Thermal characterization of a series of novel hepta cyclopentyl bridged POSS/PS nanocomposites

A series of novel hepta cyclopentyl bridged polyhedral 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 polymerization of styrene in the presence of POSS which has not polymerizable groups, aiming to obtain well-dispersed POSS/PS systems. The actual filler concentration in the obtained nanocomposites was checked by (1) H NMR and FTIR spectroscopy. Degradations were carried out into a thermobalance at various heating rates in flowing nitrogen and in a static air atmosphere, and the characteristic parameters of thermal stability, namely temperature at 5 % mass loss (T (5 %)) and activation energy (E (a)) of degradation, of the various nanocomposites were determined. We investigated the influence of the nature of POSSs cage's periphery on the thermal stability of the obtained materials, and with this aim, we compared the properties of hepta cyclopentyl bridged POSS/PS nanocomposites with those of similar hepta isobutyl bridged POSS/PS ones previously studied. The obtained results were discussed and interpreted.