Portal de Periódicos da CAPES

Physical properties of aceto‐ and butyro‐oleins, mono‐olein, and diolein

1957; Wiley; Volume: 34; Issue: 5 Linguagem: Inglês

10.1007/bf02640258

1558-9331

Audrey T. Gros, R. O. Feuge,

Phase Equilibria and Thermodynamics

Summary A series of six oleoglycerides: 1,2‐diaceto‐3‐olein, 1,2‐dibutyro‐3‐olein, 1‐aceto‐3‐olein, 1‐butyro‐3‐olein, 1,3‐diolein, and 1‐mono‐olein, was prepared and purified, and some of their physical properties were determined. Data on densities and refractive indices of the compounds revealed that substitution of short‐chain acyl groups for one or both of the hydroxyl groups in 1‐mono‐olein increases the density and decreases the refractive index. The effect is more pronounced for the aceto than the butyro groups. By the capillary tube method, melting‐ and transition‐point data were determined for each glyceride. For the triglycerides, 1,2‐diaceto‐3‐olein and 1,2‐dibutyro‐3‐olein, one melting point and two transition points for each were found. For the diglycerides, 1‐aceto‐3‐olein and 1‐butyro‐3‐olein, two melting points and two transition points for each were found. Two melting points and one transition point each for 1,3‐diolein and 1‐mono‐olein were found. These melting and transition points were substantiated by heating‐curve data. Where possible, dilatometric measurements were made for the various polymorphic forms of the glycerides. From the data were calculated expansibilities in the solid and liquid states, melting dilations or volume changes accompanying transformations, and dilatometric melting points.