Polymerization with Complete Dissociation of Initiator

There are some cases in homogeneous anionic polymerization in which the initiator dissociates completely with quantitative transformation into the active ionic form and the process is also virually instantaneous (stoichiometric polymerization). This is the case, for example, when one uses, as initiators, alkali organic 

There are some cases in homogeneous anionic polymerization in which the initiator dissociates completely with quantitative transformation into the active ioitic form and the process is also virtually instantaneous stoichiometric polymerization). This is the case, for example, when one uses, as initiators, alkali orgaiuc compounds (e.g., phenyUithium, butylhthium, or sodium naphthalene) in solvents which have unshared electron pairs (Lewis bases). The alkah forms stable positively charged complex ions with the Lewis base (Lenz, 1967), while the organic residue becomes negatively charged (carbanion) and can initiate an ioiuc polymerization [cf. Eqs. (8.11) and (8.12)]  

Since the polymerization kinetics in the above cases are extremely simple, ionic polymerization kinetics can be conveiuently classi ed according to whether the initiators are quantitatively and instantaneously dissociated or not. 

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