Is Isopropyl Myristate natural?

Coconut or palm-kernel myristic acid esterified with petrochemical isopropanol.

The industrial synthesis of Isopropyl Myristate involves the esterification of myristic acid with isopropanol. Myristic acid, a saturated fatty acid with a 14-carbon chain (C14:0), is obtained by splitting and distilling coconut or palm-kernel oil, so that part of the molecule is natural origin. Isopropanol is a petrochemical, made by hydrating propylene; it supplies the only petrochemical fragment.

The esterification reaction is typically carried out under acidic catalysis. Common catalysts include sulfuric acid (H2SO4) or p-toluenesulfonic acid (PTSA). The reaction proceeds via a Fischer esterification mechanism, where the carboxylic acid group of myristic acid reacts with the hydroxyl group of isopropanol, eliminating a molecule of water to form the ester bond.

Reaction conditions usually involve heating the mixture of myristic acid and isopropanol in the presence of the acid catalyst. Temperatures typically range from 100°C to 150°C, depending on the specific catalyst and desired reaction rate. The reaction is often performed under reflux to maintain a constant temperature and prevent the loss of volatile reactants. To drive the equilibrium towards ester formation, water produced during the reaction is continuously removed, often by azeotropic distillation.

Following the esterification, the crude Isopropyl Myristate undergoes several purification steps. These typically include neutralization of the acid catalyst, washing with water to remove residual salts and unreacted alcohol, and drying. Further purification may involve distillation under reduced pressure to remove any unreacted myristic acid or other byproducts, ensuring a high purity product suitable for cosmetic applications. The final product is a clear, colorless liquid with a light, non-greasy feel.

Isopropyl Myristate is a common ingredient found in many skincare and cosmetic products, acting primarily as an emollient. Its main job is to soften and smooth the skin by forming a light, non-greasy film on the surface. This helps to reduce water loss from the skin, keeping it hydrated and supple, and also gives products a pleasant, silky feel.

Chemically, it's an ester, which means it's formed by combining an acid and an alcohol. In this case, it's made from myristic acid (a fatty acid) and isopropyl alcohol. The myristic acid comes from coconut or palm-kernel oil, while the isopropyl alcohol is made from petroleum. By weight that makes it about four-fifths natural origin, which is why it scores 0.78.