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Determination of structure and concentration of growing species in ionic polymerizations: The 31 P NMR method
Author(s) -
Penczek Stanislaw,
Brzezinska Krystyna
Publication year - 1994
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.19940850105
Subject(s) - cationic polymerization , polymerization , polymer chemistry , monomer , chemistry , styrene , chemical shift , ionic bonding , anionic addition polymerization , reagent , living polymerization , methyl methacrylate , polymer , copolymer , organic chemistry , radical polymerization , ion
Abstract The quantitative transformation of the ionic growing species (∼ ∼ ∼*) into the P atom containing end‐groups (∼ ∼ ∼P) allows to determine by 31 P NMR their structures and concentrations, down to 10 −4 mol‐L −1 , or even lower with a further progress of the NMR equipment:The P atoms are exclusively located at the chain ends, the known excess of the reagent “P” being used as an internal standard. The chemical shifts of thus prepared chain ends, when compared with models, give information on the chemical structure of the parent active species. This paper reviews the earlier work on ionic ring‐opening polymerization and more recent work, concerning cationic and anionic vinyl polymerization, particularly polymerization of vinyl ethers, styrene, methacrylates and some diene monomers. In the polymerization of vinyl ethers the stereochemistry of the chain ends was studied; it has also been shown, that chemical shift changes with the polymerization degree; thus the first addition products could separately be observed.