Oriented Crystallization of Polycarbonate by Vapor Grown Carbon Fiber and its Application

Abstract

It is known that polycarbonate (PC) is categorized as amorphous polymer and pure PC crystallizes extremely slowly. However, we have recently found that the crystallization of PC was substantially accelerated around 200 °C in the presence of vapor grown carbon fiber (VGCF), having ultra thick multi-walled carbon nanotube (MWCNT) structure. To examine the accelerated crystallization by VGCF, the effect of pre-graphitized VGCF, carbon black, and mesophase pitch based carbon fiber (CF) on the crystallization was evaluated. In addition, polarized optical microscope observation was performed by using PC including magnetically oriented VGCF. It was suggested that the surface of ordered graphite structure from VGCF or CF induced the oriented crystallization of PC along the axial direction of VGCF or CF. To utilize the accelerated oriented crystallization of PC by CF, PC sheet having oriented crystallized surface PC layer was made by annealing the stacked structure of PC sheet and oriented CF sheet at 200 °C. The PC sheet, whose surface was crystallized along CF axial direction, was successfully produced, showing retardation property by polarized optical microscope.