Octadecylamine N-oleoyl Sarcosinate (molecular formula: C39H78N2O3) is an industrial additive that functions both as a rust-preventive agent and a surfactant. It has been widely and long-term applied in lubricating oils, hydraulic fluids, rust-preventive oils, and oilfield pipelines, and is a well-established ashless corrosion inhibitor fully validated by the market. Baischem now independently produces this classic product, and this article aims to share its practical advantages in real-world applications.

Historically, in the 1850s, oleoyl sarcosine was first discovered to exhibit good corrosion inhibition in petrochemical systems, with the added benefits of being ashless and readily soluble in olefinic compounds. By the 1860s, driven by domestic military requirements for preservation oils, oleoyl sarcosine and its derivatives, along with petroleum sulfonates, entered the Chinese market.

The more common free-acid form of oleoyl sarcosine (e.g., the well-known grade Sarkosyl O, CAS 110-25-8, Baisgrade RZ-SO) is a liquid at room temperature, but it has certain limitations: the carboxyl group is overly polar, resulting in only moderate solubility in non-polar oils; its rust-preventive performance relies mainly on carboxyl adsorption onto metal surfaces, and its effectiveness drops significantly under high temperature/humidity or in the presence of water—i.e., highly polar environments. A natural improvement is to convert the free acid into a salt. Bais chose neutralization with an organic amine, which not only enhances rust-preventive performance and solubility in non-polar oils, but also avoids introducing metal ions that would compromise its ashless nature, while improving thermal stability. The resulting product is  Octadecylamine N-oleoyl Sarcosinate – a waxy solid at room temperature that readily liquefies upon heating.

In practice,  Octadecylamine N-oleoyl Sarcosinate demonstrates the following outstanding advantages:

1. Formation of a dense protective film.

Both the carboxylate anion and the amine group in the molecule can adsorb onto metal surfaces, while the two octadecyl long chains intertwine to build a compact hydrophobic barrier, providing substantial van der Waals forces that effectively block corrosive media.

2. Excellent solubilization and neutralization capacity.

Trace amounts of water and acidic substances are inevitable in oils. This salt is alkaline and can neutralize acidic components generated during oil service (e.g., acids released by sulfur-containing extreme-pressure agents). Meanwhile, for small amounts of water, it spontaneously forms reverse micelles – with polar heads inward and hydrocarbon tails outward – thus isolating water from the metal surface.

3. Superior water-displacement performance.

When a water film remains on a metal surface, this inhibitor can displace the water and preferentially adsorb onto the surface itself. This feature makes it particularly suitable for in-process rust prevention: parts taken from water-based cutting fluids can be directly sprayed with an in-process rust preventive without additional drying, significantly improving process efficiency.

Summary,  

Octadecylamine N-oleoyl Sarcosinate as a rust-preventive additive offers better thermal stability, good solubility in non-polar formulations, suitability for in-process rust protection, and compatibility with sulfur-containing extreme-pressure agents – demonstrating broad application prospects and practical value in industrial production. Bais Technology possesses our own R&D, production, and quality control teams, providing full technical support from manufacturing to end-use. This product breaks monopoly, fills a domestic gap, and achieves world-leading quality, having passed trials with domestic and overseas customers with unanimous praise – making it a reliable and trustworthy choice for your needs.