• 한국광학회:학술대회논문집
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• 한국광학회 2005년도 제16회 정기총회 및 동계학술발표회
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• pp.230-231
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• 2005

• Bulletin of the Korean Chemical Society
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• 제31권6호
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• pp.1509-1514
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• 2010

Methyl 3,4-di-(2'-hydroxyethoxy)benzylidenecyanoacetate (3) was prepared and condensed with terephthaloyl chloride to yield novel Y-type polyester (4) containing 3,4-dioxybenzylidenecyanoacetate groups as NLO-chromophores, which constituted parts of the polymer main chains. The resulting polymer 4 is soluble in common organic solvents such as acetone and N,N-dimethylformamide. Polymer 4 shows thermal stability up to $280^{\circ}C$ in thermogravimetric analysis with glass-transition temperature obtained from differential scanning calorimetry near $105^{\circ}C$. The second harmonic generation (SHG) coefficient ($d_{33}$) of poled polymer films at the 1064 nm fundamental wavelength is around 2.42 pm/V. The dipole alignment exhibits high thermal stability up to near $T_g$, and there is no SHG decay below $100^{\circ}C$ due to the partial main-chain character of polymer structure, which is acceptable for NLO device applications.

• Bulletin of the Korean Chemical Society
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• 제30권5호
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• pp.1080-1084
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• 2009

Methyl 2,4-di-(2'-hydroxyethoxy)benzylidenecyanoacetate (3) was prepared and polymerized with terephthaloyl chloride to yield a novel Y-type polyester 4 containing 2,4-dioxybenzylidenecyanoacetate groups as NLOchromophores, which constituted parts of the polymer backbone. The resulting polymer 4 is soluble in common organic solvents such as acetone and N,N-dimethylformamide. Polymer 4 showed thermal stability up to 280 ${^{\circ}C}$ in thermogravimetric analysis with glass-transition temperature obtained from differential scanning calorimetry near 108 ${^{\circ}C}$. The second harmonic generation (SHG) coefficient ($d_{33}$) of poled polymer films at the 1064 nm fundamental wavelength was around $3.54\;{\time}\;10^{-9}$ esu. The dipole alignment exhibited a thermal stability up to near $T_g$ and no significant SHG decay was observed below 100 ${^{\circ}C}$ due to the partial main-chain character of polymer structure, which is acceptable for NLO device applications.

• Macromolecular Research
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• 제15권3호
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• pp.234-237
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• 2007

3,4-Bis-(3,4-dicarboxyphenylcarboxyethoxy)-4'-nitrostilbene dianhydride was prepared and reacted with 4,4'-(hexafluoroisopropylidene)dianiline to yield a novel Y-type polyimide containing the 3,4-dioxynitrostilbenyl group as an NLO-chromophore, which constituted part of the polymer backbone. The resulting polyimide was soluble in polar solvents such as acetone and N,N-dimethylformamide. The polymer exhibited good thermal stability up to $370^{\circ}C$ in the thermogravimetric analysis. The glass-transition temperature ($T_g$) obtained from the differential scanning calorimetry thermogram was near to $153^{\circ}C$. The second harmonic generation (SHG) coefficient ($d_{33}$) of the poled polymer film at the fundamental wavelength of $1064\;cm^{-1}$ was around $2.15\;{\times}\;10^{-8}\;esu$ (9.01 pm/V). The dipole alignment exhibited exceptionally high thermal stability even at a temperature $30^{\circ}C$ above the $T_g$, and there was no SHG decay below $180^{\circ}C$ because of the partial main chain character of the polymer structure.

• Smart Structures and Systems
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• 제13권4호
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• pp.567-585
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• 2014

The piezoelectric transverse $d_{15}$ shear sensing mechanism is firstly assessed experimentally for a cantilever smart sandwich plate made of a piezoceramic axially poled patched core and glass fiber reinforced polymer composite faces. Different electrical connections are tested for the assessment of the sensor performance under a varying amplitude harmonic (at 24 Hz) force. Also, the dynamic response of the smart sandwich composite structure is monitored using different acquisition devices. The obtained experimentally sensed voltages are compared to those resulting from the benchmark three-dimensional piezoelectric coupled finite element simulations using a commercial code where realistic features, like equipotential conditions on the patches' electrodes and mechanical updating of the clamp, are considered. Numerically, it is found that the stiffness of the clamp, which is much softer than the ideal one, has an enormous influence on the sensed voltage of its adjacent patch; therefore, sensing with the patch on the free side would be more advantageous for a cantilever configuration. Apart from confirming the latter result, the plate benchmark experimental assessment showed that the parallel connection of its two oppositely poled patches has a moderate performance but better than the clamp side patch acting as an individual sensor.

• Macromolecular Research
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• 제15권6호
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• pp.506-512
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• 2007

2,3-Di-(2'-hydroxyethoxy)-4'-nitrostilbene (3) was prepared and condensed with terephthaloyl chloride, adipoyl chloride, and sebacoyl chloride to yield novel Y-type polyesters (4-6) containing the NLO-chromophores 2,3-dioxynitrostilbenyl groups, which constituted parts of the polymer backbones. Polymers 4-6 were soluble in common organic solvents such as acetone and N,N-dimethylformamide. Polymers 4-5 showed thermal stability up to $300^{\circ}C$ in thermogravimetric analysis with glass transition temperatures $(T_g)$, obtained from differential scanning calorimetry, in the range $81-95^{\circ}C$. The second harmonic generation (SHG) coefficients $(d_{33})$ of the poled polymer films at the 1064 nm fundamental wavelength were around $3.68{\times}10^{-9}$ esu. The dipole alignment exhibited high thermal stability up to $T_g$, and there was no SHG decay below $T_g$ due to the partial main-chain character of the polymer structure.

• Macromolecular Research
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• 제8권3호
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• pp.137-141
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• 2000

3,4-Di-(2'-hydroxyethoxy)-4-nitrostilbene (2) was prepared by the reaction of 2-iodoethanol with 3,4-dihydroxy-4-nitrostilbene (1). Diol 2 was condensed with 2,4-toluenediisocyanate ,3,3-dimethoxy-4,4'-biphenylenediisocyanate , and 1,6-hexamethylenediisocyanate to yield polyurethanes 3, 4, and 5 containing the NLO-chromophore. Polymers 3-5 were soluble in common organic solvents such as acetone and DMSO. The glass transition temperatures(T$\sub$g/) of the resulting polymers 3-5 were obseved around 100-114$^{\circ}C$. Electrooptic coefficients (r$\sub$33/) of the poled polymer films were in the range of 18-25 pm/V at 633 nm. Polymers 3-5 began to decompose around 250$^{\circ}C$ in TGA thermograms.

• Bulletin of the Korean Chemical Society
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• 제31권2호
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• pp.429-434
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• 2010

A novel T-type polyester 7 containing 1-(2,5-dioxyphenyl)-2-{5-(1,2,2-tricyanovinyl)-2-thienyl}ethenes as nonlinear optical (NLO) chromophores, which are part of the polymer backbone, was prepared and characterized. Polyester 7 is soluble in common organic solvents such as dimethylsulfoxide and N,N-dimethylformamide. It showed a thermal stability up to $300^{\circ}C$ in thermogravimetric analysis thermogram and the glass-transition temperature ($T_g$) obtained from differential scanning calorimetry thermogram was around $113^{\circ}C$. The second harmonic generation (SHG) coefficient ($d_{33}$) of poled polymer films at 1,560 nm fundamental wavelength was around 1.85 pm/V. The dipole alignment exhibits a greater thermal stability even at $10^{\circ}C$ higher than $T_g$, and there is no SHG decay below $125^{\circ}C$ due to the partial mainchain character of the polymer structure, which is acceptable for nonlinear optical device applications.

• Bulletin of the Korean Chemical Society
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• 제32권9호
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• pp.3361-3366
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• 2011

New Y-type polyester (3) containing nitrophenylazoresorcinoxy groups as NLO chromophores, which are components of the polymer backbone, was prepared and characterized. Polyester 3 is soluble in common organic solvents such as N,N-dimethylformamide and acetone. It shows a thermal stability up to $240^{\circ}C$ in thermogravimetric analysis with glass-transition temperature ($T_g$) obtained from differential scanning calorimetry near $116^{\circ}C$. The second harmonic generation (SHG) coefficient ($d_{33}$) of poled polymer film at the 1064 nm fundamental wavelength is around $4.63{\times}10^{-9}$ esu. The dipole alignment exhibits a thermal stability even at $4^{\circ}C$ higher than $T_g$, and there is no SHG decay below $120^{\circ}C$ due to the partial main-chain character of polymer structure, which is acceptable for NLO device applications.

• Bulletin of the Korean Chemical Society
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• 제29권4호
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• pp.811-816
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• 2008

2,5-Di-(2'-hydroxyethoxy)benzylidenemalononitrile (3) was prepared and polymerized with 2,4-toluenediisocyanate and 3,3'-dimethoxy-4,4'-biphenylenediisocyanate to yield novel T-type polyurethanes 4 and 5 containing 2,5-dioxybenzylidenemalononitrile, nonlinear optical (NLO)-chromophores as part of the polymer backbones. Polyurethanes 4 and 5 were soluble in common organic solvents such as acetone and N,Ndimethylformamide and showed a thermal stability up to $250{^{\circ}C}$ with glass-transition temperatures ($T_g$) in the range $119-146{^{\circ}C}$. The second harmonic generation (SHG) coefficients ($d_{33}$) of poled polymer films at 1064 nm fundamental wavelength were around $5.82{\times}10^{-9}$ esu. The dipole alignment exhibited high thermal stability up to $T_g$, and there was no SHG decay below $140{^{\circ}C}$ due to the partial main-chain character of the polymer structure, which was acceptable for nonlinear optical device applications.