Octakis(ethynyldimethylsiloxy) silsesquioxane: Synthesis and application in poly(silicane arylacetylene) resin

Octakis(ethynyldimethylsiloxy)silsesquioxane (OEMS) was first synthesized via hydrolysis condensation reaction between tetramethylammonium octaanion and ethynyldimethylchlorosilane, and characterized by FT-IR, NMR, and GPC methods. A series of OEMS modified poly(silicane arylacetylene) resins (OEMS-PSAs) were prepared from OEMS and poly(silicane arylacetylene) (PSA). TEM analysis of the OEMS-PSAs confirms that the nano-sized polyhedral oligomeric silsesquioxanes (POSS) are dispersed evenly in low content, but aggregated unregularly in high content in OEMS-PSAs. The curing behavior of OEMS-PSAs was studied with DSC and FT-IR techniques. Nanoindentation test shows the incorporation of OEMS into PSA could decrease both of the elastic modulus and surface hardness of the PSA thermoset. The dielectric constants ((r)) of the OEMS-PSA thermosets approach to 2.1, depending on not only the content of POSS but also the dispersion of POSS. Furthermore, TGA results demonstrate the OEMS-PSA thermosets possess the certain thermo-oxidative resistance. (c) 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44158.