Styrene copolymer particles, carbon

Figure 3. SEM picture at SkX (top) and 17kx (hottom) of styrene copolymer particles with 0.5 wt % Regal 330 carbon black on the surface. The nodules are probably carbon black aggregates.

The changes in contact charging observed with different carbon blacks at the surface of styrene copolymer particles is shown in Figure 8. These samples all have 5% of a carbon black tacked onto the... 

Figure 8. Charge levels of particles with 5 wt % carbon black on the surface of styrene copolymer particles as a function of applied electrode potential. Key O, Vulcan XC72R A, Regal 330 , Black Pearls L and , Raven 5750.

Hradil et al. [395, 396] prepared a set of composite membranes containing fine particles of conventional macroporous resins or hypercrosslinked polystyrene adsorbing materials in films of poly(2,6-dimethyl-l,4-phenylene oxide) as a binder. Hypercrosslinked resins were either a commercial product, Lewatit EP63 (Bayer AG), or were obtained by crosslinking (i) a macroporous styrene—divinylbenzene (DVB) copolymer with carbon tetrachloride (Hyp-St—DVB) or (ii) a finear polystyrene with monochlorodi-methyl ether. In the latter case the reaction of bridging was conducted in a pretty diluted ethylene dichloride solution at stirring, which resulted in obtaining a particulate (1—5 pm) product. 

FIGURE 20.14 (a) Height image of a cluster of carbon black (CB) particles. The sample was prepared by pressing the particles into a pellet, (b) Optical micrograph of a cryo-ultramicrotome cut of a mbbery composite loaded with silica, (c, d) Phase images of a nanocomposite of polyurethane (PU) loaded with silica and a mbber blend based on natural mbber (NR) and styrene-butadiene copolymer (SBR) loaded with siUca, respectively. The samples were prepared with a cryo-ultramicrotome. 

The dispersion polymerization of styrene in supercritical CO2 using amphiphilic diblock copolymers to impart steric stabilization has been investigated. Lipophilic, C02-insoluble materials can be effectively emulsified in carbon dioxide using amphiphilic diblock copolymer surfactants. The resulting high yield (> 90%) of polystyrene is obtained in the form of a stable polymer colloid comprised of submicron-sized particles (Canelas et al., 1996). 

Mixed matrix membranes have been prepared from ABS and activated carbons. The membranes are intended for gas separation. A random agglomeration of the carbon particles was observed. A close interfacial contact between the polymeric and filler phases was observed. This morphology between inorganic and organic phases is believed to arise from the partial compatibility of the styrene/butadi-ene chains of the ABS copolymer and the activated carbon structure. A good permeability and selectivity for mixtures of carbon dioxide and methane has been reported (91,92). 

Following the guidelines established by Schechter s work, we dispersed titanium dioxide particles in 1% solutions of carboxylated styrene-butadiene block copolymers and stirred the dispersions at elevated temperatures in a nitrogen atmosphere. Typical data are shown in Table I. The dispersions (primary dispersions) in o-dichlorobenzene were quite stable. The titanium dioxide particles were isolated from these primary dispersions by centrifugation and were washed with toluene and finally with methanol. After drying in vacuo, samples of the block copolymer-titanium dioxide composites were submitted for carbon analysis. The... 

Highly hydrophobic sorbents including porous carbon and copolymers of styrene and divinylbenzene (SDB) were widely investigated for environmental applications. The particle-loaded membranes containing modified SDB particles with surface sulfonic acid groups were successfully used for recovering different alcohols, phenols, aldehydes, ketones, or esters from aqueous samples [221]. Carbon-based PLM were also used for isolation of highly polar pesticides from water [222]. 

Reversed-phase LC is ideally suited for the analysis of polar and ionogenic analytes, and as such is ideally suited to be applied in LC-MS. Reversed-phase LC is the most widely used LC method. Probably, over 50% of the analytical applications are preformed by reversed-phase LC. Nonpolar, chemically-modified silica or other nonpolar packing materials, such as styrene-divinylbenzene copolymers (XAD, PRP) or hybrid silicon-carbon particles (XTerra), are used as stationary phases in combination with aqueous-organic solvent mixtures. Silica-based packing materials are used more frequently than polymeric packing materials. 

These properties determine how carbon black will be distributed within the blend. These properties are not those of the filler but are the essential properties of the matrix. The matrix thus has strong influence on particle distribution. SEM studies showed that high vinyl polybutadiene and styrene-butadiene copolymers had morphologically identical carbon black distribution. However, their mechanical properties were very different. NMR analysis indicated that the difference in mechanical behavior is related to the interaction and more precisely to the molecular motions in rubbery matrix. 

Hydrogenation is the most well studied area among immobilized palladium catalysis. While a great majority of the applications focused on the use of support such as alumina and activated carbon, a great diversity of novel support systems have been reported in recent years, aimed at finding a catalyst with a well-characterized coordination sphere and tailor-made activity. Pd(0) catalysts dispersed on crosslinked styrene-divinylbenzene copolymers have been prepared by impregnation of lipophilic complexes followed by reduction with hydrazine. It was found that the functional groups in the polymer as well as polymer particle sizes had a major effect on catalyst activity.t [i53]-[i95]... 

Polymers are often blended or contain additives to affect the properties of the solid phase high-impact polystyrene, for example, is a blend in which particles of a rubbery polymer, typically polybutadiene or a styrene-butadiene copolymer, are dispersed in polystyrene. Many polymer composites used in molding applications contain sohd fillers, such as calcium carbonate particles, glass fibers, or even nanoscale fillers like exfoliated clays or carbon nanotubes. 

FIG. 14-16. Loss tangents reduced to 28 C for styrene-butadiene copolymer containing various proportions of calcium carbonate particles as indicated (parts Filler per 1(X) parts polymer). (Maekawa, Nakao, and Ninomiya. )... 

---