Dispersion stability of water soluble ultrafine carbon black in N-methyl morpholine-N-oxide solution

The water soluble ultrafine carbon black and encapsulated ultrafine carbon black that were suitable for dope dyeing of Lyocell fiber were prepared by direct dispersing method and emulsion polymerization method,respectively,and the particle size of the ultrafine carbon black obtained with different methods and their dispersion stabilities in the N-methyl morpholine-N-oxide(NMMO) solution were investigated.Experimental results revealed that the average particle size of encapsulated ultrafine carbon black was obviously smaller than that of dispersive ultrafine carbon black and its centrifugal stability and thermal stability in NMMO solution were higher than those of dispersive ultrafine carbon black.The apparent viscosity of NMMO solution decreased when encapsulated carbon was added,and the more amount of encapsulated carbon added,the lower viscosity of NMMO solution was.