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Evaluation of nitrosobenzoic esters as processing and photo-stabilisers for polypropylene / Boucenna, Ammar 

Public ISBD Titre : Evaluation of nitrosobenzoic esters as processing and photo-stabilisers for polypropylene Type de document : texte imprimé Auteurs : Boucenna, Ammar, Auteur ; Scott, G., Directeur de thèse Editeur : Birmingham : University of Aston Année de publication : 1984 Importance : 114 f. Présentation : ill. Format : 27 cm. Note générale : Mémoire de Magister : Génie Chimique : Birmingham, The University of Aston : 1984 Annexe f. 115 - 122 Bibliogr. f. 123 - 125 Langues : Anglais (eng) Mots-clés : Polypropylene  ;  C-nitroso  --  compounds  --  anti-oxidant  ;  Photostabilisation Index. décimale : M005784 Résumé : In the present work, the effects of C-nitroso compounds on the melt-stabilisation, thermal and photo-oxidation of polypropylene have been studied. Both aliphatic and aromatic nitroso compounds were found to be effective melt stabilisers for PP. The stabilising effects were shown to be due to the ability of these compounds to terminate macro-alkyl radicals producing nitroxyl radicals. Nitroso-tert-butane was found to be a more effective uv stabiliser than nitrosobenzene and the esters of nitrosobenzene. This has been attributed to the fact that aromatic nitroso compounds produce quinonoid structures which might sensitise the photo-oxidation process. The additives may be arranged in the following order of decreased uv stabilisation effectiveness. Nitroso-tert-butane > p-isobutyl ester nitrosobenzene > p-lauryl ester nitrosobenzene > nitrosobenzene. Aromatic nitroso compounds have been shown to be better thermal anti-oxidants than nitroso-tert-butane. This is due to the abitity of the aromatic nitroso compounds to scavenge both alkyl and alkyl peroxy radicals. The aliphatic nitroso compounds can only scavenge alkyl and alkoxy radicals. The order of efficiency of the additives as termal anti-oxidants during oven ageing at 140°C may be arranged as follows. p-lauryl ester nitrosobenzene > p-isobutyl ester nitrosobenzene > nitrosobenzene > nitroso-tert-butane. The present study also attempted to explain the mechanism of anti-oxidant action of nitroso compounds on the basis of model compound studies. Evaluation of nitrosobenzoic esters as processing and photo-stabilisers for polypropylene [texte imprimé] / Boucenna, Ammar, Auteur ; Scott, G., Directeur de thèse . - Birmingham (Birmingham) : University of Aston, 1984 . - 114 f. : ill. ; 27 cm. Mémoire de Magister : Génie Chimique : Birmingham, The University of Aston : 1984 Annexe f. 115 - 122 Bibliogr. f. 123 - 125 Langues : Anglais (eng) Mots-clés : Polypropylene  ;  C-nitroso  --  compounds  --  anti-oxidant  ;  Photostabilisation Index. décimale : M005784 Résumé : In the present work, the effects of C-nitroso compounds on the melt-stabilisation, thermal and photo-oxidation of polypropylene have been studied. Both aliphatic and aromatic nitroso compounds were found to be effective melt stabilisers for PP. The stabilising effects were shown to be due to the ability of these compounds to terminate macro-alkyl radicals producing nitroxyl radicals. Nitroso-tert-butane was found to be a more effective uv stabiliser than nitrosobenzene and the esters of nitrosobenzene. This has been attributed to the fact that aromatic nitroso compounds produce quinonoid structures which might sensitise the photo-oxidation process. The additives may be arranged in the following order of decreased uv stabilisation effectiveness. Nitroso-tert-butane > p-isobutyl ester nitrosobenzene > p-lauryl ester nitrosobenzene > nitrosobenzene. Aromatic nitroso compounds have been shown to be better thermal anti-oxidants than nitroso-tert-butane. This is due to the abitity of the aromatic nitroso compounds to scavenge both alkyl and alkyl peroxy radicals. The aliphatic nitroso compounds can only scavenge alkyl and alkoxy radicals. The order of efficiency of the additives as termal anti-oxidants during oven ageing at 140°C may be arranged as follows. p-lauryl ester nitrosobenzene > p-isobutyl ester nitrosobenzene > nitrosobenzene > nitroso-tert-butane. The present study also attempted to explain the mechanism of anti-oxidant action of nitroso compounds on the basis of model compound studies.

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité	Spécialité	Etat_Exemplaire
M005784	M005784	Papier	Bibliothèque centrale	Mémoire de Magister	Disponible

Documents numériques

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