High-pressure sulfurized isobutylene (often referred to as high sulfur isobutylene or sulfurized isobutene) is a key additive used in lubricants, particularly in extreme pressure (EP) and anti-wear applications such as gear oils, metalworking fluids, and greases.
🧪 What Is High-Pressure Sulfurized Isobutylene?
It is a sulfurized olefin, made by chemically reacting isobutylene (C₄H₈) with elemental sulfur under controlled high-pressure, high-temperature conditions. The result is a dark, viscous liquid rich in active sulfur compounds.
🛠️ Primary Roles in Lubrication
✅ 1. Extreme Pressure (EP) Performance
- Reacts with metal surfaces under high load and temperature to form metal sulfide films (like FeS).
- These films prevent welding and reduce adhesive wear in gear teeth and sliding contacts.
📌 Especially important in hypoid gears, industrial gearboxes, and heavy-duty transmissions.
✅ 2. Anti-Wear Function
- Though less effective than ZDDP in boundary wear conditions, it complements other AW additives and provides surface protection in scuffing-prone areas.
✅ 3. Load-Carrying Capacity
- Enhances the oil’s ability to withstand high loads without failure, extending gear and bearing life.
✅ 4. Friction Modification
- Helps reduce friction under boundary and mixed lubrication, improving energy efficiency in gear trains.
⚙️ How It Works (EP Mechanism)
- High temperature + high pressure
- Sulfur from the additive reacts with steel to form a soft, protective iron sulfide layer (FeS or FeS₂)
- This sacrificial layer absorbs wear and prevents metal-to-metal contact
📈 Typical Use & Treat Rates
| Application | Typical Dosage (%) | Notes |
|---|---|---|
| Gear oils (GL-4/5) | 1.0 – 5.0 | Often combined with other EP additives |
| Metalworking fluids | 1.0 – 10.0 | Used in cutting, broaching, forming oils |
| Greases | 1.0 – 5.0 | Boosts EP and adhesion |
🧪 Performance Characteristics
| Property | Behavior |
|---|---|
| Active sulfur content | Typically 10–40% |
| Color | Dark amber to black |
| Odor | Strong sulfur smell |
| Thermal stability | Moderate (can break down above 180–200°C) |
| Compatibility | May stain yellow metals (Cu, brass) unless passivators are used |
⚠️ Considerations
| Issue | Details |
|---|---|
| Corrosivity to yellow metals | Use copper passivators (e.g., triazoles) |
| Thermal degradation | Excess heat may release H₂S or degrade sulfur |
| Environmental concerns | Not biodegradable; use with caution in eco-sensitive areas |
| Odor | Pungent, sulfurous smell in high concentrations |
🔁 Alternatives or Complements
| Additive Type | Function |
|---|---|
| ZDDP | Anti-wear + mild EP |
| Phosphorus esters | Friction modifier, anti-wear |
| Chlorinated paraffins | (Legacy use) Strong EP, but environmental concern |
| Ashless sulfurized esters | Cleaner-burning sulfur EP alternatives |
🔧 Summary
High-pressure sulfurized isobutylene is:
- A cost-effective and powerful EP additive
- Critical for protecting gears, bearings, and cutting tools
- Best used in gear oils, greases, and metalworking fluids
- Often paired with ZDDP, phosphates, or copper inhibitors for balanced performance
High pressure sulfur isobutylene is a mixture of sulfur and isobutylene used as a high-pressure fluid in various industries. It is known for its high thermal stability and compatibility with a wide range of materials, making it a versatile choice for many applications.
One of the main functions of high-pressure sulfur isobutylene is as a lubricant and additive in the manufacture of rubber products. It is often added to rubber compounds to improve their processing properties and reduce viscosity. This helps fillers and reinforcements disperse better, thereby improving the mechanical properties and overall performance of the rubber product.
Another important role of high-pressure sulfur isobutylene is in the production of polymeric materials, such as polyisobutylene. It serves as a reactive diluent and chain transfer agent during the polymerization process, helping to control molecular weight distribution and improve the overall quality of the polymer.
High-pressure sulfur isobutylene is also used as a high-pressure fluid in hydraulic systems and accumulators. Its high thermal stability and low compressibility make it ideal for these applications, providing efficient energy transfer and smooth operation even under extreme conditions.
High-pressure sulfur isobutylene is an organism with special chemical properties, which has attracted widespread attention from scientific researchers and industrial people. This compound is synthesized from the reaction of isobutylene and sulfur under high temperature and high pressure conditions, and has unique physical and chemical properties. This article examines the role of high-pressure sulfur isobutylene in detail.
Table of Contents
Basic concepts and characteristics of high-pressure sulfur isobutylene
High-pressure sulfur isobutylene is a compound synthesized by the reaction of isobutylene and sulfur element under high temperature and high pressure conditions. It has the following characteristics:
High reactivity: The high-pressure sulfur isobutylene molecule contains carbon-carbon double bonds and sulfur atoms, making it highly chemically reactive.
Diversity of functional groups: The high-pressure sulfur isobutylene molecule contains functional groups such as carbon-carbon double bonds, sulfur atoms and hydrogen atoms, giving it a variety of chemical reaction properties.
Reaction medium specificity: High-pressure sulfur isobutene can only be synthesized under high temperature and high pressure conditions, and has a unique preparation method.
The mechanism of action of high-pressure sulfur isobutylene
High-pressure sulfur isobutylene can initiate and promote a variety of chemical reactions under high-temperature and high-pressure conditions. Its mechanism of action mainly includes the following aspects:
Initiating free radical reactions: The carbon-carbon double bonds in high-pressure sulfur isobutylene molecules are prone to breakage under high temperature and high pressure conditions, generating free radicals, thereby initiating free radical reactions.
Activating functional groups: The sulfur atoms in high-pressure sulfur isobutylene molecules can react with a variety of functional groups, effectively activating these functional groups and increasing the rate of chemical reactions.
Hydrogen bonding: The hydrogen atoms in the high-pressure sulfur isobutylene molecule can react with certain functional groups to form hydrogen bonds, thereby stabilizing the product.
Main application scenarios of high-pressure sulfur isobutylene
Due to the unique chemical properties and reactivity of high-pressure sulfur isobutene, it is widely used in many fields. The main application scenarios are as follows:
Polymer material synthesis: High-pressure sulfur isobutylene can be used to synthesize polymer materials, such as rubber, plastics, etc., to improve their performance and diversity.
Organic synthesis: High-pressure sulfur isobutylene can be used as an organic synthesis reagent to participate in the synthesis of a variety of organic compounds, improving synthesis efficiency and product purity.
Although high-pressure sulfur isobutylene has broad application prospects, it also has some shortcomings, such as complicated preparation process and large impact on the environment. Therefore, in future applications, it is necessary to strengthen the research on green synthesis methods of high-pressure sulfur isobutylene to achieve its sustainable development.
Future Outlook
As a compound with special chemical properties, high-pressure sulfur isobutylene still has broad room for development in future research and applications. With the continuous improvement of science and technology, the preparation methods, reaction types and application fields of high-pressure sulfur isobutylene are expected to be further expanded and optimized.
Expanded preparation methods: The current preparation method of high-pressure sulfur isobutylene is mainly through the high-temperature and high-pressure reaction of isobutylene and sulfur elements. In the future, more environmentally friendly and efficient synthesis routes can be explored, such as catalytic synthesis, electrochemical synthesis, etc.
Expanded reaction types: High-pressure sulfur isobutylene can participate in a variety of chemical reactions, such as free radical reactions, addition reactions, etc. In the future, its application in other types of reactions can be studied to expand its reaction diversity.
Optimized application fields: At present, high-pressure sulfur isobutylene has been widely used in fields such as polymer material synthesis and organic synthesis. In the future, its applications in new energy, environmental protection and other fields can be explored to promote its sustainable development.
Conclusion
High-pressure sulfur isobutylene, as a unique polymer compound, has high reactivity and diverse application scenarios. The role of high-pressure sulfur isobutylene is to enhance the performance and reliability of a variety of industrial processes and products. Its preparation and application not only provide new ways for polymer materials and organic synthesis, but are also expected to play an important role in new energy, environmental protection and other fields. However, the current high-pressure sulfur isobutylene preparation method still has certain limitations, and the application fields also need to be further expanded and optimized. Through continued research and exploration in the future, we have reason to believe that high-pressure sulfur isobutylene will show broad application prospects and play an important role in more fields.