforcement during the vulcanization of latex recycled rubber. Active zinc oxide, as the active agent of latex recycled rubber, is evenly distributed in the rubber compound, has a large contact area with hydrogen sulfide, and has a high probability of interfacial reaction. The active material in active zinc oxide 2LLYY0324 can also promote vulcanization and increase zinc oxide conversion. It is the conversion rate of zinc sulfide; increase the vulcanization speed and the degree of vulcanization. Zinc oxide as a vulcanization oxidant can increase the activity of vulcanization accelerators, reduce the amount of accelerators, and shorten the vulcanization time; as a reinforcing agent, it can improve the mechanical strength of rubber compounds.

The role of zinc oxide in different types of latex recycled rubber products is different. Generally, zinc oxide can improve the tear resistance and abrasion resistance of rubber materials in the production of tire casings containing latex recycled rubber; in latex soles and other products, it can improve the wear resistance and aging resistance of finished products; in white and light-colored latex regeneration The rubber products also have the functions of coloring and filling.

3.Zinc oxide in latex recycled rubber products

Zinc oxide is usually used in combination with stearic acid in the formulation of latex recycled rubber products. When the two are combined, the amount of zinc oxide should not exceed 5 parts, and the amount of stearic acid should be controlled below 3 parts. The main effects are as follows.

① The zinc soap formed by zinc oxide and stearic acid will react with the accelerator to form a complex with active surface properties. This complex can react with sulfur to form a strong sulfurizing agent; ② zinc formed by the reaction of zinc oxide with stearic acid The salt reacts with the pendant group of the sulfur-containing rubber accelerator to make the weak bond in a stable state, change the cleavage position of the sulfur bond, make the rubber vulcanize to form shorter cross-links, and increase new cross-links. Increasing the crosslink density and finally improving the mechanical strength of the vulcanizate; ③ Hydrogen sulfide produced by the polysulfide bond break during the processing of latex recycled rubber will accelerate the decomposition of the rubber. , And further improve the aging resistance of latex recycled rubber products.

When using latex recycled rubber instead of natural rubber to produce rubber products, the rational use of zinc oxide can improve the overall performance of rubber products. It is necessary to pay special attention that when zinc oxide is combined with hard acid, not only zinc soap and zinc salt will be generated, but also a small amount of water, which will cause latex products to vulcanize, and the amount of stearic acid should be appropriately reduced to improve the finished product Rate, avoid unnecessary losses, and reduce more production costs.