Photocatalytic and thermal degradation of poly(methyl methacrylate), poly(butyl acrylate), and their copolymers / Vinod Kumar Konaganti in Industrial & engineering chemistry research, Vol. 48 N°4 (Février 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N°4 (Février 2009) . - pp. 1712–1718 Titre : Photocatalytic and thermal degradation of poly(methyl methacrylate), poly(butyl acrylate), and their copolymers Type de document : texte imprimé Auteurs : Vinod Kumar Konaganti, Auteur ; Giridhar Madras, Auteur Année de publication : 2009 Article en page(s) : pp. 1712–1718 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Poly(methyl methacrylate) Poly(butyl acrylate) Photocatalytic degradation Thermal o-dichlorobenzene Copolymers Résumé : The photocatalytic and thermal degradations of poly(methyl methacrylate), poly(butyl acrylate), and their copolymers of different compositions were studied. The photocatalytic degradation was investigated in o-dichlorobenzene in the presence of two different catalysts, namely, Degussa P-25 and combustion synthesized nanotitania (CSN-TiO2). The samples were analyzed by using gel permeation chromatography (GPC) to obtain the molecular weight distributions (MWDs) as a function of reaction time. Experimental data indicated that the photodegradation of these polymers occurs by both random and chain end scission. A continuous distribution kinetic model was used to determine the degradation rate coefficients by fitting the experimental data with the model. Both the random and specific rate coefficients of the copolymers decreased with increasing percentage of butyl acrylate (BA). Thermal degradation of the copolymers was investigated by thermogravimetry. The normalized weight loss profiles for the copolymers showed that the thermal stability of the copolymers increased with mole percentage of BA in the copolymer (PMMABA). The Ozawa method was used to determine the activation energies at different conversions. At low acrylate content in the copolymer, the activation energy depends on conversion, indicating multiple degradation mechanisms. At high acrylate content in the copolymer, the activation energy is independent of conversion, indicating degradation by a one-step mechanism. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801646y [article] Photocatalytic and thermal degradation of poly(methyl methacrylate), poly(butyl acrylate), and their copolymers [texte imprimé] / Vinod Kumar Konaganti, Auteur ; Giridhar Madras, Auteur . - 2009 . - pp. 1712–1718. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N°4 (Février 2009) . - pp. 1712–1718 Mots-clés : Poly(methyl methacrylate) Poly(butyl acrylate) Photocatalytic degradation Thermal o-dichlorobenzene Copolymers Résumé : The photocatalytic and thermal degradations of poly(methyl methacrylate), poly(butyl acrylate), and their copolymers of different compositions were studied. The photocatalytic degradation was investigated in o-dichlorobenzene in the presence of two different catalysts, namely, Degussa P-25 and combustion synthesized nanotitania (CSN-TiO2). The samples were analyzed by using gel permeation chromatography (GPC) to obtain the molecular weight distributions (MWDs) as a function of reaction time. Experimental data indicated that the photodegradation of these polymers occurs by both random and chain end scission. A continuous distribution kinetic model was used to determine the degradation rate coefficients by fitting the experimental data with the model. Both the random and specific rate coefficients of the copolymers decreased with increasing percentage of butyl acrylate (BA). Thermal degradation of the copolymers was investigated by thermogravimetry. The normalized weight loss profiles for the copolymers showed that the thermal stability of the copolymers increased with mole percentage of BA in the copolymer (PMMABA). The Ozawa method was used to determine the activation energies at different conversions. At low acrylate content in the copolymer, the activation energy depends on conversion, indicating multiple degradation mechanisms. At high acrylate content in the copolymer, the activation energy is independent of conversion, indicating degradation by a one-step mechanism. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801646y

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