New silicon-organic polyepoxides containing epoxy side groups attached to their main chains have been synthesised by hydride addition (hydrosilylation) of dihydrosiloxanes with the diallyl ether of an epoxidised glycerol group situated at the tertiary carbon atom. General features of the reaction were studied and its kinetic rate constants and reaction order determined. The relative reactivities of various dihydridesiloxanes in the hydrosilylation reaction were determined. The modification of the polyepoxides introduced chelates containing Cu, Ni, Mn and Co atoms into the main chain. The composition and structure of the synthesised polymers were established from elemental, IR and NMR spectral analyses and from DSC, DTA and TGA data. It was established that the glass transition temperature (T) and thermo-oxidative stability of the chelate-containing polymers considerably exceeded those of the unmodified polyepoxides. [ABSTRACT FROM AUTHOR]