• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.336-336
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• 2006

The present work is focused on the synthesis of a series of fully aliphatic polyimides and the incorporation of adamantane moieties and siloxane groups to them and studies the deviation in the basic traits of the fully aliphatic polyimides. In this work, we wish to discuss how adamantyl group and siloxane moieties influence the basic properties of aliphatic polyimides (APIs), by synthesizing various fully aliphatic polyimides and polyimidesiloxanes (APISiO).

• Macromolecular Research
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• v.15 no.2
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• pp.114-128
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• 2007

Polyimides are one of the most important classes of polymers used in the microelectronics and photoelectronics industries. Because of their high thermal stability, chemical resistance, and good mechanical and electric properties, polyimides are often applied in photoresists, passivation and dielectric films, soft print circuit boards, and alignment films within displays. Recently, fully aliphatic and alicyclic polyimides have found applications as optoelectronics and inter layer dielectric materials, due to their good transparencies and low dielectric constants $(\varepsilon)$. The low molecular density, polarity and rare probability of forming inter- or intra-molecular charge transfers, resulting in lowering of the dielectric constant and high transparency, are the most striking characteristics of aliphatic polyimide. However, the ultimate end use of polyimides derived from aliphatic monomers is in their targeted applications that need less stringent thermal requirements. Much research effort has been exerted in the development of aliphatic polyimide with increased thermal and mechanical stabilities, while maintaining their transparencies and low dielectric constants, by the incorporation of rigid moieties. In this article, the recent research process in synthesizing fully aliphatic polyimides, with improved dimensional stability, high transparency and low $\delta$values, as well as the characterizations and future scope for their application in micro electric and photo-electronic industries, is reviewed.

• Journal of Korean Society on Water Environment
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• v.21 no.5
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• pp.442-447
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• 2005

Concentrations of aliphatic hydrocarbons in water, particulate matter, and sediment phase were measured at five stations in Gyeongan River. Aliphatic hydrocarbons from $n-C_{10}$ to $n-C_{17}$ were detected in the water phase and they might be originated from not only biogenic hydrocarbons also petroleum hydrocarbon. $n-C_{17}$ aliphatic hydrocarbon and fatty acids were detected in the particulate matter phase. They might be originated from biological sources such as phytoplankton. Short alkane chains from $n-C_{10}$ to $n-C_{13}$ were detected in the sediment phase. They might be originated from sedimentation of biological hydrocarbons decomposed by bacteria or adsorption of petroleum hydrocarbon from the water phase.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.475-477
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• 2003

Orientation of E7 liquid crystals (LCs) confined to 200 nm-diameter cylindrical cavities of Anodisc membranes are investigated by FTIR dichroism techniques. The cavity walls of the confining pores are chemically modified with different aliphatic acids ($C_nH_{2n+1}COOH$, n=5, 6, 7, 9). From the FTIR spectra of aliphatic acid treated alumina Anodsic membranes, we found the salt formation between -COOH group of aliphatic acid and Anodisc membrane. From the FTIR spectra of LC filled Anodisc membranes, we found abrupt alignment direction change of LC molecules between n=6 and 7 for 2% aliphatic acid treated Anodisc membranes, from parallel to perpendicular direction to the cavity walls. But 4% aliphatic acid treated Anodisc membranes, alignment direction of LC molecules changed between n=5 and n=6, from parallel to perpendicular direction. The same trend was observed for $^2H-NMR$ measurements.

• Journal of Environmental Science International
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• v.11 no.7
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• pp.737-742
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• 2002

Sorption and desorption is an important phenomenon to determine the fate of halogenated aliphatic hydrocarbons in the aqueous phase. This study was conducted to develope a predictive equation capable of estimating the sorption and desorption potentials of halogenated aliphatic hydrocarbons onto the sludge from activated process, sediment, and clay. It has shown that the sorption and desorption parameters can be accurately estimated using Quantitative Structural Activity Relationship(QSAR) models based on molecular connectivity indexes of test compounds. The QSAR model could be applied to predict the sorption and desorption capacity of the other halogenated aliphatic hydrocarbons. The QSAR modeling would provide a useful tool to predict the sorption and desorption capacity without time-consuming experiments.

• Proceedings of the Korean Fiber Society Conference
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• 1987.06b
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• pp.13-14
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• 1987

• Macromolecular Research
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• v.17 no.9
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• pp.638-645
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• 2009

We report the effect of the amount of the mesoporous material, SBA-15, on the basic traits of fully aliphatic polyimides (API). For this purpose, water soluble, fully aliphatic poly(amic acid) triethyl amine salts ($PAA_{(s)}$) were prepared and mixed with various amounts of SBA-15. Fully aliphatic polyimide hybrid composites containing the SBA 15-type mesoporous silica were synthesized successfully from bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic dianhydride and alicyclic diamine, 4,4'-methylene bis(2-methylcyclohexylamine). The structure of the hybrid composites was confirmed by IR spectroscopic analysis. Scanning electron microscopy revealed the morphology of the compounds. The hybrid composites exhibited good thermal stability, reasonable transparency, and a low dielectric constant.

• Journal of the Korean Chemical Society
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• v.67 no.4
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• pp.222-225
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• 2023

Metallic salts of C10-18 aliphatic carboxylic acids were prepared and their scanning electron microscopic images were analyzed for the morphology dependency with the metal and the carboxylic acid. Regardless of metal ion, metal salts of dicarboxylic acids showed a high crystallinity with a fiber image (SuA-Na). The aromatic dicarboxylates also represented a morphology of a rectangular-rod or board shapes (IA-Li, IA-Ba). With Na ion, most aliphatic carboxylate (MA, PA, SA) showed a fiber-like crystallinity. However, other monovalent Li, K and multivalent Mg, especially Al ion resulted a glassy-amorphous in the metallic salts of acids (MA, PA, SA). With divalent Ba and Ca ions, the metal salt of aliphatic acids expressed a branched round cluster shape as in SA-Ca, SA-Ba. Both Li and Mg ions with a similar size showed a strong morphological similarity in the metallic salts of aliphatic acids MA, PA, SA. In the case of Na and Ca ions with a similar size (98, 106 pm), both ionic salts of stearic acid gave a branching effect for a fiber or round granular image. In the case of hydroxyl-aliphatic acids (HLA, HPA, HSA), the fiber images in HLA-Na and HSA-Na was appeared about 100 nm thicker than those of nonhydroxycarboxylates (LA-Na, SA-Na). The metallic salts of unsaturated C-18 carboxylic acids (OlA, LeA and LnA) showed an amorphous glassy image due to a kinked carbon chain.

• Proceedings of the Korean Fiber Society Conference
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• 1997.04a
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• pp.328-332
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• 1997

Hot stretching focused on the improvement of properties of poly(L-lactic acid) fiber. Some aliphatic polyesters are biodegradable under microbial attack and the new unique applications are expected. Generally, these materials have a somewhat low melting temperature and low mechanical properties compared with the aromatic polyesters. In this study, melt-spinning of poly(L-lactic acid) was conducted. We investigated effects of the stretching and the molecular orientation of aliphatic polyester fibers on the change of fine-structure. Glass transition temperature, molecular orientation and crystallinity increased according to the increase of stretching ratio.

• Bulletin of the Korean Chemical Society
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• v.25 no.9
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• pp.1385-1391
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• 2004

A general route for the synthesis of optically active unhindered aliphatic alcohols, where the steric demands between two alkyl groups adjacent to the carbinol are similar, with high enantiomeric purity has been developed by sulfoxifation of chiral ${\beta}$-hydroxy sulfides, followed by alkylation and desulfurization.