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Effect of anionic substitution on the high temperature stability of polymer‐derived SiOC glasses
Author(s) -
Sorarù Gian Domenico,
Girardini Katia,
Narisawa Masaki,
Biesuz Mattia
Publication year - 2021
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.17691
Subject(s) - crystallization , materials science , annealing (glass) , silsesquioxane , pyrolysis , chemical engineering , fourier transform infrared spectroscopy , carbothermic reaction , decomposition , infrared spectroscopy , inert gas , polymer , composite material , chemistry , organic chemistry , carbide , engineering
In this study the high temperature stability (crystallization and decomposition) of two silicon oxycarbide glasses with a similar amount of free carbon (8.3 vs 9.6 wt%) but different content of Si‐C bonds (SiC 0.22 O 1.57 vs SiC 0.07 O 1.86 ) is presented. The two SiOC glasses are obtained from the same precursor (2 µm methyl‐silsesquioxane spheres) via pyrolysis at 1100°C in inert (Ar) or reactive (CO 2 ) atmospheres. Further annealing in Ar flow at temperatures above 1100°C and up to 1500°C is performed and the samples are characterized by Fourier Transformed Infrared Spectroscopy (FT‐IR) and X‐ray diffraction (XRD). For comparison purposes the same precursor was annealed in air flow to obtain SiO 2 and its high temperature evolution is also studied. Results suggest that the onset for the carbothermal reduction is not dependent on the amount of Si‐C bonds. Moreover, contrary to what is usually reported in the scientific literature, silica phase present in the SiOC glasses does not show, in the same experimental conditions, superior crystallization resistance compared to pure silica glass.