• Industry Promotion Research
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• v.9 no.2
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• pp.37-44
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• 2024

This study selected the worst-case scenario for fireball and vapor cloud explosion (VCE) of a styrene monomer storage tank installed in a petrochemical production plant and performed damage prediction and accident impact analysis. The range of influence of radiant heat and overpressure due to fireball and vapor VCE during the abnormal polymerization reaction of styrene monomer, the main component of the mixed residue oil storage tank, was quantitatively analyzed by applying the e-CA accident damage prediction program. The damage impact areas of radiant heat and explosion overpressure are analyzed to have a maximum radius of 1,150m and 626m, respectively. People within 1,150m of radiant heat of 4kW/m2 may have their skin swell when exposed to it for 20 seconds. In buildings within 626m, where an explosion overpressure of 21kPa is applied, steel structures may be damaged and separated from the foundation, and people may suffer physical injuries. In the event of a fire, explosion or leak, determine the risk standards such as the degree of risk and acceptability to workers in the work place, nearby residents, or surrounding facilities due to radiant heat or overpressure, identify the hazards and risks of the materials handled, and establish an emergency response system. It is expected that it will be helpful in establishing measures to minimize damage to workplaces through improvement and investment activities.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.4
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• pp.76-85
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• 2019

Recently, various investigation of vegetable oil which is extracted from natural resources is being progressed because of its low cost and environmental aspect. However, double bonds in vegetable oil should be substituted to other high reactive functional group due to its low reactivity for synthesizing bio-polymeric materials. ${\alpha}$-eleostearic acid, which is consist of conjugated triene, is the main component of tung oil, and the conjugated triene allows tung oil to have higher reactivity than other vegetable oil. In this study, tung oil is copolymerized with styrene and divinylbenzene to make thermoset resin without any substitution of functional group. Thermal and mechanical properties are measured to investigate the effects of the composition of each monomer on the synthesized thermoset resin. The result shows that the products have only one Tg, which means the synthesized thermoset resins are homogeneous in molecular level. Mechanical properties show that tung oil act as soft segment in the copolymer and make more elastic product. On the other hand, divinylbenzene acts as hard segment and makes more brittle product.

• Journal of Microbiology
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• v.44 no.2
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• pp.177-184
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• 2006

The characteristic biodegradation of monomeric styrene by Phanerochaete chrysosporium KFRI 20742, Trametes versicolor KFRI 20251 and Daldinia concentrica KFRI 40-1 was carried out to examine the resistance, its degradation efficiency and metabolites analysis. The estrogenic reduction effect of styrene by the fungi was also evaluated. The mycelium growth of fungi differentiated depending on the concentration levels of styrene. Additionally P. chrysosporium KFRI 20742 showed superior mycelium growth at less than 200 mg/l, while D. concentrica KFRI 40-1 was more than 200 mg/l. The degradation efficiency reached 99 % during one day of incubation for all the fungi. Both manganese-dependent peroxidase and laccase activities in liquid medium were the highest at the initial stage of incubation, whereas the lowest was after the addition of styrene. However, both activities were gradually recovered after. The major metabolites of styrene by P. chrysosporium KFRI 20742 were 2-phenyl ethanol, benzoic acid, cyclohexadiene-1,4-dione, butanol and succinic acid. From one to seven days of incubating the fungi, the expression of pS2 mRNA widely known as an estrogen response gene was decreased down to the level of baseline after one day. Also, the estrogenic effect of styrene completely disappeared after treatment with supernatant of P. chrysosporium KFRI 20742 from one week of culture down to the levels of vehicle.

• Journal of the Microelectronics and Packaging Society
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• v.23 no.3
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• pp.15-20
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• 2016

In an effort to overcome the weakness of aerogel, polymer aerogels have been prepared by copolymerizing the different types of monomers through sol-gel process. Polymerizing the successive phase of a high internal phase emulsion, which has interconnected porous structure, porous polymer aerogel can be manufactured. In this paper, we use the styrene/divinylbenzene chain as a basic monomer structure, and additionally use 2-ethylhexyl methacrylate (2-EHMA) or 2-ethylhexyl acrylate (2-EHA) as monomers for distinguishing the visible mechanical properties of synthesized polymer aerogel. We can observe the different tendency of polymer aerogels by kinds of monomer or ratio. Flexibility and microstructure can be changed by the types of monomer. EHA polymer aerogel shows high flexibility and thin microstructure, and EHMA polymer aerogel shows high hardness and thick microstructure. EHA/EHMA polymer aerogel shows the intermediate nature between them. By utilizing the mechanical properties of three types of polymer aerogels to adequate situation or environment, polymer aerogels could be used as drug agent, ion exchange resin, oil filter and insulator, and so on.

• Journal of the Korean Chemical Society
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• v.24 no.3
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• pp.259-265
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• 1980

Poly (styrene-b-methyl methacrylate) (PS-b-PMMA) was synthesized by free radical telomerization: the telomerization of styrene with $CCI_4$ by using AIBN as initiator followed by a second telomerization of methyl methacrylate using $CCI_3$ end group of the resulting polymer as the macrotelogen, with AIBN initiation, gave the styrene-methyl methacrylate block copolymer. The effects of the concentration of the macrotelogen, the concentration of monomer, the molecular weight of the macrotelogen, the reaction temperature and the concentration of the solvent on the formation of the block copolymer were investigated. Block copolymers containing up to 10 weight percent PMMA were obtained by adjusting the reaction conditions.

• Clean Technology
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• v.11 no.3
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• pp.141-146
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• 2005

The composite membranes were made by grafting using supercritical carbon dioxide (scCO2) impregnation and polymerization procedures. The membranes were synthesized by changing amount of monomer. The polypropylene grafted polystyrene sulfonic acid (PP-g-pssa) membranes were characterized with various methods. The morphology and structure of PP-g-pssa membranes were analyzed with scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). As amount of monomer was increased, ion conductivity, cell performance was increased and methanol permeability was decreased. However PP-g-pssa membranes with 1.5g monomer and over had similar values of methanol permeability, ion conductivity and cell performance.

• Polymer(Korea)
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• v.24 no.3
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• pp.287-298
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• 2000

In preparing micron-sized monodisperse polystyrene beads by dispersion polymerization, the conversion, and the particle size and its distribution were affected by the reaction temperature, concentration of the monomer, solvent and initiator, molecular weight and concentration of the steric stabilizer, amount of oxygen existing in the reactor, and an appropriate combination of these starting materials. Ethanol as a dispersing agent, styrene as a monomer, PVP as a steric stabilizer, AIBN as an initiator, DVB as a cross-linking agent and toluene as a co-solvent were the basic materials for the synthesis. The reaction rate and the conversion were increased with the reaction temperature and the amount of DVB from 1 to 4%, and the conversion was saturated after 10 hours of the reaction time. The optimum reaction recipe for the preparation of the monodisperse PS beads was 25% styrene monomer, 0.5% DVB, 25% toluene, 10-15% PVP, and 2 and 4% AIBN, thereby, 3.9~4 ${\mu}{\textrm}{m}$ and 3.4~9.3 ${\mu}{\textrm}{m}$ of polystyrene beads, respectively, were successfully synthesized.

• Macromolecular Research
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• v.14 no.4
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• pp.466-472
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• 2006

The kinetic behavior of emulsion polymerizations of styrene in the presence of sulfonated N-hydroxy ethyl aniline (SHEA) was investigated with two initiators: 2,2'-azobisisobutyronitrile (AIBN) and potassium persulfate (KPS). SHEA was synthesized using a stepwise polyurethane reaction method from 3-hydroxy-1-propane sulfonic acid sodium salt, isophorone diisocyanate (IPDI), and N-(2-hydroxyethyl) aniline. Stable core-shell poly(styrene/sulfonated N-hydroxy ethyl aniline, St/SHEA) latex particles were successfully prepared by using an appropriate amount of AIBN, in which SHEA plays the role of 'surfmer', i.e., acting as both a surfactant in the emulsion polymerization and a monomer in the chemical oxidative polymerization. The kinetic behavior was dissimilar to that of typical emulsion polymerization systems. A long inhibition period and low rate of polymerization were observed due to radical loss by the oxidative polymerization of SHEA. It was concluded, due to the low water-solubility of AIBN and retardation reaction by SHEA, that the initial loci of polymerization were monomer droplets. However, growing polymer particles as polymerization loci became predominant as polymerization proceeded. It was suggested that AIBN was more effective than KPS in the preparation of the core-shell type poly(St/SHEA) latex particles. With KPS, no substantial polymerization was observed in any of the samples.

• Polymer(Korea)
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• v.26 no.1
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• pp.9-17
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• 2002

The free radical bulk copolymerizations of perfluoroalkylethyl acrylate(FA) containing perfluoro group ($CF_3(CF_2)_nCH_2CH_2$-; n=5, 7, 9, 11) with styrene were conducted at $60^{\circ}C$ using AIBN as an initiator. Reactivity ratios($r_1$, $r_2$) were determined from monomer feed compositions and the NMR spectroscopically measured copolymer compositions using Kelen-Tudos method. The structures of copolymers were characterized with FT-IR and $^1H-NMR$ analysis. Their thermal properties investigated with DSC and TGA were decreased with increasing the content of fluorinated acrylate in the copolymer. Their surface free energies were calculated with measuring contact angles of the copolymers and PMMA blends with a small amount of them.

• Nuclear Engineering and Technology
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• v.4 no.1
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• pp.23-30
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• 1972

A study on the preparation of wood-plastic combinations by gamma-ray induced polymerization is carried out. In monomer impregnation, the rates and amounts are determined for various woods. The polymerization rates of various monomers and monomer mixtures impregnated mainly domestic woods are studied varying the total gamma-dose and gamma-dose rates. The obtained data indicate that; 1) in impregnation of monomer, populus deltoides is the fastest in rate, and the most impregnated in amount 2) the general trends of polymerization of monomers ill woods is in the order of vinyl acetate--methyl metacrylate--styrene, ranging from 3 to 15 Mard of total does in rate of 4$\times$10$^4$rad/hr., thus vinyl acetate or methyl metacrylate is suitable monomer in view of polymerization rate, 3) the successful woods in combination with monomer are pinus rigida and pinus densiflora in view of polymerization rate, 4) the monomers in woods are more easily polymerized under the conditions of moderately lower does rate, 2.1$\times$10$^4$rad/hr.