Chemical modification of carbon black by a simple non-liquid-phase approach

Chemical modification is the most popular and efficacious approach to improve dispersion stability for commercial carbon blacks in organic media. Even though this method has been used successfully in liquid systems, there have been few reports of chemical modification of carbon black in non-liquid-phase systems. In the present work, a simple non-liquid-phase approach to preparing modified carbon black with high dispersibility and stability in polar organic media from an industrial carbon black, N220, is reported. The treatment was carried out in a rheology mixer by blending carbon black with a low-molecular-weight organic compound, 3,9-bis-(1,1-dimethyl-2[beta-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl)-2,4,8,10-tetraoxaspiro[5,5]-undecane (AO-80), under proper conditions. The modified carbon black had a smaller particle size than the original carbon black, as proven by dynamic light scattering and transmission electron microscopy, and it could be dispersed facilely in acetone to form a stable suspension. Time-of-flight secondary ion mass spectroscopy was used to detect the chemical presence of AO-80 fragments on the surface of the modified carbon black and consequently the modification mechanism.