Montmorillonite (MMT) was modified through intercalative polymerization of phenol and formaldehyde catalyzed by oxalic acid. The modified montmorillonite was delaminated at large, as demonstrated by XRD and TEM studi...Montmorillonite (MMT) was modified through intercalative polymerization of phenol and formaldehyde catalyzed by oxalic acid. The modified montmorillonite was delaminated at large, as demonstrated by XRD and TEM studies. It can disperse easily in epoxy resin to form exfoliated nanocomposites. The nanoscale silicate platelets dispersed in water can be metallized by silver deposition.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
The copolymerization of propylene and 5-hexenyl-9-borabicyclo[3.3.1]nonane (5-hexenyl-9-BBN) has been conducted with an MgCl2/TiCl4 catalyst intercalated in an organically modified montmorillonite (OMMT) with triethyl...The copolymerization of propylene and 5-hexenyl-9-borabicyclo[3.3.1]nonane (5-hexenyl-9-BBN) has been conducted with an MgCl2/TiCl4 catalyst intercalated in an organically modified montmorillonite (OMMT) with triethylaluminum (AlEt3) cocatalyst and diphenyldimethoxysilane (DDS) external donor. This polymerization process simultaneously results in both the exfoliation of MMT layers to realize the preparation of polypropylene (PP)/MMT nanocomposites and the implantation of reactive borane groups in the formed PP matrix. The polymer-borne borane groups have been able to undergo an effi-cient hydrolysis process under very mild reaction conditions (40℃, 3 h, in THF), introducing hydroxy groups into PP without sacrificing the polymerization-formed nanocomposite structure (the exfoliation of MMT). The resultant hydroxyl-functionalized PP/MMT nanocomposites exhibit enhanced structural stability against processing compared with those based on unfunctionalized PP matrix.展开更多
Na +-montmorillonite(Na +-MMT) was converted to organic montmorillonite(OMMT) using modifier which was synthesized at authors’ laboratory. PA6/OMMT nanocomposite was prepared via in situ intercalative polymerization....Na +-montmorillonite(Na +-MMT) was converted to organic montmorillonite(OMMT) using modifier which was synthesized at authors’ laboratory. PA6/OMMT nanocomposite was prepared via in situ intercalative polymerization. The limiting oxygen index (LOI), UL 94V flame retardancy and thermal stability of PA6/OMMT using thermal gravity analysis (TGA) were measured. The Fourier transform infrared (FTIR) technique was used to analyze the pyrolytic residuum and the cone calorimeter (CONE) was applied to determine a number of combustion parameters which were closely related to fire safety, including heat release rate, mass loss rate, effective combustion heat, total heat release, specific extinction area and the time of ignition. In addition, the elemental composition of the surface pyrolytic residuum and the corresponding X-ray photoelectron spectroscopy (XPS) data were obtained, and the morphology of the residuum from CONE measurement was examined by scanning electron microscope (SEM).展开更多
文摘Montmorillonite (MMT) was modified through intercalative polymerization of phenol and formaldehyde catalyzed by oxalic acid. The modified montmorillonite was delaminated at large, as demonstrated by XRD and TEM studies. It can disperse easily in epoxy resin to form exfoliated nanocomposites. The nanoscale silicate platelets dispersed in water can be metallized by silver deposition.
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.
基金"One Hundred Talents Program" of the Chinese Academy of Sciences, the National Natural Science Foundation of China (Grant Nos. 20304017, 50373408 and 50573081)National "973" Project (Grant No. G2003CB615605)
文摘The copolymerization of propylene and 5-hexenyl-9-borabicyclo[3.3.1]nonane (5-hexenyl-9-BBN) has been conducted with an MgCl2/TiCl4 catalyst intercalated in an organically modified montmorillonite (OMMT) with triethylaluminum (AlEt3) cocatalyst and diphenyldimethoxysilane (DDS) external donor. This polymerization process simultaneously results in both the exfoliation of MMT layers to realize the preparation of polypropylene (PP)/MMT nanocomposites and the implantation of reactive borane groups in the formed PP matrix. The polymer-borne borane groups have been able to undergo an effi-cient hydrolysis process under very mild reaction conditions (40℃, 3 h, in THF), introducing hydroxy groups into PP without sacrificing the polymerization-formed nanocomposite structure (the exfoliation of MMT). The resultant hydroxyl-functionalized PP/MMT nanocomposites exhibit enhanced structural stability against processing compared with those based on unfunctionalized PP matrix.
文摘Na +-montmorillonite(Na +-MMT) was converted to organic montmorillonite(OMMT) using modifier which was synthesized at authors’ laboratory. PA6/OMMT nanocomposite was prepared via in situ intercalative polymerization. The limiting oxygen index (LOI), UL 94V flame retardancy and thermal stability of PA6/OMMT using thermal gravity analysis (TGA) were measured. The Fourier transform infrared (FTIR) technique was used to analyze the pyrolytic residuum and the cone calorimeter (CONE) was applied to determine a number of combustion parameters which were closely related to fire safety, including heat release rate, mass loss rate, effective combustion heat, total heat release, specific extinction area and the time of ignition. In addition, the elemental composition of the surface pyrolytic residuum and the corresponding X-ray photoelectron spectroscopy (XPS) data were obtained, and the morphology of the residuum from CONE measurement was examined by scanning electron microscope (SEM).
