Patent ID: 8883957

Claim:
A process for the preparation of a polylactone or polylactam, comprising reacting a lactone or lactam with a nonpolymeric initiator in a nonchlorinated aromatic solvent in the presence of a sulfonic acid of formula R—SO 3 H, where R denotes: a linear alkyl group including from 1 to 20 carbon atoms or a branched or cyclic alkyl group including from 3 to 20 carbon atoms, said alkyl groups are optionally substituted by one or more substituents chosen independently from oxo and halo groups, or an aryl group optionally substituted by at least: one linear alkyl substituent including from 2 to 20 carbon atoms, or one branched or cyclic alkyl group including from 3 to 20 carbon atoms, said alkyl substituent or group being itself optionally substituted by at least one halogen group chosen from fluorine, chlorine, bromine or iodine, or by a nitro group, or one halogen group chosen from fluorine, chlorine, bromine or iodine, or one nitro group, or one CR 1 R 2 R 3 group, where R 1 denotes a halogen atom and R 2 and R 3 independently denote a hydrogen atom or a halogen atom.