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When the term lithium complex is used, it normally refers to greases ie the thickener or soap used as part of the grease formulation or ingredient. The thickener is roughly 10% of the grease composition, with the rest made up of base oil 85% approx (mineral or synthetic) and additives such as antioxidants, anitwear, EP, lubricating solids etc..

In general, a complex soap grease thickener is made by reacting an acid + alkali + dibasic acid to give the complex soap. For example, 12 hydroxystearic acid + lithium hydroxide + azelaic acid to give lithium complex. There are also a number of other acids available and used in making a lithium complex thickener.

NLGI (National Grease Lubricating Institute) have a book called Lubricating Grease Guide which gives some really good explanation.
You like to know or you want us to know about chemical term of Li-complex?

Well... here it goes...A complex in chemistry usually is used to describe molecules formed by the combination of ligands and metal ions. Originally, a complex implied a reversible association of molecules, atoms, or ions through weak chemical bonds. As applied to coordination chemistry, this meaning has evolved. Some metal complexes are formed virtually irreversibly and many are bound together by bonds that are quite strong.

As Renewa said, Soap is one of the main components of grease. They are metallic (metals) based and non-metallic (meaning...no metal)based.
Metallic based further broadly divided into two 1. Metal-simple & 2. Metal-complex. Metal-simple refers to the product/soap obtained from the reaction of alkali with one acid (inorganic or organic) & Metal complex refers to the products/soaps(mixture) obtained from the reaction between alkali and more than one type of acid. Soaps are called as thickener by virtue of its typical physical& chemical properties. During the process of making it in oil medium, the same acts like a sponge- oil gets trapped into it.
Hope this information would help you to understand the chemical term of M-complex.

Cheers
thanx Renewa, thanx, Shiva.

I wanted to know what the "lithium complex" is. I am a little bit interested in its structure.
I can easily imagine the lithium soap as tiny fibers, that help to make that sponge-like structure, but it is hard to me imagine what kind of structure is created when you add a complex agent to those soapsif i do not know what this complex agent is. Does this agent act as a kind of node where the Lithium and the soap structure attach? I would like to see that deeply, i am quite intrigued.
I had not hear any kind of info regarding azelaic acid, it is the first point to look.
The idea that i have now is that the lithium complex is a mixture of fatty acids treated with LiOH to make different soaps, and that soap mixture is used as thickener, not only lithium 12-hydroxystearate.
Am i forgetting something?
Thanks for your time.
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