A novel three-cages POSS molecule: synthesis and thermal behaviour

Two novel 4-methyl phenyl (trioxyisobutyl POSS) silane and 4-methyl phenyl (trioxycyclopentyl POSS) silane were synthesized. The nanosystems were characterized by elemental analysis, 1 H NMR and FTIR spectroscopy, in order to verify that the obtained products were those we would prepare. The spectroscopic results were in very good agreement with those expected. The synthesized POSSs were thermally characterized, by the means of thermogravimetric (TGA) and differential scanning calorimetry analyses. TGA was carried out in dynamic heating conditions (25–700 °C), in both flowing nitrogen and static air atmosphere. The temperatures at 5% mass loss ( T 5% ), determined to evaluate their thermal stability, evidenced a better behaviour in inert environment. The obtained T 5% values were much higher for cyclopentyl POSSs and then for isobutyl ones, suggesting a fundamental role of organic group dimensions at the periphery of the synthesized systems, on the thermal properties. The residue at 700 °C, which were also investigated by FTIR spectroscopy, was a further confirmation of the better thermal stability of these novel nanoparticles.