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Degradation of chemical warfare agents by reactive polymers / Lev Bromberg in Industrial & engineering chemistry research, Vol. 48 N°3 (Février 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N°3 (Février 2009) . - p. 1650–1659 Titre : Degradation of chemical warfare agents by reactive polymers Type de document : texte imprimé Auteurs : Lev Bromberg, Auteur ; Heidi Schreuder-Gibson, Auteur ; William R. Creasy, Auteur Année de publication : 2009 Article en page(s) : p. 1650–1659 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Chemical  warfare  --  Degradation  Reactive  polymers Résumé : Nucleophilic hydrolysis of chemical warfare agents (CWA), S-2-(diisopropylamino)ethyl O-ethyl methylphosphonothioate (VX), O-pinacolyl methylphosphonofluoridate (soman, or GD), and isopropyl methylphosphonofluoridate (sarin, or GB) by polyacrylamidoxime (PANOx) and poly(N-hydroxyacrylamide) (PHA) has been demonstrated. The reactive PANOx and PHA were obtained by one-step oximation of polyacrylonitrile and polyacrylamide, respectively. The polymers were converted to their respective oximate salts at pH values greater than the pKa of oximate or amidoximate groups of 7.5 and 10.8, respectively. Although the PANOx and PHA exhibited spontaneous hydrolysis at ambient temperature and humidity, the conversion of the hydroxamate into the unreactive carboxylic groups was insignificant even at prolonged storage, so that the polymers maintained reactivity at ambient conditions. When exposed to ambient air or 100% humidity, the polymers imbibed up to 65 wt % water, which dramatically enhanced the polymer reactivity toward the CWA under study. The half-lives of VX in heterogeneous hydrolysis, which appeared to be pseudo-first-order in the polymer dispersions, were measured to be from 0.093 to 4.3 and 7.7 h in the presence of PANOx and PHA, respectively. The rates of hydrolytic activity of PANOx for VX exhibited a strong dependency on the degree of conversion of the amidoxime to amidoximate groups. The half-life of GB was less than 3 min. Only a minor presence of the toxic VX degradation product, S-[2-(diisopropylamino)ethyl]methylphonothioate (EA-2192), was detected in the course of degradation by the reactive polymers. The efficiency, ease of synthesis, and nontoxic nature of the PANOx and PHA polymers make them attractive materials in decontamination and as components of reactive barriers. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801150y [article] Degradation of chemical warfare agents by reactive polymers [texte imprimé] / Lev Bromberg, Auteur ; Heidi Schreuder-Gibson, Auteur ; William R. Creasy, Auteur . - 2009 . - p. 1650–1659. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N°3 (Février 2009) . - p. 1650–1659 Mots-clés : Chemical  warfare  --  Degradation  Reactive  polymers Résumé : Nucleophilic hydrolysis of chemical warfare agents (CWA), S-2-(diisopropylamino)ethyl O-ethyl methylphosphonothioate (VX), O-pinacolyl methylphosphonofluoridate (soman, or GD), and isopropyl methylphosphonofluoridate (sarin, or GB) by polyacrylamidoxime (PANOx) and poly(N-hydroxyacrylamide) (PHA) has been demonstrated. The reactive PANOx and PHA were obtained by one-step oximation of polyacrylonitrile and polyacrylamide, respectively. The polymers were converted to their respective oximate salts at pH values greater than the pKa of oximate or amidoximate groups of 7.5 and 10.8, respectively. Although the PANOx and PHA exhibited spontaneous hydrolysis at ambient temperature and humidity, the conversion of the hydroxamate into the unreactive carboxylic groups was insignificant even at prolonged storage, so that the polymers maintained reactivity at ambient conditions. When exposed to ambient air or 100% humidity, the polymers imbibed up to 65 wt % water, which dramatically enhanced the polymer reactivity toward the CWA under study. The half-lives of VX in heterogeneous hydrolysis, which appeared to be pseudo-first-order in the polymer dispersions, were measured to be from 0.093 to 4.3 and 7.7 h in the presence of PANOx and PHA, respectively. The rates of hydrolytic activity of PANOx for VX exhibited a strong dependency on the degree of conversion of the amidoxime to amidoximate groups. The half-life of GB was less than 3 min. Only a minor presence of the toxic VX degradation product, S-[2-(diisopropylamino)ethyl]methylphonothioate (EA-2192), was detected in the course of degradation by the reactive polymers. The efficiency, ease of synthesis, and nontoxic nature of the PANOx and PHA polymers make them attractive materials in decontamination and as components of reactive barriers. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801150y