• Textile Coloration and Finishing
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• v.8 no.2
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• pp.49-55
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• 1996

Poly(4, 4'-diphenyl ether pyromellitamic acid) was prepared from pyromellitic anhydride with 4, 4'-diamino diphenyl ether by means of low-temperature solution polymeriztion. The reation was exothermic and very fast when carried out at room temperature. The synthesized poly(4, 4'-diphenyl ether pyromellitamic acid) was converted to poly(4, 4'-diphenyl ether pyromellitimide) by thermal dehydrocyclization. FTIR analysis was widely used as a means of determining the course of imidization from intensity of characteristic bands of the imide ring at $1790cm^{-1}$ and $1490cm^{-1}$. The density of poly(4, 4'-diphenyl ether pyromellitimide) was higher than poly(4, 4'-diphenyl ether pyromellitamic acid) indicating the greater crystallinity, perhaps because of the reduction of molar volume of polymers

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.2
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• pp.140-146
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• 2012

A variety of dyes are commercially available today, there is an ongoing need for new chromophoric systems and low-band-gap materials. For example, near-infrared (NIR) emission has received increased attention for applications in bioassays and medicine while NIR absorption is demanded for laser-welding of plastics or efficient blocking of heat rays. Most of the commercially available NIR materials are not suitable for such purposes owing to their insufficient stability. We have developed a novel NIR-absorbing polyaromatic dye. By extending the system of perylenebis(dicarboximide)s along the molecular long axis, we have obtained the higher homologue pentarylenebis(dicarboximide). We have tried to introduce imide functional group to pentarylene in order to increase chemical and thermal stability.

• Journal of the Korean Graphic Arts Communication Society
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• v.15 no.2
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• pp.117-130
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• 1997

Studies have been conducted to explore thermal imidization of polyamic acid. Aromatic polyimides are well recognized as high temperature linear polymers, and polyimide are used as structural materials, fibers, and adhesive. Two different kinds of polyimide were prepared by theimidization of polyamic acid which were synthesized from 2,2-bis[4-(4-aminophenoxy)phenyl]- hexafluoropropane, 2,2-bis [4-(4-aminophenxy)phenyl] - hexamethylpropane and caprolactam and pyromelliti dianhydride under N-Methly-pyrrolidinone solvent. Polyamic acids were converted to polyimides containing imide bond by thermal imidization. The weight 50% loss temperatures of polyimide by TGA thermogram were recorded in the range of 700 ~ 720$^{\circ}$C in nitrogen gas. According, as a results, we conclued polyamic acid were cycliation after H2O molecule separationed, and this polyimide film could be used for Printed Circuit Boand.

• Bulletin of the Korean Chemical Society
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• v.31 no.8
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• pp.2272-2278
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• 2010

A new hybrid thermosetting maleimido epoxy compound 4-(N-maleimidophenyl) glycidylether (N-MPGE) is prepared by reacting N-(4-hydroxyphenyl) maleimide (HPM) with Epichlorohydrin by using benzyltrimethylammonium chloride as a catalyst. The resulting compound possesses both the oxirane ring and maleimide group. The curing reaction of these maleimidophenyl glycidylether epoxy compound (N-MPGE) with amines as curing agents such as ethylendiamine (EDA), diethylentriamine (DETA) and triethylenetetramine (TETA), aminoethylpiperazine (AEP) and isophoronediamine, IPDA), are studied. Incorporation of maleimide groups in the epichlorohydrin provides cyclic imide structure and high cross-linking density to the cured resins. The cured samples exhibited good thermal stability, excellent chemical (acid/alkali/solvent) and water absorption resistance. Morphological studies by the SEM technique further confirmed the phase homogeneity net work of the cured systems.

• Fibers and Polymers
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• v.5 no.2
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• pp.83-88
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• 2004

In order to assess the potential of the hydroxy-containing polyamic acid (PHAA) synthesized from 3,3'-dihydroxy benzidine and pyromellitic dianhydride for a fire-safe polymer, the cyclization pathway of PHAA has been investigated using a model compound prepared from 2-aminophenol and phthalic anhydride. The reaction was monitored. by $^1{H-nuclear}$ magnetic resonance. N-(2-hydroxyphenyl) phthalamic acid is converted to N-(2-hydroxyphenyl) phthalimide at ca. 175$^{\circ}C$, showing endothermic reaction. The imide structure is rearranged to the benzoxazole structure over ca. $400^{\circ}C$. These results are similar with that of PHAA. According to pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) data, water and carbon dioxide are released during the cyclization and rearrangement reaction. One DMAc molecule is complexed with one carboxyl acid group in PHAA, which accelerates the imidization process to release more easily the flame retardant, water.

• Bulletin of the Korean Chemical Society
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• v.23 no.5
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• pp.749-757
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• 2002

Chiral oxazolidin-2-one is easily prepared from D-mannitol and demonstrated to undergo highly diastereoselective alkylation reactions via lithium imide Z-enolates of its N-acyl derivatives to afford ${\alpha}-branched$ products. Evans syn and non-Evans sy n aldol products were also selectively obtained using this new auxiliary in high diastereomeric purity by simply changing the stoichiometry of TiCl4 and the nature of the amine base. Also, this new auxiliary is employed in diastereoselective Staudinger-type ${\beta}-lactam$ syntheses. Using 2-chloro-1-methylpyridinium iodide as the dehydrating agent, the reaction of auxiliary tethered acetic acid with trans imines gave the desired ${\beta}-lactams$ with cis-selectivity.

• Journal of the Korean Society of Clothing and Textiles
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• v.22 no.7
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• pp.911-919
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• 1998

부탄테트라카르복실 산을 이용한 면직물의 DP 가공에서 가장 효과적인 촉매로 알려진 sodium hypophosphite(SHP)를 대체하기 위하여 carbodiimide 촉매의 효과를 알아보았다. Carbo야-imide 촉매로는 cyanamide(CY), dicyandiamide(DCY)와 disodium cyanamide(DSC)를 사용하였다. DCY와 DSC가 일반적으로 CY보다 좋은 방추도와 방축도 등을 보였고 또한 독성이 낮고 저장시 안정도 등이 우수하므로 산업적인 응용이 가능하다. 필요한 방추도와 물리적성질의 균형을 위해서 가공욕의 pH 조절이 가장 중요한 인자로 나타났다. 촉매존재시에 면과 부탄테트라카르복실산의 에스터화 가교 반응 메커니즘을 제아하였다. 또한 황화 염료로 염색된 염색포에 대한 가공 효과 분석시 carbodiimide 촉매가 SHP 보다 대체로 작은 색상 변화를 유발시켰다. 이러한 연구 결과는 부양화와 여러 염료의 색상 변화를 유발시키는 SHP를 사용하지 않고 부탄테트라카르복실 산과 carbodiimide 촉매를 이용한 무포름알데히드, 무인 가공제의 면직물 DP 가공의 가능성을 보여 주고 있다.

• Proceedings of the Korean Fiber Society Conference
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• 1998.10a
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• pp.94-97
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• 1998

We have been studying :he synthesis of thermotropic polyurethanes, based on structural modifications by means of (i) the introduction of bulky substituent group in the aromatic ring to decrease the degree of lateral packing, (ii) the copolymerization of two kinds of monomers having different alkylene lengths to lower the regularity of the polymer structure, and (iii) the use of nonlinear monomers to lower the persistence length of the polymer chain in the liquid crystalline phase and to decrease the lateral interactions in the solid state. (omitted)

• Journal of the Korean Applied Science and Technology
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• v.11 no.2
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• pp.151-155
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• 1994

Polyamic acid alkylamine (N, N-dimethylhexadecylamine)(PAAS)염을 합성하여 그 합성여부를 확인하였으며 PAAS염의 Langmuir막의 ${\pi}-A$ 등온선 및 표면 전위 특성 등을 조사 하였다. Langmuir-Blodgett법에 의하여 PAAS염의 LB막을 여러종류의 기관에 누적하였으며 누적여부를 자외선 흡수 스펙트럼 및 적외선 투과 스펙트럼을 이용하여 조사하였다. 그리고 PAAS LB막을 열처리에 의하여 이미드(imide)화시켜 폴리이미드 LB막을 제조하였으며 그 이미드화 여부를 자외선 및 적외선 스펙트럼을 이용하여 조사하였다.

• The Korean Journal of Ceramics
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• v.7 no.1
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• pp.1-5
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• 2001

Inorganic-organic hybrid Li$^+$ ion conductors were prepared by the sol-gel process. Tetramethyl orthosilicate (TMOS), polyethylene glycol 200 (PEG$_200$) and lithium bis (trifluoro-methylsulfony) imide were used as raw materials and $H_2O$ was used as a solvent. Hybrid Li$^+$ ion conductor prepared by the sol-gel process showed very high ion conductivities of log${\sigma}_R.T$(S/cm)=-3.73, log${\sigma}_60$(S/cm)=-3.00 at room temperature and $60^{\circ}C$, respectivery. Decomposition voltage was 3.1 V.