• KSBB Journal
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• 제21권3호
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• pp.188-193
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• 2006

본 연구에서는 신 개념의 바이오필터 시스템인 RDBF를 이용하여 기상의 styrene을 제거하고자 하였다. 다양한 운전조건에서 시스템의 성능을 평가하고, 진공흡입을 통해 과다성장 미생물을 제어하고자 하였다. RDBF에서는 sheet 형태의 충진 담체를 사용하므로 영양원 및 공기의 균일한 공급이 가능하였고, 빠른 속도로 균일한 미생물 층을 담체 표면에 형성할 수 있었다. 또한 기-액 접촉면적을 증대 시켜 95% 이상의 안정적이고 높은 styrene 분해 효율과 $125g/m^3{\cdot}hr$의 높은 제거 용량을 가질 수 있게 해주었다. 하지만 우수한 성능은 미생물의 과다성장에 따른 기공의 폐쇄현상 때문에 오래 지속되지 않았고 반응기의 성능과 안정성은 급속히 저하되었다. 이를 해결하기 위해 진공흡입을 통한 미생물 제거를 시도하였으나 제한적인 효과만을 확인하였다. 향후 RDBF 반응기의 상업화를 위해서는 보다 효율적인 미생물 제어 방법이 개발될 필요가 있다.

• 멤브레인
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• 제29권5호
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• pp.252-262
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• 2019

서로 다른 술폰화 정도에 따라 sulfonated star branched poly(styrene-b-butadiene-b-styrene) triblock copolymer (SSBS)가 합성되었다. 술폰화된 butadiene block은 FT-IR spectroscopy로 확인할 수 있다. 술폰화 정도를 측정 비교하기 위해서 산-염기 적정을 통하여, ion exchange capacity (IEC)를 계산하였다. 술폰화된 SSEB 전해질막은 높은 water uptake와 proton conductivity를 보였다. 실온에서 25 mol% 술폰화된 SSBS는 0.114 S/cm라는 높은 값을 나타냈으며, 이는 Nafion과 비슷한 수치였다. 일정한 상대 습도에서 온도의 증가는 현저하게 높은 수소이온전도도를 나타냄을 알 수 있었다. 모든 술폰화된 막은 Nafion과 비교했을 때 낮은 methanol 투과도를 보여주었다. AFM을 이용하여 술폰화된 전해질막의 구조는 이른바 분리된 나노구조의 미세상과 ionic channel의 접속으로 이루어졌음을 확인할 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제27권9호
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• pp.1381-1385
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• 2006

Cobalt (cyclam) complex has been successfully immobilized onto SBA-15, and proven to be an active catalyst for the epoxidation of styrene with tert-butyl hydroperoxide as a terminal oxidant. The selectivity for styrene oxide was observed to be up to 66% with 40% styrene conversion after 12h reaction time. The reversible redox cycle between Co(III) and Co(II) couple which was supposed to play key role during the epoxidation reaction was supported by a cyclic voltametry analysis. The textural properties of the catalyst was characterized by XRD, N2 adsorption-desorption, and TEM analysis.

• 대한화학회지
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• 제24권1호
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• pp.64-72
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• 1980

새로운 acrylimide로서 N-acrylylpyrrolidone을 합성하였다. N-Acrylylpyrrolidone은 N-methacrylyl-lactam과는 다르게 homopolymerization을 열적으로도 함을 관찰하였다. Styrene과 N-acrylylpyrrolidone의 공중합시 각 monomer의 reactivity ratio를 구하였다. 그 결과 생성되는 copolymer는 pyrrolidone의 음이온 중합에 적절한 acyl-lactam function을 가지고 있음을 알았다.

• 한국응용과학기술학회지
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• 제26권1호
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• pp.74-79
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• 2009

The inorganic-organic composite particles with core-shell structure were polymerized by using styrene and potassium persulfate (KPS) as a shell monomer and an initiator, respectively. We studied the effect of surfactants on the core-shell structure of silicone dioxide/styrene composite particles polymerized in the presence of sodium dodecyl sulfate(SDS), polyoxyethylene alkylether sulfate (EU-S133D), and at none surfactant condition. We found that $SiO_2$ core / polystyrene(PS) shell structure was formed when polymerization of styrene was conducted on the surface of $SiO_2$ particles, and the concentration SDS and EU-Sl33D was $8.34{\times}10^{-2}mole/L$. The core-shell structure was confirmed by measuring the thermal decomposition of the polymer composite using thermogravimetric analyzer (TGA), and the morphology of the composite particles was characterized by transmission electron microscope (TEM).

• Bulletin of the Korean Chemical Society
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• 제32권4호
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• pp.1327-1330
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• 2011

Dehydration of 1-phenylethanol to produce styrene has been studied in liquid phase with three solid acid catalysts such as H-ZSM-5, H-Y and Amberlyst-15. Amberlyst-15 shows the highest conversion and styrene yield, suggesting the applicability of a resin catalyst in the dehydration. The good performance of the Amberlyst-15 may be due to high acid concentration and ready diffusion of reactants and products. A possible reaction scheme (such as the formation of styrene from diphenylethylether) has also been suggested.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.380-380
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• 2006

Styrene-Butadiene diblock or styrene-butadiene-styrene triblock copolymers are industrially important materials for asphalt modification and adhesives. A kinetic modeling study on non-isothermal anionic styrene-butadiene diblock copolymerization system is presented. The model deals with the association/dissociation reaction of initiator and propagating ion pairs in its kinetic scheme. By comparing model calculation results with real plant data, it is possible to obtain useful ideas for more efficient plant operation. For example, the model clearly provides important relation between the reaction temperature profile and the conversion of monomers.

• 한국환경과학회지
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• 제22권6호
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• pp.687-694
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• 2013

To investigate organoclay, high styrene resin masterbatch (HSR), high impact polystyrene (HIPS), and polystyrene (PS) as reinforcing materials for the improvement of the abrasion resistance of poly(styrene-block-butadiene-block-styrene) (SBS), SBS/organoclay nanocomposites, SBS/HSR, SBS/HIPS, and SBS/PS blends were prepared. The effect of organoclay and blends on the abrasion resistance and mechanical properties of SBS was investigated. Even though intercalations of organoclay are observed for SBS/Cloisite 20A nanocomposites and not for SBS/Cloisite 30B composites, the abrasion resistance of SBS/Cloisite 20A nanocomposites is worse than that of SBS/Cloisite 30B composites. When SBS was blended with HSR, HIPS and PS, the abrasion resistance of the blends increases with increasing of HSR, HIPS and PS content from 0 to 20 wt%.

• Macromolecular Research
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• 제17권7호
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• pp.469-475
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• 2009

We investigated the feasibility of dispersion polymerization without any stabilizer, which has been considered essential for ensuring colloidal stability. By employing small amounts of a lyophilic comonomer, 4-vinyl pyridine, styrene was successfully polymerized by dispersion polymerization in aqueous alcohol without stabilizer to afford stable poly(styrene-co-4-vinyl pyridine) copolymer microspheres. The stable microspheres were produced in the 4-vinyl pyridine range of 2-15 wt% to styrene. Without 4-vinyl pyridine, severely coagulated particles were obtained, implying that the poly(4-vinyl pyridine) moiety endowed colloidal stability. The polymerization kinetics, behavior, and properties of the ultimate particles showed general features of dispersion polymerization. The study results suggest that stabilizer- tree dispersion polymerization is possible, thereby facilitating the synthesis of impurity(stabilizer)-tree polymer particles.

• Preventive Nutrition and Food Science
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• 제4권2호
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• pp.152-158
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• 1999

Polystyrene is frequently used for food packaging because of its eaxy processing rigidity , and low cost. Styrene, which is present in detectable amouts in the polymer, is usually considered to be the substance responsible for the possible tainting of a polystyrene-packed food by migration. The contamination of foods and beverages by trace amounts of materials which have migrated from plastics use din packaging is a concern both on the grounds of adversely affecting product quality and of food safety. These lead to increasing attention to the potentional hazards of a large variety of plastic materials and foods. In this paper we reviewed the history of Styrene and various analytical methods of sample preparation and detection to assess the extent to which styrene is present in food-grade polystrene materials and to what extent it leaked into foods and food stimulants.