TONY O’LENICK
Siltech LLC, Lawrenceville, USA

Abstract

As the quest for natural, renewable, biodegradable and green products continue there has been increased interest in working with a variety of esters and triglycerides. Esters when applied to the skin, not only act as emollients but also provide an aesthetic effect which can be varied by structure. 

This article is the second of two that deal with the formulation properties of polyol esters based upon specific highly branched polyols namely; neopentyl glycol (2 OH groups), trimethylol propane (3 OH groups) and pentaerythritol (4 OH groups). These esters find their main use in industrial lubrication because not only are they effective lubricants, they are oxidatively stable and have a relatively low viscosity when one considers their molecular weight.

The proper selection of esters for personal care product development often determines if the consumer perceives a smooth spreading, less oily feeling, dry product or a greasy wet product when applied to the skin. In short, the feel of a skin care formulation is very dramatically affected by the choice of ester in the oil phase.

TERMINOLOGY (1,2)

Emollient - an emollient is an ingredient that provides a barrier to the skin. An emollient minimizes natural moisture loss, preventing the natural evaporation of water and improving the smooth feel of the skin. 

Dehydration is the leading cause of dry skin and for any moisturizer to really improve the condition of the skin it must first prevent, or slow, that natural moisture loss. Oils, and derivatives, are all emollients.

Slip - when you apply a cream, or lotion, to your skin the first thing that you notice is how it feels on your skin and how well it spreads across the skin. A sticky oil drags on the skin as you try to spread it, producing ‘tack’ or ‘drag’. The absence of that ‘tack’ ...