"Polymer Infiltration and Pyrolysis Processing of Carbon/Carbon Composites" 

Edwin Romero, MSE PhD Candidate 

Advisor: Professor Rodney Trice

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Abstract:

The low density and high thermostability of bulk carbon make carbon fiber-reinforced carbon matrix composites a good candidate for hypersonic applications. To obtain a pure carbon matrix, a polymer matrix composite is thermally decomposed in an oxygen-free atmosphere, resulting in weight loss and a porous matrix structure. The thermomechanical properties of the porous composite can be improved using polymer infiltration and pyrolysis (PIP) processing, where infiltration and conversion of a secondary polymer causes a carbon build-up on pore walls. This simultaneously decreases the total pore volume and increases the carbon matrix density, but since a portion of the secondary polymer is gasified, some residual porosity is left behind. As a result, several cycles of PIP are needed to obtain bulk densities >90%. This review focuses on some aspects of infiltration for carbon/carbon composites that have been used to reduce densification cycles.