Although there is only one word for stearic acid and zinc stearate difference, and both can be used as lubricants, but their differences are very different. Let’s learn about the supply of stearic acid and zinc stearate:
1. Properties and structure:
Zinc stearate is an organic salt obtained by combining stearic acid and zinc elements. It is a white powder, insoluble in water, and soluble in hot ethanol, benzene, toluene, turpentine and other organic solvents; The acid decomposes into stearic acid and corresponding salts; it is fire hazard under dry conditions, with an auto-ignition point of 900°C; it is hygroscopic. Stearic acid is a fatty acid that is widely found in nature. It is a white flake, bead or massive solid at room temperature. It is composed of saturated fatty acids mainly C16 and C18. It is insoluble in water, slightly soluble in benzene and carbon disulfide, easily soluble in hot ethanol, non-toxic and tasteless, and has the general chemical properties of organic carboxylic acids.
2. Melt flow rate:
The addition of zinc stearate and stearic acid both increases the melt flow rate of some polymer/elastomer systems, but the increase of stearic acid on the melt flow rate of the system is very small, and as its dosage increases Its melt flow rate basically no longer increases; zinc stearate is different, it significantly increases the melt flow rate, and as its dosage increases, the melt flow rate increases, but when the dosage is greater than 0.5%, the melt flow rate The flow rate basically does not change.
3. Friction coefficient:
Hard grease The addition of zinc stearate and stearic acid has an impact on the friction properties of the polymer/elastomer blend system. Both reduce the friction coefficient, and the friction coefficient of stearic acid is lower than that of zinc stearate. This is because the two Although both of them play a role in external lubrication, the external lubrication effect of stearic acid is stronger than that of zinc stearate.
4. Principle of lubrication:
Hard The lubrication principles of zinc stearate and stearic acid are different. Zinc stearate mainly acts as internal lubrication, while stearic acid mainly acts as external lubrication. The internal lubrication of zinc stearate makes The intermolecular force of the blend is reduced, the interface effect is weakened, and it has a certain plasticizing effect, so it has the effect of reducing the fluidity, but stearic acid has little effect on the fluidity.
微信扫一扫打赏
