Synthesis And Characterization Of POSS-Containing Crosslinked Polymer

Polyhedral oligosilsesquioxanes (POSS) consists of a well-defined cluster with an inorganic silica-like core (SiO_1.5)n surrounded by eight organic corner group (functional or inert). POSS-based polymeric materials have excellent thermal properties relative to polymeric materials, so they have attracted great interest of many researchers recently. Because of their unique performance in the field of catalyst, micro- and meso-porous and low dielectric materials, the crosslinked polymers containing POSS are becoming a focus of research. Series of crosslinked polymers containing POSS were synthesized in this thesis. The main contents are as follows:(1) The preparation of different POSS molecules containing multiple functional groups and the development of polyhedral oligomeric silsesquioxanes(POSS) was reviewed and their synthesis methods and the applications were discussed.(2) A kind of POSS molecule (T₈H₈) with multiple functional groups and three organic compounds that contain different structures with double bond in the molecular end were synthesized and their structures were characterized by FTIR, NMR, element analysis.(3) The crosslinked polymers containing POSS were prepared by hydrosilycation between organic compounds and the multifunctional POSS molecule, respectively, and the synthetic conditions were optimized and their structures were characterized by FTIR, ²⁹Si-NMR, and X-ray. The results show that their cross-link density can be controlled by altering the molar ratio of the organic compound to the POSS molecule. The thermal stabilities of the polymers were tested by TGA and it was found that the thermal properties of polymer were affected by crosslinking degree and increase with creasing the crosslinking degree.