Sulfur containing EP additive and Sulfurized Isobutylene

Sulfurized isobutylene (SIB) is a kind of widely used lubricating oil sulfur-containingEP additive, its extreme pressure and anti-wear performance are very good. CHORUS Lubricant Additives Company can provide low-odor sulfurized isobutylene Contact us to obtain samples and prices.

What is an Extreme pressure (EP) additive?

In boundary lubrication, when the metal surface only bears a moderate load, if there is an additive that can be adsorbed on the metal surface or wear violently with the metal surface, this additive is called an anti-wear additive.

When the metal surface is subjected to a high load, a large amount of metal surface comes into direct contact, generating a large amount of heat, and the film formed by the anti-wear agent is also destroyed, no longer playing a role in protecting the metal surface. For example, there is an additive that can react chemically with the metal surface to form a chemical reaction film, which acts as a lubricant to prevent scratches and even welding on the metal surface. This most stringent boundary lubrication is usually called extreme pressure lubrication, And this type of additive is called an extreme pressure additive.

Sulfur-containing compounds are widely used as extreme pressure additives in the formulation of lubricating oils and greases

In traditional industrial lubricants, sulfurized olefins are commonly used as extreme-pressure additives. To match the effectiveness of extreme pressure and anti-wear agents, friction improvers, such as long-chain compounds such as fatty acid esters or amine salt long-chain phosphites, are also added to certain oils. These additives play a role in lubricating the metal surface of friction pairs, reducing friction and wear, avoiding metal sintering, and are generally classified as extreme pressure and anti-wear agents.

Sulfurized olefin EP additive is a sulfur-containing compound with high reactivity, which can reduce wear and prevent welding on the metal surface of friction pairs. It has been widely used in gear oil, grease, and metalworking fluids. At present, most lubricating oils use sulfurized olefins as the main extreme-pressure additives. The development of extreme pressure agents mainly focuses on improving the quality of sulfurized olefins, reducing usage, and reducing costs.

Sulfurized isobutene(SIB) is a traditional sulfur-containing extreme-pressure additive with a sulfur content of over 40%. The S- S bond in the structure is short, the carbon chain is short, and the structure is relatively strong. Its structural formula is shown in the figure

Chemical Structure of Sulfurized Isobutylene

This type of sulfur-containing extreme pressure additive is relatively stable, with good thermal stability and moderate chemical activity. Its chemical structure determines its ability to effectively protect friction pair metals under high loads and pressures, thus it has been widely used in modern lubricants.

Sulfurized isobutene is a transparent liquid with a yellow to amber color and a lighter color. It has high sulfur content and good extreme pressure performance, especially for equipment with high-speed impact loads. Its scratch resistance performance is good, and it is compatible with phosphorus compounds. It is often used as the main sulfur-containing extreme pressure additive in lubricating oil, it has wide applications in industrial equipment, vehicle lubricating oil, and grease.

Sulfurized isobutylene also has significant drawbacks

1. The traditional production method of sulfurized isobutylene causes serious environmental pollution and equipment corrosion, resulting in a large amount of wastewater and waste residue

2. Due to the poor solubility of sulfurized isobutene in PAO synthetic oil

Sulfurized isobutylene has good solubility in ordinary mineral oil, but poor solubility in PAO synthetic oil. At present, the application of PAO synthetic lubricating oil in industries such as wind power, cement, high-speed rail, and textile is developing rapidly, and the oil solubility of sulfurized isobutylene also limits its use.

3. The strong odor of sulfurized isobutylene

The strong odor of sulfurized isobutylene produced in China has greatly limited its application

Due to the high dosage of sulfurized isobutylene in lubricating oil, and even up to nearly 50% usage in gear oil additives, lubricating oil products formulated with it generally have a strong odor. The strong odor limits the range of use of sulfurized isobutylene

CHORUS can provide low-odor sulfurized isobutylene Contact us to obtain samples and prices