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        검색결과 18

        1.
        2012.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        탄소 한외여과막 및 광촉매 혼성 수처리를 위해 관형 여과막 외부와 원통형 막 모듈 내부 사이 공간에 광촉매를 충전하였다. 광촉매는 PP (polypropylene) 구에 이산화티타늄 분말을 플라즈마 화학증착 공정으로 코팅한 것이다. 휴믹산과 카올린 모사용액을 대상으로 막오염을 최소화하기 위해 10분 주기로 10초 동안 물 역세척을 시행하였다. 기존 결과와 동일하게 휴믹산을 10 mg/L부터 2 mg/L로 변화시킴에 따라, 막오염에 의한 저항(Rf)이 감소하여 2 mg/L에서 최대 총여과부피 (VT)를 얻었다. 탁도와 휴믹산의 처리효율은 각각 98.9%와 88.7% 이상이었다. UF 및 UF + TiO2, UF + TiO2 + UV 공정의 처리 분율 결과, 광촉매 흡착과 광산화에 의해 탁도는 거의 처리되지 않았으나, 광촉매 흡착 및 광산화에 의한 휴믹산 처리 분율은 각각 2.5%, 12.3%이었다. 기존 결과와 비교하면, 분리막의 재질과 기공의 크기에 따라 광촉매 흡착과 광산화에 의한 휴믹산의 처리 분율이 다르게 나타났다. 공정이 단순화될수록 180분 운전 후 막오염 저항(Rf,180)은 증가하였고, 최종 투과선속(J180)은 소폭 감소하였다.
        4,000원
        2.
        2010.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this research, we were prepared the glazed ceramic samples by the change of the pigment content and investigated to reveal the standardized color. The chemical composition of the pigment was analyzed using a ICP-OES. XRF mapping and UV-Vis spectroscopy were used to evaluate the color property and surface homogeneity. The color development was observed as a result of analyzing the pigment content and change of the color. The pigment content and the spectral reflection showed the relation of the inverse proportion and the standardized color which could be revealed through analysis data.
        4,000원
        3.
        2007.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The aim of this study is to enhance the flame retardancy by the synergism effect of phosphorus and bromine groups. The flame-retardant polyurethane coatings containing phosphorus and bromine compounds were synthesized. After synthesizing the intermediate products of tetramethylene bis(orthophosphate) (TBOP) and trimethylolpropane/2,3-dibromopropionic acid (2,3-DBP) [2,3-DBP-adduct], the condensation polymerization was performed with four different monomers of two intermediate products, 1,4-butanediol, and adipic acid to obtain four-components copolymer. In the condensation polymerization, the content of phosphorus was fixed to be 2wt%, and the content of 2,3-DBP that provides bromine component was varied to be 10, 20, and 30wt%, and we designated the prepared modified polyesters containing phosphorus and bromine as DTBA-10C, -20C, -30C. Average molecular weight and polydispersity index of the preparation of DTBAs were decreased with increasing 2,3-DBP content because of increase of hydroxyl group that retards reaction. We found that the thermal stability of the prepared DTBAs increased with bromine content at high temperature.
        4,500원
        4.
        2007.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In order to prepare high-solid coatings, acrylic resins, HSCs [poly (EA/EMA/2-HEMA/CLA)] that contain 90% solid, were synthesized by copolymerization of ethyl acrylate (EA), ethyl methacrylate (EMA), 2-hydroxyethyl methacrylate (2-HEMA) and caprolactone acrylate (CLA). The high-solid coatings named as CHSCs (HSCs/HDI-trimer) were prepared by the curing reaction between the acrylic resins containing 90% solid contents and the isocyanates (HDI-trimer) curing agent room temperature. The curing behavior and various properties were examined on the film coated with the both high-solid coatings. The glass transition temperatures (Tg) of CHSCs increased proportionally with increasing the predicted Tg value by Fox equation, and had nothing to do with the solid contents. The prepared film showed good properties for 60˚ specular gloss, impact resistance, cross-hatch adhesion and heat resistance, and bad properties for pencil hardness, drying time, and pot-life. Among the film properties, the heat resistance was very excellent and could be explained by the introduction of functional monomers of CLA.
        4,200원
        5.
        2006.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The high-solid coatings were prepared by blending the synthesized acrylic resin in the previous paper, and hexamethylene diisocyanate-trimer and curing it at room temperature. The characterization of the films of the prepared coatings was performed. The 60˚ specular gloss, impact resistance, cross-hatch adhesion, and heat resistance of the films proved to be good, and the pencil hardness, drying time, and pot-life proved to be slightly poor. From a viscoelastic measurement using a rigid-body pendulum, curing was accelerated with the Tg value.
        4,000원
        6.
        2006.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Acrylic resins (HSCs : EA/EMA/2-HEMA/CLA) which contain 80% solid content were synthesized by the copolymerization of monomers (ethyl acrylate, ethyl methacrylate, 2-hydroxyethyl methacrylate) and functional monomer (caprolactone acrylate : CLA) which improves the crosslinking density and physical properties of films. The physical properties of the prepared acrylic resins (HSCs) containing CLA, are as follows: viscosity 1440~2630 cps ; Mn 1590~1660 ; and conversions, 81~86%, respectively. From the correlation of Tg values, viscosities, and Mn of the HSCs, it was found thst viscosity and Mn increased with Tg value.
        4,000원
        7.
        2004.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        An emulsion of octadecamidoethylaminoethyl dodecate (which provides softness) and an emulsion silicone oil KF-96 (which provides lubricity) were separately synthesized. Then PP finishing softeners (SSA-7) was prepared by blending of the synthesized emulsions with beef tallow hardened oil (a softness improving agent). PP finishing treatment was carried out with the prepared SSA-7 and PP finishing resin by a one bath method, and several physical properties were tested. As a result, crease recovery, tear strength, softness, lubricity, and bending resistance were all good, indicating that the prepared SSA-7 is a good PP finishing softener.
        4,000원
        8.
        2004.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Reaction intermediates PCP/BZA (PBI) and tetramethylene bis(orthophosphate) (TBOP) wer synthesized from polycaprolactone (PCP) and benzoic acid (BZA) and from pyrophosphoric acid and 1,4-butanediol, respectively. Benzoic acid modified polyesters containing phosphorus (APTB-5, -10, -15) were synthesized by polycondensation of the prepared PBI (containing 5, 10, 15wt% of benzoic acid), TBOP, adipic acid, and 1,4-butanediol. The structure and characteristics of APTBs were examined using FT-IR, NMR, GPC, and TGA analysis. The increase of the amount of BZA in the synthesis of APTBs resulted in decrease in average molecular weight and kinematic viscosity. From the TGA analysis of APTBs, it was found that the afterglow decreased with the amount of BZA content at the high temperatures.
        4,200원
        9.
        2003.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A copolymer 〈HSAs : EA/EMA/2-HEMA/AAEM) which is an acrylic resin containing 70% solid content was synthesized by the reaction of monomers, including ethyl acrylate, ethyl methacrylate, and 2-hydroxyethyl methacrylate with a functional monomer, such as acetoacetoxyethyl methacrylate, which may give improvements in cross-linking density and physical properties of films. The physical properties of prepared acrylic resins, HSA containing AAEM, are as follows : viscosity, 203~550cps ; Mn, 2590~2850 ; and conversion, 82~89%, respectively. It was found from the plotting of Tg versus viscosity and Tg versus molecular weight that viscosity increased with Tg while number averaged molecular weight decreased with increasing Tg.
        4,000원
        10.
        2003.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Two-component polyurethane flame retardant coatings (ATTBC) were prepared by blending polyisocyanate (TDI-adduct) with ATTBs mentioned at the previous paper. Most of the physical properties of the flame retardant coatings were comparable to those of non-flame retardant coatings. Especially, the hardness, impact resistance, and accelerated weathering resistance were remarkably improved with the increase of the content of 1,4-butanediol. Coatings containing 10 and 15 wt% 1,4-butanediol, ATTBC-10C and ATTBC-15C, were not flammable in vertical flame-retardancy test. Their char area recorded 1.1~11.6 cm2 in 45˚ eckel burner method.
        4,000원
        11.
        2003.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        An intermediate, tetramethylene bis (orthophosphate), was prepared by the esterification of pyrophosphoric acid and l,4-butanediol. Then pyrophosphoric-containing modified polyesters (ATTBs) were synthesized by polycondensation of tetramethylene bis(orthophosphate), trimethylolpropane, adipic acid, and l,4-butanediol. The content of l,4-butanediol was varied from 10 to 20wt% for the reaction. The increase of the amount of l,4-butanediol in the synthesis of ATTBs resulted in increase in average molecular weight and decrease in kinematic viscosity owing to the excellent flowability and reactivity of l,4-butanediol.
        4,000원
        12.
        2003.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Acidic degreasing agent(AADA) was prepared by blending sorbitol, Newpol PE-68, Na-dioctyl sulfosuccinate, Tetronix T-70l, MJU-100A, n-octanoic acid, and phosphoric acid, The physical properties of AADA tested with aluminum specimen showed the following results ; when 3wt% AADA-5 was performed at 70℃, the degreasing rate was 95% which is comparitively good, and the percentage of etching was 0.277% which was found to be less than that of commercialized product. when 20wt% of AADA-5 was added at 65℃, the percentage of derusting was 91% and the good defoaming effect proved by following low foaming power tests respectively : Ross and Miles, and Ross and Clark methods.
        4,000원
        13.
        2002.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Environmental friendly acrylic/urea high-solid paint(MUHC) were prepared through the curing reaction of acrylics resin(EBHC) containing 70wt% of solids content and butylated urea curing agent. The synthesis of EBHC Was done at 150℃ for 6 hours, and the results were obtained as follows : Mn=1830~2190, Mw 3290~4000, Mw/Mn=1.80~1.83 viscosity=110~352 cps, and conversion=82~92%. After the film was coated with MUHC, the various physical properties were measured. They showed that enhancement of the coating properties such as adhesion, flexibility, abrasion resistance, impact resistance, and water resistance could be expected through introdl1cing caprolactone acrylate component in acrylics resin for the high-solids content acrylics/urea coatings.
        4,000원
        14.
        2002.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Fatty polyamide that gives softness, lubrication and bulky property and alkyl imidazoline that gives durable softness and antistatic property were synthesized. then, an O/W-type durable softener (DSN) was prepared by the emulsion of the synthesized fatty polyamide and alkyl imidazoline. Emulsion stability of the DSN was good, and the mixed HLB value was 11.2. From the measurement of softness, lubrication, antistatic property, bending resistance, and color fastness, it was proved that the prepared DSN was a good durable softener for nylon.
        4,000원
        15.
        2002.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A silicone softner (SS-5), a permanent press (PP) finish, was prepared by blending silicone oil KF-96 (as a lubricating component) and beef tallow hardened oil (as a softening component) which was synthesized from fatty polyamide salts. The prepared SS-5 and the PP finishing resin were applied to PP finishing cotton cloth and P/C gingham sample by one-bath method. The properties such as crease recovery, tear strength, and bending resistance were tested. The samples treated with SS-5 and PP finishing resin showed improved properties when comparing with the untreated ones, with the ones treated only with PP finishing resin, with ones treated with commercial PP finishing softners and PP finishing resin. The grades of fabric samples treated with 3% SS-5 were fifth grade in the bending resistance test.
        4,000원
        16.
        2001.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        An ACR/HMMM film was prepared by blending high-solid ACR with curing agent, hexamethoxymethyl melamine (HMMM). An active curing reaction was observed at 170℃. The dynamic viscoelastic Tg of the final film increased with the static viscoelastic Tg of the film. The log damp value, which means a viscoelastic ratio, decreased with the increase in the curing temperature of the film. Physical properties of the films were within a suitable range for films, and by an accelerated weathering resistance test the films were proved weather resistible ones.
        4,300원
        17.
        2001.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Curing reaction was carried out with the acrylic resin (ACR) [n-butyl acrylate/atyrene/2-hydroxyethyl methacrylate/acetoacetoxyethyl methacrylate (AAEM)] synthesized before and a curing agent, hexamethoxymethylmelamine (HMMM). With rotational rheometer, the effect of catalysts on curing rate of acrylic resin/melamine was examined. Among the four catalysts used, p-toluene sulfonic acid showed the highest reactivity, and the optimum amount of catalyst was 0.5 phr. It was observed that in the ACR/HMMM curing reaction, gelation point was lowered with the increasing the amount of AAEM and HMMM in the ACR.
        4,000원
        18.
        2000.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Pyrophosphoric lactone modified polyester(PATT) that contains two phosphorous functional groups in one unit base resin structure was synthesized to prepare a non-toxic reactive flame retardant coatings. Then the PATT was cured at room temperature with isocyanate, Desmodur IL, to get a two-component polyurethane flame retardant coatings(PIPUC). Comparing the physical properties of the films of PIPUC with the film of non-flame retardant coatings, there was no degradation observed in physical properties by the introduction of a flame-retarding component into the resin. We found that the char lengths measured by 45˚Meckel burner method were 3.1~4.4cm and LOI values recorded 27~30%. These results indicate that the coatings prepared in this study is good flame retardant one. The surface structure of coatings investigated with SEM does not show any defects and phase separation.
        4,000원