• Macromolecular Research
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• v.8 no.2
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• pp.95-101
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• 2000

Clay/poly(styrene-co-acrylonitrile) copolymer (SAN) hybrids have been prepared by simple meltmixing of two components, SAN and organophilic clays with a twin screw extruder. Effects of intercalant on the dispersibility of silicate layers in clay-dispersed nanocomposite were studied by using five different organophilic clays modified with the intercalants of different chemical structures and different fractions of intercalant. The dispersibility of 10-$\AA$-thick silicate layers of clay in the hybrid was investigated by using an X-ray diffractometer and a transmission electron microscope. It was found that if the fraction of intercalant in the organophilic clay becomes too high, SAN is difficult to intercalate into the inter-gallery of silicate layers in the hybrid prepared at 180$\^{C}$, and thus the hybrid shows poor dispersibility of silicate layers. The flexural modulus of the hybrid increases as the dispersibility of silicate layers in the hybrid increases.

• Polymer Science and Technology
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• v.21 no.2
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• pp.141-148
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• 2010

• Macromolecular Research
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• v.11 no.3
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• pp.172-177
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• 2003

Biphenyltetracarboximide-phenylene diamine polyimide/silica-titania ternary hybrid composites were Prepared by thermal imidization and sol-gel reaction. Fluorescence spectroscopic, scanning electron microscopy, and atomic force microscopy studies revealed that the addition of small amount of titania showed profound effects on the microstructure and photophysical behaviors of polyimide/silica hybrid composites, when the content of silica-titania mixture was small or when the ratio of silica to titania in the mixture was high.

• Polymer Science and Technology
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• v.15 no.6
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• pp.692-701
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• 2004

• Rapid Communication in Photoscience
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• v.4 no.1
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• pp.16-18
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• 2015

Luminescence properties of anthracene chromophores were investigated. Anthracene chromophores were incorporated in cyclosiloxane-based hybrid polymers through one-pot hydrosilylation reaction. Using four-armed cyclosiloxanes, divinylterminated siloxane monomers, and 9-vinylanthracenes, anthracene-labeled hybrid polymers were prepared. Free-standing hybrid polymer films were prepared successfully by doctor-blade method and thermal treatment. The polymer films exhibit strong blue fluorescence from anthracene and its fluorescence lifetime was not influenced by the temperature, indicating that the movement of anthracene chromophores was restrained in cyclosiloxane-based hybrid polymer films.

• Macromolecular Research
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• v.15 no.5
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• pp.449-458
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• 2007

The aims of this study were to investigate the intercalation of polymer chains with organoclays and improve the thermo-mechanical properties of poly(butylene terephthalate) (PBT) hybrids by comparing PBT hybrids synthesized using two different organoclays. The organoclays; dodecyltriphenylphosphonium-montmorillonite ($C_{12}PPh-MMT$) and dodecyltriphenylphosphonium-mica ($C_{12}PPh-Mica$), were used to fabricate the PBT hybrid fibers. Variations in the properties of the hybrid fibers with the organoclays within the polymer matrix, as well as the draw ratio (DR), are discussed. The thermo-mechanical properties and morphologies of the PBT hybrid fibers were characterized using differential scanning calorimetry, thermogravimetric analysis, wide-angle X-ray diffraction, electron microscopy and mechanical tensile properties analysis. The nanostructures of the hybrid fibers were determined using both scanning and transmission electron microscopies, which showed some of the clay layers to be well dispersed within the matrix polymer, although some clustered or agglomerated particles were also detected. The thermal properties of the hybrid fibers were found to be better than those of the pure PBT fibers at a DR = 1. The tensile mechanical properties of the $C_{12}PPh-MMT$ hybrid fibers were found to worsen with increasing DR. However, the initial moduli of the $C_{12}PPh-Mica$ hybrid fibers were found to slightly increase on increasing the DR from 1 to 18.

• Macromolecular Research
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• v.8 no.1
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• pp.6-11
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• 2000

In this study, we examined the charging behavior of chopped carbon fibers during electro-flocking process, which is one of the key processes of the novel technique for fabricating conductive polymer composite films. Short carbon fibers (CF) during electroflocking were electrically charged by the combined effect of contact charging, corona charging and tribocharging. The specific charge built on CF surface was measured by using Faraday cup method. Specific charge increased not only with increasing electric field strength and potential impressed to mesh electrode as expected from theoretical considerations in literature, but with decreasing mesh opening size due to the improved contact charging condition. However, CF length was found unexpectedly to influence the amount of CF specific charge due to the agglomerated nature of CF flocks leading to the change in charging conditions.

• Macromolecular Research
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• v.17 no.9
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• pp.638-645
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• 2009

We report the effect of the amount of the mesoporous material, SBA-15, on the basic traits of fully aliphatic polyimides (API). For this purpose, water soluble, fully aliphatic poly(amic acid) triethyl amine salts ($PAA_{(s)}$) were prepared and mixed with various amounts of SBA-15. Fully aliphatic polyimide hybrid composites containing the SBA 15-type mesoporous silica were synthesized successfully from bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic dianhydride and alicyclic diamine, 4,4'-methylene bis(2-methylcyclohexylamine). The structure of the hybrid composites was confirmed by IR spectroscopic analysis. Scanning electron microscopy revealed the morphology of the compounds. The hybrid composites exhibited good thermal stability, reasonable transparency, and a low dielectric constant.

• Carbon letters
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• v.5 no.1
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• pp.1-5
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• 2004

The effects of fiber surface-treatment and sizing on the dynamic mechanical properties of unidirectional and 2-directional carbon fiber/nylon 6 composites by means of dynamic mechanical analysis have been investigated in the present study. The interlaminar shear strengths of 2-directional carbon/nylon 6 composites sized with various thermosetting and thermoplastic resins are also measured using a short-beam shear test method. The result suggests that different surface-treatment levels onto carbon fibers may influence the storage modulus and tan ${\delta}$ behavior of carbon/nylon 6 composites, reflecting somewhat change of the stiffness and the interfacial adhesion of the composites. Dynamic mechanical analysis and short-beam shear test results indicate that appropriate use of a sizing material upon carbon fiber composite processing may contribute to enhancing the interfacial and/or interlaminar properties of woven carbon fabric/nylon 6 composites, depending on their resin characteristics and processing temperature.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.275-275
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• 2006

A series of organoboron polymer electrolytes were prepared and their ion conductive characteristics was investigated in detail. Alkylborane type polymer electrolytes prepared by hydroboration polymerization exhibited improve lithium transference number due to efficient anion trapping of alkylborane unit. A lithium borate type polymer/salt hybrid was also successfully prepared by dehydrocoupling polymerization of lithium mesitylhydrorate. Ionic conductivity of single ion conductive polymer/salt hybrid was further improved in the case of comb like polymer/boron stabilized imido anion hybrid prepared via polymer reaction of poly(organoboron halide) with hexylamine and PEO monomethylether and subsequent neutralization with lithium hydride.