Preparation of Polystyrene by an Anionic Polymerization Method

Electron-withdrawing substituents adjacent to an olefinic bond tend to stabilize carbanion formation and thus activate the compound toward anionic polymerization [19], 

The relative initiator activities are not always simple functions of the reactivity of the free anion but probably involve contributions by complexing ability, ionization, or dissociation reactions [20-25], 

Waack and Doran [26] reported on the relative reactivities of 13 structurally different organolithium compounds in polymerization with styrene in tetrahydro-furan at 20°C. The reactivities were determined by the molecular weights of the formed polystyrene. The molecular weights are inversely related to the activity of the respective organolithium polymerization initiators. Reactivities decreased in the order alkyl benzyl allyl phenyl vinyl triphenylmethyl as shown in Table 3.1. 

The structure-reactivity behavior found for similar organosodium polymerization initiators of styrene [27] or that for addition reactions with 1,1-diphenylethylene [28] is almost identical with that found for the lithium initiators of Table 3.1. It is interesting to note from Table 3.1 that the reactivity of lithium 

The anionic polymerization of styrene using the organolithium initiators can be described as a termination-free polymerization, as shown in Eqs. (1) 

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