Six polyhedral oligomeric silsesquioxanes (POSSs)with general formula R7 R01 (SiO1.5)8, where R- was anisobutyl group and R0- a variously substituted phenyl group,namely hepta isobutyl polyhedral oligomeric silsesquioxane(hib-POSS), were prepared and their composition waschecked by elemental analysis and 1H NMR spectroscopy.The degradation of compounds obtained was studied bysimultaneous differential thermal analysis/thermogravimetry(DTA/TG) technique, in both inert (flowing nitrogen) andoxidative (static air atmosphere) environments, in order todraw useful information about their thermal stability. Experiments,performed in the 35–700 C temperature range,showed different behaviour between the two used atmospheres.The formation of volatile compounds only, with anabout complete mass loss, was observed under nitrogen,while a solid residue (&40–50% in every case), due to theformation of SiO2, as indicated by the FTIR spectra, wasobtained in static air atmosphere. The results obtained werediscussed and compared, and the classifications of resistanceto thermal degradation in the studied environments weremade. A comparison between the thermal stabilities of hib-POSSs and analogous cyclopentyl POSSs previously studiedwas also performed.
Hepta isobutyl polyhedral oligomeric silsesquioxanes (hib-POSS) A thermal degradation study
I. BLANCO;L. ABATE;F. A. BOTTINO;P. BOTTINO
2012-01-01
Abstract
Six polyhedral oligomeric silsesquioxanes (POSSs)with general formula R7 R01 (SiO1.5)8, where R- was anisobutyl group and R0- a variously substituted phenyl group,namely hepta isobutyl polyhedral oligomeric silsesquioxane(hib-POSS), were prepared and their composition waschecked by elemental analysis and 1H NMR spectroscopy.The degradation of compounds obtained was studied bysimultaneous differential thermal analysis/thermogravimetry(DTA/TG) technique, in both inert (flowing nitrogen) andoxidative (static air atmosphere) environments, in order todraw useful information about their thermal stability. Experiments,performed in the 35–700 C temperature range,showed different behaviour between the two used atmospheres.The formation of volatile compounds only, with anabout complete mass loss, was observed under nitrogen,while a solid residue (&40–50% in every case), due to theformation of SiO2, as indicated by the FTIR spectra, wasobtained in static air atmosphere. The results obtained werediscussed and compared, and the classifications of resistanceto thermal degradation in the studied environments weremade. A comparison between the thermal stabilities of hib-POSSs and analogous cyclopentyl POSSs previously studiedwas also performed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
