• 한국식품과학회지
• /
• 제32권3호
• /
• pp.691-698
• /
• 2000

Rhizopus japonicus균을 파종하여 만든 누룩으로 담금한 탁주 술덧의 발효과정 중 휘발성 향기성분을 GC와 GC-MS를 사용하여 분석 동정한 결과 ester 24종, alcohol 19종, acid 9종, aldehyde 10종, 기타 4종 등 66종의 향기 성분이 동정 되었다. 동정된 향기성분 수는 담금일에 ester 14종, alcohol 12종을 비롯한 총 39종 이었으나, 발효 2일에 ester 6종, alcohol 4종을 포함한 17종이 추가 검출되어 56종으로 증가 되었다. 발효 12일에는 66종으로 향기 성분수가 최대에 달하였다. ethanol, 3-methyl-1-butanol, 2-methyl-1-propanol등 alcohol류 12종, ethyl acetate, ethyl caprylate, isoamyl acetate 등 ester류 14종 acetaldehyde 등 aldehyde 6종, pentanoic acid 등 acid 5종등 총 38종은 발효 전과정을 통하여 검출되었다. 향기 성분의 면적비율은 ethanol이 $76.2149{\sim}92.1155\;%$로 발효 전기간을 통하여 탁주 술덧에서 타 성분 보다 월등히 높았다. ethanol을 제외하고 발효 전과정을 통하여 면적비율이 높은 성분은 3-methyl-1-butanol, 2-methyl-1-propanol, ethyl caprylate, benzene-ethanol, 2,3-butanediol이었다. 이외 발효기간에 따라서 ethyl acetate, diethyl succinate, octanoic acid, acetic acid, isobutyl aldehyde 등의 성분도 동종 계열간의 향기 성분중 면적비율이 높게 나타나기도 하였다.

• 한국섬유공학회:학술대회논문집
• /
• 한국섬유공학회 1997년도 추계총회 및 학술발표회 논문집
• /
• pp.126-130
• /
• 1997

A series of Thermoplastic polyurethane elastomers was prepared via a two-step polymerization process. The NCO/OH feed ratio of polyurethane synthesized in this study was varied from 1 to 1.3. Studies have been made on the effects of chemical and physical cross-linkina, and the properties of thermoplastic polyurethane elastomers based on isophorone diisocyanate (IPDI)/1,4-butanediol (BD)/poly(propylene glycol) (PPG, MW:2000), isophorone diisocyanate (IPDI)/BD /poly(oxytetramethylene) glycol (PTMG, MW:2000) was compared. These materials were characterized using FTIR spectrometer, dynamic mechanical thermal analyzer, and tensile retraction tester. PTMG based polyurethane elastomers showed higher elasomeric behavior than PPG based polyurethane elastomers at the same NCO/OH ratio. This feature has been connected with the specific nature of the polyols. The permanent set(%) was decreased with increasing maximum elongation from 50% to 300%.

• Bulletin of the Korean Chemical Society
• /
• 제18권1호
• /
• pp.38-43
• /
• 1997

Poly(ethylene 2, 6-naphthalate-co-tetramethylene 2, 6-naphthalate) (PEN/PBN) copolymers were synthesized and studied by 13C NMR spectroscopy, DSC analysis and X-ray diffraction. A minimum in the melting point vs. composition curve was found at approximately 60 mol% tetramethylene 2, 6-naphthalate. The PEN/PBN copolymers were shown to be statistically random throughout the range of 1, 4-butanediol compositions. The melting point depression behavior of annealed PEN/PBN copolymers depended upon the sequence propagation probability, PS, which is suggested by indivisual crystal formation of two pure comonomers; that is, ethylene-naphthalate-ethylene, EE, and tetramethylene-naphthalate-tetramethylene, BB. However, it can be seen from the X-ray curve that the peaks of PEN/PBN copolymers appear from a crystal lattice which is governed only by the rich component between two different aliphatic units in the copolymer composition.

• 한국재료학회:학술대회논문집
• /
• 한국재료학회 1993년도 춘계학술발표회
• /
• pp.99-100
• /
• 1993

Calorimetric (D.S.C) studies were carried out on the nylon 4,6 single crystals grown from 1,4-butanediol solution at various crystallisation temperatures, based on the assessment of the lamellar thickness by small angle x-ray scattering. Samples were annealed mainly ot get rid of residual solvents inside the crystals. The effect of annealing on the crystal perfection is inferred from the measured thermal properties of the crystals. Accordig to the scanning rates less than 80 K/min., D. S C. melting peaks indicate that changes in the internal morphology of nylon 4,6 crystals preapred at different crystallisation temeratures yield a thermodynamic melting temperature. Tm, of 319 $^{\circ}C$, for the infinitely extended crystal thickness (1/ι). The obtained heat of fusion value for the inginite crystal thickness, Ho, was 270 J/g from the plot of measured feat of fusion ($\Delta$Hm) vs. reciprocal crystal thickness (1/ι). based on these values, the fold surface energy, $\delta$e. of 65.4 erg/$\textrm{cm}^2$ was obtained from Hoffman-Waeeks equation. The thermodynamic melting temperature and heat of fusion of the infinite crystal thickness for the solution grow nylon 4,6 single crystals are found to be higher than of the reported corresponding solution grown nylon 6,6 single crystals. pbtained crystallinity from D. S. C measurements ranges from 40 to 50 %, which is close to the reported yalue for the nylon 6,6 single ctystals but lower than we expected.

• 한국안광학회지
• /
• 제6권1호
• /
• pp.119-124
• /
• 2001

디메틸 테레프탈레이트 (DMT), 1.4-부탄디올 (1.4-BD) 그리고 분자량이 2000인 폴리테트라 메틸렌 에테르 글리콜 (PTMG)로 부터 폴리에스터계 열가소성 탄성체 (TPEE)를 합성할 수 있었다. 열적 안정성 및 기계적 물성을 증대시킬 목적으로 열처리를 하였으며, 이에 따라 결정성 hard segmen의 보다 규칙적인 배열로 인한 향상된 물성을 확인 할 수 있었다. 본 실험에서 합성된 공중합체는 soft segment의 함량이 증가함에 따라 융점 및 결정화도가 감소함을 보여 주었다. 기계적 물성의 경우, soft segment의 함량이 35%인 공중합체가 soft segment와 hard segment간 최적의 물리적 가교점 형성으로 인하여 가장 우수함이 관찰되었다.

• Elastomers and Composites
• /
• 제27권4호
• /
• pp.267-274
• /
• 1992

Polydimethylsiloxane(PDMS)-containing polyurethane coating materials were synthesized because PDMS-based elastomers have unique properties including an extremely low glass transition temperature, good thermal and oxidative stability, and good dielectric properties. In this experiment a vinyl copolymer which consisted of vinyl chloride, vinyl acetate, vinyl alcohol, and maleic acid was used, and Coronate L was used as a polyisocyanate. PDMS-containing polyurethane was synthesized from polydimethylsiloxane, MDI, and 1,4-butanediol. Films were casted by reaction of viny copolymer, Coronate L, and PDMS-containing polyurethane. Thickness of tile films were $150-170{\mu}m$ and the films were characterized by IR, DSC, and Instron.

• 공업화학
• /
• 제7권5호
• /
• pp.970-976
• /
• 1996

생분해성 지방족폴리에스터인 poly(butylene succinate) (PBS)의 기계적 물성을 변화시키기 위해서 에스터 주쇄 구조에 카보네이트 구조를 도입시킨 에스터-카보네이트 공중합체를 합성하였다. 이 공중합체는 일단계에서 succinic acid와 1,4-butanediol(BD)을 에스터 반응시켜 oligo(butylene succinate)를 합성하였고, 이 단계에서 oligohexamethylenecarbonate biol(OHMCG)을 첨가하고 고진공하에서 축중합하여 제조하였다. 촉매로는 titanium(IV) isopropoxide(TIP)를 사용하였다. 합성된 공중합체의 구조는 FT-IR과 $^1H$-NMR을 이용하여 확인하였으며, 열적, 기계적 물성은 각각 DSC와 UTM을 이용하여 조사하였다. 고분자량의 공중합체를 얻을 수 있는 적정 촉매양은 succinic acid에 대해서 1wt%였다. Diol 혼합물의 몰비(BD:OHMCG)가 249:1~149:1일 때, 높은 점도를 갖는 공중합체를 얻을 수 있었다 또한, OHMCG의 함량이 증가함에 따라 공중합체의 용융점은 계속 감소하였다. 혼합물의 몰비가 149:1인 경우의 공중합체의 물성은 PBS에 비해 초기탄성율은 약간 감소하였지만 파단신장율은 2배 정도 증가되었다.

• Transactions on Electrical and Electronic Materials
• /
• 제14권6호
• /
• pp.324-328
• /
• 2013

An alternating current (AC) electrical treeing phenomena in an epoxy system with low chlorine BDGE (1,4-butanediol diglycidyl ether) was studied in a needle-plate electrode arrangement. To measure the treeing propagation rate and breakdown time, a constant AC of 10 kV with three different electric field frequencies (60, 500, and 1,000 Hz) was applied to the needle-plate electrode specimen at $130^{\circ}C$ in aninsulating oil bath. The treeing propagation rate of the DGEBA/high-chlorine BDGE system was higher than that of the DGEBA/low-chlorine BDGE system and the breakdown time of the system with high-chlorine BDGE was lower than that of the system with low-chlorine BDGE. These results implied that chlorine had a negative effect on the electrical insulation property of the epoxy system. As the electric field frequency increased, the treeing propagation rate increased and the breakdown time decreased.

• Transactions on Electrical and Electronic Materials
• /
• 제14권6호
• /
• pp.317-320
• /
• 2013

Partial discharge resistance for the epoxy systems with two diluents was investigated in the rod-plane electrodes arrangement, and the effect of electric frequency on the partial discharge resistance was also studied. Diglycidyl ether of bisphenol A (DGEBA) type epoxy was used as a base resin, and 1,4-butanediol diglycidyl ether (BDGE) or polyglycol (PG) as a reactive diluent was introduced to the DGEBA system, in order to decrease the viscosity of the DGEBA epoxy system. BDGE was acted as a chain extender, and PG acted as a flexibilizer, after the curing reaction. To measure the partial discharge resistance, 5 kV alternating current (ac) with three different frequencies (60, 500 and 1,000 Hz) was applied to the specimen in a rod-plane electrode arrangement, at $30^{\circ}C$. PG had a good effect, while BDGE had a bad effect on the partial discharge resistance of the DGEBA system, regardless of the electric frequency.

• 한국축산식품학회:학술대회논문집
• /
• 한국축산식품학회 2005년도 제36차 추계 학술발표대회
• /
• pp.234-239
• /
• 2005

본 연구는 재래흑돼지육의 진공포장 숙성중 지방산 조성과 SPME-GC/MS에 의한 향기성분을 구명하고자 실시하였다. 지방산 조성으로 C14:0, C16:1n7은 재래흑돼지육이 개량종 돼지육보다 낮았으며(p<0.05), C18:1n7, C22:4n6는 재래흑돼지육이 높았다(p<0.05). 숙성기간 동안 향기성분은 숙성 0일에 2-decanone, 2-ethyl hexanol, hexa -noic acid가 재래흑돼지육에서만 검출되었으며, 숙성 6, 12일에는 butanoic acid, 2.3-butanediol, benzen -acetaldehyde, benzeneethanol, 2-hexadecal, hexanoic acid가 재래흑돼지육에서만 검출되었다.