• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.6
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• pp.1056-1062
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• 2004

Migration of low molecular weight components from expanded polystyrene (ESP) to distilled water was measured at different temperature conditions. Overall migration and specific monomer migration were measured. Diffusion model based on Fick's law was used to determine the apparent diffusion coefficients at various experimental conditions. The overall and specific migration levels were estimated to give some practical implications for regulatory guideline development and safe package design. Diffusion coefficients for overall migration in KMnO$_4$ oxidizable extractives and specific migration of styrene monomer from ESP at 6$0^{\circ}C$ were 0.030 and 6.8${\times}$10$^{-5}$ $\textrm{mm}^2$/h, respectively. Their temperature dependence could be explained by Arrhenius equation with respective activation energies of 80.5 and 98.6 kJ/㏖. Experimental conditions ensuring desired migration level were suggested for reliable examination of migration from the packaging material. Some explanatory estimations of migrations were given for some typical conditions of potential usages.

• Journal of the Korea Concrete Institute
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• v.18 no.6 s.96
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• pp.785-791
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• 2006

The purpose of this study is to clarify the effect of the monomer ratio on properties of the polymer-modified mortars based on styrene and butyl acrylate latexes, and to obtain basic data necessary to develop appropriate latexes for cement modifiers. This paper deals with the effects of monomer ratio on the typical properties of the polymer-modified mortars with styrene and butyl acrylate latexes. The polymer-modified mortars using the styrene and butyl acrylate latexes polymerized with various monomer ratios are prepared with different polymer-cement ratios, and tested for the particle size of polymer latexes, air contents, water-cement ratios, flexural and compressive strengths, water absorption, and chloride-ion penetration. From the test results, the polymer-modified mortars using styrene and butyl acrylate latexes with the mix proportions of synthesis having monomer ratios of 50:50 to 60:40 for the appropriate mix proportions can be recommended for practical applications. Their basic properties are greatly affected by the polymer-cement ratio rather than the monomer ratio, and are improved over un-modified mortar.

• Journal of the Korean Chemical Society
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• v.24 no.1
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• pp.64-72
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• 1980

The synthesis of N-acrylylpyrrolidone has been carried out by the reaction of pyrrolidone and acrylyl chloride. The study on the copolymer of N-acrylylpyrrolidone and styrene is attempted.The copolymerization of N-acrylylpyrrolidone and styrene is carried out in benzene.Monomer reactivity ratio of N-acrylylpyrrolidone and styrene was calculated by Fineman and Ross equation. It is observed that the copolymer of N-acrylylpyrrolidone and styrene has random distributed acyl-lactam function on the vinyl polymer backbone.

• Polymer(Korea)
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• v.33 no.4
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• pp.342-346
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• 2009

The effects of the monomer ratios on the typical properties of polymer modified mortars that contain styrene and butyl acrylate latexes was investigated. Basic data was also obtained that is necessary for the development of appropriate latexes for cement modifiers. Polymer modified mortars that contain styrene and butyl acrylate latexes polymerized with various monomer ratios were prepared for different polymer-cement ratios. They were then tested to obtain the particle size of the polymer latexes, air contents, water-cement ratios, flexural and compressive strengths, water absorption, and chloride-ion penetration. From the test results, the polymer modified mortars that have styrene and butyl acrylate latexes (with the mix proportions of synthesis having monomer ratios of between 40:60 to 60:40 for the appropriate mix proportions) could be recommended for practical applications. The basic properties of the polymer modified mortars were more affected by the polymer-cement ratio than by the monomer ratio, and were improved over unmodified mortar.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2019.11a
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• pp.268-268
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• 2019

The purpose of this study is to understand the risk of chemical product, Styrene Monomer(SM), shipped in a vessel. SM is harmful chemical product which can make injury, explosion and/or fire in a vessel. The understand of SM risk is very important to protect seafarer's body and vessel safety. This research can be expected that the understanding of SM risk by a seafarer's to prevent accidents by SM explosion and/or fire.

• Polymer(Korea)
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• v.25 no.4
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• pp.451-459
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• 2001

Fabric ion-exchanger, aminated PP-g-styrene was synthesized with styrene monomer onto PP staple fiber by pre-irradiational grafting with E-beam and subsequent chloromethylation and amination. Degree of grafting was increased with increasing the styrene monomer concentration and the highest degree of grafting was obtained 118% at a monomer concentration of 80% styrene. Optimum condition of Mohr's salt and sulphuric acid were 1.0 ${\times}\;10^{-3}$ M and 0.1 M. Amount of amination was increased with increasing degree of grafting. Swelling ratio of aminated PP-g styrene was higher than that of trunk polymer. Ion-exchange capacity was 6.7 meq/g, which was three times greater than commercial ion-exchanger. Optimum condition of baron ion adsorption was pH 4 and amount of adsorption were increased with increasing the amount of amination.

• Membrane Journal
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• v.17 no.4
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• pp.294-301
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• 2007

To improve oxidative stability of non-fluorinated styrene-based polymer electrolyte membranes, copolymerized membranes were prepared using styrene derivatives such as p-methylstyrene, t-butylstyrene, and ${\alpha}-methylstyrene$ by monomer sorption method. Prepared membrane was characterized by measurement of weight gain ratio, water content, ion-exchange capacity, proton conductivity, and oxidative stability under the accelerated condition. It was found that each step of monomer sorption method including sorption, polymerization and sulfonation could be affected by the properties and the structures of styrenederivatives. Due to difficulty of polymerization, ${\alpha}$-methylstyrene was copolymerized with styrene or p-methylstyrene. Prepared membrane using ${\alpha}-methylstyrene$ and styrene showed higher performance and stability comparing to copolymerized membrane with styrene. However, copolymerized membranes with ${\alpha}-methylstyrene$ did not showed much improved oxidative stability comparing to styrene membrane due to their lower molecular weight. The t-butylstyrene membrane showed a low performance due to substituted bulky-butyl group which prevents sorption and sulfonation reaction. However, copolymerized t-butylstyrene membranes with p-methylstyrene showed good performance and much improved stability than the styrene membranes.

• Applied Chemistry for Engineering
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• v.20 no.4
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• pp.386-390
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• 2009

In this study, sulfadiazine acrylamide monomer was synthesized by the reaction of sulfadiazine, known as an antibiotic substance, with acryloyl chloride. The monomer was characterized by $^1H-NMR$, and $^{13}C-NMR$. Using the synthesized sulfadiazine acrylamide monomer and styrene monomer, a copolymer, poly(styrene-co-sulfadiazine), was obtained by the free radical copolymerization and characterized by $^1H-NMR$, GPC, DSC and TGA. The copolymer nanofibers web has been successfully prepared by electrospinning technique under DMF solution. The diameter of the nanofibers was in the range between 500 and 800 nm. Antibacterial activity of the nanofiber web was evaluated utilizing the colony counting method against Staphylococcus aureus and Escherichia coli.

• Applied Chemistry for Engineering
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• v.16 no.3
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• pp.397-402
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• 2005

Core-shell Poly(styrene-co-N-isopropylacrylamide) (poly(St-co-NIPAm) was prepared by soap-free emulsion polymerization of styrene (St) and N-isopropylacrylamide (NIPAm) in aqueous solution with potassium persulfate (KPS) as an initiator. The effects of St/NIPAm ratio, concentrations of monomer and crosslinker were studied. Also, Thermo sensitivity of microgels prepared was investigated. Particle size of microgels increased with increasing mol ratio of NIPAm to styrene. Transmittance of the microgel dispersion decreased rapidly when heated above a low critical solution temperature (near $32{\sim}34^{\circ}C$, cloud point). Swelling ratio of the microgel increased with increasing of the concentration of monomer (NIPAm) and decreased proportional to the concentration of crosslinker.

• Journal of the Korean Society of Safety
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• v.17 no.3
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• pp.81-89
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• 2002

The runaway reaction was analyzed experimently and theoretically at the batch styrene suspension polymerization process. In the experiments, the reaction temperature with time was measured at various experimental conditions. According to the experimental results, the risk of the runaway reaction was increased with increasing the ratio of the monomer(styrene, M) to the dispersion medium(water, W), the concentration of the initiator(BPO), and the monomer mass, respectively. And simulation results showed that the runaway reaction was significantly affected by the reaction rate constant of the propagation and that the phenomena of the runaway reaction occurred at about 70% conversion. Also, we found that the runaway reaction did not occur under the operating condition of below 0.5 for M/W, approximate 3 wt% BPO, and below 75$^{\circ}C$ for the cooling temperature.