HYDROLYTIC STABILITY OF AROMATIC POLYIMIDE FILMS: IMPACT OF CHEMICAL STRUCTURE OF POLYMER

The hydrolytic stability of aromatic polyimide films in concentrated alkali solutions is studied. The problem definition: to precise the possibilities of optimization of the hydrolytic stability of these materials by varying their chemical composition. The poly(pyromellite)imide films are characterized by the stability essentially lower, in comparison with polynuclear polyimide. Mechanical properties of the last are stable during 1000 hours of hydrolysis. The long hydrolysis duration provokes the increase of glass transition temperature and decrease in thermal stability of the material.