• Macromolecular Research
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• v.12 no.6
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• pp.604-607
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• 2004

We report an important and useful method for preparing ${\omega}-sulfonated$ polystyrene-stabilized cadmium sulfide (CdS) nanoclusters. The ${\omega}-sulfonated$ polystyrene $(M_n\;=\;5000\;g/mol)$ was prepared successfully through chain-end sulfonation of poly(styryl)lithium using 1,3-propanesultone; the resulting polymer was used successfully as a polymeric stabilizing agent for the preparation of semiconductor CdS nanoclusters by reduction of cadmium acetate in a mixture of toluene and methanol (9:1, v/v). The nanoclusters that formed were characterized by a combination of transmission electron microscopy, X-ray diffraction, and UVN is spectroscopic analysis. The ${\omega}-sulfonated$ polystyrene-stabilized CdS nanoclusters synthesized in this study exhibited the cubic phase (zinc-blende phase) structure in the range of 2-8 nm.

• Advances in nano research
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• v.1 no.2
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• pp.105-109
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• 2013

We report dry thermal development of negative resist polystyrene with low molecular weight. When developed on a hotplate at $350^{\circ}C$ for 30 min, polystyrene showed reasonable high contrast and resolution (30 nm half-pitch), but low sensitivity. Resist sensitivity was greatly improved at lower development temperatures, though at the cost of reduced contrast. In addition, we observed the thickness reduction due to thermal development was higher for larger remaining film thickness, implying the thermal development process is not just a surface process and the more volatile chains below the top surface may diffuse to the surface and get evaporated.

• Journal of Pharmaceutical Investigation
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• v.18 no.2
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• pp.69-81
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• 1988

We studied on the synthesis of chloromethylated polystyrene as a precursor of optically active polymers for direct resolution of optical isomers. Changing the degree of crosslinking and the kind of crosslinking agents, several polystyrene resin matrices were synthesized. The matrices were chloromethylated with methylal and chlorosulfonic acid as chloromethylating agents. The effects of solvents of various dielectric constants on the chloromethylation were quantitavely examined. We also synthesized chloromethylated polystyrene of macroreticular type that retained large surface area and good physical stability. The differences between the macroreticular type and macroporous type were investigated.

• Elastomers and Composites
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• v.31 no.5
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• pp.327-334
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• 1996

A correlative analysis has been carried out to predict the average particle size of rubber dispersed phase In high impact polystyrene manufactured by bulk polymerization. To do the correlation, a mechanistic model suggested previously by the author was used for describing the size of stabilizing particles agitated under the turbulent viscous shear subranges in a prepolymerization reactor, where the rubber particles were assumed to be formed at the time of phase inversion in the reactor. Viscosities required for the model were postulated to describe the overall behavior of butadiene rubber and polystyrene mixture along the wide range of conversion. The good agreement between the model and the experimental data from a plant was quite satisfactory for the prediction of the average rubber particle size of high impact polystyrene.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.318-318
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• 2006

4-Vinylbenzyl maltohexaoside peracetate, 1, was copolymerized with divinylbenzene using the initiator for nitroxide-mediated living radical polymerization, 2, to afford the polystyrene microgel with acetyl maltohexaose, 3. The deacetylation of 3 was achieved by treatment with sodium methoxide in dry 1,4-dioxane to produce the polystyrene microgel with maltohexaose, 4. A good coating property of the polystyrene microgel was combined with an excellent hydrophilic property derived from maltohexaose. In addition, 4 showed the ability to solubilize fullerene in aqueous solution. Therefore, 4 has a potential application as a special coating using functional but incompatible compounds such as fullerene on the surface of various hydrophilic materials.

• Journal of Korea Foundry Society
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• v.23 no.1
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• pp.47-51
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• 2003

This experimental study was carried out to investigate the solidification characteristics of polystyrene added styronaphthalene pattern materials using various castability test methods. The styronaphthalene showed an excellent filling capacity and shaping behavior having about 0.2 mm meniscus radius. The shell thickness of styronaphthalene showing smooth wall at the solid/liquid interface increased with the increasing of polystyrene addition. The solidification microstructure of styronaphthalene showed a typical thin ribbon reinforced composite structure, which has fibrous amorphous skeleton of polystyrene and crystalline naphthalene. From the results of this study, it was found that the polystyrene added styronaphthalene showed a precision shaping behavior as disposable pattern material under the atmospheric condition.

• Mass Spectrometry Letters
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• v.12 no.3
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• pp.118-124
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• 2021

Many previous studies have focused on revealing the harmfulness of microplastic particles, whereas very few studies have focused on the effects of chemicals, particularly photooxidation product. In this study, products of photodegradation from expanded polystyrene (EPS), compounds produced by photolysis by ultraviolet (UV) light, were investigated. EPS was directly irradiated and photolyzed using a UV lamp, and then the extracted sample was analyzed using high-resolution mass spectrometry (HRMS). Multiple ionization techniques, including electrospray ionization, atmospheric pressure chemical ionization, and atmospheric pressure photoionization, were used. In total, >300 compounds were observed, among which polystyrene monomer, dimer, and oxidized products were observed. In this work, the data presented clearly demonstrate that it is necessary to identify and monitor oxidized plastic compounds and assess their effect on the environment.

• Bulletin of the Korean Chemical Society
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• v.33 no.9
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• pp.3119-3121
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• 2012

• 한국도로학회:학술대회논문집
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• 2004.10a
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• pp.405-412
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• 2004

• Applied Chemistry for Engineering
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• v.10 no.5
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• pp.743-747
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• 1999

The component polymer was modified to enable the formation of intermolecular hydrogen bonding in the immiscibile polystyrene(PS)/polymethacrylate(PMA) blends. The mole percentages of hydroxystyrene of the poly(styrene-co-4-hydroxystyrene) copolymer(modified polystyrene, MPS) were controlled to 7%, 10% and 18%, respectively. MPS was used with PMA to study the variation of the miscibility in blends. PMA which had such different length of side chain as methyl, butyl, hexyl and ethylhexyl, respectively, was selected to study the effect of side chain length on the formation of intermolecular hydrogen bonding. As the hydroxyl content of MPS increased, the formation of intermolecular hydrogen bonding increased. The length of side chain of PMA had enormous effect on the miscibility of blend as confirmed from the result of cloud point measurement. As the length of side chain increased, the formation and the strength of intermolecular hydrogen bonding decreased severely due to the steric effect and the increased chain mobility.