Types and working mechanism of friction modifiers

1. Types of organic friction modifiers and their mechanism of action

(1) Types of organic friction modifiers

Usually organic friction modifiers have a polar group at one end. This polar group is one of the leading factors in the effectiveness of friction modifiers. In terms of chemical structure, the commonly used organic friction modifiers mainly include: ① carboxylic acid or its derivatives; ② imides, amines and their derivatives; ③ phosphorus or phosphonic acid derivatives; ④ organic polymers.

(2) The mechanism of action of organic friction modifiers

The mechanism of action of organic friction modifiers usually has the following three forms:

①Form a chemical reaction film. Such products mainly include saturated fatty acids, phosphoric acid and thiophosphoric acid, and sulfur-containing fatty acids. The mechanism is basically similar to that of anti-wear agents. The additives react with the metal surface to form a protective film, thereby reducing friction. But the most fundamental difference between the two is that the chemical reaction film of the friction modifier appears under milder load and temperature conditions in the mixed lubrication state, and the chemical activity of the friction modifier is required to be quite high, such as a chemical structure similar to sulfur and phosphorus. Stearic acid is an exception. In theory, as the temperature increases, the antifriction effect of stearic acid should decrease due to the desorption of molecules from the metal surface. However, experiments have shown that with the increase of temperature, stearic acid forms a chemical reaction film, and the anti-friction effect is enhanced;

②Form a physical adsorption film. Such products mainly include long-chain carboxylic acids, esters, ethers, amines, amine-based compounds, and imides. The friction modifier dissolved in the oil is adsorbed on the metal surface by the molecular polar groups, and the long hydrocarbon chain is dissolved in the oil, perpendicular to the metal surface, resulting in a multilayer matrix of friction modifier molecules. The thickness and anti-friction effect of the friction modifier film on the metal surface are related to the following parameters: first, the stronger the polarity of the polar group, the greater the thickness and strength of the friction modifier film on the metal surface; the second is the friction modifier Hydrocarbon straight chain is conducive to producing a stronger anti-friction film; thirdly, the chain length of the base oil and the chain length of the friction modifier are similar, which is conducive to producing a stronger anti-friction film, but the chain length of the friction modifier is longer than that of the base oil. The effect of long-term growth is greater; fourth, the increase in temperature can improve the thickness and strength of the friction modifier film, but if the temperature is too high, the friction modifier molecules may be desorbed from the metal surface;

③Form a polymer. Such products mainly include unsaturated complex esters, methacrylates (esters), unsaturated fatty acids, and sulfurized paraffins. The formation of low-friction polymers is a special example. It does not form a solid film, but forms a liquid film under contact temperature and load, and the metal surfaces on both sides of the film do not react. The formation of this polymer requires the following characteristics: first, relatively low activity; second, the polymer has good mechanical and thermal stability, and is insoluble in lubricating oil; third, strong adsorption or chemical bonds are formed between the polymer and the metal surface ; Fourth, the polymer film formation speed is fast.

2. Types of other friction modifiers and their principle of action

(1) Metal organic compound friction modifier

The types of metal organic compound friction modifiers mainly include molybdenum or copper compounds, such as molybdenum dithiophosphate, dithiocarbamate, copper oleate, salicylate or ester, and dihydrocarbyl dithiophosphate Wait.

The mechanism of action of the metal-organic compound friction modifier: one is that molybdenum may penetrate into the rough surface, the other is to form a polymer film, the third is to form polymorphic molybdenum disulfide (the most acceptable theory), and the fourth is due to metal The selective transfer of (copper) results in a thin metal film that is easy to shear, etc. The mechanism of action of metal organic compound friction modifiers is not fully known.

(2) Non-oil-soluble friction modifier

The more classic non-oil-soluble friction modifiers are graphite, molybdenum disulfide and the newly emerged Teflon (polytetrafluoroethylene), polyamide, fluorinated graphite, borate and so on. The mechanism of action of this type of friction modifier is mainly to form a layered structure with a low shear rate or to form a ductile or plastic layer on the metal surface, resulting in a reduction in friction.

3. The main difference between different friction modifiers

Relatively speaking, the molybdenum-based metal organic compound is very active in the boundary lubrication state, but the organic friction modifier is more active in the mixed lubrication state.

In fact, the effect of organic friction modifiers is greater than the use of low-viscosity oil to compensate for the growth of the mixed lubrication state. To a certain extent, molybdenum-based metal compounds show the same effect as organic friction modifiers, but the latter shows a small friction coefficient in the mixed lubrication state, especially under the most demanding low-speed and high-load conditions. The organic friction modifier mainly acts in the form of an absorbing layer, which occurs at a relatively low temperature. The molybdenum compound acts as a polymer of molybdenum disulfide, which can only appear in a high-temperature environment. In addition, although molybdenum-based metal compounds will improve fuel economy, there are data showing that adding it to base oils or fully formulated engine oils will increase TEOST deposit levels, which is undesirable

Overview of friction modifier MoDTC powder

Friction modifier MoDTC is an additive that reduces the friction coefficient of lubricating oil under boundary lubrication conditions. Its function is mainly to form a lubricating protective film on the metal surface to avoid direct contact between metal peaks, and to make mixed lubrication and boundary lubrication state The lower friction coefficient is reduced, the friction resistance and wear are reduced, and the purpose of fuel saving is achieved.

The powder is mainly used as friction modifier, extreme pressure anti-wear agent and pro-oxidant in lubricating grease. MoDTC and other additives (such as antioxidants) can produce a specific synergistic effect, thereby delaying the oxidation-induced friction degradation. The friction decomposition product of MoDTC is the main MoS2.The layered structure of molybdenum disulfide is connected by van Van der Waals force and shear stress are small, so MoDTC can significantly reduce the friction coefficient and play a role in reducing friction. With the gradual decrease in the amount of phosphorus-containing organic molybdenum, MoDTC has reached the low phosphorus standard for internal combustion engine oil.

Application of friction modifier MoDTC powder

Friction modifier MoDTC powder sliding parts are coated with a metal-containing carbon layer to improve wear and friction properties through friction applications under lubricating conditions. Wear-resistant and anti-friction, protect mechanical parts and reduce friction and wear.

Friction modifier MoDTC powder price

The price of friction modifier MoDTC powder will vary with the production cost, transportation cost, international situation and market supply and demand of friction modifier MoDTC powder randomly. Tanki New Materials Co.,Ltd. aims to help various industries and chemical wholesalers find high-quality, low-cost nanomaterials and chemicals, and provide a full set of customized services. If you are looking for friction modifier MoDTC powder, please feel free to send an inquiry to get the latest price of friction modifier MoDTC powder.

Supplier of friction modifier MoDTC powder

The friction modifier MoDTC powder supplier, Tanki New Materials Co.,Ltd. has extensive experience in the performance, application and cost-effective manufacturing of advanced engineering materials. The company has successfully developed a series of powder materials (the best engine oil additives, lithium stearate, nano copper and nano oil additives), high-purity targets, functional ceramics and structural devices, and provides OEM services.

Physical and chemical data of MoDTC Powder