Chemical, Mechanical and Electrical Properties of Glassy Polymeric Carbon

Abstract

Glassy Polymeric Carbon (GPC) is obtained by a molding technique, in various shapes, from a phenolic resin precursor. The heat treatment of the precursor is achieved in three stages up to 1000 °C. Similar GPC materials produced in our laboratory displayed large strain to failure ratio, small thermal expansion coefficient and low density. Like all carbon forms, is attacked by oxygen, especially atomic oxygen. Nevertheless the kinetics for reaction with atmospheric oxygen is very slow. We investigated the composition and structural changes of the phenolic precursor as a function of temperature and evaluated material's stability when exposed to high temperatures in presence of hydrogen (H 2 ) or oxygen (O 2 ).

Electrical Transport Behavior in Phenolic Resin-based Composites Doped with Multi-walled Carbon Nanotubes

“…Fitzer et al [12] consider that below 300 o C long-chain polymers are formed. The Raman results are in agreement with Muntele et al [10] but disagree with Ko et al [11] who did not observe graphitic formation in their phenolic resin heat treated below 500 o C. We have used the same phenolic resin precursor as the first cited authors; a different precursor was used by the latter authors. Figure 2 presents the Raman spectra of the samples heat-treated at 250 o C and 450 o C. The Raman spectrum of the pure phenolic resin heat-treated to 450 o C shows the appearance of the D band around 1360 cm -1 and a small peak correspondent to the G band around 1590 cm ñ1 .…”

“…In the case of phenolic resin, the effects of heat treatment temperature (HTT) have been shown [10,11] to produce significant chemical and mechanical changes that depend on the degree of cross-linking, and there is references of the HTT influence on the materialís electrical properties [4]. In the case of phenolic resin, the effects of heat treatment temperature (HTT) have been shown [10,11] to produce significant chemical and mechanical changes that depend on the degree of cross-linking, and there is references of the HTT influence on the materialís electrical properties [4].…”