The effect of substrate on Reinforced Pyrolytic Graphite

Abstract

Reinforced Pyrolytic Graphite, RPG † † Registered trademark for Reinforced Pyrolytic Graphite, fabricated by the Super-Temp Company, a Division of Ducommun, Incorporated, 11120 South Norwalk Boulevard, Santa Fe Springs, California 90670. , was prepared from various substrates including rayon, nylon, wool, cotton, and polyurethane foam. In all cases, the ultimate flexure or compressive strength increases with the final bulk density of the RPG. Most of the experiments were done with rayon where it was found that for a given final density, the strength increased as the fiber length or the initial rayon density decreased, but that the strength was not noticeably affected by changes in fiber diameter or carbonization process. RPG produced from wool gave the highest flexural strength for a given density. The carbons resulting from nylon and cotton were, in general, mechanically inferior to carbons from wool or rayon. The carbon from polyurethane foam was not infiltrated and thus had very low final densities and compressive strengths, and these were independent of pore size in the foam. However, this material is primarily for use as a thermal insulator and direct comparisons of strength with rayon and wool carbons were not intended.