• Title, Summary, Keyword: polymer modifier

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Development of Polymer-Modified Cementitious Self-Leveling Materials for Thin Coat

  • Kim, Wan-Ki;Do, Jeong-Yun;Soh, Yang-Seob
    • KCI Concrete Journal
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    • v.13 no.2
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    • pp.58-66
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    • 2001
  • Recently, polymer-modified mortar has been studied for proposed use on industrial floors as top coat with thin thickness, typically 5~15mm. The purpose of this study is to evaluate basic properties of self-leveling materials using polymer dispersions as kinds of SBR, PAE, St/BA with thin coat (under 3mm). Superplasticizer and thickener have been included in the mixes to reduce bleeding and drying shrinkage as well as to facilitate the workability required. The self-leveling materials using four types of polymer dispersion are prepared with polymer-cement ratio which respectively range from 50% and 75%, and tested for basic characteristics such as unit weight, air content, flow, consistency change and adhesion in tension. From the test results, the self-leveling materials using PAE emulsion at curing age of 28days are almost equal to those of conventional floor using urethane and epoxy resin. The adhesion in tension of self-leveling mortars using SBR latex and PAE emulsion at curing age of 3days is over 17 kgf/cm$^2$(1.67MPa). Consistency change is strongly dependent on the type of polymer dispersion. It is concluded that the self-leveling materials using polymer dispersions can be used in the same manner as conventional floor using thermosetting resin in practical applications, in the selection of polymer dispersions.

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Physical Properties of Polymer Composite Recycling Recycled Aggregate (순환골재를 재활용한 폴리머 복합재료의 물성)

  • Hwang, Eui-Hwan;Jeon, Jong-Ki
    • Applied Chemistry for Engineering
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    • v.20 no.1
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    • pp.67-74
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    • 2009
  • Nowadays, recycling of recycled aggregates from the waste concrete is seriously demanded for the protection of environment and the shortage of aggregates owing to the large scale construction project. In this study, for the development of polymer composite recycling recycled aggregates from the waste concrete, twenty five specimens of the polymer composite were prepared with the five levels of replacement ratios of recycled aggregates (0, 25, 50, 75, 100%) and polymer-cement ratios (0,5, 10, 15, 20%), respectively. For the evaluation of the performance of polymer composite specimens, various physical properties such as compressive and flexural strengths, water absorption, hot water resistance, total pore volume and porosity were investigated. As a result, physical properties of polymer composite were remarkably improved with an increase of polymer cement ratios, but greatly decreased with the replacement ratios of recycled aggregates.

Polymer-directed Crystallization of Sibutramine using Cellulose Derivatives

  • Bae, Ha-Rim;Lee, Hye-Seung;Lee, Min-Kyung;Lee, Jong-Hwi
    • Journal of Pharmaceutical Investigation
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    • v.41 no.1
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    • pp.45-50
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    • 2011
  • Nonclassical pathway of crystallization has been utilized to modify the properties and morphologies of inorganic and organic/inorganic materials. In here, the polymer-directed crystallization method has been applied to the pharmaceutical active ingredient to assess the applicability for as a particle engineering tool. The polymer-directed crystallization was successful to modifying the crystal size, habit and morphology, but it was not effective to discover the novel polymorphs of Sibutramine (SB). SB was selected as a model drug and polyacrylic acid (PAA), polyethylene imine (PEI) and chitosan (CHI) were added as a crystallization pathway modifier. SB was crystallized via drowning crystallization using methanol or ethanol as a solvent and water as a non-solvent. The significant interactions between polymer and the drug were confirmed by measuring the solubility of the drug in presence of polymer during the crystallization. The crystal forms of SB are characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and optical microscope (OM). The polymer-directed crystallization seems to be able to modify the crystal properties of pharmaceutical active ingredient, which is critical in determining the bioavailability, processability, and stability.

The Study on Synthesis and Application of Polymer Dispersion for Cement Modifier -The Waterproffing Effeet of Cement Mortar by Poly[DMA-co-DAMA] Emulsion- (시멘트 혼화용 폴리머 합성과 그 응용에 관한 연구 -Poly[DMA-co-DAMA] 에멀젼을 이용한 시멘트 모르타르의 방수성-)

  • Kim, Young-Geun;Herh, Dong-Seop;Park, Hong-Soo
    • Applied Chemistry for Engineering
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    • v.5 no.4
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    • pp.669-680
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    • 1994
  • DMA-co-DAMA were synthesized from 2-diethylaminoethyl metacrylate and dodecyl-metacrylate containing long chain hydrocarbon group with hydrophilic and hydrophobic radicals. To facilitate water emulsification,acrylic copolymer was cationized by acetic acid to produce acetated acrylic copolymer. The structures of the synthesized copolymer and acetated copolymers were confirmed by IR, NMR, and molecular weight was measured by GPC, and C. H. N elemental analysis. Acetated acrylic copolymers were perfectly emulsified in water and showed increased emulsion stability. Polymer dispersion for cement modifier(PDCM-PDD) was prepared by blending of the guaternized acrylic copolymer synthesized above sodium silicate sodium gluconate oleic acid and triethanol amine. The result with prepared polymer dispersion of cement modfier was examined, and it was found that excellent waterproffing effect; Water permeability ratio is 0.44 under the water pressure of $100g/cm^2$ and 0.55 under $3kg/cm^2$, and water absorption ratio is 0.36~0.47 and 1.02 compressive strength ratio at mixed ratio of water/PDCM-PDD is 45 times.

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Effects of Admixtures in Properties of Polymer Cement Mortar for Concrete Repair (혼화재료가 보수용 폴리머 시멘트 모르타르의 성질에 미치는 영향)

  • Song, Hyung-Soo;Lee, Chin-Yong;Min, Chang-Shik
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.11 no.1
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    • pp.85-94
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    • 2007
  • The EVA polymer is used as a modifier in the repair mortar, which contains various admixtures and mineral admixtures. It has been reported that the effect of polymer in cement mortar by the cement-polymer ratio only, but effect of admixtures over the polymer mortar was unknown. In this study, the fresh and mechanical properties of polymer cement mortar influenced by the range of admixtures(CSA expansive addictive, CSA accelerator, gypsum, silica fume) ratio were investigated.

Flow Characteristics, Mechanical Properties and Chemical Resistance of Polycarbonate/Polybutylene Terephthalate/Impact Modifier Blends (Polycarbonate/polybutylene Terephthalate/Impact Modifier 블렌드의 유동특성, 기계적 성질 및 내화학성)

  • 류민영
    • Polymer Korea
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    • v.26 no.2
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    • pp.237-244
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    • 2002
  • Mechanical properties, flow characteristics and chemical resistance of polycarbonate (PC)/polybutylene terephthalate (PBT) /impact modifier (IM) blends were investigated over the various composition ranges of PC and PBT. Mechanical properties of the PC/PBT/IM blends for different IMs, butadiene based IM and butyl acrylate based IM, were studied for various compositions of the IMs. Impact strength at low temperature was also observed. For the study of chemical resistance of the PC/PBT/IM blends, the blonds were dipped in organic solvent, thinner, and then variations of mechanical properties were analyzed. Tensile and flexural strengths were increased linearly and heat distortion temperature (HDT) also increased as PC content in the blends increased. Impact strength increased drastically as PC content increased up to 50 wt% and stayed stable value. Flowability decreased as PC content increased. Impact strengths of the blend were various for different IMs. Butyl acrylate based IM showed slightly higher impact strength than butadiene based IM for the temperature above $0^{\circ}C$. However, butadiene based IM showed remarkably higher impact strength than butyl acrylate based IM for the temperature below $0^{\circ}C$. Through the experiment of chemical resistance it was observed that tensile and flexural strengths decreased, and impact strength increased as PC content in the blends increased. PC in the blend would become mild and ductile when it contacted with organic solvent. Thus the impact strength increased while tensile and flexural strength decreased.

Characterization of polymer inclusion membrane containing Aliquat 336 as a carrier

  • Manzak, Aynur;Yildiz, Yasemin;Tutkun, Osman
    • Membrane Water Treatment
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    • v.6 no.2
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    • pp.95-102
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    • 2015
  • The presented research is about characterization of Cellulose Triacetate (CTA) based Polymer Inclusion Membranes (PIMs) which incorporated the commercial extractant Aliquat 336, Tributylphosphate (TBP) as modifier and 2-Nitro Phenyl Pentyl Ether (NPPE) as plasticizer, for the preparation of the membranes. Chemical and physical characteristics of the synthesized membranes especially membrane thickness and side difference effects were investigated. Different surface structures and membrane thickness affect the extraction efficiency of membranes. Membrane extraction experiments were studied where the glass-facing surface of the membranes placed next to feed phase and the air-facing surface to stripping phase. The membrane was characterized by means of AFM, FT-IR and SEM.

Performance of PEG on immobilization of zero valent metallic particles on PVDF membrane for nitrate removal

  • Chan, Yi Shee;Chan, Mieow Kee;Ngien, Su Kong;Chew, Sho Yin;Teng, Yong Kang
    • Membrane Water Treatment
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    • v.9 no.1
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    • pp.1-7
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    • 2018
  • The principal objective of this study is to investigate the effect of Polyethylene Glycol (PEG) crosslinking in Polyvinylidene Fluoride (PVDF) in immobilization of Fe and bimetallic Fe/Cu and Cu/Fe zero valent particles on the membrane and its efficiency on removal of nitrate in wastewater. PVDF/PEG polymer solution of three weight compositions was prepared to manipulate the viscosity of the polymer. PEG crosslinking was indirectly controlled by the viscosity of the polymer solution. In this study, PEG was used as a modifier of PVDF membrane as well as a cross-linker for the immobilization of the zero valent particles. The result demonstrates improvement in immobilization of metallic particles with the increase in crosslinking of PEG. Nitrate removal efficiency increases too.

Lining of Reinforced Spun Concrete Pipes using Polymer-Modified Mortars (폴리머 시멘트 모르타르를 이용한 원심력 철근콘크리트관의 라이닝)

  • 조영국
    • Journal of the Korea Concrete Institute
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    • v.13 no.4
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    • pp.406-413
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    • 2001
  • Up to this day, reinforced spun concrete pipes have been widely used as drain pipes. However, many reinforced spun concrete pipes are exposed to the deteriorated environment such as freezing-thawing damage and chemical attack by the growth of a sulfur-oxidizing bacterium isolated from corroded concrete. The purpose of this study is to evaluate the effects of lining by polymer-modified mortar using polymer dispersions as cement modifier on the development in durability of reinforced spun concrete pipe. The polymer-modified mortars were prepared with various polymer types and polymer-cement ratios, and tested for compressive and flexural strengths, acid, freezing-thawing, and heat resistances. And then, the reinforced spun concrete pipe product lined by polymer-modified mortars was tested for adhesion in tension and surface conditions according to curing temperatures in the field. From the test results, it is apparent that the polymer-modified mortars have good mechanical properties and durability as a lining material. In practice, all polymers can be used as lining the materials for reinforced spun concrete pipe, and types of polymer, and polymer-cement ratio and curing conditions are controlled for a good lining product.

Reactive Dispersion and Mechanical Property of Dicyanate/Montmorillonite Nanocomposite (반응이 수반된 Dicyanate/Montmorillonite Nanocomposite의 분산과 물성특성 연구)

  • 장원영;이근제;남재도
    • Polymer Korea
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    • v.27 no.1
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    • pp.75-83
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    • 2003
  • Dicyanate-clay nanocomposite has been prepared by a melt in-situ polymerization method for different modifiers and cation exchange capacity (CEC) values in order to study dispersion and mechanical property. Various dicyanate nanocomposites were prepared by using different MMT systems containing different intercalants which led to different initial gallery heights and packing density. Depending on compatibility between dicyanate and clays, the degree of dispersion varied. Dispersion of clay plates in dicyanate resin depended mainly on CEC and aliphatic chain length of modifier. The lower CEC and shorter aliphatic chain length of modifier gave the exfoliation structure. It was also found that the reactivity of intercalant with dicyanate resin was one of the key factors facilitating the intercalation/exfoliation process of dicyanate/MMT nanocomposites. Shear modulus of reaction-induced dicyanate nanocomposite was significantly increased.