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Thermal and photocatalytic degradation of poly(methyl methacrylate), poly(butyl methacrylate), and their copolymers / Nagu Daraboina in Industrial & engineering chemistry research, Vol. 47 N°18 (Septembre 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 N°18 (Septembre 2008) . - p. 6828–6834 Titre : Thermal and photocatalytic degradation of poly(methyl methacrylate), poly(butyl methacrylate), and their copolymers Type de document : texte imprimé Auteurs : Nagu Daraboina, Auteur ; Giridhar Madras, Auteur Année de publication : 2008 Article en page(s) : p. 6828–6834 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Poly(methyl  methacrylate)--degradation  Poly(butyl  methacrylate)--degradation  o-dichlorobenzene  Combustion  synthesis  TiO2 Résumé : The photocatalytic degradation of the homopolymers, poly(methyl methacrylate) (PMMA), poly(butyl methacrylate) (PBMA), and their copolymers (PMMABMA) was studied in o-dichlorobenzene in the presence of commercial TiO2 (Degussa P-25) and TiO2 synthesized by combustion synthesis (CSN-TiO2). Gel permeation chromatography was used to determine the evolution of molecular weight distributions with reaction time. The experimental data indicated that the polymers PMMA and PBMA and their copolymers degrade by simultaneous random and chain end scission. A continuous distribution model was developed for the mechanism involved in degradation by both random and chain end scission and used to determine the degradation rate coefficients. The degradation rate coefficients of the polymers in the presence of CSN-TiO2 were higher than the degradation rate coefficients obtained with commercial TiO2 (Degussa P-25). The degradation rate coefficient of copolymers was in between that of the homopolymers and increased linearly with the increase of mol % of PMMA. The degradation of PMMA, PBMA, and their copolymers was also investigated by thermogravimetric analysis. The copolymers exhibited better thermal stability than the homopolymers in contrast to that observed for photocatalytic degradation. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800883n [article] Thermal and photocatalytic degradation of poly(methyl methacrylate), poly(butyl methacrylate), and their copolymers [texte imprimé] / Nagu Daraboina, Auteur ; Giridhar Madras, Auteur . - 2008 . - p. 6828–6834. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N°18 (Septembre 2008) . - p. 6828–6834 Mots-clés : Poly(methyl  methacrylate)--degradation  Poly(butyl  methacrylate)--degradation  o-dichlorobenzene  Combustion  synthesis  TiO2 Résumé : The photocatalytic degradation of the homopolymers, poly(methyl methacrylate) (PMMA), poly(butyl methacrylate) (PBMA), and their copolymers (PMMABMA) was studied in o-dichlorobenzene in the presence of commercial TiO2 (Degussa P-25) and TiO2 synthesized by combustion synthesis (CSN-TiO2). Gel permeation chromatography was used to determine the evolution of molecular weight distributions with reaction time. The experimental data indicated that the polymers PMMA and PBMA and their copolymers degrade by simultaneous random and chain end scission. A continuous distribution model was developed for the mechanism involved in degradation by both random and chain end scission and used to determine the degradation rate coefficients. The degradation rate coefficients of the polymers in the presence of CSN-TiO2 were higher than the degradation rate coefficients obtained with commercial TiO2 (Degussa P-25). The degradation rate coefficient of copolymers was in between that of the homopolymers and increased linearly with the increase of mol % of PMMA. The degradation of PMMA, PBMA, and their copolymers was also investigated by thermogravimetric analysis. The copolymers exhibited better thermal stability than the homopolymers in contrast to that observed for photocatalytic degradation. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800883n