Please use this identifier to cite or link to this item: https://hdl.handle.net/11147/7816
Title: Processing and thermal characterization of polymer derived SiCN(O) and SiOC reticulated foams
Authors: Santhosh, Balanand
Ahmetoğlu, Çekdar Vakıf
Ionescu, Emanuel
Reitz, Emanuel
Albert, Barbara
Sorarù, Gian Domenico
Ahmetoğlu, Çekdar Vakıf
Keywords: Foams
Polymer derived ceramic
SiCN(O)
SiOC
Thermal conductivity
Issue Date: 2020
Publisher: Elsevier Ltd.
Abstract: Highly porous polymer-derived SiCN(O) and SiOC ceramics with low thermal conductivity were developed by replicating polyurethane (PU) foams. The PU templates were impregnated with polysilazane or polysiloxane precursor, followed by pyrolysis at different temperatures (1200 °C - 1500 °C) yielding SiCN(O) or SiOC ceramic foams, respectively. The swelling and cross-linking behavior of the used precursors had a significant impact on the morphology of the prepared foams. The samples had bulk densities ranging from 0.03 g.cm-3 to 0.56 g.cm-3 and a total porosity in the range from 75 to 98 vol%. Fourier transform infrared (FT-IR), Raman spectroscopy, X-ray diffraction (XRD) were employed to follow the structural evolution together with morphological characterization by scanning electron microscopy (SEM). The obtained ceramics were thermally stable up to 1400 °C, and the linear thermal expansion coefficient values of the porous SiCN(O) and SiOC components in the temperature range from 30 to 850 °C were found to be ~1.72 x 10-6.K-1 and ~1.93 x 10-6.K-1, respectively. Thermal conductivity (?) as low as 0.03 W.m-1 K-1 was measured for the SiCN(O) and SiOC foams at room temperature (RT). The ? of the ceramic struts were also assessed by using the Gibson-Ashby model and estimated to be 2.1 W.m-1 K-1 for SiCN(O), and 1.8 W.m-1 K-1 for SiOC. © 2019 Elsevier Ltd and Techna Group S.r.l.
URI: https://doi.org/10.1016/j.ceramint.2019.11.003
https://hdl.handle.net/11147/7816
ISSN: 0272-8842
Appears in Collections:Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

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