High temperature kinetics of the thermal decomposition of the lower alkanoic acids

The thermal decomposition of propanoic acid dilute in argon has beenstudied in a single‐pulse shock tube over the temperature range of 1100‐1500 K and over the pressure range of 14‐18 atm. The decomposition kinetics have been satisfactorily computer modelled by means of afree radical mechanism involving H and OH chains. Recent single‐pulse shock tube product analyses of acetic acid decomposition have been computer modelled using a free radical mechanism for decarboxylation coupled to a unimolecular dehydration reaction. A comparison between the thermal decomposition kinetics of the C1C3 alkanoic acids is made. The present studies do notprovide evidence for the participation of transition states involving a pentavalent carbon atom in the pyrolyses of the lower alkanoic acids.