Preceramic polymer as precursor for near‐stoichiometric silicon carbon with high ceramic yield |
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| Authors: | Xi Qian Quan Zhou LiZhong Ni |
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| Affiliation: | Key Laboratory for Special Functional Polymer Materials and Related Technology of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai, People's Republic of China |
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| Abstract: | Precursor polycarbosilane containing acetylenic and Si? H group (PCAS) has been successfully prepared by the reaction of dilithioacetylene with methyl dichlorosilane, and characterized by gel permeation chromatography, Fourier transform infrared spectroscopy, 1H‐NMR, 13C‐NMR, and 29Si‐NMR. Thermogravimetric analysis curve in nitrogen showed the temperature of 5 wt % weight losses (Td5) was 613°C, while the ceramic yield of PCAS was 88% at 1000°C. Pyrolysis behavior and structure evolution of the cured PCAS were studied by means of X‐ray diffraction, Raman, scanning electron microscope‐energy dispersive X‐ray spectrometer, transmission electron microscope (selected area electron diffraction and high resolution transmission electron microscope), and elemental analysis. The polymer to ceramic conversion was completed at 1600°C and the results revealed that the ceramic consisted of β‐SiC and α‐SiC. The composition of the ceramic was near‐stoichiometric with molar ratio of Si/C (1.02 : 1) except rare and localized free carbon inclusions. The SiC ceramics exhibited high thermo‐oxidation resistance at elevated temperatures in air atmosphere. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41335. |
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| Keywords: | applications microscopy thermogravimetric analysis TGA thermosets X‐ray |
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