Documents disponibles écrits par cet auteur

Synthesis and characterization of all acrylic block copolymer / clay nanocomposites prepared via surface initiated atom transfer radical polymerization (SI - ATRP) / Dhruba J. Haloi in Industrial & engineering chemistry research, Vol. 51 N° 29 (Juillet 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9760-9768 Titre : Synthesis and characterization of all acrylic block copolymer / clay nanocomposites prepared via surface initiated atom transfer radical polymerization (SI - ATRP) Type de document : texte imprimé Auteurs : Dhruba J. Haloi, Auteur ; Souvik Ata, Auteur ; Nikhil K. Singha, Auteur Année de publication : 2012 Article en page(s) : pp. 9760-9768 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Polymerization  Nanocomposite Résumé : Surface initiated polymerization (SIP) is an emerging powerful tool to modify and tailor the surface properties of nanoparticles. Among different methods of SIP, surface initiated atom transfer radical polymerization (SI-ATRP) has several strategic advantages over other methods of polymerizations. This investigation reports the preparation and characterization of poly(2-ethylhexyl acrylate) (PEHA)/clay nanocomposite from nanoclay surface via SI-ATRP and poly(2-ethylhexyl acrylate)-block-poly(methyl methacrylate) (PEHA-b-PMMA)/clay nanocomposite via conventional ATRP. To carry out SI-ATRP, the nanoclay (Cloisite Na+) surface was first modified by incorporating an ATRP initiator (2-bromopropionyl bromide) to nanoclay surface via a grafting reaction. The prepared bromo-functionalized nanoclay (Clay—Br) was then used to carry out SI-ATRP of 2-ethylhexyl acrylate (EHA) at 90 °C using CuBr as catalyst in combination with N, N, N', N", N"- pentamethyl diethylenetriamine (PMDETA) as the ligand. The macroinitiator (clay-PEHA-Br) was used to prepare PEHA-b-PMMA/clay nanocomposites via conventional ATRP using the same reaction conditions as SI-ATRP of EHA. A series of PEHA-b-PMMA/ clay nanocomposites were prepared via ATRP. The prepared PEHA/clay nanocomposites and PEHA-b-PMMA/clay nanocomposites were characterized by WAXD and TEM analyses. DSC analysis of PEHA-b-PMMA/clay nanocomposites showed two Tg values corresponding to two blocks present in the block copolymers. TGA analysis was also carried out to study the thermal stability of PEHA/clay nanocomposites and PEHA-b-PMMA/clay nanocomposites at different nanoclay loading. The chemical structure and molecular weights of the prepared polymers were analyzed by Fourier transform infrared (FT-IR), 1H NMR, and gel permeation chromatography (GPC) analyses. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26184954 [article] Synthesis and characterization of all acrylic block copolymer / clay nanocomposites prepared via surface initiated atom transfer radical polymerization (SI - ATRP) [texte imprimé] / Dhruba J. Haloi, Auteur ; Souvik Ata, Auteur ; Nikhil K. Singha, Auteur . - 2012 . - pp. 9760-9768. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 29 (Juillet 2012) . - pp. 9760-9768 Mots-clés : Polymerization  Nanocomposite Résumé : Surface initiated polymerization (SIP) is an emerging powerful tool to modify and tailor the surface properties of nanoparticles. Among different methods of SIP, surface initiated atom transfer radical polymerization (SI-ATRP) has several strategic advantages over other methods of polymerizations. This investigation reports the preparation and characterization of poly(2-ethylhexyl acrylate) (PEHA)/clay nanocomposite from nanoclay surface via SI-ATRP and poly(2-ethylhexyl acrylate)-block-poly(methyl methacrylate) (PEHA-b-PMMA)/clay nanocomposite via conventional ATRP. To carry out SI-ATRP, the nanoclay (Cloisite Na+) surface was first modified by incorporating an ATRP initiator (2-bromopropionyl bromide) to nanoclay surface via a grafting reaction. The prepared bromo-functionalized nanoclay (Clay—Br) was then used to carry out SI-ATRP of 2-ethylhexyl acrylate (EHA) at 90 °C using CuBr as catalyst in combination with N, N, N', N", N"- pentamethyl diethylenetriamine (PMDETA) as the ligand. The macroinitiator (clay-PEHA-Br) was used to prepare PEHA-b-PMMA/clay nanocomposites via conventional ATRP using the same reaction conditions as SI-ATRP of EHA. A series of PEHA-b-PMMA/ clay nanocomposites were prepared via ATRP. The prepared PEHA/clay nanocomposites and PEHA-b-PMMA/clay nanocomposites were characterized by WAXD and TEM analyses. DSC analysis of PEHA-b-PMMA/clay nanocomposites showed two Tg values corresponding to two blocks present in the block copolymers. TGA analysis was also carried out to study the thermal stability of PEHA/clay nanocomposites and PEHA-b-PMMA/clay nanocomposites at different nanoclay loading. The chemical structure and molecular weights of the prepared polymers were analyzed by Fourier transform infrared (FT-IR), 1H NMR, and gel permeation chromatography (GPC) analyses. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26184954