In the past, different halogen salts were tested as co-initiators, chloride salt was found to produce the highest yield, and the final weight percent product depends on the mole ratio of chloride salt to hydrogen peroxide and the mole ratio of hydrogen peroxide to lignin. The initiation process has been speculated, but not proven. Lignin was grafted by using an initiation system that attacks repeat units in lignin to create a site for polymer chain growth. The reaction works for almost all ethene monomers including styrene. Because of the grafting process, lignin has been converted into a material that can and will prove useful for industrial use and commercial products.
Additions can occur in a variety of ways, since there are two double bonds in the monomer.
In a polymer chain, these linkages are often joined together randomly. The preparation of the lignin graft copolymer was performed under oxygen-free conditions, with a reaction mixture containing DMSO, calcium chloride, a halide salt, one or more polymerizable monomers, and lignin. The reactants were mixed for a given time for graft polymerization to occur. In order to make a homogenous KBr pellet all components must be ground well. This mixture was rotated on a roller for 2 hours for homogenization.