Wber die Synthese nichtionogener grenzfladknaktiver N-n-Alkylcarbamidsaure-D,L-manit-mono-und di-ester aus D,L-Mannit und n-Alkylisocyanaten der Kettenlange C,, C , 'und C,, wird beridtet. Die Konstitution dieser Ester wird ermittelt; ferner werden ihre Eigenschaften beschrieben und die Oberflachenspannungen ihrer waDrigen Losungen verschiedener Konzentrationen bei 750 C gemessen. Auf die betrachtliche Oberfllcbenaktivitat dieser Substanzen in LuDerst geringer Konzentration wird hingewiesen.Surface-Active Polyhydroxy-Compounds XVIII: Conversion of D,L-Mannitol with n-Octyl-, n-Decyl-and n-Dodecyl-Isocyanate to Electro-Neutral Surface-Active UrethanesThe synthesis of nonionic surface-active mono-and diesters of D,L-mannitol and N-n-alkyl-carbamic acid from D,L-mannitol and n-alkyl-isocyanates of chain-length C,, C,, and C,, is reported. The constitution of these esters is established and their properties are reported along with the surface tension of their aqueous solutions of various concentrations, measured at 75, C. The considerable surface activity of these substances in. extremely small concentrations is pointed out.