Polystyrene composites

It was apparent that the dense adsorption layer of HPC which was formed on the silica particles at the LCST plays a part in the preparation of new composite polymer latices, i.e. polystyrene latices with silica particles in the core. Figures 10 and 11 show the electron micrographs of the final silica-polystyrene composite which resulted from seeded emulsion polymerization using as seed bare silica particles, and HPC-coated silica particles,respectively. As may be seen from Fig.10, when the bare particles of silica were used in the seeded emulsion polymerization, there was no tendency for encapsulation of silica particles, and indeed new polymer particles were formed in the aqueous phase. On the other hand, encapsulation of the seed particles proceeded preferentially when the HPC-coated silica particles were used as the seed and fairly monodisperse composite latices including silica particles were generated. This indicated that the dense adsorption layer of HPC formed at the LCST plays a role as a binder between the silica surface and the styrene molecules. 

The MWCNT-filled polystyrene composites have good electromagnetic interference shielding properties (Snow and Perkins, 2005). The shielding effectiveness of MWCNT-filled composites was frequency independent, and increased with the... 

T. E. Chang, A. Kisliuk, S. M. Rhodes, W. J. Brittain, A.P. Sokolov, Conductivity and mechanical properties of well-dispersed single-wall carbon nanotube/polystyrene composite, Polymer, vol. 47, pp. 7740-7746, 2 0 06. 

Liu H, Pan L, Lin Q, Xu N, Lu L, Pang S, Fu S (2010) Preparation and characterization of poly (propylene carbonate)/polystyrene composite films by melt-extrusion method, e-polymers 2010 38, http //www.e-polymers.org/joumal/papers/qlin 270310.pdf. Accessed 01 April 2011... 

Pan et al recently reported the preparation and characterization of polystyrene/graphite composites prepared by cationic grafting polymerization. Graphite/polystyrene composites were produced with cationic grafting... 

The effect of fiber diameter on the tensile strength of a glass-fiber-reinforced polystyrene composite is shown in Figure 5.100. Some reinforcements also have a distribution of fiber diameters that can affect properties. Recall from the previous section that the fiber aspect ratio (length/diameter) is an important parameter in some mechanical property correlations. 

Rubber-toughened polystyrene composites were obtained similarly by polymerising the dispersed phase of a styrene/SBS solution o/w HIPE [171], or a styrene/MMA/(SBS or butyl methacrylate) o/w HIPE [172], The latter materials were found to be tougher, however, all polymer composites had mechanical properties comparable to bulk materials. Other rubber composite materials have been prepared from PVC and poly(butyl methacrylate) (PBMA) [173], via three routes a) blending partially polymerised o/w HIPEs of vi-nylidene chloride (VDC) and BMA, followed by complete polymerisation b) employing a solution of PBMA in VDC as the dispersed phase, with subsequent polymerisation and c) blending partially polymerised VDC HIPE with BMA monomer, then polymerisation. All materials obtained possessed mixtures of both homopolymers plus some copolymer, and had better mechanical properties than the linear copolymers. The third method was found to produce the best material. 

If both continuous and dispersed phases of highly concentrated emulsions contain monomeric species, it is possible to obtain hydrophilic/hydrophobic polymer composite materials. Polyacrylamide/polystyrene composites have been prepared in this manner [180], from both w/o and o/w HIPEs containing aqueous acrylamide and a solution of styrene in an organic solvent. 

Figure 12. Thermomechanical behavior of an acetylated-propionylated wood sample and the acetylated-propionylated wood-polystyrene composites prepared by the y-ray induced graft copolymerization in a pyridine medium. Numerical values on the curves represent the total dose of the irradiated y-ray. Key (total irradiation, resultant weight increase based on the weight of wood) A, 0.1 Mrad, 4.2% , 0.5 Mrad, 12.2% , 1.9 Mrad, 49.1% A, 2.4 Mrad, 66.0% and ,...

Figure 13. Thermomechanical behavior of O, the acetylated wood and , the acetylated wood-polystyrene composite prepared by the y-ray induced graft copolymerization in a pyridine medium. Conditions total dose, 2 Mrad resultant...

Figure 13. Electron microscope picture of the surface morphology of zinc polystyrene composites deposited from, from top to bottom, surfactant-free, PS = 0.05 0.3 mol kg CTAC, 4>ps = 0.02 and 0.2 mol kg CPC.

Table 7. The amounts of the components used in the preparation of the polyacrylamide polystyrene composite...

Barraza [2] prepared single-walled nanotube/polystyrene composites by miniemulsion polymerization, using surfactants, styrene, and nanotubes grafted with varying degrees of glucosamine, (11). 

Fig. 1. Kinetic curves of styrene absorption. Curve 1 viscose staple fibre, curve 2 cotton, curve 3 graft copolymer of viscose staple fibre and polystyrene, composition 86.1% 13.9%, curve 4 graft copolymer of cotton and polystyrene, composition 84.8% 15.2%, curve 5 grafted polystyrene isolated from the copolymer with staple fibre, curve 6 grafted polystyrene isolated from the copolymer with cotton absorption conditions [St] -1%, M-25, emulsifier concentration 0.2%, temperature - 65°...

In a similar way, well-dispersed nickel nanopartides in polystyrene were obtained by a sonochemical method [62]. The first step in this synthesis was the preparation of nickel formate, which was prepared according to a previously described method. The preparation of the nickel-polystyrene composite was carried out by the sonochemical method. Typically, 500 mg of nickel formate and 1 g of polystyrene (Aldrich Mw = 350,000) are dissolved in 100 mL of N,N-dimethylform-... 

Figure 15.27. Debonded glass bead fraction, vs. strain for polystyrene composites. [Adapted, by permission, from Meddad A, Fisa B, Macromol. Symp., 108. 1996, 173-82.]...

Li D, Flan BX. Impregnation of polyethylene (PE) with styrene using supercritical CO2 as the swelling agent and preparation of PE/polystyrene composites. Ind Eng Chem Res 2000 39 4506 509. 

Zeolite shells on polystyrene beads were prepared by a combination of layer-by-layer (LbL) and hydrothermal synthesis techniques. The negatively charged polystyrene beads were surface modified in order to adsorb zeolite Beta nanocrystals. Such particles were then adsorbed on the surface of the beads and induced to grow into a continuous film of intergrown crystals of zeolite Beta. The effect of the preliminary treatment on the formation of the zeolite film was studied. Finally the polystyrene beads used as macro-templates were removed by calcination in air, yielding hollow spheres of zeolite Beta. The zeolite Beta/polystyrene composites and the corresponding hollow zeolite spheres were characterized by XRD, SEM, TG/DTA and BET surface area measurements. 

Yan F, Li J, Zhang J, et al. (2(X)9) Preparation of Fe304/polystyrene composite particles from monolayer oleic acid modified Fe304 nanoparticles via miniemulsion polymerization. J Nanopart Res 11 289-296... 

The fabrication and electrical properties of carbon nanofiber-polystyrene composites and their potential applications for EMI shielding have been reported [42]. Being lightweight is a key technological requirement for the development of practical EMI shielding systems. Thus the fabrication of foam structures to further reduce the weight of carbon nonofiber-ploymer composites has been recently demonstrated and simple preparation routine has been reported [43] by which this novel foam structure can be prepared. 

D.B. Cairns, S.P. Armes, and L.G.B. Bremer, Synthesis and characterization of submicrom-eter-sized polypyrrole-polystyrene composite particles, Langmuir, 15(23), 8052-8058 (1999). 

D. Aussawasathien, S. Sahasithiwat, and L. Menbangpung, Electrospun camphorsulfonic acid doped poly(o-toluidine)-polystyrene composite fibers Chemical vapor sensing, Synth. Met., 158, 259-263 (2008). 

Wang, Y, Xu, J., Bechtel, S. E., and Koelling, K. W, Melt shear rheology of carbon nan-otube/polystyrene composites, Rheol. Acta, 45, 919-941 (2006b). 

Fig. 2 Le/i Silica/polystyrene composite particles elaborated through emulsion polymerization using MPTMS as silane coupling agent. Right TEM images reproduced (a) from [25] (scale bars 200 nm) with permission of Wiley-VCH, (b) from [26] with permission of Springer, (c) from [27] with permission of American Chemical Society, and (d) from [28] with permission of Wiley-VCH...

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