| Abstract: | This study covers the results of synthesis and investigation of thermal stabilities of several organometallosiloxanes and organometal compounds containing Group IV elements. Investigations indicate, in general, that heat resistance is related to the dissociation energies of the M? O bonds, the number of organic groups connected to the metal atom, and the structure of the molecule as a whole. More specifically, the substitution of Ge? O and Sn? O bonds for some Si? O linkages in organosiloxanes produces a reduction in heat stability. The influence of the Ge? O bond to decrease the resistance of siloxanes is less than that of the Sn? O linkage; an increase in the number of Sn? O linkages producing a corresponding decrease in heat stability of the organosiloxane. The resistances of the germoxysiloxanes to heat degradation are less than that which would be expected from indications given by the relative stabilities of more simple organometallic compounds. |
