Synthesis and characterization of three kinds of bifunctionalized polyhedral oligomeric silsesquioxanes with the same cage structure

A facile, single-step synthetic pathway leading to bifunctionalized polyhedral oligomeric silsesquioxanes (POSS) with two different reactive functional groups attached to the same cage structure, namely Vi-Cl POSS, is reported in this paper. The Vi-Cl POSS were synthesized through the cohydrolysis and cocondensation of (3-chloropropyl)trimethoxysilane, vinyltrimethoxysilane and propyltrimethoxysilane in ethanol media under acidic conditions, the number of vinyls and chloropropyls which attached to cage structure can be controlled by the monomers feed ratio of three kinds of trialk-oxysilanes. In this method, three different bifunctional polyhedral oligomeric silsesquioxanes were synthesized, including [Si8O12 (CH-CH2)(C3H6Cl)(2)(C3H7)(5)] (POSS1), [Si8O12(CH-CH2)(2)(C3H6Cl)(C3H7)(5)] (POSS2) and [Si8O12(CH-CH2)(C3H6Cl)(C3H7)(6)] (POSS3). Due to the reactive functional groups attached to the cage, these specific bifunctional polyhedral oligomeric silsesquioxanes can be copolymerized with other organic monomers by free radical polymerization, hydrosilylation reactions and atom transfer radical polymerization to obtain organic-inorganic hybrid nanocomposites, respectively. The outstanding advantage of cohydrolysis-cocondensation routes is that the substitution pattern of different substituents around the POSS cage can be precisely controlled.