Abstract
Abstract The objectives of this study are utilizing thermoplastic polymer Poly(ethylene oxide) to modify Novolac type phenolic resin and to prepare carbon-carbon composites. Various Poly(ethylene oxide) contents were added to the Novolac type phenolic resin to fabricate carbon-carbon composites at different heat treatment temperatures and to investigate the physical properties and the microstructure change from carbonization to graphitization. The results show that the density increases with heat treatment temperatures before 2000℃and decreases with heat treatment temperatures after 2000℃；the change of porosity opposites to the change of density. But, both of the turning point are 2000℃ The performance of flexural strength of carbon/carbon composites is similar to the changing tendency of density. The performance of flexural strength of carbon/carbon composites is highest；the interlaminar shear strength is highest at 2200℃。 With the increasing of heat treatment temperatures, the X-ray diffraction peak of (002) changes from broadened and symmetricless to sharp and symmericless. It shows the microstructure becomes crystalline structure. With the increasing of heat treatment temperatures,d002 decreases to approach to the ideal graphite d002, 3.354A。Lc increases with the increasing of heat treatment temperatures。It shows that the degrees of graphitization increases with the increasing of heat treatment temperatures。 The peak of Raman spectra at 1590cm-1 shows there is the graphite structure in the microstructure of carbon/carbon composites by graphitized at 2000℃。 However，D mode peak of Raman spectra indicates there is the turbostratic structure in the microstructure of carbon/carbon composite by graphitized at 2400℃。Besides, La increases with the increasing of heat treatment temperatures。