A kinetic study of the thermal and thermal oxidative degradations of new bridged POSS/PS nanocomposites.

The thermal degradation of a series of three novel bridged polyhedral oligomeric silsesquioxanes (POSS)/polystyrene (PS) nanocomposites, at different POSS content (3%, 5% and 10%), was studied in both inert(flowing nitrogen) and oxidative (static air) atmospheres, in order to investigate the effects of this newdumbbell-shaped structure on the fillerepolymer interaction and then on the thermal stability of theobtained materials. Nanocomposites were synthesized by in situ polymerization of styrene in thepresence 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 1H NMR spectroscopy.Scanning electron microscopy (SEM) and FTIR spectroscopy evidenced the presence of fillerepolymerinteractions. Degradations were carried out into a thermobalance, in the scanning mode, at variousheating rates, and the characteristic parameters of thermal stability, namely temperature at 5% mass loss(T5%) and the activation energy (Ea) of degradation, of the various nanocomposites were determined. Theresults were discussed and interpreted.