Continuous carbon nanotube-polycarbonate composite fibers through melt spinning

Among the many potential applications of carbon nanotubes (CNT), its usage to strengthen polymers has been paid considerable attention due to the exceptional stiffness, excellent strength and the low density. This has provided numerous opportunities for the invention of new material systems for applications requiring high strength and high modulus. In this paper, composite fibers of polycarbonate (PC) and multiwall carbon nanotubes (MWNTs) are prepared in dimethyl. formamide (DMF) using melt mixing-coagulation technique followed by melt spinning at 220 degrees C. The spinning of the coagulated PC-MWNTs is done at various draw ratios and the resultant fibers are studied by optical microscope, SEM and AFM. The mechanical properties of the composite fiber are determined and it is found that the addition of 1-1.5 wt% of MWNT increased the tensile strength of the polymer fiber from 900 MPa to 1890 MPa and Young's modulus from 1372 MPa to 2060 MPa. The results show that the mixing of MWNT with the polycarbonate matrix, above its melting point followed by coagulation in water might have developed a strong interfacial bonding between functionalized MWNTs and PC.