Thermal Characterization of a Series of Novel Hepta Cyclopentyl Bridged POSS/PS Nanocomposites

A series of novel hepta cyclopentyl bridgedpolyhedral oligomeric silsesquioxanes (POSSs)/polystyrene(PS) nanocomposites, at different POSS contents(1, 3 and 5 % w/w), was synthesized and characterized.Nanocomposites were prepared by in situ polymerizationof styrene in the presence of POSS which has not polymerizablegroups, aiming to obtain well-dispersed POSS/PS systems. The actual filler concentration in the obtainednanocomposites was checked by 1H NMR and FTIRspectroscopy. Degradations were carried out into a thermobalanceat various heating rates in flowing nitrogen andin a static air atmosphere, and the characteristic parametersof thermal stability, namely temperature at 5 % mass loss(T5 %) and activation energy (Ea) of degradation, of thevarious nanocomposites were determined. We investigatedthe influence of the nature of POSSs cage’s periphery onthe thermal stability of the obtained materials, and with thisaim, we compared the properties of hepta cyclopentylbridged POSS/PS nanocomposites with those of similarhepta isobutyl bridged POSS/PS ones previously studied.The obtained results were discussed and interpreted.