Anthony J. O'Lenick, Jr., Siltech LLC; Dean Smith, Colonial Chemical

Key words: phospholipids, lipids, natural oils, surfactants, phosphobetaines, phosphoquats

Abstract: Natural phospholipids have many cellular functions such as being constituents of cell membranes. Certain types of products based upon phospholipid chemistry offer desirable surfactant properties including foaming, detergency, while others offer outstanding
conditioning. The two classes offer the formulator a variety of new options when making cosmetic products.

During the last 25 years, a great deal of work has been done to develop surface-active agents that contain phosphorous. This is due in part to the natural occurrence of phospholipids, a chemical necessary for life as we know it. Synthetic phosphorous-based surface-active agents can provide a number of properties to formulations including wetting, emulsifi cation, foaming, conditioning and having antimicrobial properties.

While there is no single compound with all of these various properties, the properties are a direct consequence of the structure of the compounds. There are three very different classes of phosphorus-based compounds with different properties. These include the mild, high-foaming, detergent molecules called phosphobetaines; the emollient conditioning compounds, which have become known as phospholipids; and the antimicrobial super conditioning agents called phosphoquats.

This article offers a review of the chemistry of natural phospholipids, synthetic phospholipids, phosphobetaines and phosphoquats. Naturally occurring lipids are actually triglycerides made by the reaction of a fatty acid and glycerin. These materials can be made in the laboratory with catalyst at a high temperature (180-200°C). However, the reaction occurs in living cells at low temperatures using specifi c enzyme systems (Figure 1). For the complete article, click on "Purchase this article."