TAB LE 2 Dialkylmethylamine Oxides: Selected Typical Physical Properties I Summary
Carbon number of alkyl group present: C 10' C10 C10 ' CIS'
Solution property Active molecular weight 327 201 313
Solvent present Water Water Water
Viscosity cp at 25°C 456 13.9 Solid cp at 50°C 56.3 6.2 11,000
Specific gravity at 25°C 0.9035 0.9733 Solid
Pour point (OF) 43 30 108
Flash point (OC) >100 >100 >100
Vapor pressures mmHg at 20°C 17.3 24.4 mmHg at 50°C 78.8
Aliphatic amine oxides most often are utilized as about 30% aqueous solutions, although occasionally they are prepared in alcohol (ethanol, isopropyl alcohol, etc.) solutions at greater (about 70%) concentrations. In this fashion, these oxides are fluid, readily pourable materials. At increased concentrations, however, at moderate temperatures these surfactant systems form intractable aqueous gels that pose special handling difficulties.