• Transactions on Electrical and Electronic Materials
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• 제14권4호
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• pp.199-202
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• 2013

In order to study the effect of reactive diluents on the electrical insulation breakdown strength and mechanical properties of, a polyglycol and an aliphatic epoxy were individually introduced to an epoxy system. Reactive diluents were used in order to decrease the viscosity of the epoxy system; polyglycol acted as a flexibilizer and 1,4-butanediol diglycidyl ether (BDGE) acted as an aliphatic epoxy, which then acted as a chain extender after curing reaction. The ac electrical breakdown strength was estimated in sphere-to-sphere electrodes and the electrical breakdown strength was estimated by Weibull statistical analysis. The scale parameters of the electrical breakdown strengths for the epoxy resin, epoxy-polyglycol, and epoxy-BDGE were 45.0, 46.2, and 45.1 kV/mm, respectively. The flexural and tensile strengths for epoxy-BDGE were lower than those of the epoxy resin and those for epoxy-polyglycol were lower than those of the epoxy resin.

• 한국응용과학기술학회지
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• 제20권4호
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• pp.275-282
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• 2003

Aqueous polyurethane dispersion was synthesized using phosphorus compound which received significant attention for the replacement of halogenated flame retardants. In this study, polyols which have phosphorus moity in their structural unit were synthesized by two-step polycondensation reaction using dimethyl phenylphosphonate, ethylene glycols. adipic acid, and 1,4-butanediol. In the next step, polyurethane dispersion was prepared using these polyols, isophorone diisocyanate with dimethyl propionic acid. The particle size of polyurethane latex was reduced from 347 nm to 240 nm with increasing DMPA content. It was observed that the LOI values of prepared coatings increased from 27% to 35% with increasing phosphorus content.

• Elastomers and Composites
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• 제34권4호
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• pp.292-298
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• 1999

Lactide oligomer with number averagae molecular weight of 460 was synthesized and reacted with poly(oxyteramethylene)glycol(PTMG, Mn = 650) to obtain oligolactide oligomer-terminated PTMG. Polyurethanes were synthesized from the oligolactide-terminated PTMG, 4,4'-diphenylmethane diisocyanate, and 1,4-butanediol. The mechanical and thermal properties of the polyurethanes and PTMG based polyurethane as control were measured by means of DSC and tensile tester. Degradation behavior of these polyurethanes put into a compost was evaluated by variation of mechanical properties, surface state, and weight loss. Modulus and weight significantly decreased with increasing time. The surface of the oligolactide polyurethane put into the compost during 6 weeks had a number of voids. On the other hand, These properties of the PTMG based polyurethane as control did not change. These results suggest that the novel polyurethanes incorporated oligolactide easily degrade under biodegradable condition.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1993년도 제2회 신약개발 연구발표회 초록집
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• pp.145-145
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• 1993

일반적으로 단백질의 정제를 위한 가장 효과적인 방법은 affinity chromatography법으로 알려져 있다. 본 연구에서는 베타 수용체의 순수정제를 위한 효과적인 affinity matrix를 제조하고 이의 특징을 확인함으로써 수용체 정제를 위한 기초를 수립하고자 하였다. Bisoxirane reagent인 1,4-butanediol diglycydyl ether를 Sepharose CL-4B gel과 반응시켜 탄노원자 10개 길이의 spacer arm을 부착시켰다. 여기에 sodium persulfate, dithiothreitol을 연속적으로 사용하여 -SH기를 도입시긴 추 free radical 반응을 이용하여 베타수용체 길항제인 alprenolol을 부착시킴으로써 affinity gel을 제조하였다. alprenolol치 부착반응을 위한 최적온도는 4$0^{\circ}C$로 나타났으며, semimicro Kjeldahl 질소 분석법을 적용하여 gel을 분석한 결과 ml당 0.4-0.6 $\mu$ mol의 alprenolol이 결합하였음을 확인하였다.

• 폴리머
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• 제25권3호
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• pp.391-398
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• 2001

난연성분인 트리브로모아세트산의 함량을 10, 20, 30wt%로 변화시키면서 1,4-부탄디올, 아디프산 및 트리메틸올프로판과 축합중합을 하여 트리브로모 변성폴리에스테르(TBAO)를 합성한 후에, TBAO류와 이소시아네이트를 블렌드하여 2성분계 폴리우레탄(PU) 난연도료를 제조하였다. 제조된 난연도료의 도막물성을 측정한 결과, 결코 비난연도료보다 물성이 저하되지는 않았다. 또한 난연도료의 난연성 시험결과, 수직법에서 트리브로모아세트산 20 wt%에서 불꽃에 타지 않아서 양호한 난연도료임을 알 수 있었다.

• 전기학회논문지
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• 제62권2호
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• pp.213-218
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• 2013

In this study, epoxy/mica composite was prepared by mixing with mechanical stirrer together with homogenizer, and the effect of amino-type silane coupling agent was also studied. To reduce the viscosity without any decrement of other properties, 1,4-Butanediol diglycidyl ether (1,4-BDGE) as an aliphatic epoxy reactive diluent was introduced to the epoxy/mica composite in order to use as vanish for high voltage motor and generator stator winding. It was confirmed by scanning electron microscopy (SEM) observation that interfacial characteristics between organic epoxy and inorganic mica was modified by coupling agent treatment so that glass transition temperature increased, and tensile strength and electrical breakdown strength increased. The properties were estimated by Weibull statistical analysis and the ac electrical breakdown strength was 20.2% modified by treating silane coupling agent.

• KSBB Journal
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• 제9권3호
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• pp.246-252
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• 1994

유기용매 THF에서 bis(2, 2, 2-trichloroethyl) glutarate와 diol을 기질로 하여 PPL에 의한 tran sesterification 반응을 통해 polyester를 합성하였다. 1. 서로 다른 source의 lipase로 이 반응을 시켜본 결과 PPL이 가장 반응을 잘 진행시켰으며 Humi cola lanuginos와 Pseudomonas sp.의 Ii pase들도 어느 정도 반응을 진행사켰으며 Rhizopus의 lipase들 은 반응을 전혀 진행시키지 못했다. 2. Diol로 ethyleneglycol, 1, 3~propanediol, 1,4­b butanedi이은 모두 거의 비슷한 정도로 반응이 진행 되었으며 secondary alcohol인 glycerol의 경우 이들에 비해 반응이 매우 느리게 진행되었다. 이는 glycer이 에 의 해 효소가 steric hinderance를 받기 때문인 것으로 추정된다. 3. Diol로 여러 가지 분자량의 PEG(M = 300-1000)를 사용한 결과 PEG-400이 가장 잘 반응되었으며 이를 제외하고는 분자량이 클수록, 즉 chain의 길이가 갈수록 반응속도가 느렸다. 그리고 이렇게 chain의 길이가 비교적 긴($C_{12}-C_{45}$) PEG플 diol 로 사용했을 때는 monotransesterication 반응이 끝 난 이후에는 반응이 거의 더 이상 진행되지 않았다. 4. 유기용매로는 비교적 hydrophilic한 THF, ether, acetonitrile 등에 셔 잘 반응되었다. 5. $20^{\circ}C$ 에서 $60^{\circ}C$의 온도범위에서 반응온도가 높 을수록 반응속도가 빨랐으며 184시간 반응된 반응 생 생물의 평균분자량은 모두 2200←2300 daltons로 반응온도의 영향을 받지 않는 것으로 관찰되었다. 8. NMR에 의한 end group analysis를 이용하여 반응 생성물을 분석한 결과 수평균분자량은 1500­4 4000 daltons이었다.

• Elastomers and Composites
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• 제54권4호
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• pp.271-278
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• 2019

Polyurethane elastomers (PUEs) were synthesized using trans-1,4-bis(isocyanatomethyl) cyclohexane (1,4-H₆XDI), poly(oxytetramethylene) glycol, 1,4-butanediol (BD), and 1,1,1-trimethylol propane (TMP). To control the molecular aggregation state and mechanical properties of these PUEs, hard segment contents of 20 and 30 wt% and BD/TMP ratios of 10/0 and 8/2 were chosen. Differential scanning calorimetry and small-angle X-ray scattering measurements revealed that the degree of microphase separation increased with an increase in both hard segment content and BD ratio. The Young's modulus and strain at break of the 1,4-H₆XDI-based PUE were 6-20 MPa and 5-15, respectively. Incorporation of 20% TMP as a cross-linking agent into BD increased the melting temperature of the hard segment chains, that is, heat resistance, and decreased the Young's modulus. This could be due to the low density of the physical cross-linking network and the dispersion of hard segment chains in the soft segment matrix in the PUE in the presence of 20% TMP.

• 한국응용과학기술학회지
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• 제22권1호
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• pp.1-8
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• 2005

Chlorine-containing modified polyester polyols were synthesized by two-step condensation reactions. Intermediate was synthesized by the esterification of monochloroacetic acid with trimethylolpropane in the first step. Polycondensation of the intermediate (MCAOs), 1,4-butanediol, and trimethylolpropane with adipic acid was carried out. Two-component polyurethane (PU) coatings were prepared by blending MCAOs and IPDI-isocyanurate. There new flame-retardant coatings showed various properties comparable to other non-flame-retardant coatings. They were superior to flammable coatings from the experimental results showing rapid and 10 to 13 hours of pot-life. Coatings with 30wt% monochloroacetic acid was not flammable by the vertical flame retardancy test.

• Macromolecular Research
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• 제10권6호
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• pp.365-368
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• 2002

Thermoplastic polyurethanes (TPUs) with different hard segment length has been prepared from a fixed molar ratio of poly(tetramethylene ether glycol), 4,4'-diphenylmethane diisocyanate, and 1,4-butanediol by different polymerization procedures. Results reveal that the on-set temperature of endotherms ( $T_{cc}$ ) due to the crystallization of hard segments by cooling the TPUs from melt and the peak temperature of endotherms due to the melting of hard segments ( $T_{mh}$ ) by heating the TPUs increased and levelled off with increasing the hard segment length of TPUs. It has also been observed that soft segment glass transition temperature ( $T_{gs}$ ) of TPU decreased slightly with increasing the hard segment length, which explains less mixing of soft segments and hard segments. In tensile measurement of TPUs, strain hardening is observed with increasing the hard segment length, which is attributed to the strain induced crystallization of soft segments.