The thermal degradation of two Polyhedral Oligomeric Silsesquioxane/Polystyrene (POSS/PS) nanocomposites of formula R8(SiO1.5)8 POSS/PS and R’1R7(SiO1.5)8 POSS/PS (where R’ = Phenyl and R = Cyclopentyl), at 5% of POSS concentration, was studied in both inert (flowing nitrogen) and oxidative (static air) atmospheres. Compounds were prepared by the polymerization of styrene in the presence of POSS. Degradations were carried out into a thermobalance, in the scanning mode, at various heating rates, and the obtained thermogravimetric (TG) curves were discussed and interpreted. The initial decomposition temperature (Ti), the temperature at 5% mass loss (T5%), the glass transition temperature (Tg) and the activation energy (Ea) of degradation of nanocomposites were determined and compared with each other and with those of unfilled Polystyrene (PS). The Ti, T5% and degradation Ea values of nanocomposites were higher than those of neat PS, thus indicating a better heat resistance and lower degradation rate, and then a better overall thermal stability. The nanocomposite obtained by using of POSS with symmetric structure showed a worst Tg value not only than that obtained from asymmetric POSS but also than that of polystyrene thus suggesting an influence of filler structure in the thermal properties of the materials.
|Titolo:||Influence of symmetry/asymmetry of the nanoparticles structure on the thermal stability of Polyhedral Oligomeric Silsesquioxane (POSS)/Polystyrene (PS) nanocomposites|
|Data di pubblicazione:||2012|
|Appare nelle tipologie:||1.1 Articolo in rivista|