The key difference between cetyl alcohol and cetearyl alcohol is that cetyl alcohol is a single chemical compound, whereas cetearyl alcohol is a mixture of chemical compounds.
Cetyl alcohol and cetearyl alcohol have different chemical and physical properties and different applications. Cetyl alcohol is a type of fatty alcohol having the chemical formula CH3(CH2)15OH while cetearyl alcohol is a mixture of fatty alcohols containing cetyl (carbon-16) compounds and stearyl alcohols (carbon-18) compounds.
CONTENTS
1. Overview and Key Difference
2. What is Cetyl Alcohol
3. What is Cetearyl Alcohol
4. Side by Side Comparison –Cetyl Alcohol vs Cetearyl Alcohol in Tabular Form
5. Summary
What is Cetyl Alcohol?
Cetyl alcohol is a type of fatty alcohol having the chemical formula CH3(CH2)15OH. This substance occurs as a waxy white solid or in the form of flakes at room temperature. Cetyl alcohol has a very faint, waxy odour as well. This name comes from the term “Cetus”, which means “whale oil” in Latin. This substance was first isolated from whale oil.
Figure 01: Chemical Structure of Cetyl Alcohol
This substance is insoluble in water and very soluble in ether, benzene, and chloroform. It is soluble in acetone and slightly soluble in alcohol. Cetyl alcohol was first prepared from sperm whale oil by the French chemist Michel Chevreul. He heated the spermaceti (a waxy material obtained from whale oil) in the presence of caustic potash (potassium hydroxide). This heat treatment produced flakes of cetyl alcohol which were left behind for cooling. However, the modern method of cetyl alcohol production involves the reduction of palmitic acid obtained from palm oil.
There are many uses of cetyl alcohol, including its use in the cosmetic industry as an opacifier in shampoos, as an emollient, emulsifier or thickening agent in skin creams and lotions. Further, this substance is useful as a lubricant for nuts and bolts. It is an active ingredient in some liquid pool covers, as well. Apart from that, we can use this substance as a non-ionic co-surfactant in emulsion applications.
Some people can be sensitive to cetyl alcohol, mainly those suffering from eczema. However, this sensitivity comes mainly due to the impurities that are present in cetyl alcohol. But sometimes, this substance is used in some medications as well.
What is Cetearyl Alcohol?
Cetearyl alcohol is a mixture of fatty alcohols containing cetyl (carbon-16) compounds and stearyl alcohols (carbon-18) compounds. The chemical formula for this mixture of compounds can be given as CH3(CH2)nCH2OH, where n can be a variable number typically ranging from 14 to 16. The other names for this compound mixture include cetyl-stearyl alcohol, ceto-stearyl alcohol, and cetyl/stearyl alcohol. The chemical structure can be given as follows:
Figure 02: Chemical Structure of Cetearyl Alcohol
This mixture of compounds is important as an emulsion stabilizer, opacifying agent, and a foam boosting surfactant. It is also important as an aqueous and non-aqueous viscosity-increasing agent. Cetearyl alcohol leaves an emollient feel on the skin, and it is useful in water-in-oil emulsions, oil-in-water emulsions and in anhydrous formulations. Commonly, this mixture is used in hair conditioners and other hair products.
What is the Difference Between Cetyl Alcohol and Cetearyl Alcohol?
Cetyl alcohol is a type of fatty alcohol having the chemical formula CH3(CH2)15OH. Cetearyl alcohol is a mixture of fatty alcohols containing cetyl (carbon-16) compounds and stearyl alcohols (carbon-18) compounds. The key difference between cetyl alcohol and cetearyl alcohol is that cetyl alcohol is a single chemical compound, whereas cetearyl alcohol is a mixture of chemical compounds.
The below infographic summarizes the difference between cetyl alcohol and cetearyl alcohol in tabular form.
Summary – Cetyl Alcohol vs Cetearyl Alcohol
The key difference between cetyl alcohol and cetearyl alcohol is that cetyl alcohol is a single chemical compound, whereas cetearyl alcohol is a mixture of chemical compounds. Cetyl alcohol is useful in the cosmetic industry as an opacifier in shampoos, as an emollient, emulsifier or thickening agent in skin creams and lotions. Cetearyl alcohol is important as an emulsion stabilizer, opacifying agent, and a foam boosting surfactant.
Reference:
1. “Cetyl alcohol.” Britannica, Available here.
Image Courtesy:
1. “Cetyl alcohol structure” By Хорев Сергей – Own work (Public Domain) via Commons Wikimedia
2. “Fatty alcohol – generic” By Edgar181 – Own work (Public Domain) via Commons Wikimedia