Why is the lower the acid value, the pentaerythritol esters base oil better?

Pentaerythritol ester has good biodegradability, thermal stability, low-temperature performance, and wear resistance. It is a high-performance synthetic base oil and has been widely used in the aviation field.

We hope that ester-base oils do not contain residual free fatty acids during the production process, so we require the acid value to be as low as possible. Therefore, the acid value is a reflection of the process accuracy of production control.

When evaluating the performance of base oil, the hydrolysis characteristics of ester base oil are a key point. If the acid value is too high, it means that it is easy to hydrolyze and accelerate the decline of ester oil. At the same time, excessive free acid can cause corrosion and oxidation problems. Therefore, the lower the acid value, the better.

Acid value and hydroxyl value

Acid value and hydroxyl value are the most direct quality control indicators for pentaerythritol ester, and the quality of the product is controlled by controlling these two parameters in production.

Acid value

The acid value of the lubricant is a quality indicator that characterizes the total organic acid content in the lubricant. The acid value of lubricating oil has a significant impact on its use. For new lubricants, the acid value can be used to measure whether the content of certain additives is sufficient. A high acid value of the oil indicates a high organic acid content, while Low molecular organic acids easily corrode machine parts. Therefore, So the higher the acid value, the more likely it is to cause corrosion.

In addition, the degree of oxidation and deterioration during oil storage and use can be determined by the acid value and its variation. During use, due to the oxidation and decomposition process, the acid value continuously increases. When it reaches a certain level, new oil should be replaced, otherwise it will cause corrosion to the parts.

Hydroxyl value

The milligrams of potassium oxychloride with equivalent hydroxyl content per gram of sample (i.e. hydroxyl value). It can be directly used to evaluate the complete degree of synthesis reaction