Thermal decomposition studies of the polyhedral oligomeric silsesquioxane, POSSh, and when it is impregnated with the metallocene bis(eta5-cyclopentadienyl)zirconium (IV) dichloride or immobilized on silica.
Thermal decomposition studies of the free polyhedral oligomeric silsesquioxane, POSSh, and when this compound has been impregnated with Cp2ZrCl2 (Cp = eta5-C5H5) or immobilized on SiO2 were conducted using infrared emission spectroscopy (IES) over a 100-1000 degrees C temperature range and by thermogravimetric analysis (TGA). The organic groups in POSS(h) apparently decompose thermally into Si-CH3, Si-H and other fragments. Upon impregnation with Cp2ZrCl2, however, a different thermal decomposition pathway was followed and new infrared emission bands appeared in the 1000-900 cm(-1) region suggesting the formation of Si-O-Zr moieties. When immobilized on SiO2 and subjected to thermal decomposition, the POSSh compound lost its organic groups and the inorganic structure remaining was incorporated into the SiO2 framework.
Bianchini
D
D
Universidade Federal do Rio Grande do Sul, Instituto de Química, Av. Bento Gonçalves 9500, 91501-970 Porto Alegre, Rio Grande do Sul, Brazil.
Butler
I S
IS
Barsan
M M
MM
Martens
W
W
Frost
R L
RL
Galland
G B
GB
dos Santos
J H Z
JH
D002384:Catalysis; D002621:Chemistry / Q000379:methods; D006358:Hot Temperature; D008956:Models, Chemical; D009942:Organometallic Compounds / Q000737:chemistry*; D017646:Organosilicon Compounds / Q000737:chemistry; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*; D013053:Spectrophotometry / Q000379:methods*; D013055:Spectrophotometry, Infrared / Q000379:methods; D013696:Temperature; D013818:Thermogravimetry / Q000379:methods
D009942:Organometallic Compounds; D017646:Organosilicon Compounds; D000644:Quaternary Ammonium Compounds; C526672:bis(eta(5)-cyclopentadienyl)zirconium(IV) dichloride; C018408:3-(trimethoxysilyl)propyldimethyloctadecylammonium; D012822:Silicon Dioxide