Selecting PEG/PPG Dimethicone Silicone Surfactants – The Agony and the Ecstasy
Personal care formulations are like fine gourmet meals in which proper choice for the silicone polymers is to function as the spice of the meal, not the meat or potatoes. This means that small amounts of silicone polymers added to formulation (less than 5%) can make a tremendous difference on consumer perception. We have called this type of formulation minimally disruptive technology (MDT). These versatile polymers need to be used at low concentrations to provide formulations that cannot achieve the overall effect without them. The task of selecting the proper PEG/PPG dimethicone polymers is a complicated but necessary one.
Silicone polyethers, also known as PEG/PPG dimethicone in the personal care industry, contain one or more of a silicone-soluble (siliphillic) group and a water-soluble PEG/PPG (hydrophilic) pendant groups. The ratio of the two groups, the molecular weight of the polymer and ratio of the PEG/PPG portion in the molecule in great part determine the solubility and specific properties of polymers from this diverse class of compounds. For purposes of this article we refer to these materials as PEG/PPG dimethicone, although they have many other more trivial names.
PEG/PPG dimethicone polymers are chosen for formulation to fulfill a basic need that cannot be achieved using other chemistries. PEG/PPG dimethicone polymers have a handful of salient properties that make them valuable in formulation. It is the job of the formulator to optimize the polymer to a specific application and even to a specific formulation. The job of the silicone chemist to make the optimized polymer. The desirable properties are outlined in Table 1.
The formulator must first decide which of these properties is required in each formulation then evaluate the proper type of silicone. We suggest the mi ...