What's the difference between a lactate and a lactylate? The answer to this question relates to structure, function and the raw materials used to make the products.
In this case, both groups are esters of lactic acid. The following explains.
Lactic acid has the CAS number 50-21-5, and EC number 200-018-0. The structure of lactic acid1 is shown in Figure 1:
Lactic Acid Esters
Since lactic acid contains both a hydroxyl and carboxyl group, the hydroxyl group on lactic acid can be reacted with an acid to make an ester, and the carboxyl group on lactic acid can be reacted with a hydroxyl group to make an ester. However, they are very different, structurally, functionally and when used in formulations.
Reaction 1: Carboxyl Group of Lactic Acid Reacted with Fatty Alcohol (Lactate)
Reaction 2: Hydroxyl Group of Lactic Acid Reacted with Fatty Acid (Lactylate)
The presence of two different reactive groups on a molecule can be used to make a series of related products. Their relationship is based upon a common raw material only; in this case, lactic acid. Derivatives will have different structures, properties—both physical and chemical, and function differently in formulations.