TY - JOUR
T1 - Modification of perhydropolysilazane with aluminum hydride
T2 - Preparation of poly(aluminasilazane)s and their conversion into Si-Al-N-C ceramics
AU - Toyoda, Ryoji
AU - Kitaoka, Satoshi
AU - Sugahara, Yoshiyuki
PY - 2008
Y1 - 2008
N2 - Perhydropolysilazane (PHPS) was modified with trimethylamine-alane adduct, AlH3·NMe3, with two nominal Si/Al molar ratios (1 and 5), and the resulting poly(aluminasilazane)s were pyrolyzed under an N2 atmosphere. Poly(aluminasilazane) with a nominal Si/Al molar ratio of 5 (PAS5) was insoluble because of the formation of cross-link points via dehydrocoupling. In the system with a nominal Si/Al molar ratio of 1 (PAS1), on the contrary, AlH3·NMe3 cleaved the Si-N bonds in addition to forming Al-N bonds, drastically modifying the Si-N backbone of PHPS. In addition, a large portion of aluminium was lost in the PAS1 preparation. Thermogravimetric analysis revealed that PAS5 exhibited a ceramic yield of 78% up to 900 °C, while the ceramic yield for PAS1 was 61%. The XRD patterns of the pyrolyzed residues from PAS1 and PAS5 suggest the formation of a 2H wurtzite-type compound and silicon nitride.
AB - Perhydropolysilazane (PHPS) was modified with trimethylamine-alane adduct, AlH3·NMe3, with two nominal Si/Al molar ratios (1 and 5), and the resulting poly(aluminasilazane)s were pyrolyzed under an N2 atmosphere. Poly(aluminasilazane) with a nominal Si/Al molar ratio of 5 (PAS5) was insoluble because of the formation of cross-link points via dehydrocoupling. In the system with a nominal Si/Al molar ratio of 1 (PAS1), on the contrary, AlH3·NMe3 cleaved the Si-N bonds in addition to forming Al-N bonds, drastically modifying the Si-N backbone of PHPS. In addition, a large portion of aluminium was lost in the PAS1 preparation. Thermogravimetric analysis revealed that PAS5 exhibited a ceramic yield of 78% up to 900 °C, while the ceramic yield for PAS1 was 61%. The XRD patterns of the pyrolyzed residues from PAS1 and PAS5 suggest the formation of a 2H wurtzite-type compound and silicon nitride.
KW - Carbides
KW - Composites
KW - Nitrides
KW - Precursors-organic
KW - X-ray methods
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U2 - 10.1016/j.jeurceramsoc.2007.06.001
DO - 10.1016/j.jeurceramsoc.2007.06.001
M3 - Article
AN - SCOPUS:35448964656
VL - 28
SP - 271
EP - 277
JO - Journal of the European Ceramic Society
JF - Journal of the European Ceramic Society
SN - 0955-2219
IS - 1
ER -