Factors affecting the sensitivity to acid inhibition in novel acrylates characterized by secondary functionalities

Autor: Daniel Konopka, Jeffrey W. Stansbury, Harini Kilambi, Christopher N. Bowman
Rok vydání: 2007
Předmět:
Zdroj: Journal of Polymer Science Part A: Polymer Chemistry. 45:1287-1295
ISSN: 1099-0518
0887-624X
DOI: 10.1002/pola.21897
Popis: Here we demonstrate that acrylates exhibit significant rate reductions in the presence of small concentrations of protic acids (0.1–0.5 wt %) compared with the bulk monomer concentration. Dramatically different sensitivities to acid inhibition, differing by up to 2 orders of magnitude, are exhibited for various acrylates. This study examines the various factors that cause enhanced sensitivity toward acid inhibition in novel acrylates characterized by carbamate and cyclic carbonate secondary functionalities. Acid inhibition studies conducted in the presence of a highly polar solvent, such as propylene carbonate, have been performed to determine the impact of overall medium polarity and the extent of acid dissociation on the sensitivity to acid inhibition. The studies depict only a twofold increase in the parameters associated with acid inhibition, upon the addition of 70 wt % propylene carbonate, in comparison with an increase of 2 orders of magnitude for the novel acrylates. These studies indicate that the susceptibility to acid inhibition is primarily determined by the stability of the hypothesized radical–acid complex as well as its propensity to terminate with other species in the system and not by the extent of acid dissociation in the system. Furthermore, it is implied that the stability of the radical–acid complex and its propensity to terminate with other species in the system are dominated by intramolecular interactions. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1287–1295, 2007
Databáze: OpenAIRE
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