• Proceedings of the Korean Fiber Society Conference
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• 1993.06a
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• pp.73-74
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• 1993

• Proceedings of the Materials Research Society of Korea Conference
• /
• 1997.05a
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• pp.94-94
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• 1997

• Bulletin of the Korean Chemical Society
• /
• v.17 no.10
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• pp.944-945
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• 1996

• Bulletin of the Korean Chemical Society
• /
• v.9 no.6
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• pp.407-408
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• 1988

• Bulletin of the Korean Chemical Society
• /
• v.18 no.4
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• pp.441-442
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• 1997

• Bulletin of the Korean Chemical Society
• /
• v.10 no.5
• /
• pp.471-472
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• 1989

• Bulletin of the Korean Chemical Society
• /
• v.20 no.11
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• pp.1253-1254
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• 1999

• Macromolecular Research
• /
• v.12 no.6
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• pp.545-552
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• 2004

The long-term stability of sulfonic acid-containing polyimides has been investigated. The hydrolytic degradation of homopolyimide and the block copolyimide comprising $27\;mol\%$ of 2,2'-bis(trifluoromethyl)benzidine and $9\;mol\%$ of m-phenylenediamine (BTFMB27mPl0[7/(3+1)]), was quantified through viscosity measurements and FT-IR spectroscopic analyses. The viscosity decrease with respect to time and the degradation rate were similar. The degrees of degradation with respect to time under ambient conditions and at elevated temperature in water were monitored by FT-IR spectroscopy. A new absorption peak was observed at $1786\;cm^{-1},$ which we corresponds to the presence of anhydride end groups formed by hydrolytic scission of the imide rings.

• Applied Chemistry for Engineering
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• v.20 no.3
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• pp.351-353
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• 2009

Pyrylium fluoroborates undergo a wide range of synthetically useful reactions because of the positive charge. And the electron accepting nature has resulted in their widespread use as sensitizers for photo-induced electron transfer (PET) reactions. In this experiment, 2,6-disubstituted pyrylium fluoroborates are synthesized from the reaction between $3^{\prime}$-chloroacetophenone and excess orthoformate in an acidic medium (acetic anhydride/acid). Synthesized products are confirmed by $^1H-NMR$, FT-IR and TOF Mass spectroscopies. Also, photo-properties are analyzed with an UV-Vis spectrophotometer.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2001.05a
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• pp.118-121
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• 2001

The investigation of cure kinetics and morphology studies on DGEBA/PEI/Anhydride system were performed by differential scanning calorimetry and scanning electron microscopy. Autocatalystic kinetics model was applied by isothermal scan test. Ozawa method and Kissinger method was applied by temperature scan. Activation energy was 95kJ/mol for neat DGEBA/NMA, 120kJ/mol for DGEBA/PEI(10p.h.r.)/NMA. The generation of secondary phase of PEI was observed and its size was grown up by increasing contents of PEI.