Synthesis Of Polyhedral Oligomeric Silsesquioxane (POSS) And POSS/Polymer Composite Prepared By Atom Transfer Radical Polymerization (ATRP)

Four kinds of multifunctional polyhedral oligomeric silsesquioxane (POSS) were synthesized. The structures of POSS were characterized by FTIR, NMR, XRD and GPC, and then POSS/PMMA-PS block copolymer and star-shaped POSS/PMMA composite were prepared by atom transfer radical polymerization (ATRP). After the incorporation of POSS molecule, the thermal properties of composite were also studied. The main content of this dissertation is as follows.1. The synthesis of POSS and POSS/polymer composite were reviewed, and the thermal properties, mechanical properties, flame retardancy, oxidation resistance and dielectric properties were summarized after POSS molecule was introduced into polymers.2. Macroinitiator POSS/PMMA and the block copolymers POSS/PMMA-PS was prepared through ATRP. The structures of macroinitiator and block copolymer were characterized by FTIR, NMR, GPC and XPS, which showed the mono-dispersion of POSS, was achieved. The TGA investigation indicated that the thermal stability of polymer was improved.3. Using octa(γ-chloropropyl) POSS as a ATRP initiator, a star-shaped POSS/PMMA composite was synthesized. The well-defined structures of POSS/PMMA composite were fully characterized, which showed the mono-dispersion of POSS was achieved by ATRP. The TGA results indicated the thermal stability of POSS/PMMA composite enhanced from 281℃to 303℃with the increase of POSS content.