Synthesis And Application Of POSS/DDSQ Containing Carboxyl/Furfuran Groups

Polyhedral oligomeric silsesquioxanes (POSS) and double dekker silsesquioxanes (DDSQ) are kinds of nanoscale organic-inorganic hybrid materials in which skeleton structure is Si-O-Si. The POSS or DDSQ contain different reactive groups. POSS or DDSQ are not only used as modifiers to improve the performance of the polymeric materials but also can be used as monomers to prepare hybrid materials with excellent properties. Different types of POSS or DDSQ can be designed and prepared by means of reaction between POSS or DDSQ with different small molecule compounds. We can use a number of different types of POSS or DDSQ to enhance properties of some resins.Fristly, five kinds of bifunctional POSS or DDSQ monomers including di-carboxyl DDSQ, di-furfuran DDSQ, tetra-carboxyl DDSQ, tetra-furfuran DDSQ, di-furfuran-S-DDSQ were synthesized in this thesis. They were characterized by FT-IR, GPC, NMR, MALDI-TOF-MS, DSC, XRD, TGA and other means respectively.Secondly, five kinds of bifunctional POSS monomers including di-carboxyl POSS, octa-carboxyl POSS,16-carboxyl POSS, mono- furfuran amide- POSS, di- furfuran -amide POSS were prepared in this thesis. They were characterized by FT-IR, GPC, NMR, MALDI-TOF-MS, DSC, XRD, TGA and other means respectively.Lastly, We mixed bifunctional POSS with benzoxazine/bisoxazoline resins to obtain POSS modified thermosetting resins with excellent comprehensive properties. The curing mechanism of those systems was explored by FT-IR at different temperatures. The curing process and curing kinetics of the hybrid resins were studied by non-isothermal DSC. DMA and TGA were used to study the dynamic viscoelastic properties and thermal stability. The dispersion of bifunctional POSS or DDSQ in the composites was analyzed by SEM.