Protonic Acids with Non-Complex Anions

(10) recombinatfon of counterions and formation of the covalent macro-molecule is described as an irrevo-sible reaction. Howevo-, this can be a reversible process in which ionization involves nucleophilic attack of a nwnomer molecule or a polymer segment. 

One of the few systems for which the initiation with protonic acid has been comprehensively studied is the cationic polymerization of lactams Initiation of the cationic polymerization of lactams with HCl gives predominantly a nwnomer molecule protonated at the oxygen atom but a small amount of N-protonated lactam is assumed to be present in the tautomeric equilibrium  

For the sake of simplicity the protonated monomer molecule is further represented by 11b. (See however Addendum p. 131). The acylation of the monomeric lactam results in the formation of an aminoacyUactam  

The protonated primary amino group is in equilibrium with the protonated lactam  

The reactions described above were deduced from the structures of the oligomeric products separated by electrophoresis and identified by comparison with independently synthesized compounds. 

---