| Popis: |
Equilibrium vapour pressures of six saturated and seventy-four mono-unsaturated C10-C16 even-carbon aldehydes were determined using a method based on gas chromatographic (GC) retention data. GC measurements were carried out on a 3-m HP-1 capillary column at five to seven temperatures in the range of 35–140 °C by utilising saturated n-12,n-13, n-17 and n-18 hydrocarbons as vapour pressure reference standards. A close correlation, viz. In P [Pa] = 14.008 - 1.105nc (r = 0.99%) has been found between the vapour pressures P and the number of carbon atoms (nc), indicating a vapour pressure decrease by a factor of 3.02 for each CH2 group added in the alkanal chain. For structurally similar subseries of alkenals (ω−3, ω−5 and ω−7 unsaturation), the vapour pressures were also shown to have a simple dependence on nc. Within each alkenal subseries, isomers having Z-configuration had mostly greater vapour pressures than their E-counterparts. |
