Synthetic oil comes from ethylene and propylene dispersed by gas or natural gas in crude oil, and then refined into base oil composed of macromolecules through complex chemical reactions such as polymerization and Catalysis (Fischer Tropsch synthesis technology, i.e. GTL technology). In essence, it uses better components in crude oil, which are chemically reacted and artificially controlled to achieve the expected molecular morphology. Its molecules are arranged neatly and have a strong ability to resist external variables. Therefore, synthetic oil has better quality, and its ability to thermal stability, antioxidant reaction and viscosity change is naturally much stronger than mineral oil.
Synthetic lubricants were first used to meet military needs, but with the rapid development of industry, synthetic lubricants are also widely used in civil fields. The main types are as follows:
One of the most common synthetic hydrocarbons used as a base oil for lubricants, made from α- Olefins are polymerized under the action of catalyst, with excellent comprehensive properties. Compared with mineral oil with the same viscosity, it has high viscosity index, high flash point, low pour point, good low-temperature fluidity, wider working temperature range, small evaporation loss, good high-temperature stability, good oxidation stability, strong hydrolysis resistance, less carbon deposition and non-toxic. And it has good compatibility with mineral oil. It is mainly used for vehicle lubricating oil and industrial lubricating oil.
Ester oil was first used as aviation turbine engine lubricating oil, which was prepared by esterification dehydration of fatty acid and fatty alcohol under the action of catalyst. Due to the different types of fatty acids and fatty alcohols, synthetic esters can be divided into polyol esters, diesters and monoesters, while the commonly used synthetic ester base oils are polyol esters and diesters.
Generally speaking, synthetic esters have the following excellent properties: high viscosity index, high flash point, low pour point, good low-temperature fluidity, wider working temperature range, small evaporation loss, good high-temperature stability, good oxidation stability, less carbon residue, excellent lubrication performance, extremely low toxicity, good environmental protection and biodegradability. The disadvantage is poor hydrolysis resistance and general compatibility with rubber parts. It is mainly used for vehicle lubricating oil and industrial lubricating oil.
Polyether has a wide range of applications and is the most widely used synthetic base oil. It is prepared from ethylene oxide (EO), propylene oxide (PO), epoxy butane (Bo) and other raw materials through ring opening homopolymerization or copolymerization. It can be divided into water-soluble polyether, water-insoluble polyether and oil-soluble polyether. Polyether has many excellent properties: high viscosity index, excellent lubrication performance, high flash point, low pour point, wider working temperature range, good compatibility with rubber parts, low toxicity, less carbon residue, complete volatilization at high temperature without residue. Because its molecular structure can be customized and its molecular weight can be large or small, different polyethers can be prepared to meet different application requirements.
Additive for neutralizing acid calcium carbonate. Gasoline and air burn to produce sulfur oxide and nitrogen oxide, which are mixed with water to produce sulfuric acid and nitric acid and wear parts. This kind of wear requires neutralizing agent to neutralize acid. The ability of neutralizing acid can be improved by attaching cleaning dispersant to tiny calcium carbonate molecules and evenly dispersing it in engine oil.
Dispersion additives. Incomplete combustion of gasoline and diesel will cause soot, which will increase the viscosity of engine oil, form sediment and hinder the oil circuit and filter. Therefore, dispersing additives must be added to the engine oil to prevent the ash smoke from condensing into blocks and harming the engine.
Cleaning additives and ashless dispersants. Inhibit the generation of piston sediment and oil sludge, and disperse the oil sludge generated in the crankcase and circulating oil circuit when the engine starts at low temperature in the engine oil.
Antioxidants. Slow down the oxidation, aging and deterioration of oil, so as to prolong the service life of oil and protect the machine.
Viscosity index improver. When starting at low temperature, the oil has low viscosity and can quickly reach the surface of the parts to ensure that the engine will not be worn; At high temperature, there is a good oil film to ensure the normal operation of the engine.
Antiwear agent. A layer of chemical reaction film is formed on the metal surface, which can prevent scratch and fusion welding on the metal surface, so as to protect the operation of the engine.
Rust inhibitor. The polarity gene of rust inhibitor has strong adsorption force on the metal surface, forming a close single molecule or multi molecule protective layer on the metal surface to prevent the corrosive medium from contacting with the metal and play the role of rust prevention.
Anti emulsifier. The engine oil will be polluted by water during use, and the water will emulsify the engine oil. Therefore, after adding anti emulsifier, it can change the interface tension between oil and water and quickly isolate water and oil.
According to different types of synthesis, the application fields are also different, as follows:
Vehicle lubricating oil: gasoline engine oil, manual transmission oil, axle oil and automatic transmission oil.
Industrial lubricating oil: gear oil, worm gear oil, air compressor oil, gas turbine engine oil, low temperature hydraulic oil and food grade lubricating oil.
Components of air compressor oil, vehicle air conditioner compressor oil, high-pressure polyethylene and petroleum gas compressor oil, gear oil, worm gear oil, brake fluid, fire-resistant hydraulic oil, quenching oil and metalworking fluid.