• 한국고분자학회지:고분자과학과기술
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• 제7권6호
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• pp.738-749
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• 1996

• 한국고분자학회지:고분자과학과기술
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• 제9권4호
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• pp.256-273
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• 1998

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.333-333
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• 2006

We synthesized two novel polynorbornene derivatives, chiral poly(norbornene acid methyl ester) (C-PNME) and racemic poly(norbornene acid n-butyl ester) (R-PNME), which are potential low dielectric constant materials for applications in advanced microelectronic and display devices. Thin films of these polymers deposited on substrates were investigated by structural analyses using synchrotron grazing incidence X-ray scattering, specular reflectivity and ellipsometry. These analyses provided important information on the structure, electron density gradient across film thickness, chain orientation, refractive index and thermal expansion of the polymers in substrate-supported thin films. The structural characteristics and properties of the thin films were first dependent on the polymer chain' tacticity and further influenced by film thickness and thermal annealing.

• Composites Research
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• 제27권3호
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• pp.115-121
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• 2014

The effect of addition of gypsum on the rheology, physico-mechanical properties, thermal properties and morphology development of polymer composites based on polyvinyl chloride (PVC) and waste-gypsum with and without methylene-butadiene-styrene (MBS) has been studied. It was shown that the replacement of gypsum for methylene-butadiene-styrene (MBS) component in PVC/gypsum polymer composites enhanced the tensile strength and stiffness of composites, but gradually decreased its impact strength. The observation of morphology, the results of the physico-mechanical properties and thermal properties proved simultaneously that PVC/gypsum composite with the waste-gypsum content of 22.56 wt% reached the optimum results among five kinds of PVC/gypsum polymer composite materials investigated.

• Macromolecular Research
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• 제10권5호
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• pp.266-272
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• 2002

Although the reptational model of Doi and Edwards gives a successful description of viscoelasticity of flexible linear polymers, the success is restricted to the terminal region./sup 1/ There have been several attempts to modify the Doi-Edwards model to describe wider range of time or frequency./sup 2-6/ This paper suggests a simple phenomenological model which can describe wider range of molecular weight than such molecular models can. Although our model is a phenomenological one, it is practical and convenient to predict the effect of molecular weight distribution on linear viscoelastic data because of its simple mathematical form.

• Journal of Electrochemical Science and Technology
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• 제2권4호
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• pp.198-203
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• 2011

A polymer electrolyte was prepared by using polyvinylidenefluoride-co-hexafluoropropylene (PVdF-HFP) or poly(ethylene glycol) dimethacrylate (PEGDMA) as polymer matrices, succinonitrile as an additive, and lithium perchlorate as a lithium salt. Compared to the polymer electrolyte employing PVdF-HFP, the PEGDMA-based polymer electrolyte exhibits substantially superior thermal stability when exposed to high temperatures. Nonetheless, the ionic conductivity of the PEGDMA-based polymer electrolyte was preserved in a wide temperature range between $-20^{\circ}C$ and $80^{\circ}C$.

• Journal of Pharmaceutical Investigation
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• 제20권2호
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• pp.79-88
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• 1990

A numerical model for diffusion and dissolution controlled transport from dispersed matrix is presented. The rate controlling process for transport is considered to be diffusion of drug through a concentration gradient coupled with time-dependent surface change and/or disappearance of the dispersed drug in response to the dissolution. The transport behavior of drug was explained in terms of ${\nu}$ parameter: ${\nu}$ value means a ratio of diffusion time constant and dissolution time constant. This general model has wide range of application from where release is controlled by the diffusion rate to where release is governed by the dissolution rate. Based on this model, theoretical drug concentration, particle size distributions in the polymer matrix system and the resulting release rate were also investigated.

• 한국고분자학회지:고분자과학과기술
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• 제2권5호
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• pp.332-340
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• 1991

• 한국고분자학회지:고분자과학과기술
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• 제7권6호
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• pp.667-678
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• 1996

• Macromolecular Research
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• 제14권1호
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• pp.81-86
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• 2006

Poly(fluorenylenevinylene-terphenylenevinylene) containing phenyl pendant group was synthesized by Suzuki coupling reaction and characterized by ${1}^H$-NMR, ${13}^C$-NMR, and IR-spectrum. The weight average molecular weight ($M_{w}$) of the obtained polymer was 31,000 with a polydispersity index of 1.9. The polymer showed good solubility in common organic solvents, and the solution and film emitted blue emission ($\lambda_{max}$=460 nm) on irradiation with UV light. The ITO/PEDOT/polymer/Al device fabricated using the polymer as an emitting layer emitted blue light with a maximum peak around 460 nm. The maximum efficiency of the device was 0.011$\%$.