• Title/Summary/Keyword: styrene(St)

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Synthesis and Characterization of Thermo Sensitive Poly(styrene-co-N-isopropylacrylamide) Microgels (열 감응성 Poly(styrene-co-N-isopropylacrylamide) 마이크로겔의 합성 및 특성)

  • Cho, Suk Hyeong;Kim, Kong Soo;Jung, Tea Uk
    • 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.

Synthesis and Characterization of Poly(vinyl alcohol-b-styrene) via Atom Transfer Radical Polymerization and Saponification

  • Li, Guang-Hua;Cho, Chang-Gi
    • Macromolecular Research
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    • v.10 no.6
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    • pp.339-344
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    • 2002
  • Poly(vinyl alcohol-b-styrene) (poly(VA-b-St)) diblock copolymer containing high syndiotactic poly (vinyl alcohol) (PVA) was synthesized by the saponification of poly(vinyl pivalate-b-styrene) (poly(VPi-b-St)). For the block copolymer, poly(vinyl pivalate) (PVPi) with trichloromethyl end group was obtained via telomerization of vinyl pivalate with carbon tetrachloride as a telogen and 2,2-azobisisobutyronitrile (AIBN) as an initiator. Then resulting poly(vinyl pivalate) with trichloromethyl end group was used as an effient macroinitiator for the synthesis of poly(VPi-b-St) using atom transfer radical polymerization (ATRP) in the presence of CuCl/2,2'-bipyridine at 130 $^{\circ}C$. The poly(vinyl pivalate) macroinitiator, poly(VPi-b-St), poly(VA-b-St) were characterized by GPC, FT-IR and $^1$H-NMR. And the analysis showed that integrity of the block copolymer was maintained during saponification reaction.

Bond Strength and Tensile Strength of Polymer-Modified Mortar Using Styrene and Butyl Acrylate (St/BA를 혼입한 폴리머 시멘트 모르타르의 부착강도 및 인장강도 특성)

  • You, Kipyo;Hyung, Wongil
    • Polymer(Korea)
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    • v.38 no.6
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    • pp.820-826
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    • 2014
  • The objective of this study is to find the relationship between the tensile strength of the polymer film and the bond strength and tensile strength of the polymer-modified mortar using styrene (St) and butyl acrylate (BA), and porosity. In the test results, the bond strength and tensile strength of the polymer-modified mortar increased with increases in the tensile strength of polymer film and the fine pore volume.

Monitoring of Endocrine Disruptors (Bisphenol A and Styrene Oligomers) in the Streams of Cholla-namdo Province in South Korea (전라남도 지역의 하천수에 존재하는 내분비 장애물질(Bisphenol A와 Styrene oligomer)의 실태조사)

  • Park, Song-In;Chung, Seon-Yong;Kstsuhiko, Saido;Hideto, Sato;Na, Suk-Hyun
    • Journal of Korean Society on Water Environment
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    • v.28 no.5
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    • pp.669-675
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    • 2012
  • Recently, there have been active researches regarding endocrine-disrupting chemicals (EDCs). In this study, fifteen small freshwater streams in Cholla-namdo province, South Korea were investigated with respect to the concentration of the endocrine disruptors - Bisphenol A (BPA), styrene monomer (SM), styrene dimer (SD), and styrene trimer (ST) by gas chromatography-mass spectrometry (GC-MS). Measured concentration of the target compounds in the sampled water ranged from

Fabrication and Characteristics of Hetero-junction EL Devices Containing Electron Transport Layer and PPV as Emitting Layer (PPV 발광층 및 전자 수송층을 가진 이종 접합구조 EL 소자의 제작 및 특성)

  • Park, Lee Soon;Han, Yoon Soo;Kim, Sung Jin;Shin, Dong Soo;Shin, Won Gi;Kim, Woo Young;Lee, Choong Hun
    • Applied Chemistry for Engineering
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    • v.9 no.5
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    • pp.710-714
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    • 1998
  • Organic electroluminescence devices (ELD) with hetero-junction structure were fabricated utilizing poly(p-phenylne vinylene) (PPV) as emitting layer and electron transport layer (ETL). 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD) was used as an electron transport agent. Copolymers with stilbene type comonomers, such as poly(styrene-co-PVTS), poly(styrene-co-MeO-PVTS) and poly(styrene-co-MeO-ST) were synthesized to be used as a matrix polymer to disperse electron transport agent (PBD). Among the hetero-junction EL devices fabricated with the above materials, the device with poly(styrene-co-PVTS) as matrix polymer for ETL gave the highest luminance ($120.7cd/m^2$, 13 V). EL devices made with poly(styrene-co-MeO-PVTS) or poly(styrene-co-MeO-ST) matrix exhibited lower luminance than the one with polystyrene matrix and the single layer EL (ITO/PPV/Mg) device.

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A Study on the Development of Polymer-Modified Mortars Using Styrene-Butyl Acrylate Latexes (St/BA의 모노머 비에 따른 폴리머 시멘트 모르타르 개발에 관한 연구)

  • Hyung, Won-Gil;Mun, Kyung-Ju;Song, Hun
    • 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.

The Kinetics of Radical Copolymerization and Thremal Decoposition of Poly(Styrene-co-2- Hydroxypropylacrylate) (Poly(Styrene-co-2-Hydroxypropylacrylate)의 라디칼 공중합 및 열분해 속도론)

  • Kim, Nam-Seok
    • Journal of the Korean Applied Science and Technology
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    • v.26 no.2
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    • pp.205-212
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    • 2009
  • Solution copolymerization of Styrene(St.) with 2-Hydroxypropylacrylate(2-HPA) was carried out with Benzoylperoxide(BPO) as an initiator in toluene at $80^{\circ}C$ in a batch reactor. Reaction volume and reaction time were 0.3 liters, 8 hours respectively. The time to reach steady state was about the six time. The monomer reactivity ratios, $r_1$(St.) and $r_2$(2-HPA) were determined by both the Kelen-Tudos method and the Fineman-Ross method ; $r_1$(St.)=0.376(0.330), $r_2$(2-HPA)=0.408(0.778). The activation energy of thermal decomposition was in the range of $33{\sim}55kcal/mol$.

Physical Properties and Durability of Polymer Modified Mortar Using Styrene and Butyl Acrylate Latexes (St/BA 폴리머 시멘트 모르타르의 물리적 특성 및 내구성)

  • Hyung, Won-Gil
    • 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.

Thermal Decomposition Characteristics of Ethyl Methacrylate and Styrene Copolymer

  • Kwon, Jae Beom;Lee, Nae Woo;Kim, Nam Seok;Park, Keun Hok;Seul, Soo Duk
    • International Journal of Safety
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    • v.2 no.1
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    • pp.28-33
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    • 2003
  • Thermal decomposition characteristics of ethyl methacrylate (EMA) and Styrene (St.) copolymer was investigated with synthesis at 8$0^{\circ}C$ in a continuous stirred tank reacto (CSTR) using toluene and benzoyl peroxide(BPO) as solvent and initiator, respectively. The thermal decomposition was considered to be side scission at below 30$0^{\circ}C$ and estimated 2nd-order reaction kinetics of EMA/St. copolymer. The activation energies of decomposition on this copolymers were in the ranges of 38-43 kcal/mol for EMA/St. and a good additivity rule was observed in each composition. The thermogravimetric trace curves agreed well with the theoretical calculation.

Thermal Decomposition of Copolymers of Butyl methacrylate and Styrene Produced in a CSTR

  • Kim, Duck-Sool;Kim, Nam-Seok;Park, Keun-Ho
    • Journal of the Korean Applied Science and Technology
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    • v.19 no.4
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    • pp.273-280
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    • 2002
  • Thermal decomposition of the copolymer of butyl methacylate(BMA) with styrene(St) was investigated. The copolymer Was obtained at 80 $^{\circ}C$ in a continuous stirred tank reactor(CSTR) using toluene and benzoyl peroxide(BPO), as solvent and initiator, respectively. The reactor volume was 0.3 liters and residence time was 3 hours. The thermal decomposition followed the second order kinetics for BMA/St copolymer. The activation energies of thermal decompositon were in the ranges of 38 ${\sim}43$ kcal/mol for BMA with St copolymer and a good additivity rule was observed with the composition of copolymer. The thermogravimetric trace curve agreed well with the theoretical calculation.