Some vinyl polymers/montmorillonite nanocomposites were prepared via in-situ-atom transfer radical polymerization (ATRP) in presence of clay. Methyl methacrylate, styrene and n-butyl methacrylate were involved in the ...Some vinyl polymers/montmorillonite nanocomposites were prepared via in-situ-atom transfer radical polymerization (ATRP) in presence of clay. Methyl methacrylate, styrene and n-butyl methacrylate were involved in the formation of such polymeric nanocomposites. Their dielectric properties were extensively studied to invest them in the a.c. power applications. Several dielectric parameters such as dielectric constant loss (ε") and a.c. conductivity (σ) were measured at both different frequencies (0.1 Hz to 100 KHz) and temperature ranged from (20℃ to 90℃). From the dielectric results, it was realized that the dielectric a.c. conductivity was enhanced by increasing the temperature for the four prepared polymer nanocomposites.展开更多
Well-defined homo glycopolymer/montmorillonite (MMT) nanocomposite (gly1) was prepared successfully by the “grafting from” technique from the modified surface of MMT via surface initiated atom transfer radical polym...Well-defined homo glycopolymer/montmorillonite (MMT) nanocomposite (gly1) was prepared successfully by the “grafting from” technique from the modified surface of MMT via surface initiated atom transfer radical polymerization (SI-ATRP) of 3-O-methacryloyl-1,2:5,6-di-O-isopropylidene-α-D-glucofuranose (gly) in the presence of Cu(I)Br/ bi- pyridyl at 90?C in xylene. Well-defined diblock copolymers (gly2, gly3, gly4 and gly5) were also synthesized via the same technique by using comonomers of methylmethacrylate (MMA) or styrene (St) with glycomonomer (gly) using the same catalytic system. The formed nanocomposites showed both intercalated and exfoliated structures, as judged by XRD and TEM measurements. Further analyses were performed on such nanocomposites to confirm their formation such as TGA and DSC. The structures of the attached polymers to MMT were characterized by 1H NMR.展开更多
文摘Some vinyl polymers/montmorillonite nanocomposites were prepared via in-situ-atom transfer radical polymerization (ATRP) in presence of clay. Methyl methacrylate, styrene and n-butyl methacrylate were involved in the formation of such polymeric nanocomposites. Their dielectric properties were extensively studied to invest them in the a.c. power applications. Several dielectric parameters such as dielectric constant loss (ε") and a.c. conductivity (σ) were measured at both different frequencies (0.1 Hz to 100 KHz) and temperature ranged from (20℃ to 90℃). From the dielectric results, it was realized that the dielectric a.c. conductivity was enhanced by increasing the temperature for the four prepared polymer nanocomposites.
文摘Well-defined homo glycopolymer/montmorillonite (MMT) nanocomposite (gly1) was prepared successfully by the “grafting from” technique from the modified surface of MMT via surface initiated atom transfer radical polymerization (SI-ATRP) of 3-O-methacryloyl-1,2:5,6-di-O-isopropylidene-α-D-glucofuranose (gly) in the presence of Cu(I)Br/ bi- pyridyl at 90?C in xylene. Well-defined diblock copolymers (gly2, gly3, gly4 and gly5) were also synthesized via the same technique by using comonomers of methylmethacrylate (MMA) or styrene (St) with glycomonomer (gly) using the same catalytic system. The formed nanocomposites showed both intercalated and exfoliated structures, as judged by XRD and TEM measurements. Further analyses were performed on such nanocomposites to confirm their formation such as TGA and DSC. The structures of the attached polymers to MMT were characterized by 1H NMR.
