1. Studies on the Pyrolysis Kinetic Behaviours of Polycarbosilan
- Author
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Ming Wei Chen, Jian Jiao, Shu Ya Gao, Xu Qian Li, Hai Peng Qiu, and Yu Wang
- Subjects
chemistry.chemical_classification ,Reaction mechanism ,Materials science ,Mechanical Engineering ,Activation energy ,Polymer ,Silane ,law.invention ,Amorphous solid ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Mechanics of Materials ,law ,Organic chemistry ,General Materials Science ,Thermal stability ,Crystallization ,Pyrolysis - Abstract
The pyrolysis kinetic behaviors and reaction mechanism of polycarbosilane (PCS) were characterized by means of XRD, SEM and on-line TG-DSC-FTIR-MS coupling technique, which showed that the pyrolysis process accorded with the F2 integral model (300-600°C), and the values of apparent activation energy (Ea) and pre-exponential factor (A) were 56.10KJ/mol and 10.84, respectively. During the pyrolysis process, PCS was converted into amorphous inorganic solid from organic polymer with breakage and rearrangement of chemical bonds, then to well-defined crystal structure of good thermal stability. Furthermore, the weight loss occurred mainly among 300°C and 800°C with CH4, (CH3)4Si,(CH3)3SiH,(CH3)2SiH2and other silane gases releasing from pyrolysis product leading to the conversion from organic polymers to inorganic ceramic. The pyrolysis product was converted into β-SiC crystal completely at 1400°C, and the crystallization of α-SiC phase occurred after 1550°C which might influence the stability of SiC matrix. Key words:polycarbosilane, organic precursor, pyrolysis kinetic behavior
- Published
- 2014
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