Dibenzoyl peroxide redox initiation systems

It must be emphasized that, in contrast to the initiation of polymerization with peroxo compounds or azo compounds, not every redox system is suitable for initiating polymerization of every unsaturated monomer. Before attempting to polymerize a new compound with a redox system it is, therefore, advisable first to test its radical polymerizability with dibenzoyl peroxide. 

Redox initiators have been proposed. The initiation system is composed from iron sulfate, dibenzoyl peroxide, and a reductant. Of the latter, hydroxyacetone, 2-hydroxy-2-phenylacetophenone, ascorbic palmitate, and toluene sulfinic acid are among the most economical. The reaction conditions are such that the cyclic oxida-... 

The initiation of a radical polymerization of a monomer can be achieved with practically every peroxo or azo compound. This means that in these cases the type of initiator influences only the rate and degree of polymerization, the nature of the end groups and branching but not the polymerizability of the monomer as such. This is not the case with redox systems as radical initiators. As a consequence, the determination of whether a new substance polymerizes radically or not is rather simple to the purified compound (as a 30-50% solution) is added under nitrogen 1% of dibenzoyl peroxide and this mixture is heated for several hoius to 60-120°C. The occurrence of turbidity or an increase of viscosity (if the polymer is soluble in the reaction mixmre) are first indications that a polymerization has taken place. Final proof is the analysis of the reaction mixture after separation of the polymer... 

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