Decyl palmitate is a saturated medium-chain wax ester formed by the esterification of palmitic acid (C16:0) with decyl alcohol (C10H21OH). It represents a shorter-chain member of the simple wax lipid series, prioritizing fluidity over structural rigidity. Derived from coconut or palm kernel fractions, this lightweight emollient provides rapid absorption and minimal occlusion, contrasting with longer homologs such as cetyl stearate or behenyl behenate.
Chemical Structure
Decyl palmitate has the molecular formula C26H52O2 and a molecular weight of 396.69 g/mol. Its linear ester structure —CH3(CH2)14COO(CH2)9CH3—contains 24 rotatable bonds, no hydrogen bond donors, a TPSA of 26.3 Ų, and an estimated LogP of ~12. These characteristics promote loose lamellar packing with high chain mobility, typical of the C10/C16 asymmetry.
Physical Properties
Decyl palmitate is a colorless viscous liquid to soft wax, with a melting point of approximately 30°C and a boiling point around 438.7°C. It has a density of about 0.86 g/cm³ and a refractive index of 1.451. Although insoluble in water, it exhibits excellent solubility in ethanol, oils, and chloroform. Its low viscosity (Sp.Gr. 0.87) and flash point of 225.6°C support cold processing, while its floral-green odor contributes to fragrance fixation.
Synthesis and Production
Decyl palmitate is typically produced through acid-catalyzed condensation of palmitic acid and 1-decanol obtained from coconut oil, followed by purification via distillation (EINECS 255-724-1). Enzymatic synthesis using CALB lipase offers an alternative route, achieving >99% purity from sustainable feedstocks.
