Method of making carbon-carbon composite

A method of making a carbon-carbon composite from thermosetting polymer resin comprising the steps of:

• a) infusing bis-Schiff base resin into carbon fiber reinforcement to form an uncured resin embedded composite, the bis-Schiff base resin comprising the structure of Formula (I):
• wherein:
• R comprises at least one aromatic moiety,
• X comprises an aromatic moiety, an aliphatic moiety, or a hydrogen and X′ comprises an aromatic moiety, an aliphatic moiety, or a hydrogen;
• b) positioning the resin embedded composite on a substrate under a vacuum enclosure;
• c) curing the carbon fiber reinforcement embedded with bis-Schiff base resin at a first elevated temperature under vacuum to form a polymer matrix composite;
• d) heating the polymer matrix composite at a second elevated temperature under inert atmosphere to form a porous carbon-carbon composite;
• e) re-infusing bis-Schiff base resin into the porous carbon-carbon composite resulting from step (d) and curing the newly infused bis-Schiff base resin at a third elevated temperature to generate a reinfused porous carbon-carbon composite;
• and
• f) heating the reinfused porous composite resulting from step (e) at a fourth elevated temperature under inert gas to densify the resulting reinfused carbon-carbon composite from step (e) and form the carbon-carbon composite;
• wherein the second elevated temperature and/or the fourth elevated temperature is less than 900° C.