Abstract
PAN-based carbon fibers, impregnated with phenolic resin used as a precursor of carbonized matrix, was modified by the addition of molybdenum disilicide (MoSi2) in different concentrations, i.e., 0, 4, 12 and 20% by weight. Thus, the unidirectional carbon fiber-reinforced phenolic matrix composites were manufactured by prepreg method, and were submitted to carbonization (heat treated to 1100°C) and graphitization (to 2300°C). The influence of MoSi2 concentrations having oxidation inhibition and brittle-to-ductile transition (BDT) properties at high temperatures on the thermal stability of the composites was investigated by using thermogravimetric analysis (TGA) in air atmosphere. Thermal stabilities of the composites were characterized by the integral procedural decomposition temperature (IPDT) obtained from the analytical method of Doyle and the activation energy derived from the integral method of Horowitz-Metzger. It was found that the thermal stabilities increased with increasing the final heat treatment temperature (HTT) and the concentration of MoSi2 in C/C composites. This seems to be a consequence of the improvement in physical adhesion between fiber-matrix-MoSi2 of the composites, due to the BDT at high temperatures.
Original language | English |
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Pages (from-to) | 305-311 |
Number of pages | 7 |
Journal | Polymer (Korea) |
Volume | 23 |
Issue number | 2 |
State | Published - 1999 |
Externally published | Yes |
Keywords
- Activation energy
- Carbon/carbon composites
- MoSi
- Thermal stability