Abstract: New organo-organosiloxanes (MOS) were synthesized by hydrosilylation of acetylacetonates Ti(IV), Zr(IV), Hf(IV), V(IV) α,ω–
dihydrooligodimethylsiloxane. The reaction products were studied by DTGA and IR-spectroscopy. The effect of the obtained
metallosiloxanes on the thermal stability of composites based on low molecular weight polydimethylsiloxane rubber containing
various types of reinforcing fillers is investigated. It was revealed that the introduction of MOS additives in the amount of 7.
(kg of mixture) increases the time of the beginning of gelation of the compound based on polydimethylsiloxane rubber from 5 to 54
hours at 2500C. In addition, silicone vulcanizates have increased resistance to the processes of thermal oxidative degradation, after
prolonged temperature exposure, rubber samples retain satisfactory physical and mechanical properties. Organosilicon liquids
modified with synthesized thermostabilizers have high dielectric characteristics and thermal stability in the temperature range from
25 to 2700C. The synthesized MOS are soluble in polyorganosiloxanes, which makes it possible to evenly distribute small amounts of
the modifier in the polymer. The presence of metal thermostabilizers in macromolecules with a high coordination stability makes it
possible to actively inactivate free radicals in a wide temperature range. The resulting filled silicone vulcanizates can be used as heatresistant cable insulation, high-temperature sealants, and organosilicon liquids modified by MOS as an analogue of mineral oils for
Index terms: polyorganosiloxanes, thermostabilizers, destruction, liquid dielectrics, rubbers.