Chemistry of leaf waxes in relation to wetting

Abstract

Abstract The hydrophobic property of waxes depends upon their chemical constitution and almost certainly upon the orientation of molecules of their constituents. Contact angles of the most important classes of constituent range from 94° to 109°. No class of constituent is very water‐repellent; alkenes are the most hydrophobic but esters, ketones and secondary alcohols are almost as hydrophobic. Waxes containing large amounts of alkanes are the least wet table. the least hydrophobic classes are α‐ω‐diols, sterols and triterpenoids. the wettability of wax constituents increases with an increase in polarity especially as a result of terminal substitution of the aliphatic molecule or a cyclic structure.