Organic–inorganic polyimides with double decker silsesquioxane in the main chains
In this contribution, we report a facile synthesis of a well-defined POSS diamine via the Heck reaction. First, 3,13-divinyloctaphenyl double decker silsesquioxane (3,13-divinyl DDSQ) was synthesized via the silylation reaction of octaphenyldicycloocatasiloxane tetrasodium silanolate with methylvinyldichlorosilane. Thereafter, the 3,13-divinyl DDSQ was reacted with 4-bromoaniline with a palladium catalyst. This POSS diamine (viz. 3,13-dianilino DDSQ) has been employed to synthesize the organic–inorganic polyimides with DDSQ in the main chains. Compared to the plain polyimide, the organic–inorganic hybrids displayed improved thermal stability and surface hydrophobicity. The dielectric analysis indicates that the dielectric constants of the organic–inorganic polyimides were significantly decreased with the inclusion of the DDSQ in the main chains whereas the dielectric loss of the polyimides remained almost unchanged.