• Title, Summary, Keyword: emulsion polymerization

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Core-Shell Poly(Styrene/Sulfonated N-hydroxy Ethyl Aniline) Latex Particles Prepared by Chemical Oxidative Polymerization in Emulsion Polymerization

  • Shin Jin-Sup;Lee Jung-Min;Suzuki Kiyoshi;Nomura Mamoru;Cheong In-Woo;Kim Jung-Hyun
    • 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.

Graft Polymerization of Methyl Methacrylate onto Cotton Fiber -Comparison of two step graft polymerization and emulsion graft polymerization- (면섬유에 Methyl Methacrylate의 그라프트중합 - 이단계 그라프트중합과 유화 그라프트중합의 비교 -)

  • Bae Hyun-Sook;Kim Sung-Reon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.13 no.1
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    • pp.89-97
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    • 1989
  • Graft polymerization of MMA onto cotton fiber was carried out in two ways, two step graft polymerization and one step emulsion graft polymerization, using tetravalent cerium ion as an initiator. At two step graft polymerization, the first step was the pretreatment of cotton fiber with an aqueous initiator solution and the second was the grafting pretreated cotton fiber in the monomer solution. In case of one step emulsion graft polymerization, MMA was emulsified with SLS in initiator solution. Under the various graft polymerization conditions, graft yield, graft efficiency and from the Arrhenius plot the apparent activation energy were compared. The results of this study were as follows: 1. Graft yield and graft efficiency of emulsion graft polymerization were higher than those of two step graft polymerization. 2. In case of two step graft polymerization, graft yield was affected by the pretreatment time of cotton fiber with an aqueous initiator solution. And graft yield of emulsion graft polymerization was increased with the concentration of emulsifier below cmc of SLS and was decreased thereafter. 3. Elevation of temperature resulted increase in graft yield for both grafting methods. The apparent activation energy of emulsion graft pelymerzation was lower than that of two step graft polymerization. 4. Increased reaction time increased in graft yield, but decreased in graft efficiency. 5. Moisture regain of grafted cotton was decreased with graft yield.

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Emulsion Polymerization of Vinyl Acetate with Triton-X as Emulsifier (Triton X 系를 乳化劑로 하는 Vinyl Acetate 의 乳化重合)

  • Chung, Ki-Hyun;Han, Sang-Ku
    • Journal of the Korean Chemical Society
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    • v.6 no.1
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    • pp.19-24
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    • 1962
  • In the emulsion polymerization of vinyl acetate with Triton-X(Alkyl-aryl-polyether alcohol) and polyvinyl alcohol as emulsifier, some relations between the conditions of polymerization and the polymerization rate, polymerization degree and stability of the emulsion are studied and discussed.

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Preparation of Micron-size Monodispersed PMMA/PDVB and PS/PDVB Particles by Multi-staged Seeded Emulsion Polymerization (다단계 유화중합을 이용한 마이크론 크기의 PMMA/PDVB 및 PS/PDVB 단분산 입자의 제조)

  • Choi, Bong-Cheol;Um, Ki-Beom;Byun, Ja-Hoon;Park, Hong-Soo;Wu, Jong-Pyo;Baik, Baik
    • Journal of the Korean Applied Science and Technology
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    • v.21 no.4
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    • pp.370-379
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    • 2004
  • Highly crosslinked micron-size monodispersed PMMA/PDVB and PS/PDVB particles were prepared using seeded multi-stage emulsion polymerization. PMMA and PS seed particles were synthesized by seeded multi-stage emulsion polymerization and soap-free emulsion polymerization. Then PMMA/PDVB and PS/PDVB particles were obtained using semi-batch type emulsion polymerized using divinyl benzene as a cross-linkable monomer in the presence of seed particles. PMMA particles with size of ca. 730 nm and polydispersity of 1.03 were successfully prepared in this experiment. PS particles with size of ca. 1.5 ${\mu}m$ and polydispersity of 1.01 were prepared in this experiment. Highly crosslinked PS/PDVB particles with size of ca. 1.3 ${\mu}m$ and polydispersity of 1.00 were obtained.

Preparation and Physical Properties of Poly(Styrene/Acrylate) Core-Shell Latex Particles (Poly(Styrene/Acrylate) Core-Shell 라텍스 입자의 제조와 물성에 관한 연구)

  • Lee, Kyoung-Goo;Park, Keun-Ho
    • Journal of the Korean Applied Science and Technology
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    • v.20 no.1
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    • pp.27-32
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    • 2003
  • The core-shell latex particles were prepared by sequential emulsion polymerization of alkyl methacrylate and styrene(ST) by using an water-soluble initiator(APS) after preparing monomer pre-emulsion in the presence of an anionic surfactant(SDBS). In organic/organic core-shell polymerization, the pre-emulsion method, which minimized required quantity of sulfactant, has been used to increase the conversion rate and the stability of core-shell latex particles as well as to reduce the formation of secondary particle that cause problems of soap-free emulsion during shell polymerization. We used several methods to observe the core-shell structure. The core-shell structure was studied by measuring pH change during hydrolysis by NaOH, glass transition temperature($T_g$) by differential scanning calorimeter(DSC), morphology of latex by transmission electron microscope(TEM) and change of particle size and distribution by a particle analyzer.

Synthesis of PMMA/Clay Nanocomposite via Emulsion Polymerization (유화중합을 이용한 PMMA/Clay 나노컴포지트의 제조)

  • Kim, Cheol-Woo;Wu, Jong-Pyo
    • Journal of the Korean Applied Science and Technology
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    • v.20 no.3
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    • pp.243-250
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    • 2003
  • Poly(methyl methacrylate)/clay nanocomposite particles with particle size of 275${\sim}$292 nm range were successfully prepared using emulsion polymerization. The content of montmorillonite based on the methyl methacrylate monomer was chosen as 30 wt.%. 2,2-azobis(isobuthylamidine hydrochloride) and n-dodecyltrimethylammonium chloride were used as an initiator and a surfactant in cationic emulsion system. Potassium persulfate and sodium lauryl sulfate were used as an initiator and a surfactant in anionic emulsion system. The evidence of intercalated /exfoliated structure of montmorillonite in the nanocomposite prepared in our experiment was confirmed by wide angle x-ray diffraction patterns of $d_{001}$ plane. Thermal behavior of nanocomposite was traced using DSC and TGA. It was found that the nanocomposite particle prepared by cationic emulsion system showed intercalated structured. We also found that the nanocomposite particle obtained from anionic emulsion system resulted in the fully exfoliated structure.

Effect of Initiator on Performance of Polyvinylacetate as Emulsion Adhesive

  • Lee, Kangseok;Shim, Sang Eun
    • Elastomers and Composites
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    • v.50 no.4
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    • pp.286-291
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    • 2015
  • Polyvinylacetate (PVAc) was prepared using thermal initiation and redox initiation via emulsion polymerization at $80^{\circ}C$. The polymerization conditions had a significant effect on the properties of the synthesized PVAc. When hydrogen peroxide and tartaric acid as the initiator for redox polymerization were used, the synthesized PVAc had a low molecular weight. In comparison with thermal polymerization, smaller PVAc particles were formed during the redox polymerization due to relatively faster polymerization rate, which in turn resulted in improved adhesion property. It is considered that the rapid generation of smaller particles induces the formation of a large surface area.

Electrolyte Effect on the Particle Characteristics Prepared by Soap-Free Emulsion Polymerization

  • Han, Seung-Tak;Lee, Kang-Seok;Shim, Sang-Eun;Saikia, Prakash J.;Choe, Soon-Ja;Cheong, In-Woo
    • Macromolecular Research
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    • v.15 no.5
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    • pp.403-411
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    • 2007
  • Monodisperse micron-sized polystyrene (PS) spheres were successfully obtained using a single stage soap-free emulsion method in aqueous media mixed with ethanol (co-solvent) containing NaCI as the electrolyte. The optimum conditions for preparing the monodisperse PS microspheres, using soap-free emulsion polymerization in a water/ethanol mixture with an electrolyte, were studied. The presence of the co-solvent and electrolyte controlled the particle dispersion stability during the polymerization. The microspheres formed using PS, with a weight-average diameter of $2.6{\mu}m$, coefficient of variation of 5.3% and zeta potential of -15.1 eV, were successfully obtained in the presence of 0.1 wt% NaCI, 10 wt% monomer, 0.1 wt% initiator and 95/5 (g/g) of a water/ethanol mixture reacted at $70^{\circ}C$ for 24 h.

Emulsion Polymerization of Vinyl Acetate Using AAPH (AAPH를 이용한 아세트산비닐의 유화중합)

  • Kwak, Jin-Woo;Kim, Joon-Ho;Lyoo, Won-Seok
    • Proceedings of the Korean Fiber Society Conference
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    • pp.13-16
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    • 2003
  • Vinyl acetate monomer can be polymerized through bulk, solution, emulsion, and suspension polymerization processes. However, in the preparation of PVA from bulk or solution polymerization, there are several technical limitations for obtaining high yield and high molecular weight simultaneously. Thus, the improvement of polymerization method is necessary to prepare the PVA with high yield and high molecular weight because that the difficulty in control of high viscosity and in removal of the heat of polymerization, which might lead to side reactions like branching. (omitted)

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Preparation of Micron Size Poly(n-Butyl Acrylate) Latex Particle by Sequential Seeded Emulsion Polymerization (연속적 Seed 유화중합법에 의한 마이크론 크기의 Poly(n-Butyl Acrylate) 라텍스입자 제조)

  • Kim, Jee-Hoon;Suh, Soong-Hyuck;Nam, Wan-Woo;Kim, Kyung-Chan;Kang, Shin-Won;Ha, KiRyong
    • Applied Chemistry for Engineering
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    • v.10 no.6
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    • pp.889-894
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    • 1999
  • Preparation of micron size polymer particles which have desired morphology, size, and structure by emulsion polymerization is very difficult due to coagulation of latex particles and formation of second generation particles. But there are attractive merits such as preparation of structural and functional polymer particles in seeded emulsion polymerization. Seeded emulsion polymerization of n-butyl acrylate(BA) was carried out to investigate the effects of stirring rate, reaction temperature, concentration of initiator, emulsifier, and cross-linking agent on the particle size and size distribution. By the combination of suitable reaction conditions, we succeeded in preparing $0.14{\sim}3.67{\mu}m$ diameter of poly(n-butyl acrylate)(PBA) particles using sequential seeded emulsion polymerization.

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