炭黑的表面氧化与接枝

为把炉法炭黑作为色素炭黑使用，需要对其进行水性高分子接枝，以提高炭黑在水中的分散稳定性．研完了液相氧化剂氧化两种炭黑前后表面挥发分和pH值的关系及表面官能团组成的变化，并对比了氧化前后炭黑的自由基接枝效果．实验发现，低结构、高比表面的炭黑易被液相氧化剂氧化，且氧化剂的浓度和氧化强度直接影响炭黑的氧化效果．氧化炭黑的挥发分与其pH值之间存在一阶指数衰减函数关系．氧化后炭黑表面的羧基和醌基含量增加造成了炭黑和水亲合力及炭黑接收自由基能力增加，从而提高了炭黑接枝水溶性高分子的接枝率．

Surface Oxidation and Grafting of Carbon Black

To apply furnace black as a pigment, grafting of water-soluble polymers is usually required to increase the dispersion stability of carbon black. Studies ou the relationship between volatile content and pH value as well as the changes of functional groups on the surface of two kinds of carbon black before and after oxidation were carried out in this paper. The effect of radical group graft was also discussed. It is found that the carbon black with low structure and high specific surface area tends to be oxidized by liquid oxidants and the concentration and intensity of the oxidants are the direct factors that influence the effect of oxidation. The volatile content is proved to be associated with pH value in the form of a first order exponential decay function. The increase of carboxyl and quinone groups on the surface of carbon black after oxidation increases the affinity between carbon black and water, and the ability of carbon black to accept radical groups, consequently increases the grafting ratio of water-soluble polymers on carbon black.