Methyl methacrylate grafting azobisisobutyronitrile

Benzoyl Peroxide and Azobisisobutyronitrile-Initiated Graft Copolymerization. Cellulose nitrate (CN) (10 g) was dissolved in methyl isobutyl ketone (90 ml) in a three-necked flask and to this solution methyl methacrylate (10 ml) and benzoyl... 

Figure 10. Effect of initiator concentration on the graft copolymerization of methyl methacrylate onto cellulose nitrate initiated by a, benzoyl peroxide and b, azobisisobutyronitrile. Key O, grafting efficiency 9, percent grafting.

The reactivity of the initiating radicals toward the backbones can vary and this can also change the efficiency of grafting. Benzoyl peroxide initiated polymerizations of methyl methacrylate monomer, for instance, in the presence of polystyrene yield appreciable quantities of graft copolymers. Very little graft copolymers, however, form when di-r-butyl peroxide initiates the same reactions. Azobisisobutyronitrile also fails to yield appreciable quantities of graft copolymers. This is due to very inefficient chain transferring to the polymer backbones by r-butoxy and isobutyronitrile radicals. 

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