The polymerization reaction of vinyl monomers in the presence of a radical initiator is a chain-growth polymerization process. The overall reaction order depends on the initiation, propagation, and termination steps. However, the initiation step is typically considered to be the rate-determining step in this process.In general, the reaction rate R can be expressed as:R = k[I]^m[M]^nwhere k is the rate constant, [I] is the concentration of the initiator, [M] is the concentration of the monomer, and m and n are the reaction orders with respect to the initiator and monomer, respectively.For a typical free-radical polymerization of vinyl monomers, the reaction is first-order with respect to both the initiator and the monomer. This means that the reaction rate is directly proportional to the concentration of both the initiator and the monomer:R = k[I]^1[M]^1As a result, if the concentration of the initiator or the monomer is doubled, the reaction rate will also double. If both the initiator and monomer concentrations are doubled, the reaction rate will increase four times.