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Propagation Rate Coefficient and Fraction of Mid‐Chain Radicals for Acrylic Acid Polymerization in Aqueous Solution
Author(s) -
Buback Michael,
Hesse Pascal,
Lacík Igor
Publication year - 2007
Publication title -
macromolecular rapid communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.348
H-Index - 154
eISSN - 1521-3927
pISSN - 1022-1336
DOI - 10.1002/marc.200700396
Subject(s) - polymerization , aqueous solution , polymer chemistry , radical polymerization , acrylic acid , solution polymerization , chain propagation , acrylate , materials science , chemistry , analytical chemistry (journal) , polymer , chromatography , monomer , organic chemistry
In acrylate polymerizations both SPRs and tertiary MCRs occur. Via pulsed laser polymerization, using a wide range of LPRRs, in conjunction with aqueous‐phase size‐exclusion chromatography, the polymerization of 1.35 mol · L −1 acrylic acid in aqueous solution has been investigated at 6 °C. The sigmoidal decrease in the apparent propagation rate coefficient, k p app , towards lower LPRRs is in line with recent predictions. At the highest LPRRs, k p appapproaches the rate coefficient of SPR propagation, k p SPR , whereas the limiting value of k p appat low LPRRs approaches the effective propagation rate coefficient, k p eff , which allows for an estimate of the fraction of MCRs under polymerization conditions, x MCR .