Study On The Synthesis And Properties Of Multifunctional Polyhedral Oligomeric Silsesquioxane And Its Polymer Hybrid Materials

Ferrocenyl octasubstituted octakis(dimethylsiloxy)octasilsesquio -xanes was synthesized via the hydrosilylation reaction of vinylferrocene with octakis(hydrodimethylsiloxy)octasilsesquioxane, catalyzed by Karstedt's catalyst. The synthesized compound was characterized by FTIR, ¹H-, ²⁹Si-NMR and its structure was certified.Reaction of ferrocenecarboxaldehyde with octa(aminophenyl)silsesquiox -ane(OAPS) in ethanol and tetrahydrofiiran solution gave new ferrocenyl disubstituted POSS. The synthesized compound was characterized by FTIR, UV, ²⁹Si- NMR, GPC and its structure was certified. On the basis of above research, POSS3- acrylate emulsion of various organosiloxane content was synthesized by a semi-continuous polymerization. DSC date showed the thermal stabilities had been improved. The POSS3- acrylate emulsion also displayed much higher glass transition temperatures (Tg) in comparison with neat acrylate emulsion. when POSS3 content was 3wt%, Tg was increased distinctly. Viscoelastic properties of POSS-acrylate emulsion were investigated by DMTA. The results showed the storage modulus (E') values were increased when POSS3 content was up to 3wt%. TEM and SEM studies indicated that POSS3 was completely dispersed in acrylate emulsion matrix when 1 wt% POSS1 was introduced, while some POSS3-rich nanoparticals were present when content of POSS3 was beyond 3 wt %.We synthesized disubstituted POSS precursor in one chain, the incompletely condensed silsesquioxane (cyclo-C₅H₉)₇Si₇O₉(OH)₃ was prepared in good yield by Feher's method. The reaction between (cyclo-C₅H₉)₇Si₇O₉(OH)₃, 4-chlorobenzyl trichlorosilane and excess pyridine in dry THF gave the corner-capped product, and then reaction with 2,5-dimethylphenol.