Carbon black grafting

Carbon black grafting has a similar effect on dispersion stability (Figure 6.20)." Modified carbon black is substantially improved. The graphs show that... 

Carbon black grafting has a similar effect on dispersion stability (Figure... 

Fujiki, K Tsubokawa, N. Sone, Y. (1990). Radical Grafting from Carbon Black. Graft Polymerization of Vinyl Monomers Initiated by Azo Groups Introduced onto Carbon Black Surface. Polymer Journal, 22,661-670... 

Tsubokawa, N. Funaki, A. Hada, Y. Sone, Y. (1982). Grafting onto Carbon Black Graft Polymerization of 5-Propiolactone onto Carbon Black Surface. Journal Polymer Science, Polymer Chemistry Edition, 20,3297-3304... 

Tsubokawa, N. Tsuchida, H. (1992b). Heat-resistant Polymer-grafted Carbon Black Grafting of Poly(organophosphazenes) onto Carbon Black Surface. Journal of Macromolecular Science, Pure Applied Chemistry, A29,311-321 Tsubokawa, N. Yanadori, K. (1992c). Reaction of Polymer Radicals formed by the Decomposition of Azopolymer with Carbon Black Surface. Kobunshi Ronbunshu, 49, 865-870... 

Among the two ionic polymerization techniques mentioned above, a living anionic polymerization should show the best possible control of polymer architecture and composition. Mono dispersed homopolymers, complex-block, graft, star, and miktoarm architectures have been accessible primarily by anionic polymerization methods [22]. They have been used to grow polymer brushes from various small particles such as silica gels graphite,carbon black, and flat surfaces [23-26]. Recent results have been reported on living anionic polymerizations on clay [27] and silica nanoparticles [28,29]. 

Carbon blacks have been reported to be capable of initiating the cationic polymerization of vinyl monomers such as vinyl ethers, indene, and acenaphthylene. The grafting sites of the polymer were based on carboxyl groups present on the surface [88]. The polymerization was inhibited by treatment of the carbon blacks with NaHCOs, CH2N2, pyridine, and DMF. Also, the degree of conversion was found to be dependent on temperature and time of polymerization [89]. 

Table 11. Properties of vulcanizates filled with a polystyrene HAF grafted carbon black 641...

Another way for increasing filler-elastomer interactions could be the grafting of a polymer on the solid surface. A number of methods exist to secure the attachment of macromolecules to the surface of carbon black particles e.g., a polymeric chain may be grown on an initiation site on the surface, small molecules previously attached to the surface may be copolymerized with a monomer, a polymeric chain, either radical, cationic, or anionic in nature, may be terminated on an active site of the solid surface, etc. 55 63). 

It appears (Table 11) that the reinforcing ability exhibited by a HAF carbon black in polybutadiene or EPR is much lower after its surface has been previously modified by grafting of polystyrene M). Such results cannot, however, be associated with the elastomer s incompatibility towards the polystyrene grafts since poly-isoprene-grafted carbon blacks yield similar conclusions 65). 

The mobility in both tightly and loosely bound BR and isoprene rubbers increases, and the fraction of bound rubber decreases with a decreasing concentration of silanol groups on the silica surface [124], This led to the suggestion that the silanol groups on the silica surface are active sites for the chain adsorption. The grafting of aliphatic chains to the silica surface leads to a decrease in BR-silica interactions [125]. The effect is less pronounced in BR filled with carbon black containing aliphatic chains at the surface. 

Tsubokawa N. (1992) Functionalization of carbon black by surface grafting of polymers. Polym Sci 17 417-470. 

Polyaniline-grafted carbon black was prepared by Srinivas [3] and then platinized with chloroplatinic acid, as illustrated below, and used as a fuel cell component. Sulfurized analogues, (II), were prepared by Srinivas [4] and were also used as fuel cell components. 

Grafting of Macromolecules onto Carbon Blacks, J. B. Donnet, E. Papirer, and A. Vida ... 

The groups present on the carbon black surface may also come from chemical treatments. In one report,peroxide groups were introduced by radical trapping and then used for radical graft polymerization. In such a method, the entrapped radical plays the role of an initiator. 

Improvement in colloidal stability kaolin carbon black polyurethane coating grafting 8 11... 

Figure 6.20. Stability of grafted carbon black (A), carbon black with physically absorbed polymer (B) and untreated carbon black (C). [Adapted, by permission, from Tsubokawa N, Hosoya M, Kurumada J, Reactive Functional Polym., 11, No.l, 1995, 75-81.]...

---