• Title, Summary, Keyword: hydrophilic polymer

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The Effect of Various Hydrophilic Acrylic Comonomers on Soap-Free Emulsion Polymerization of Styrene-Butadiene Rubber (Styrene-Butadiene 무유화제 유화공중합에서의 아크릴계 친수성 공단량체의 영향)

  • Chung, Huey-Sil;Lee, Chang-Sung;Kim, Byung-Kyu;Shin, Young-Jo
    • Elastomers and Composites
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    • v.28 no.4
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    • pp.267-273
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    • 1993
  • A number of hydrophilic acrylic comonomers were incorporated into styrene-butadiene soap-free emulsion polymerization. It was found that reaction rate decreased according to : AN>AA>MMA>EA>IA>AAM>MA>HEMA. It was also observed that reaction rate increased with decreasing H-bonding factor contribution to the solubility parameter of the hydrophilic comonoer. The SBR latexes were very monodisperse with the particle size distribution of $1.03{\times}1.12$. Since growth rate is proportional to polymerization time, the difference in conversion rates between various comonomers was resulted from the particle number density of SBR latexes for the various hydrophilic comonomers. It was also found that the colloidal stability of the latexes was excellent because no external emulsifier was incorporated.

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Polystyrene Microgel with Maltohexaose. Synthesis and Potential Application for Fullerene-Coating on Hydrophilic Surface

  • Narumi, Atsushi
    • Proceedings of the Polymer Society of Korea Conference
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    • pp.318-318
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    • 2006
  • 4-Vinylbenzyl maltohexaoside peracetate, 1, was copolymerized with divinylbenzene using the initiator for nitroxide-mediated living radical polymerization, 2, to afford the polystyrene microgel with acetyl maltohexaose, 3. The deacetylation of 3 was achieved by treatment with sodium methoxide in dry 1,4-dioxane to produce the polystyrene microgel with maltohexaose, 4. A good coating property of the polystyrene microgel was combined with an excellent hydrophilic property derived from maltohexaose. In addition, 4 showed the ability to solubilize fullerene in aqueous solution. Therefore, 4 has a potential application as a special coating using functional but incompatible compounds such as fullerene on the surface of various hydrophilic materials.

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Effect of Hydrophilic Polymer on Early Stages of Plant Growth of Euonymus fortunei 'Emerald and Gold' and Hedera japonica in a Vertical Greenery System for Low Maintenance (저관리 용기일체형 벽면녹화에서 황금줄사철과 송악의 초기활착에 미치는 친수성 중합체의 효용성)

  • Ju, Jin-Hee;Kim, Hea-Ran;Xu, Hui;Kim, Won-Tae;Choi, Eun-Young;Yoon, Yong-Han
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.19 no.3
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    • pp.1-9
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    • 2016
  • The objective of this study was to exam early stages of plant growth of Euonymus fortunei 'Emerald and Gold' and Hedera japonica grown in fabric felt bag attached on vertical greenery system with the ratio of hydrophilic polymer to substrate, 0(referred as Control), 0.1, 0.2, or 0.4% (v/v), in order to effectively utilize rainfall for low maintenance. After rainfall, the increase in volumetric water content of substrate amended with the hydrophilic polymer was between 13% and 87%, compared to that in Control. During drought period, higher ratio of hydrophilic polymer to substrate slowly decreased the volumetric water content, and increased plant height, leaf length, leaf width, number of leaves, branch number, and stem diameter of both Euonymus fortunei 'Emerald and Gold' and Hedera japonica with the highest fresh and dry weights of shoots or roots under the 0.1% ratio of hydrophilic polymer.

Decreasing Particle Size of Paclitaxel Using Polymer in Fractional Precipitation Process (고분자물질을 이용한 분별침전 공정에서 파클리탁셀의 입자크기 감소)

  • Kim, Min Jae;Kim, Jin-Hyun
    • Korean Chemical Engineering Research
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    • v.54 no.2
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    • pp.278-283
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    • 2016
  • In this study, we have for the first time applied fractional precipitation with hydrophilic polymer in order to decrease the particle size of the anticancer agent paclitaxel from plant cell cultures. When compared with the case where no hydrophilic polymer was employed, the addition of hydrophilic polymer in fractional precipitation resulted in a decrease in the size of the paclitaxel precipitate. Among the polymers used, HPMC 2910 was the most effective for inhibition of precipitate growth. A polymer concentration of 0.2% (w/v) obtained the smallest particle size. The particle size was reduced by ~35% compared to control. In addition, the precipitate size was inversely correlated with the absolute value of the zeta potential.

Self-Organization of Dendron-Poly(ethylene glycol) Conjugates in an Aqueous Phase

  • Kim, Kyoung-Taek;Lee, Im-Hae;Park, Chiyoung;Song, Yu-Mi;Kim, Chul-Hee
    • Macromolecular Research
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    • v.12 no.5
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    • pp.528-533
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    • 2004
  • We have prepared amide dendrons having alkyl peripheral units and various focal moieties through a convergent synthetic approach. The amphiphilic properties, due to hydrophilic amide branches and the hydrophobic peripheral units, provide an opportunity for the amide dendrons to self-organize in water. The dendritic architecture itself is also one of the critical factors in the self-organization of the amide dendrons in water. In particular, function-alization was performed at the focal point to elucidate the relationship between the focal functionality and the self-organized structures of the dendritic building blocks in the aqueous phase. The dendron having a short poly(ethylene glycol) monomethyl ether (MeO-PEG) unit (M$\_$n/ =750) as the focal moiety formed a vesicular organization in water. As the size of the hydrophilic focal MeO-PEG increased to M$\_$n/ =2,000 and 5,000, the self-organized structures became rod-type and spherical micelles, respectively. Our observation of multiple morphologies for amide dendrons is in good agreement with previous reports that indicated that the micellar structures changed from vesicles to rod-types and then to spheres upon increasing the size of the hydrophilic moiety of the amphiphiles.

Surface modification of polymeric membranes for low protein binding

  • Higuchi, Akon;Tamai, Miho;Tagawa, Yoh-Ichi;Chang, Yung;Ling, Qing-Dong
    • Membrane Water Treatment
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    • v.1 no.2
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    • pp.103-120
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    • 2010
  • Surface modification of microfiltration and ultrafiltration membranes has been widely used to improve the protein adsorption resistance and permeation properties of hydrophobic membranes. Several surface modification methods for converting conventional membranes into low-protein-binding membranes are reviewed. They are categorized as either physical modification or chemical modification of the membrane surface. Physical modification of the membrane surface can be achieved by coating it with hydrophilic polymers, hydrophilic-hydrophobic copolymers, surfactants or proteins. Another method of physical modification is plasma treatment with gases. A hydrophilic membrane surface can be also generated during phase-inverted micro-separation during membrane formation, by blending hydrophilic or hydrophilic-hydrophobic polymers with a hydrophobic base membrane polymer. The most widely used method of chemical modification is surface grafting of a hydrophilic polymer by UV polymerization because it is the easiest method; the membranes are dipped into monomers with and without photo-initiators, then irradiated with UV. Plasma-induced polymerization of hydrophilic monomers on the surface is another popular method, and surface chemical reactions have also been developed by several researchers. Several important examples of physical and chemical modifications of membrane surfaces for low-protein-binding are summarized in this article.

The Effect of Aggregation States on ionic Conductivity of Stolid Polymer Electrolytes Based on Waterborne Polyurethane

  • Bae, Sang-Sik;Jo, Nam-Ju
    • Macromolecular Research
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    • v.9 no.6
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    • pp.332-338
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    • 2001
  • Waterborne polyurethane as a new polymer electrolyte was synthesized by using relatively hydrophilic polyols. The morphology of polyurethane was changed as it was dispersed in water. In contrast to polyurethane ionomer, waterborne polyurethane did not form an ionic cluster but produced a binary system composed of hydrophilic and hydrophobic groups. In the colloidal system, the former and the latter existed at outward and inward, respectively. Waterborne polyurethane was prepared from poly(ethylene glycol) (PEG) /poly(propylene glycol) (PPG) copolymer, 4,4'-diphenylmethane diisocyanate(MDI), ethylene diamine as a chain extender, and three ionization agents, 1,3-propane sultone, sodium hydride and lithium hydroxide. PEG/PPG copolymer was used for suppressing the crystallinity of PEG and N-H bond was ionized for increasing the electrochemical stability of polyurethane. Low molecular weight poly(ethylene glycol) and poly(ethylene glycol dimethyl ether) (PEGDME) were used as plasticizers. DSC, FT-IR and $^1$H-NMR of the waterborne polyurethane were measured. Also, the ionic conductivity of solid polymer electrolytes based on waterborne polyurethane and various concentrations of low molecular weight poly(ethylene glycol) or PEGDME were measured by AC impedance.

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Synthesis and Characterization of Biodegradable Elastic Hydrogels Based on Poly(ethylene glycol) and Poly(${\varepsilon}-caprolactone$) Blocks

  • Im, Su-Jin;Choi, You-Mee;Subramanyam, Elango;Huh, Kang-Moo;Park, Ki-Nam
    • Macromolecular Research
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    • v.15 no.4
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    • pp.363-369
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    • 2007
  • Novel biodegradable elastic hydrogels, based on hydrophilic and hydrophobic polymer blocks, were synthesized via the radical crosslinking reaction of diacrylates of poly(ethylene glycol) (PEG) and poly(${\varepsilon}-caprolactone$) (PCL). PEG and PCL diols were diacrylated with acryloyl chloride in the presence of triethylamine, with the reaction confirmed by FT-IR and $^1H-NMR$ measurements. The diacrylate polymers were used as building-blocks for the syntheses of a series of hydro gels, with different block compositions, by simply varying the feed ratios and molecular weights of the block components. The swelling ratio of the hydrogels was controlled by the balance between the hydrophilic and hydrophobic polymer blocks. Usually, the swelling ratio increases with increasing PEG content and decreasing block length within the network structure. The hydrogels exhibited negative thermo-sensitive swelling behavior due to the coexistence of hydrophilic and hydrophobic polymer components in their network structure, and such thermo-responsive swelling/deswelling behavior could be repeated using a temperature cycle, without any significant change in the swelling ratio. In vitro degradation tests showed that degradation occurred over a 3 to 8 month period. Due to their biodegradability, biocompatibility, elasticity and functionality, these hydrogels could be utilized in various biomedical applications, such as tissue engineering and drug delivery systems.

Tetrapyrazinoindoloporphyrazine Langmuir-Blodgett Films

  • Kim, Jong-Min;Jaung, Jae-Yun;Ahn, Hee-Joon
    • Macromolecular Research
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    • v.16 no.4
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    • pp.367-372
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    • 2008
  • We fabricated tetra(5-n-nonyl-8-tert-butyl-2,3-pyrazino[2,3-b]indolo)porphyrazinato copper(II) (Cu-Pc-$C_8$) Langmuir-Blodgett (LB) films. We further investigated the influence of arachidic acid (AA) as a transfer promoter, as well as the effect of dipping speed, on the deposition of the films on hydrophilic and hydrophobic substrates. In the case of pure Cu-Pc-$C_8$ LB deposition on a hydrophilic substrate, the transfer ratio was close to one for up-stroke depositions, but the previously deposited film was peeled off and re-spread onto water at down-stroke depositions. Whereas the stability of the Cu-Pc-$C_8$ LB films was not improved by AA addition on hydrophilic substrates, the deposition of Cu-Pc-$C_8$ was significantly improved by the presence of AA on a hydrophobic substrate. The AA-assisted deposition had transfer ratio of close to 1 and was essentially stable up to 10-layer depositions. Comparison of the UV-visible spectrum of a Cu-Pc-$C_8$/AA LB film with that of Cu-Pc-$C_8$/AA solution in dichloroethane revealed that the Soret and Q bands for the Cu-Pc-$C_8$/AA LB film were broadened and red-shifted due to the aggregation of phthalocyanines upon assembly in the LB film.

Preparation of Poly(2-biphenylyl acrylate-co-methacrylic acid) and Release of 2-Phenylphenol (2-비페닐릴아크릴레이트와 메타크릴산의 공중합체 제조와 2-페닐페놀의 방출)

  • Hyun Seok-Hee;Kim Min-Woo;Jeon Il-Ryon;Son Seog-Ho;Baek Chang-Hoon;Kim Woo-Sik
    • Polymer(Korea)
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    • v.30 no.1
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    • pp.80-84
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    • 2006
  • 2-Biphenylyl acrylate(BPA) was synthesized by the reaction of acryloyl chloride with 2-phenylphenol (2PP). Hydrophilic copolymers with the moiety of the microbicide, 2PP, were prepared by the radical copolymerization of BPA and methacrylic acid (MA). From the compositions of the BPA unit and the MA unit in the copolymers, the monomer reactivity ratios were determined to be 0.86 for BPA and 1.21 for MA by means of Kelen-Tudos plot. This result indicates that the copolymers have a random structure. The amount of 2PP released through the hydrolysis of the copolymers was examined by UV spectrometry. The result showed that the release of 2PP increased with an increase in the hydrophilic MA content in the copolymers and with an increase in the pH of the release medium. Therefore, these results indicate that the hydrophilic polymers bearing 2-phenylphenol moiety can be controlled release microbicides.