ZnO holds a special position in the rubber industry. ZnO is an essential rubber component in the vulcanization process (Figure 1), and zinc oxide serves as an activator to accelerate vulcanization. Promoters are only effective in the presence of inorganic activators, and the most commonly used and important inorganic activator is ZnO.
Figure 1 Widespread Application of ZnO
The important role of ZnO in the rubber industry is as follows:
1、activate
In the vulcanization process of natural rubber and most synthetic rubber, the chemical reactivity of ZnO is utilized to accelerate the vulcanization rate of organic accelerators. Unreacted ZnO can still be used to neutralize the acidic decomposition products formed during the vulcanization process A sufficient amount of ZnO helps with chemical reinforcement, controlling scorching, heat aging, and compressive fatigue resistance.
2、Promote vulcanization
ZnO Can serve as a promoter for certain elastomers There are various forms of induced crosslinking. In some systems, ZnO can serve as an effective promoter in the vulcanization process.
3、Latex gel
ZnO It is especially effective in foam gel and has enough stability. It can be used in the production process of latex foam rubber products.
4、pigment
ZnO It can endow rubber products (such as tire sidewalls, rubber plates, and surgical gloves) with high whiteness and coloring strength, mainly due to its high brightness, high refractive index, and optimal particle size.
5、reinforce
ZnO It can reinforce natural rubber and some synthetic elastomers, such as polysulfide rubber and chloroprene rubber. The degree of reinforcement depends on the particle size. The finer the particle size, the better the reinforcement effect, and zinc oxide can react with rubber. In addition, it can be endowed with thermal stability by reacting with acidic decomposition products.
When rubber is bonded to brass, ZnO reacts with copper oxide on the surface of brass to form tightly adhered zinc copper salts.
6、Stickiness retention characteristics
ZnO A special property is the ability to maintain the viscosity of the unvulcanized rubber on the storage tape.
Although preparing rubber products requires multiple additives, zinc oxide has a very unique position.
