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        검색결과 2,503

        2221.
        1996.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Chitosan itself has been prepared using chitin, one of the most abundant compounds in nature, as a starting material. We have synthesized the water-soluble chitosan derivative, N-dithiocarboxy chitosan sodium salt, through the reaction of water-soluble chitosan with carbon disulfide in the presence of alkali metal hydroxide. To elucidate this natural polymer capacity of adsorbing heavy metal ions, we have performed adsorption experiments using the water-soluble chitosan derivative various average molecular weight and of different percent contents of sulfur. The effect of pH, adsorption time and temperature on adsorption efficiency was also studied. The adsorbent derived from water-soluble chitosan of average molecular weight ranging 9,000~120,000 was shown to have the highest capacity of adsorbing heavy metal ions. On the whole, adsorbing efficiency was increased as the reaction time goes longer and also increased as the reaction temperture goes higer in temperture range of 15℃~45℃. The adsorption capacity at various pH, however, was appeared to vary depending on the heavy metal ions studied Judging from these finding, water-soluble N-dithiocarboxy chitosan sodium salt, a derivative of a biodegradable nature polymer, is believed to be a potential adsorbent for heavy metal ions since it not only is shown to lower the concentration of heavy metal ions to below the drainage quality standard, but also it would not cause acidification and hardening of soil which is one of the detrimental effects of synthetic macromolecular adsorbents present.
        4,000원
        2222.
        1996.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Poly(vinyl acetate)와 poly(vinyl acetate-co-2-ethylhexyl acrylate)를 여러 조건에서 semicontinuous emulsion 중합으로 합성하였다. Overall conversion, emulsion 입자크기, pH, 점도 등을 합성한 두 emulsion polymer에 대해 측정하였다. Vinyl acetate monomer에 2-ethylhexyl acrylate를 도입함으로서 emulsion 입도, 점도, 중합 속도, 유리 전이 속도가 감소함을 확인하였다.
        4,000원
        2223.
        1996.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        저분자량 (M=1970)을 갖는 poly(styrene)(PS)와 poly(vinymethylether) (PVME)의 블렌드를 열산화시킬 때 PVME의 분자량 감소 속도는 높은 분자량을 갖는 PS와 PVME의 블렌드를 열산화 시킬 때의 PVME 분자량 감소 속도보다 훨씬 느리다. 열산화 과정 동안 PS의 분자량은 변화하지 않았으며 저분자량의 PS의 일부가 산화된 PVME를 분리할 때 함께 녹음을 알 수 있었다. 저분자량의 PS의 모델 화합물로써 2. 4-diphenylpentane을 합성하였고 1%,5%,10%의 모델 화합물을 PVME에 첨가하여 열산화 시켰다. 이 모델 화합물을 첨가하여 PVME의 열산화를 약간 지연시킬 수 있음을 알 수 있었다.
        4,000원
        2224.
        1996.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The antioxidant effects of freeze-drying acorn were examined to find how much the freeze-drying acorn can reduce peroxidized corn oil poisoning, which influenced cholesterol, triglyceride, phospholipids, lipidperoxides, GOT(glutamate oxaloacetate transaminase), GPT(glutamate pyruvate transaminase) in serum, and cholesterol, triglyceride, lipidperoxides, fatty acid of phospholipids, SOD(superoxide dismutase), catalase in liver. In this experiment, male rats of Sprague-Dawley strain were used. The rats were divided into 6 groups, which were fed differently for 5 weeks : basal diet, 10% peroxidized corn oil added to basal diet, 1% acorn flour and 10% peroxidized corn oil added to basal diet, 5% acorn flour and 10% peroxidized corn oil added to basal diet, 10% acorn flour and 10% peroxidized corn oil added to basal diet, and 0.25% tannic acid and 10% peroxidized corn oil added to basal diet. The results were as follows : It was found that the peroxidized corn oil-fed 5 weeks induced the elevation of cholesterol, triglycerides, lipid peroxides, GOT, GPT in serum, and cholesterol, triglycerides, lipid peroxides in liver as compared to the basal diet-fed rats, but the acorn flour-fed rats reduced the elevation of these components. In addition, saturated fatty acid in rat liver phospholipids induced the elevation by feeding of peroxidized corn oil and, on the other hand, the acorn flour-fed rats reduced the elevation of saturated fatty acids. The acorn flour-fed rats reduced the activity of SOD in liver while they enhanced the activity of catalase in liver as compared with the peroxidized corn oil-fed rats.
        4,200원
        2225.
        1996.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The procedure to prepare an acrylic emulsion water repellents by blending of arcylic copolymer, activated polyethylene, wax, and emulsifiers was published in the previous paper. After the treatment of the prepared water repellents on a cotton fabrics with and without textile finishing resin, washability, contact angle, tearing strength, and crease recovery were tested. As the result, there were remarkable improvements in physical properties. Proper curing temperature of the synthesized water repellents impellents was 150℃ : proper using concentration was 5wt% : sodium acetate was the best catalyst for water repellents among the used, and proper concentration was 1.0wt%.
        4,000원
        2226.
        1996.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Durable softening water-repellenting agent such as PODCW, PDDCW and PEDCW were prepared by blending cationized compound such as poly(octadecyl methacrylate-co-2-diethylaminoethyl methacrylate)[PODC], poly(2-dodecyl methacrylate-co-2-diethyl-aminoethyl methacrylate)[PDDC] and poly(2-ethylhexyl methacrylate-co-2-diethyl-aminoethyl methacrylate)[PEDC], and cationized compound of fatty carbamide, of which synthetic methods were reported in the previous paper, waxes, and emulsifiers. The results of physical tests of the P/C blended fabrics treated with PODCW, PDDCW and PEDCW with and without textile finishing resin, showed a remarkable improvement of the physical properties. The prepared water-repellenting agents, PODCW-6 and PDDCW-1, were treated on P/C blended fabrics with and without resin. For any cases, there are a little changes between initial water repellency and repellency after 3 times washing of the fabrics. Therefore, the water-repellenting agents proved to be a durable agents, and initial water 100+ and 90+ point, respectively.
        4,000원
        2227.
        1996.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The phase separated structure and the electo-optical properties of the polymer /liquid crystal(LC) composite films including a dye were investigated. The phase separated structure of the polymer /LC / dye composite film(GH composite film) including below 2wt% dye against LC was almost same with the composite film which does not include dye. But the electro-optical properties of the GH composite film strongly depended on weight fraction of the dye against the LC. The response time of the GH composite film increased with the increase of the dissolved dye in LC because the dye acts as a registivity for the orientation of LC molecules by the electric filed.
        4,000원
        2228.
        1996.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Diazotization of STA synthesized by the indirect diazotization method. The effect of catalyst and agitation (rpm) about STA and H-acid reaction were examined and the optimum conditions were investigated experimentally. The yields and characteristics of 1.st coupling and diazotization synthesis were identified by HPLC and FT-IR analysis. 1.st condensation of CNC and mPDSA were synthesized at 5℃ and pH=6.5. The conditions of alkaly coupling of H-acid were synthesized at 5℃ and pH=8. The condensation of products was identified by U. V. analysis. From this results, It was obtained to reactive dyestuffs of bi-functional reactivity with high fastness and high adsorption.
        4,000원
        2229.
        1996.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Surfactants are the surface-active molecules that display amphiphilicity, Because of this surface activity and amphiphilicity, surfactants have been used in wide industrial applications such as foods, detergents, cosmetics, medicine, polymers, paints, flotation, textiles. These days, their applications extend to high-technology industries such as microelectronics, magnetic recording material, advanced batteries, novel separations, etc. As new applications of surfactants are found and the demand of the surfactants increases, surfactant industry has been more pressed to face a formidable challenge, which is to develop surfactants that are envirionmentally friendly. In this regard biosurfactants may be alternatives to chemical surfactants, since biosurfactants are biologically compatible, more biodegradable, less toxic, and highly specific. Because of these excellent advantages over those of chemical surfactants, much efforts have been made in biosurfactant research. This article reviews biosurfactants in several aspects, that is, their definition, structures, properties, applications, and prospects.
        5,500원
        2230.
        1996.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Fluorenylidene chalcone derivatives were synthesized by condensation. The structure of these compounds were ascertained by means of UV, melting point, IR and 1H-NMR spectra. The nucleophilic addition reaction kinetics of Thioglycolic acid to fluorenylidene chalcone was investigate by UV in 20% dioxane-H2O at 25℃. The rate equation which were applied over a wide pH1.0~13.0 range. On the basis of general base catalysis and confirmation of addition reaction product, the nucleophilic addtion reaction kinetics of thioglycolic acid to fluorenylidene chalcone were measured by the pH change. From the result of the above caption, a plausible nucleophilic addition reaction mechanism of thioglycolic acid to fluorenylidene chalcone was proposed. These compounds may be used as the starting materials for the preparation of the engineering plastics or the germicide.
        4,000원
        2231.
        1996.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Furfurylidene acetophenone derivatives were synthesis, it was measured that hydrolysis made use of UV at a wide pH 1.0~13.0 range in 30% dioxane-H2O solution, 25±1℃. On the basis of general base catalysis, substitutent effect, confirmation of hydrolysis products, it was measured the reaction rate of furfurylidene acetophenone derivatives for the pH change. It maybe concluded that a part was unrelated to pH and another part was in proportion to concentration of hydroxide ion : Above pH 10.0, It was in proportion to concentration of hydroxide ion, a part having no concern with pH was added to the neutral H2O molecule. From the result of measurement the reaction rate, hydrolysis of furfurylidene acetophenone derivatives confirmed to the irreversible first order. Through measurement the substituent effect, It found that reaction rate was accelerated by electron attracting group. Also, From the result of final product, There were furfural and acetophenone. On the basis of these findings, Hydrolysis for the furfurylidene acetophenone derivative was proposed a fitting mechanisms.
        4,000원
        2232.
        1996.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, benzoxazolo carbocyanine dye was used as sensitizer for photographic emulsion, and the photographic characteristics were examined. The basic properties of sensitizer such as stability in various solvents were examined. The sensitizer was very stable in methanol, acetonitrile, acetone, dimethylformamide, and chloroform solution. Absorption spectra of benzoxazolo carbocyanine dye 2.5×10-6M and 5×10-6M concentrations in 10% aqueous methanol solutions containing 10-2M potassium chloride show the monomer-J-aggregation characteristics. Compared to the absorption peak of the monomer in pure methanol solution, the red shifts of the monomer-J-aggregate peaks of benzoxazolo carbocyanine dye of 2.5×10-6M and 5×10-6M concentrations in 10% aqueous methanol solutions containing 10-2M potassium chloride are 34nm respectively, and the sensitizing peak of benzoxazolo carbocyanine dye in photographic emulsion has red shift of 34nm. Therefore, if was concluded that benzoxazolo carbocyanine dye can be used as green sensitizing dye for the spectral sensitization of photographic emulsion.
        4,300원
        2233.
        1996.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The absorption spectra of synthesis of long chain fatty acid containing azobenzene start from p-(p'-hydroxy phenyl azo)-benzoic acid was investigated by ultraviolet spectrophotometery in chloroform solvent at the various temperature. In addition, The pressure-area of the water-air interface was obtained and the LB film was fabricated onto a quartz slide and quartz crystal by conventional Langmuir-Blodgett(LB) method. The UV absorption spectra of Langmuir-Blodgett(LB) film on quartz slide and spectrum of monolayer formed on quartz crystal have been measured. Long chain fatty acid containing azobenzene are induced phtoisomerization by the application of u. v. and visible light irradiation alternatively the reversibility of phtoisomerization was more clear difference when the number of Cn increased but, not so good at C14-azo. At the pressure-area isotherms, the value of surface pressure increment were decreased when the number of Cn increased. A surface pressure of 20mN/m was obtained as a proper one for a film deposition. The photoisomerization at LB films were induced by application of UV and visible light irradiation alternatively. So the LB film of long chain fatty acid containing azobenzene has possibility to being applied to functional molecular devices such as photomemory and light switching.
        4,200원
        2234.
        1996.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to find a catalyst system which has high conversion and selectivity for the oxidative coupling of methane to produce ethane and ethylene. Various catalysts were tested in a fixed bed reactor ar 750℃, 1 atm, and the feed ratio(CH4/O2) of 2/1. Under the reaction condition, 10wt%PbSO4/MgO catalyst showed the highest catalytic activity : methane conversion, C2 selectivity and yield were 50, 40 and 20%, respectively. Catalysts containing sulfate compounds, 10wt%PbSO4/MgO, 10wt%MgSO4/MgO and Na2SO4/MgO revealed a moderate methane conversions such as 38, 50 and 50%, respectively and low C2 selectivities such as 18, 5 and 9%, respectively. Catalysts containing carbonate compounds, 10wt%PbCO3/MgO, 10wt%Li2CO3/MgO and NaCO3/MgO, also showed a moderate methane conversions such as 64, 44 and 51%, respectively and low C2 selectivities such as 5, 6 and 2%, respectively. With the existence of chlorine and mercury, C2 selectivity was decreased.
        4,000원
        2235.
        1996.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        저 분자량(Mw=1970)의 poly(styrene)(PS)와 poly(vinylmethylether)(PVME)의 블렌드를 열 산화시킬 때 저 분자량의 PS의 첨가량이 증가할수록 유도기간이 증가하며 열 산화속도는 감소함을 알 수 있었다. 열 산화과정 동안 저 분자량 PS와 PVME 블렌드는 상 분리를 보이지 않았다. 저 분자량을 갖는 PS와 PVME 블렌드에서 PVME의 산화 속도는 높은 분자량을 갖는 PS와 PVME 블렌드에서 PVME의 열 산화 속도보다 훨씬 느려짐을 보였다.
        4,200원
        2236.
        1996.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Cinnamoyl ester(PGEFC) of poly(phloroglucinol-formaldehyde) glycidyl ether which has photosensitive functional group was prepared to apply to photoresist. Photosensitivity of PGEFC was estimated by the solubility difference in organic solvent before and after exposure to light. The yield of residual film was calculated by immersing the sample-coated quartz plates in the solvent which was used in coating. The yield of the residual film which was closely related to the sensitivity of the film, was affected by the degree of polymerization of the backbone resin, sensitizers and their concentration. The sensitivity was depended upon the degree of polymerization. Most of effective sensitizer for PGEFC among the sensitizers was 2, 6-dichloro-4-nitroaniline.
        4,000원
        2237.
        1996.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Durable softening water repellents such as PODCWs were prepared by blending cationized compound of poly(octadecyl methacrylate-co-2-diethylaminoethyl methacrylate), of which synthetic methods were reported in the previous paper, activated polythylene, waxes, and emulsifiers. Water repellency of prepared PODCWs was measured by performing water repellent finish to various fabrics, PODCWs showed a good water repellency for P/C blended fabrics and their repelling tendency was in the order of P/C blended fabrics〉cotton fabrics〉nylon taffeta. The initial water repellencies of PODCW-1 and PODCW-2 were 100 and 100- points, respectively, for P/C blended fabrics. And also, PODCW-1 and PODCW-2 were confirmed as durable water repellents with the results of making little difference of water repellency as ±5 point after and before washing.
        4,000원
        2238.
        1996.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, sensitizing dye was prepared by the reaction of 2-methyl-3-sulfopropyl-4, 5-naphthothiazolium(inner salt) with triethyl orthoformate in the presence of triethylamine. The product was identified by using various analytical tools such as Elemental analyzer, IR spectrophotometer, UV-Vis spectrophotometer, 1H-NMR spectrometer, TGA and DSC. Therefore, it was concluded that naphthothiazolo carbocyanine dye can be used as red-sensitizing dye for the spectral sensitization of photographic emulsion.
        4,000원
        2239.
        1996.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        박과식물(科植物) 종실(種實)에는 총지질량(總脂質量)이 21.9~50.7%의 범위(範圍)로 비교적(比較的높았으며, 특(特)히 박, 하늘타리의 경우는 41.9%와 50.7%로 조사(調査)한 시료(試料)중에 제일 높았으며, 또 모든 시료(試料)가 약(約) 98% 이상(以上)의 중성지질(中性脂質)을 함유(含有)하고 있었다. 호박, 수세미오이, 수박, 참외, 오이 및 박종자(種子)의 총지질(總脂質)에는 리놀산(酸)의 함량(含量)이 제일(第一) 많아 56.8~84.0%이였으며, α-리놀레산(酸)의 함량(含量)은 0.0~0.6%로 매우 적었고, 올레산(酸)이 주성분(主成分)인 모노엔산(酸)과 팔미트산(酸)이 대부분(大部分)인 포화지방산(飽和脂肪酸)은 그 함량(含量)이 각각(各各) 5.7~22.2%와 9.9~20.6%로 시료(試料)에 따라 심한 차이(差異)를 보였다. 하늘타리 종자(種子)의 총지질(總脂質)에는 C18:2Ω6과 9c.11t.13c-C18:3(Punicic acid)이 40.5%와 34.9%로 주요(主要) 성분(成分)이였고, 그 다음으로 C18:1Ω9가 13.8% 함유(含有)되어 있었으며, 그러나 9c/11t.13t-C18:3(α-eleostearic acid)는 2.2%에 지나지 않았다. 한편 여주의 경우(境遇)에는 9c.11t.13c-C18:3이 66.9%로 제일(第一) 많았으며, 그 다음으로 C18:1Ω9와 C18:1Ω6이 17.7%, 10.4% 각각(各各) 함유(含有)되어 있었고, 하늘타리에 많이 함유(含有)되어 있는 9c.11t.13c-C18:3는 9t.11t.13c-C18:3(β-eleostearic acid)와 함께 1.1% 정도(程度)로 소량(少量) 포함(包含)되어 있었다. 9c.11t.13c-C18:3와 9c.11t.13t-C18:3와 같은 conugate trienoic acid는 여타시료(餘他試料)에서는 전연 검출(檢出)되지 않았다. 하늘타리와 여주의 종자유(種子油)의 극성지질(極性脂質)에는 이틀의 중성지질(中性脂質)에 다량(多量)으로 존재(存在)하는 conjugate trienoic acid가 극(極)히 소량(少量)밖에 존재(存在)하지 않는 것은 매우 특징적(特徵的)이며, 포화지방산(飽和脂肪酸)이 중성지질(中性脂質)(9.9~20.6%)에 비(比)하여 극성지질(極性脂質)(25.0~29.4%) 에 보다 많이 함유(含有)되어 있다는 사실(事實)을 나머지 시료(試料)에서 공통적(共通的)으로 찾아볼 수 있었다. 박과식물(科植物) 종자(種子)는 리놀산(酸)을 많이 함유(含有)하고 있는 군(群)과, 9c.11t.13c-C18:3 및 9c.11t.13t-C18:3와 같은 conjugate trienoic acid를 가진 군(群)으로 대별(大別)할 수 있었다.
        4,000원
        2240.
        1996.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The liposomes have been developed in many drugs and cosmetics fields. The liposomes prepared with main compounds of the intercellular lipids and lecithin. Amphiphile nonionic surfactants used for (PEG) n-sitosterol(n=5), diethanolamine cetylphosphate. The effect of gelation for liposomes have been on swelling reaction which have been mixed phospholipid with polyol-group at the high temperature. There were very good encapsulated properties of the active ingredients whether hydrophilic-group(magnesium ascorbyl phosphate, allantoin, sodium hyaluronate) and hydrophobic-group(vitamin-E acetate, vitamin-A palmitate). Optimum condition of liposomes were passed five times in the microfluidizer(700bar), wetting reaction temperature was at 95±5℃ for a hours. Particle size distribution of the vesicles should be within range 50-560nm(mean 200nm). The stability of liposomes for the course of time was stabilized for six months at 45℃. Application of the cosmetic was prepared moisturizing cream with liposomes of the phospholipid base.
        4,000원