THERMAL STUDIES OF ORGANOZINC FILMS .11.

The thermal stability of organozinc films was studied by thermogravime tric analysis (TGA) between 25 and 550-degrees-C min-1. The decomposit ion temperatures were obtained from the maximum of the first derivativ es of the TG curve. The kinetic parameters of the thermal decompositio n were determined by the Arrhenius equation. All the films degraded in one step with a very small weight loss. Films prepared with toluene a nd THF exhibit higher weight losses, 23.77% and 12.48%, respectively, and zinc-2-propanol film is the most stable (1.11% weight loss). The v ariation in thermal stability is discussed in relation to the various solvents used and comparisons are made with the results reported for P d, Ge and In organo films. For organozinc films, the stability decreas es for the solvents used in the order: dimethyl sulphoxide (DMSO), iso butyl methyl ketone, 2-butanone, ethanol, 2-propanol, acetone, dimethy lformamide (DMF), tetrahydrofuran (THF). The activation energies of th e thermal degradation are comparable with those for organo-Pd films. T he order of reaction for the thermal decomposition of organozinc films was found to be -0.5 for most of them, with films prepared from ethan ol and toluene having zero reaction order. The pre-exponential factor, the reaction order and the activation energy of the decomposition for organozinc films have been determined for most of the solvents.