Synthesis and Characterization of Differently Substituted Phenyl Hepta Isobutyl-Polyhedral Oligomeric Silsesquioxane/Polystyrene Nanocomposites

Variously substituted polyhedral oligomeric silsesquioxanes (POSSs)/polystyrene (PS) nanocomposites of general formula R7R(SiO1.5)(8)/PS (where R=isobutyl and R=4-methoxyphenyl, 4-methylphenyl, 3,5-dimethylphenyl, 4-fluorophenyl, 2,4-difluorophenyl, 4-chlorophenyl) were prepared by in situ polymerization of styrene in the presence of 5% w/w of POSS. The actual filler concentration in the obtained nanocomposites was checked by H-1 NMR spectroscopy. Scanning electron microscopy and FTIR spectroscopy evidenced the presence of filler-polymer interactions. Inherent viscosity ((inh)) determinations indicated that the average molar mass of polymer in halogenated derivatives was lower than neat PS, and were in agreement with calorimetric glass transition temperature (T-g) measurements. Finally, a comparative study concerning the thermal stability of synthesized nanocomposites was carried out in both inert (flowing nitrogen) and oxidative (static air) atmospheres into a thermobalance, in the scanning mode, at 10 degrees C min(-1), and the temperatures at 5% mass loss (T-5%), of various compounds were determined. The results were discussed and interpreted. POLYM. COMPOS., 35:151-157, 2014. (c) 2013 Society of Plastics Engineers