Collection of Czechoslovak Chemical Communications - digital archive 

Abstract

A simple computational method has been developed to determine vapor pressures of pheromone-like acetates, This input parameters required, i.e. critical temperatures and critical pressures are obtained from the known molecular structures by using group contribution methods. Subsequently, the vapor pressures are estimated by the three parameter corresponding states equation of Lee and Kesler. The validity of this approach was tested on a homogeneous experimental material (eleven C₁₀ to C₁₆ acetates) by standard methods of statistical analysis, as well as by comparison of the results with corresponding experimental data. When compared with GC based experimental values, the estimated vapor pressures show mean relative error ±10%, achieving thus a better accuracy than other experimental methods when compared among themselves. A close correlation, viz. In t_1/2 = -0.294 In P + 1.82 (r = 0.9986) has been found between first order half-lives for evaporative loss of acetates from rubber septa and calculated vapor pressures.