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An In‐Situ NMR Study of Radical Copolymerization Kinetics of Acrylamide and Non‐ I onized Acrylic Acid in Aqueous Solution
Author(s) -
Preusser Calista,
Hutchinson Robin A.
Publication year - 2013
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.201300048
Subject(s) - monomer , copolymer , acrylic acid , aqueous solution , acrylamide , polymer chemistry , kinetics , isothermal process , reactivity (psychology) , chemistry , aqueous two phase system , materials science , polymer , organic chemistry , thermodynamics , medicine , physics , alternative medicine , pathology , quantum mechanics
Summary An in‐situ NMR technique has been developed to study the aqueous phase copolymerization of non‐ionized acrylic acid (AA) and acrylamide (AM) under near‐isothermal conditions at much higher monomer contents than previously reported in the literature. The composition data obtained over the entire conversion range provides a precise estimate of monomer reactivity ratios not available from low conversion data. The set of experiments, with initial monomer content in aqueous solution varied between 5 and 40%, were well‐fit over the complete conversion range by r AA = 1.24 ± 0.02, and r AM = 0.55 ± 0.01. It was found that the rate of monomer conversion increases with increasing monomer concentration, a trend contrary to the known decrease in the AA and AM chain‐end propagation rate coefficients.