An infrared dichroism study on the orientation of PS in the shear induced ordered structure in PS/montmorillonite nanocomposite was carried out. The results showed that the phenyl ring oriented apparently parallel to ...An infrared dichroism study on the orientation of PS in the shear induced ordered structure in PS/montmorillonite nanocomposite was carried out. The results showed that the phenyl ring oriented apparently parallel to the film surface, whereas no obvious orientation of the aliphatic chain could be observed. On the basis of both of our previous and present investigations, a possible formation mechanism was presented. [WT5HZ]展开更多
A shear induced ordered structure in an exfoliated polystyrene(PS)/clay nanocomposite is reported. Self\|assembly behavior was reported for the first time of a shear induced ordered structure in the nanocomposite. The...A shear induced ordered structure in an exfoliated polystyrene(PS)/clay nanocomposite is reported. Self\|assembly behavior was reported for the first time of a shear induced ordered structure in the nanocomposite. The self assembly behavior was measured by X ray diffraction(XRD) patterns, transmission electron microscopy(TEM), and FTIR dichroism technique. Compared with the broad amorphous peaks of the PS, a series of sharp XRD peaks were observed for the exturded PS/clay nanocomposite pellet sample, showing that an ordered sructure occurred under shear flow. The intensities of the four sharp XRD peaks of the ordered sructure decreased significantly with temperature. However, at 95 ℃, the XRD peaks increased significantly, the FTIR dichroism showing that and the phenyl ring of PS changed its orientation from parallel to perpendicular to the monmorillonite primary particles, whereas no obvious orientation of the alkyl chain of PS could be found. At 110 ℃, a disordered structure occurred for the phenyl ring. TEM images confirmed directly that the origin of the ordered structure was mainly due to the planar orientation of the primary particles of silicate layers as well as local ordered microsructure of the primary particles, induced by shear flow. Basd on these investigations, a possible mechanism was deduced for the formation of the ordered strucure induced by shear flow in the exfoliated PS/clay nanocomposite.展开更多
A shear induced ordered structure in PS/montmorillonite nanocomposite was observed for the first time by wide angle X ray diffraction technique. A transmission electron microscopy result showed that the randomly place...A shear induced ordered structure in PS/montmorillonite nanocomposite was observed for the first time by wide angle X ray diffraction technique. A transmission electron microscopy result showed that the randomly placed primary particles of montmorillonite were oriented parallel to the pellet surface, and the interior of the primary particles became more ordered as well. These results suggested that the orientation of the primary particles as well as the interior ordered structure induced by the shear flow were perhaps the origin of the ordered structure in the PS/montmorillonite nanocomposite.展开更多
Poly(styrene-acrylonitrile) emulsion particles with positive charges on the surface were synthesized by emulsion polymerization using cationic surfactant octotyltrimethyl ammonium chloride (OTAC) as emulsifier.The sus...Poly(styrene-acrylonitrile) emulsion particles with positive charges on the surface were synthesized by emulsion polymerization using cationic surfactant octotyltrimethyl ammonium chloride (OTAC) as emulsifier.The suspension of montmorillonite was slowly dropped into the emulsion.Through the interaction between the negative charges on the montmorillonite layers and the cations on the surface of poly(styrene-acrylonitrile) particles, the montmorillonite layers and emulsion particles could assemble and absorb on each other by themselves.The change of δ voltage and particle size of the emulsion during the process of dropping was characterized, which demonstrated that the emulsion particles and montmorillonite layers absorbed on each other by the electrovalent bond and an intersectional structure was formed in the complex emulsion.Poly(styrene-acrylonitrile)/ montmorillonite nanocomposite was obtained after coagulation.The structure of nanocomposite was characterized with XRD and TEM.The results indicated that montmorillonite was exfoliated into layers with a thickness of several nanometers and uniformly dispersed in the polymer matrix.展开更多
文摘An infrared dichroism study on the orientation of PS in the shear induced ordered structure in PS/montmorillonite nanocomposite was carried out. The results showed that the phenyl ring oriented apparently parallel to the film surface, whereas no obvious orientation of the aliphatic chain could be observed. On the basis of both of our previous and present investigations, a possible formation mechanism was presented. [WT5HZ]
文摘A shear induced ordered structure in an exfoliated polystyrene(PS)/clay nanocomposite is reported. Self\|assembly behavior was reported for the first time of a shear induced ordered structure in the nanocomposite. The self assembly behavior was measured by X ray diffraction(XRD) patterns, transmission electron microscopy(TEM), and FTIR dichroism technique. Compared with the broad amorphous peaks of the PS, a series of sharp XRD peaks were observed for the exturded PS/clay nanocomposite pellet sample, showing that an ordered sructure occurred under shear flow. The intensities of the four sharp XRD peaks of the ordered sructure decreased significantly with temperature. However, at 95 ℃, the XRD peaks increased significantly, the FTIR dichroism showing that and the phenyl ring of PS changed its orientation from parallel to perpendicular to the monmorillonite primary particles, whereas no obvious orientation of the alkyl chain of PS could be found. At 110 ℃, a disordered structure occurred for the phenyl ring. TEM images confirmed directly that the origin of the ordered structure was mainly due to the planar orientation of the primary particles of silicate layers as well as local ordered microsructure of the primary particles, induced by shear flow. Basd on these investigations, a possible mechanism was deduced for the formation of the ordered strucure induced by shear flow in the exfoliated PS/clay nanocomposite.
文摘A shear induced ordered structure in PS/montmorillonite nanocomposite was observed for the first time by wide angle X ray diffraction technique. A transmission electron microscopy result showed that the randomly placed primary particles of montmorillonite were oriented parallel to the pellet surface, and the interior of the primary particles became more ordered as well. These results suggested that the orientation of the primary particles as well as the interior ordered structure induced by the shear flow were perhaps the origin of the ordered structure in the PS/montmorillonite nanocomposite.
文摘Poly(styrene-acrylonitrile) emulsion particles with positive charges on the surface were synthesized by emulsion polymerization using cationic surfactant octotyltrimethyl ammonium chloride (OTAC) as emulsifier.The suspension of montmorillonite was slowly dropped into the emulsion.Through the interaction between the negative charges on the montmorillonite layers and the cations on the surface of poly(styrene-acrylonitrile) particles, the montmorillonite layers and emulsion particles could assemble and absorb on each other by themselves.The change of δ voltage and particle size of the emulsion during the process of dropping was characterized, which demonstrated that the emulsion particles and montmorillonite layers absorbed on each other by the electrovalent bond and an intersectional structure was formed in the complex emulsion.Poly(styrene-acrylonitrile)/ montmorillonite nanocomposite was obtained after coagulation.The structure of nanocomposite was characterized with XRD and TEM.The results indicated that montmorillonite was exfoliated into layers with a thickness of several nanometers and uniformly dispersed in the polymer matrix.
