Research progress in preparation of functionalized polyhedral oligomeric silsesquioxanes

As a series of novel organic/inorganic hybrid nanomaterials, nanostructured POSS (polyhedral oligomeric silsesquioxanes) particles are one of the best choices for molecular structure design and modification owing to their fascinating physical and chemical properties. The preparation of functionalized POSS has attracted widespread attention, and it is of major academic significance to investigate the synthesis methods and reaction mechanism in depth. The development process and structural characteristics of POSS were summarized and the synthesis methods of functionalized POSS commonly used in polymer modification were reviewed in this paper, including silane hydrolysis/condensation reactions, functional group transformation derivation method and corner-capping reactions. The nanomaterials investigated in this review include methylacryloxypropanyl-POSS, vinyl-POSS, amino-POSS, epoxy-POSS, hydroxyl-POSS and partial mono-functional POSS. Finally, the influencing factors of these methods were discussed and the domestic research on functionalized POSS was prospected : the future research will focus on the further clarification of the synthesis mechanism and the stability of the existing processes for reducing the cost based on the improvement of the yield and providing technical support for industrial production; likewise, the introduction of functional groups can be precisely designed to prepare additional up-to-date reactive POSS.