PEG-7 Propylheptyl Ether is a synthetic ether compound used primarily in cosmetic formulations. It is known for its ability to enhance skin feel, improve product spreadability, and provide moisturizing benefits.

Chemical Composition and Structure

The chemical composition of PEG-7 Propylheptyl Ether includes:

• PEG (Polyethylene Glycol): A polymer of ethylene oxide that contributes to its solubility and moisture-retaining properties.
• Propylheptyl Group: A branched alkyl chain that enhances the emollient properties and helps to improve the texture of formulations.

Structurally, PEG-7 Propylheptyl Ether consists of a polyethylene glycol backbone linked to a propylheptyl group, allowing for its multifunctional properties in personal care products.

Physical Properties

• Appearance: Typically a clear to slightly yellow liquid.
• Solubility: Soluble in water and oils, making it versatile for various formulations.
• pH: Generally neutral, around 6-7 in solution.
• Odor: Mild, characteristic of synthetic compounds.
• Stability: Stable under normal storage conditions; should be protected from extreme temperatures.

Production Process

• Synthesis: PEG-7 Propylheptyl Ether is produced through the reaction of polyethylene glycol with propylheptyl alcohol, forming the ether bond.
• Purification: The crude product may undergo purification to remove unreacted materials and impurities.
• Formulation: The purified compound is incorporated into cosmetic products, often combined with other ingredients to enhance performance and stability.

Applications

• Medical: Limited use in medical formulations that require emollient properties.
• Cosmetics: Commonly included in lotions, creams, shampoos, and conditioners for its moisturizing and texture-enhancing effects.

INCI Functions:

Emulsion stabilizer. Emulsions are thermodynamically unstable. Emulsion stabilisers improve the formation and stability of single and double emulsions. It should be noted that in the structure-function relationship, molar mass plays an important role.

Surfactant - Emulsifying agent. Emulsions are thermodynamically unstable. Emulsifiers have the property to reduce the oil/water or water/oil interfacial tension, improve emulsion stability and also directly influence the stability, sensory properties and surface tension of sunscreens by modulating their filmometric performance.

Since the PEG (Polyethylene glycol) family is very numerous and can be found in cosmetic, industrial, pharmaceutical, medical and other products, we need to make an introductory statement on the subject, which is rather complex from a safety point of view because these products not only come into contact with the skin, but, as in the case of medical products, are ingested.

PEGs (polyethylene glycol) polymerise condensed ethylene oxide and water and are referred to as polyethylene glycols, but are actually complex chemical components, polymers bonded together. For example, plastic is polyethylene and has a hard consistency, while polyethylene combined with glycol forms a liquid. PEGylation is produced not only as etherification, but also as transesterification, which is the transformation of an alcohol by an ester. 

The number appearing after the abbreviation PEG represents the molecular weight and the higher this number is, the less it penetrates the skin.

Safety. The term 'eth' refers to the ethoxylation reaction with ethylene oxide after which residues of ethylene oxide and 1,4-dioxane, chemical compounds considered carcinogenic, may remain. The degree of safety therefore depends on the degree of purity of the compound obtained. At present, no manufacturer is known to provide this information on the label.