• Proceedings of the Korean Society of Rheology Conference
• /
• 2006.06a
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• pp.195-198
• /
• 2006

• Proceedings of the Korean Society of Rheology Conference
• /
• 2003.05a
• /
• pp.159-162
• /
• 2003

No Abstract, See Full Text

• Polymer Science and Technology
• /
• v.8 no.1
• /
• pp.4-11
• /
• 1997

• Journal of Photoscience
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• v.6 no.1
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• pp.25-27
• /
• 1999

• Applied Chemistry for Engineering
• /
• v.4 no.2
• /
• pp.229-239
• /
• 1993

• Polymer Science and Technology
• /
• v.11 no.6
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• pp.766-776
• /
• 2000

• Polymer Science and Technology
• /
• v.17 no.2
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• pp.226-235
• /
• 2006

• Macromolecular Research
• /
• v.9 no.1
• /
• pp.1-19
• /
• 2001

Poly(p-phenylene pyromellitimide) and poly(4,4'-biphenylene pyromellitimide) are representatives of fully rod-like polyimides. Their structure and properties in thin films are reviewed. The polymers exhibit some excellent properties such as high molecular packing coefficient, high mechanical modulus, and low thermal expansion coefficient, and low interfacial stress, so that they are very attractive to both industry and academia. However, these polymers are very brittle and thus practically useless. Some chemical modifications to improve such drawback with a little sacrifice of the high modulus are described: i) incorporation of short side groups into the polymer backbone and ii) insertion of proper linkages into the polymer backbone.

• Macromolecular Research
• /
• v.8 no.3
• /
• pp.120-124
• /
• 2000

Clay-dispersed nanocomposites have been prepared by simple melt-mixing of two components, styrenic polymers with different content of functional groups and two different organophilic clays (Cloisite(R) 25A and Cloisite(R)30A) with a twin screw extruder. Dispersibility of 10-$\AA$-thick silicate layers of clay in the hybrid was investigated by using an X-ray diffraction method and a transmission electron microscope. It was found that if the interaction force between intercalant and matrix polymer is attractive, the matrix polymer intercalates more rapidly into the gallery of silicate layers. The faster intercalation of matrix polymer leads to the better dispersibility of silicate layers in the matrix polymer.

• Polymer(Korea)
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• v.33 no.5
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• pp.496-500
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• 2009

Optically compensated bend liquid crystal display (OCB-LCD) has many application fields owing to its fast response time and wide viewing angle. However, in order to operate the OCB-LCD in bend state, this device needs quick transitions from the initial splay state to bend state. Unlike conventional approach using transient high voltage for the transition, the OCB-LCD with high surface tilt angle, which was achieved by polymerization of UV curable reactive mesogen monomer under certain voltage, was manufactured and the cell showed bend state initially. Electro-optic and electrical characteristics of the cell were analyzed. The cell shows a fast response time owing to high surface pretilt angle and very low residual DC less than 0.1 V although another polymer layer is formed above polymer alignment layers.