Polystyrene nanocomposites

FLAME RETARDANT MECHANISM OF POLYMER-CLAY NANOCOMPOSITES 

FIGURE 3.3 Mass loss rate data for PS, PS with micro-dispersed NaMMT, and a PS/mass fraction 10% MMT nanocomposite with a mixed intercalated-delaminated structure. The times at which partially pyrolized samples were exposed to pyrolysis wrae 82, 

FIGURE 3.4 TEM images of MMT layers in a PS/mass fraction 10% MMT nanocomposite (a) before and (b) after pyrolysis. 

FIGURE 3.5 Image of a PS/mass fraction 10% MMT nanocomposite pyrolized for 82 s. The image on the right shows a cross section and has had the surface char partially removed. (See insert for color representation of figure.) 

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Beckert, F., et al., Sulfur-functionalized graphenes as macro-chain-transfer and RAFT agents for producing graphene polymer brushes and polystyrene nanocomposites. Macromolecules, 2012. 45(17) p. 7083-7090. 

Carroll JB, Waddon AJ, Nakade H, Rotello VM. Plug and play polymers. Thermal and X-ray characterizations of noncovalently grafted polyhedral oligomeric silsesquioxane (POSS)-polystyrene nanocomposites. Macromolecules 2003 36 6289-6291. 

Chigwada, G., Jiang, D. D., and Wilkie, C. A. Polystyrene nanocomposites based on carbazole-containing surfactants, Thermochimica Acta (2005), 436, 13-121. 

Interesting thermal response of the polystyrene nanocomposites was reported when untreated and polystyrene grafted nanotubes were used for the reinforcement of polymer (49). The glass transition temperature of the pure polystyrene matrix was observed to be 99 °C. Similar transition temperature of 98 °C was observed for the composites containing 2.5 vol% of the untreated nanotubes. The nanocomposites containing polymer functionalized nanotubes... 

Gilman, J.W. Jackson, C.L. Morgan, A.B. Harris, R. Manias, E. Giannelis, E.P. Wuthenow, M. Hilton, D. Phillips, S.H. Flammability properties of polymer-layered-silicate nanocomposites. Polypropylene and polystyrene nanocomposites. Chem. Mater. 2000, 12, 1866-1873. 

Morgan, A.B. Chu, L.L. Harris, J.D. A flammability performance comparison between synthetic and natural clays in polystyrene nanocomposites. Proceedings of Flame Retardants, 27-28, January 2004 Interscience Communications London, U.K., 2004 85-96. 

Bellayer S, Gilman JW, Eidehnan N et al (2(X)5) Preparation of homogeneously dispersed multiwalled caibon nanotube/polystyrene nanocomposites via melt extrusion using trialkyl imidazolium compatibilizer. Adv Fund Mater 15 910-916... 

In this part of the chapter we discuss (a) the controlled thermolysis of thiolate solutions in polystyrene matrix at temperatures above the polymer glass transition temperature and (b) the reaction mechanism in the case of silver-polystyrene nanocomposite systems. However, the same reaction mechanism is probably involved in the thermolysis of other mercaptide-polystyrene systems. This technique has proven to be an excellent new preparative scheme for the generation of both metal and sulfide clusters in polymers. In particular, high-molecular-weight n-alkanethiolates have shown to be the most effective compound class since the low volatility of thermolysis by-products avoids film foaming during the annealing process. 

CdS and CdS/polyacrylonitrile (PAN) nanocomposites were prepared by y-irradiation and emulsion polymerization by different groups (Qiao et al. 2000, Choi et al. 2003). In photoluminescence spectroscopy analysis, the maximum peak of CdS/PAN nanocomposites prepared by y-irradiation and emulsion polymerization was at about 485 nm, whereas the maximum peak of CdS nanocomposites was at about 460 nm. CdS-polystyrene nanocomposite microspheres were fabricated by gamma-ray irradiation (Wu et al. 2003). Dispersion polymerization induced by gamma-ray irradiation was exploited to prepare monodispersed polystyrene microspheres and CdS nanoparticles were generated on the polystyrene microsphere surface via subsequent precipitation reaction of Cd + with S released from the decomposition of Na2S203 upon gamma-ray irradiation (Equation 23.3). The TEM images demonstrated that well-dispersed CdS nanoparticles ( 23 nm) were attached to the surface of polystyrene microspheres of 380 nm. 

Further, Wu et al. (2004) exploited radiation chemical technique to synthesize CdS/polystyrene nanocomposite hollow spheres with diameters between 240 and 500 nm under ambient conditions in which the polymerization of styrene and the formation of CdS nanoparticles were initiated by y-irradiation. It was demonstrated that the walls of the hollow spheres were porous and composed of polystyrene containing homogeneously dispersed CdS nanoparticles (Figure 23.14). The quantum-confined effect of the CdS/polystyrene nanocomposite hollow spheres was confirmed by the ultraviolet-visible (UV-vis) and PL spectra. They proposed that the walls of these nanocomposite hollow spheres originated from the simultaneous synthesis of polystyrene and CdS nanoparticles at the interface of microemulsion droplets. 

Wu, D., Ge, X., Huang, Y., Zhang Z., and Ye, Q. 2003. y-Radiation synthesis of silver-polystyrene and cadmium sulfide-polystyrene nanocomposite microspheres. Mater. Lett. 57 3549-3555. 

Wu, D., Ge, X., Zhang, Z., Wang M., and Zhang, S. 2004. Novel one-step route for synthesizing CdS/polystyrene nanocomposite hollow spheres. Langmuir 20 5192-5195. 

BaUly B, Donnenwitth AC, Bartholome C, et td. (2006) Silica-polystyrene nanocomposite particles synthesized by nitroxide-mediated polymerization and their encapsulation through miniemulsion polymerization. J Nanomater 2006 1—10... 

Quian Z, Zhicheng Z, Yun C (2008) A novel preparation of surface-modified paramagnetic magnetite/polystyrene nanocomposite microspheres by radiation-induced miniemulsion polymerization. J Colloid Interface Sci 327 354-361... 

Hoffmann, B., Dietrich, C., Thomann, R., Friedrich, C., andMulhaupt, R., Morphology and rheology of polystyrene nanocomposites based upon organoclay, Macromol. Rapid Commun.,... 

FIGURE 15.6 TE micrographs showing the inner microstructure of a gold-polystyrene nanocomposite (3 wt% of AUSC12H25) obtained by rapid solvent evaporation during the blend preparation stage. 

FIGURE 15.8 Large-angle x-ray powder diffraction of (a) gold-polystyrene nanocomposites and (b) CdS-polyst5n ene nanocomposites. 

Bartholome, C., Beyou, E., Bourgeat-Lami, E., Cassagnau, Ph., ChaumonL Ph., David, L., and Zydowicz, N., Viscoelastic properties and morphological characterization of sUica/polystyrene nanocomposites synthesized hy nitroxide-mediated polymerization. Polymer, 46,9965-9973 (2005). 

Okamoto, M., Morita, S., Taguchi, H., Kim, Y. H., Kotaka, T., and Tateyama, H., Synthesis and structure of smectic clay/poly(methyl methacrylate) and clay/polystyrene nanocomposites via in situ intercalative polymerization. Polymer, 41, 3887-3890 (2000). 

Zhang SW, Zhou SX, Weng YM et al (2005) Synthesis of Si02/polystyrene nanocomposite particles via miniemulsion polymerization. Langmuir 21 2124-2128... 

More recently, the fabrication of multihollow superparamagnetic magnetite/ polystyrene nanocomposite particles via water-in-oil-in-water (W/O/W) double emulsions (Fig. 15) was demonstrated [148]. 

Frankowski, D. J., Capracotta, M. D., Martin, J. D., Khan, S. A., and Spontak, R. J. 2007. Stability of organically modified montmorillonites and their polystyrene nanocomposites after prolonged thermal treatment. Chemistry of Materials 19 2757-2767. 

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