KINETICS AND MECHANISM OF THE PYROLYSIS OF 1-CHLORO-1,1-DIFLUOROETHANE IN THE PRESENCE OF ADDITIVES

The thermal dehydrochlorination CF2ClCH3 --> CF2=CH2 + HCl has been st udied in a static system between 597 and 664 K in the presence of CCl4 , C2Cl6, CF2=CH2, HCl, and CF3CH3. A kinetic radical and molecular rea ction model has been developed. in addition to describing earlier resu lts on the acceleration of the pyrolysis by CCl4 and the further accel eration by HCl, this model describes quantitatively up to conversions of 20% (i) the dependence of the catalytic effect of CCl4 at low conce ntrations, (ii) the stronger catalytic effect of C2Cl6, and (iii) the inhibitory effect of added CF2CH2 and CF3CH3 when CCl4 is used as a ca talyst. (C) 1998 John Wiley & Sons, Inc.