Аннотация:Organosoluble polyimides with tetramethyldisiloxane fragments in the main chain were synthesized by one-step high-temperature polycondensation and their properties were studied. Heat resistant polymers (Tg = 195—240 С, T10% = 420—490 С) were tested as protective coatings for quartz optical fi bers. The new developed coatings have high thermal (72 h at 300 С) and hydrolytic stability.