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Investigating the effect of pristine and modified silica nanoparticles on the kinetics of methyl methacrylate polymerization / Mehdi Salami-Kalajahi in Chemical engineering journal, Vol. 174 N° 1 (Octobre 2011) 

Public ISBD [article]  in Chemical engineering journal > Vol. 174 N° 1 (Octobre 2011) . - pp.368–375 Titre : Investigating the effect of pristine and modified silica nanoparticles on the kinetics of methyl methacrylate polymerization Type de document : texte imprimé Auteurs : Mehdi Salami-Kalajahi, Auteur ; Vahid Haddadi-Asl, Auteur ; Saeid Rahimi-Razin, Auteur Année de publication : 2012 Article en page(s) : pp.368–375 Note générale : Génie chimique Langues : Anglais (eng) Mots-clés : In  situ  polymerization  Kinetics  Rate  coefficient  Poly(methyl  methacrylate)  Silica  nanoparticles Résumé : To study the effect of silica nanoparticles on the kinetics of methyl methacrylate free radical polymerization, a number of batch polymerizations were performed using pristine and methacrylate-modified silica nanoparticles at 75 °C. In addition, effect of temperature was investigated on the kinetics of polymerization with 1 wt% loading of pristine nanoparticles. Monomer conversion, reaction rate, molecular weight and polydispersity index (PDI) of each polymerization were monitored during polymerization. According to results, no considerable change was obtained on the polymerization kinetics by introduction of any type of nanoparticles, while there is an optimum loading value in which the polymerization rate reaches its maximum level. A similar trend is observed for molecular weight of free chains; however, increasing silica content results in increased PDI values. Also, polymerizations rate is slower for batches containing modified nanoparticles. For chains which are grafted on the surface of modified nanoparticles, molecular weight and PDI values increase by increasing nanoparticle content. ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science/article/pii/S1385894711010667 [article] Investigating the effect of pristine and modified silica nanoparticles on the kinetics of methyl methacrylate polymerization [texte imprimé] / Mehdi Salami-Kalajahi, Auteur ; Vahid Haddadi-Asl, Auteur ; Saeid Rahimi-Razin, Auteur . - 2012 . - pp.368–375. Génie chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 174 N° 1 (Octobre 2011) . - pp.368–375 Mots-clés : In  situ  polymerization  Kinetics  Rate  coefficient  Poly(methyl  methacrylate)  Silica  nanoparticles Résumé : To study the effect of silica nanoparticles on the kinetics of methyl methacrylate free radical polymerization, a number of batch polymerizations were performed using pristine and methacrylate-modified silica nanoparticles at 75 °C. In addition, effect of temperature was investigated on the kinetics of polymerization with 1 wt% loading of pristine nanoparticles. Monomer conversion, reaction rate, molecular weight and polydispersity index (PDI) of each polymerization were monitored during polymerization. According to results, no considerable change was obtained on the polymerization kinetics by introduction of any type of nanoparticles, while there is an optimum loading value in which the polymerization rate reaches its maximum level. A similar trend is observed for molecular weight of free chains; however, increasing silica content results in increased PDI values. Also, polymerizations rate is slower for batches containing modified nanoparticles. For chains which are grafted on the surface of modified nanoparticles, molecular weight and PDI values increase by increasing nanoparticle content. ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science/article/pii/S1385894711010667