文摘
Finding sustainable and commercially viable sources of occlusive materials, as an alternative to petroleum, is of great interest. Inspired by the fundamental role of long chain fatty acids in maintaining skin barrier, ultralong fatty acyl derivatives with diverse structures (varied acyl chain length and different polar head; i.e. glycerol, ethylene glycol, and diethylene glycol) were synthesized. These molecules can be feasibly obtained via enzymatic esterification of fatty acids or fractionated from commercial glycerides mixture via short path distillation. The molecular packing behaviors of compounds were characterized via differential scanning calorimetry, Fourier transform infrared, and Langmuir isotherm measurements. The structure–property relationship study reveals that a glycerol molecule monoacylated with an ultralong fatty acyl is the derivative which entails the most occlusive properties of the series of ultralong chain fatty acid derivatives. Fast Fourier transform filtering (FFTF) analysis of atomic force microscopy images verified a homogeneous monolayer packing of glyceryl monobehenate monolayer, and the water vapor transmission study demonstrated that the formulation of glyceryl monobehenate at 3% w/w in a phospholipid-containing emulsion generates an occlusive film significantly superior to a 3% w/w petrolatum formulation. This work demonstrated that natural glyceryl monobehenate can be a novel source of sustainable occlusive structuring agents and green replacements for petrolatum.