The antioxidant performance of fully synthetic air compressor oil in high temperature environment is crucial, which directly affects the service life and operating efficiency of the compressor. As the main component of compressor oil, the base oil has a decisive role in its high temperature antioxidant performance.
The base oil of fully synthetic air compressor oil usually includes polyalphaolefin (PAO), ester oil and other types. PAO has good low temperature fluidity and high viscosity index, and its molecular structure is relatively regular, and its antioxidant performance is good. Ester oil has excellent lubricity and natural polarity, and can be better adsorbed on the metal surface, but the antioxidant performance of different esters varies. For example, the antioxidant performance of polyol esters is generally better than that of diesters, because polyol esters contain more stable groups in their molecular structure, which can better resist oxidation reactions at high temperatures.
The purity and refining degree of base oil have a significant impact on its high temperature antioxidant performance. High-purity base oil has less impurities. Impurities such as aromatics, sulfur, and nitrogen will accelerate oxidation reactions. They are easy to react with oxygen at high temperatures to generate free radicals, which in turn trigger chain oxidation reactions. After deep refining, these impurities are removed from the base oil, which can provide a more stable chemical structure, reduce the starting point of the oxidation reaction, and thus improve the high-temperature antioxidant performance. For example, the use of advanced hydrorefining technology can effectively remove impurities in the base oil, so that the antioxidant performance of the base oil can be greatly improved.
The molecular structure of the base oil determines the internal mechanism of its antioxidant performance. Straight-chain hydrocarbon molecules are relatively stable, but they are also prone to chain breakage and oxidation reactions at high temperatures. Molecules with branches increase the steric hindrance of the molecules due to the presence of the branches, making it difficult for oxygen molecules to approach the carbon-carbon bond, thereby improving the antioxidant performance. In addition, if the base oil contains an appropriate amount of cyclic structures, such as cycloalkanes, it can absorb free radicals to a certain extent and play an antioxidant role. However, too many cyclic structures may also increase the viscosity of the oil and affect its fluidity, so it is necessary to make a reasonable design and balance in the molecular structure.
Although the base oil itself has certain antioxidant properties, in order to meet the use requirements in high temperature environments, additives such as antioxidants are usually added. There is a synergistic effect between antioxidants and base oils. For example, phenolic antioxidants can capture free radicals and interrupt oxidation chain reactions, while amine antioxidants can decompose peroxides to prevent them from further initiating oxidation reactions. The formula of base oil needs to match the additives. Different types of base oils have different solubility and compatibility with additives. Only when the two are well matched can the additives play their full role and improve the high-temperature antioxidant performance of compressor oil.
The oxidation of base oil at high temperature will also lead to the formation of carbon deposits, and the base oil formula has an important influence on this. Base oils with good antioxidant properties can maintain good stability at high temperatures, reduce the formation of macromolecular substances due to oxidation polymerization, and thus reduce the formation of carbon deposits. For example, the PAO-ester oil mixed base oil formula can effectively inhibit the formation of carbon deposits while maintaining good lubrication performance by reasonably adjusting the ratio of the two. This is because the polarity of ester oil can enhance the solubility and dispersion of additives, while the stability of PAO helps to reduce the formation of oxidation products.
The base oil formula of fully synthetic air compressor oil has an important influence on its high-temperature antioxidant performance through the type, purity, molecular structure and other aspects of the base oil. In practical applications, it is necessary to comprehensively consider various factors, select a suitable base oil formula, and through the synergistic effect with additives, meet the requirements of long-term stable operation of air compressors in high temperature environments and improve the reliability and service life of the equipment.
