• Title/Summary/Keyword: 괴상중합

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The Effects of the Content of Hydroxyethyl Methacrylate in Fluorine-containing Acrylate Copolymers on Physical Properties (불소함유 아크릴계공중합체에서 히드록시에틸메타크릴레이트 함량에 따른 물리적 특성 변화)

  • Kim, KiSang;Shim, Sang-Yeon
    • Journal of the Korean Applied Science and Technology
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    • v.35 no.2
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    • pp.502-508
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    • 2018
  • The acrylate copolymer having good coating, water-repellent and adhesion properties was designed and prepared. We prepared copolymers with high yield of > 95% using methyl methacrylate(MMA), 2,2,2-trifluoroethyl acrylate (FMA) and 2-hydroxyethyl methacrylate monomers(HEMA) by either bulk or emulsion polymerization techniques. The $^1H-NMR$ spectrum was used to identify chemical structure and DSC and DMA analysis were conducted. As a result, the glass transition temperature decreased by $3^{\circ}C$ as FMA content increased from 5% to 10%, and decreased by $2{\sim}8^{\circ}C$ when HEMA content increased from 5 % to 10 %. The physical properties were measured using Instron and TGA. As FMA or HEMA content increased by 10%, tensile strength decreased from 29 MPa to 22 MPa and Td decreased from $200^{\circ}C$ to $180^{\circ}C$ in both bulk and emulsion. The contact angle relatively decreased as hydrophilic HEMA content increased.

The Effects of the Content of Isobornyl Methacrylate in Acrylate Copolymers on Physical Properties (아크릴계 공중합체에서 이소보닐 메타크릴레이트의 함량에 의한 물리적 특성 변화)

  • Kim, Ki Sang;Shim, Sang-Yeon
    • Journal of the Korean Applied Science and Technology
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    • v.33 no.4
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    • pp.771-776
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    • 2016
  • The acrylate copolymer having good thermal stability, coating and adhesion properties was designed and prepared. We prepared copolymers in >95% high yield using methyl methacrylate, isobornyl methacrylate and 2-hydroxyethyl methacrylate monomers by the bulk and emulsion polymerization techniques. The $^1H$-NMR spectrum was used to identify chemical structure and glass transition temperatures increased from $123^{\circ}C$ to $140^{\circ}C$ confirmed by DSC, DMA and TGA analysis. In addition, as the content of IBMA increased, storage modulus and thermal decomposition temperature increased. As the content of IBMA increased from 10% to 30% in the composition for the entire monomer, tensile strength increased from 22 to 30 MPa in both polymers prepared by bulk and emulsion techniques. The contact angle increased from 70 to up to 88 degrees due to hydrophobic property of IBMA.

Formaton of Macrozwitterions in the Cationic Polymerization of Propylene Sulfide Initiated with o-Sulfobenzoic Anhydride (o-Sulfobenzoic Anhydride로 개시된 Propylene Sulfide의 양이온중합시 고분자양성이온의 생성)

  • Man Jung Han
    • Journal of the Korean Chemical Society
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    • v.22 no.3
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    • pp.173-183
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    • 1978
  • Bulk polymerization of propylene sulfide with o-sulfobenzoic anhydride as initiator was carried out and the polymerization proceeded by a zwitterionic mechanism. Chemical and spectroscopic investigation of the purified polymer revealed that the polymer contained two end groups-thiolester of benzoic acid o-sulfonate anions and acyclic tert-sulfonium ions which were formed by termination of episulfonium ions with sulfide groups in the polymer chains. The concentration of sulfonate anions was nearly the same as the concentration of acyclic tert-sulfonium ions, as expected for macrozwitterions. The cocatalysis mechanism by a trace of water was excluded and the other possible mechanisms were discussed on the basis of end group analysis.

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Synthesis and Characterization of New Polyesters Having Unsaturated Groups from Bis [4-(alkyloxy)benzilidene]succinic Anhydride (Bis[4-(alkyloxy)benzilidene]succinic anhydride로부터 유도된 불포화기를 가지는 새로운 폴리에스터의 합성)

  • 김용석;진왕철;정진철
    • Polymer(Korea)
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    • v.26 no.4
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    • pp.439-444
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    • 2002
  • Several monomeric benzilidene anhydrides (2a~d) haying n-alkyloxy groups with various n-alkyl chain lengths were prepared by Stobbe condensation of diethyl succinate with 4-(n-alkyloxy)benzaldehyde (1a,b) followed by hydrolysis by the succinates and cyclodehydration of the benzilidenated succinic acids. Configurational isomerism of the monomer was investigated by spectroscopic means. It was found that monomers (2a~d) exist in (Z,Z)-isomeric structure. Polymerization was carried out in bulk at 150~$210^{\circ}C$ range in nitrogen flow. The chemical structure and thermal properties of the polymers were characterized by spectroscopic means, TGA and DSC. Their properties highly depended on their chemical structures in accordance with a side chain length.

Characteristics of PMMA Sheet with Phosphorous Flame Retardant Additives (인계 첨가제를 이용한 PMMA판재의 난연성 물성 특성)

  • Kim, Yong-Ryeol;Lim, Sun-Young
    • Journal of the Korean Applied Science and Technology
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    • v.29 no.2
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    • pp.224-230
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    • 2012
  • In this paper, flame-resisting PMMA(polymethyl methacrylate) sheet was manufactured and its characteristics were tested. PMMA was synthesized by bulk polymerization of a monomer methyl methacrylate with addition of phosphorous flame retardant, triethyl phosphate and ethylene glycol dimethacrylate as a cross linking agent. PMMA sheet was manufactured by using the cell molding method, which does not alter or affect the existing property of PMMA. Then the characteristics of PMMA sheet were tested for the TEP content, the content and curing time of EGDMA. As TEP content increases, the length of carbonization lessens and the amount of char production increases. As a result, it strengthened the effect of flame retardants. But the hardness of the sheet decreased as TEP content increased. However, hardness increased when EGDMA was added up to 3 wt% while curing time was decreased from 3 hours to 2 hours. There was no change of hardness when more than 3 wt% of EGDMA was used.

Effects of Zinc Stearates on the Thermal and Rheological Properties of Polystyrene Ionomers (폴리스티렌 이오노머의 열적·유변학적 성질에 미치는 스테아린산 아연의 영향)

  • Kim, Jong-sang;Doo, Jun Kil;Lee, Dai Soo
    • Applied Chemistry for Engineering
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    • v.10 no.8
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    • pp.1216-1220
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    • 1999
  • Different amounts of zinc stearate were incorporated as a plasticizer into poly(styrene-co-sodium methacrylate) ionomers prepared by bulk-suspension plymerization and neutralization with sodium hydroxide and effects of the zinc stearate on the thermal and rheological properties were investigated. It was obseved that the crystallization of zinc stearate in the ionomers were partially suppressed depending on the content of ionic moieties. It is postulated that the ionic moieties dissolved zinc stearate and suppressed crystallization of the zinc stearates. We speculated that 0.4~0.6 mole of zinc stearate was dissolved by one mole of the ionic moiety. Poly(styrene-co-sodium methacrylate) containing only the dissolved zinc stearates showed typical rheological properties of homogeneous systems in Cox-Mertz plots. However, poly(styrene-co-sodium methacrylate) containing crystallizable zinc stearates as well as dissolved ones showed typical rheological properties of heterogeneous systems.

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