Garment skin leather 표면 코팅에 사용된 폴리우레탄 수지는 polyethylene glycole(PEG)의 함유를 [NCO]/[OH] mole % 비로 달리하면서 합성하였으며, 합성된 폴리우레탄 수지의 기계적 특성은 SEM, FT-IR, UTM 등을 이용하여 측정하였다. 비이온성을 띄고 있는 PEG(poly ethylene glycol)의 [NCO]/[OH] mole % 비가 증가함에 따라 내굴곡성(건식, 습식)의 변화는 없었으며, 내마모도, 인장강 도수치가 낮아짐을 알 수 있었다. 반대로 연신율 물성은 증가함을 알 수 있었다. 점도 변화 측정 결과에 는 PEG의 [NCO]/[OH] mole % 증가에 따라 점도가 묽어짐을 알 수 있었다.

Ag nanoparticles are extensively studied and utilized due to their excellent catalysis, antibiosis and optical properties. They can be easily synthesized by chemical reduction methods and it is possible to prepare particles of uniform size and high purity. These methods are divided into vapor methods and liquid phase reduction methods. In the present study, Ag particles are prepared and analyzed through two chemical reduction methods using solvents containing a silver nitrate precursor. When Ag ions are reduced using a reductant in the aqueous solution, it is possible to control the Ag particle size by controlling the formic acid ratio. In addition, in the Polyol process, Ag nanoparticles prepared at various temperatures and reaction time conditions have multiple twinned and anisotropic structures, and the particle size variation can be confirmed using field emissions scanning electron microscopy and by analyzing the UV-vis spectrum.

PPG와 PTMG의 몰비를 달리하면서 첨가하여 합성된 폴리우레탄 수지의 물리적 특성을 SEM, FT-IR, UTM 을 이용하여 측정하였다. 본 연구를 통해 4개의 메틸렌기를 포함한 PTMG의 몰비 가 증가함에 따라 내마모도(60.26 mg.loss), 인장강도(5.24 kgf/㎟)가 증가함을 알 수 있었다. 반대로 연 신율(297 %)은 감소함을 확인 할 수 있었으며. 톨루엔을 이용한 내용제성 물성측정 결과로부터 PTMG 의 반응 몰비 증가에 따른 물성 증감 효과는 없었다. 또한 PTMG의 몰비가 증가함에 따라 점도(4.8 cp) 가 상승함을 확인 할 수 있었다.

A rapid cold hardening (RCH) and supercooling capacity usually play crucial roles in survival during the overwintering period in the tobacco budworm, Helicoverpa assulta, a freeze-susceptible species. Cryoprotectants such as polyol or sugar affect RCH and maintain fluid status of hemolymph. This study is performed to identify cryoprotectants as a RCH factor in H. assulta. Pre-exposure of H. assulta larvae to 4℃ significantly increased survival at -10℃ in all developmental stages from egg to adult. RCH was dependent on the duration of the pre-exposure period. RCH also significantly enhanced the supercooling capacity. Analysis of cryoprotectants from the hemolymph revealed that the pre-exposure treatment allowed the larvae to accumulate glycerol and trehalose among polyols examined. In addition, unknown materials from 2 peaks were also increased. TIC analysis revealed 3 predicted formulas for unknown materials, C26H24O20S or C3H4N6OS and C22H20O21. Glycerol-3-phosphate dehydrogenase (GPDH) and glycerol 3-phosphatase (G3P) that involving in glycerol biosynthesis were identified from the transcriptome of H. assulta 4th instar larvae. Based on the expression level of transcripts, the expressions of GPDH and G3P were relatively increased when compared to that of the control, suggesting that these genes contribute to overwintering and biosynthesis of glycerol.

In this study, cobalt nanopowder is fabricated by sonochemical polyol synthesis and magnetic separation method. First, sonochemical polyol synthesis is carried out at 220oC for up to 120 minutes in diethylene glycol (C4H10O3). As a result, when sonochemical polyol synthesis is performed for 50 minutes, most of the cobalt precursor (Co(OH)2) is reduced to spherical cobalt nanopowder of approximately 100 nm. In particular, aggregation and growth of cobalt particles are effectively suppressed as compared to common polyol synthesis. Furthermore, in order to obtain finer cobalt nanopowder, magnetic separation method using magnetic property of cobalt is introduced at an early reduction stage of sonochemical polyol synthesis when cobalt and cobalt precursor coexist. Finally, spherical cobalt nanopowder having an average particle size of 22 nm is successfully separated.

본 논문에서는 피혁에 사용되는 수용성 폴리우레탄 사슬 연장제인 1,4-butanediol(1,4-BD)의 함유에 따른 물성변화를 조사하였다. 합성에 사용된 시약은 poly propylene glycol(PPG), isoporon diisocyanate((IPDI), dimethylolpropionic acid(DMPA), 1,4-BD를 사용하였다. 1,4-BD의 함유에 따른 내용제성과 내굴곡성 측정값은 시료 전부 우수한 물성을 보였다. 인장강도, 내마모성 측정결과 1,4-BD가 많이 함유된 시료들이 각각 1.80kgf/mm2, 49.54 mg.loss로 우수한 물성을 확인하였다. 연실율 측정결과 1,4-BD가 적게 함유된 시료가 364%로 가장 우수한 측정값을 나타냈다.

본 연구에서는 캐비테이션에 의한 부식에 강한 도료를 개발하기 위하여 고탄성의 우레탄 수지에 내마모 성능을 향상시키기 위한 첨가제로서 Polypropylene glycol(PPG), Polycarbonate diol(PCD), Polycaprolactone polyol(PCL-1), Polycaprolactone-tetramethylene glycolether(PCL-2) 등 4가지 종류의 Polyol을 첨가하여 제조한 도료의 물성과 캐비테이션 저항성을 평가하였다. 합성된 도료의 물성을 비교한 결과 Polyol 중에서는 PCD을 첨가한 경우 경도와 내마모성이 높아 캐비테이션 저항성이 높을 수 있는 물성을 가진 것으로 나타났으나 고점도를 가지고 있어서 도료화에 어려움이 있을 것으로 예상되어 점도가 낮은 도료를 위하여 PCL-1을 적절한 첨가제로 선정하였다. PCL-1이 첨가된 도료의 캐비테이션 저항성을 평가한 결과 저항성이 높은 것으로 나타났고 SEM을 이용하여 표면 분석을 통한 기공의 침식현상을 관찰하였다.

To synthesize Sn nanoparticles (NPs) less than 30 nm in diameter, a modified polyol process was conducted at room temperature using a reducing agent, and the effects of different pH values of the initial solutions on the morphology and size of the synthesized Sn NPs were analyzed. tin(II) 2-ethylhexanoate, diethylene glycol, sodium borohydride, polyvinyl pyrrolidone (PVP), and sodium hydroxide were used as a precursor, reaction medium, reducing agent, capping agent, and pH adjusting agent, respectively. It was found by transmission electron microscopy that the morphology of the synthesized Sn NPs varied according to the pH of the initial solution. Moreover, while the size decreased to 11.32 nm with an increase up to 11.66 of the pH value, the size increased rapidly to 39.25 nm with an increase to 12.69. The pH increase up to 11.66 dominantly promoted generation of electrons and increased the amount of initial nucleation in the solution, finally inducing the reduced-size of the Sn particles. However, the additional increase of pH dominantly induced a decrease of PVP by neutralization, which resulted in acceleration of the agglomeration by collisions between particles.

Upon freezing temperatures, most insects should avoid cellular freezing by migration to warm hibernating sites, by becoming cold-hardy or by undergoing diapause development. However, a highly threatened butterfly, Parnassius bremeri, terminates egg diapause at early winter season and grows during entire winter and spring. Thus, the cold hardiness of P. bremeri needs to be explored to understand its cold tolerance limit and physiological factors. Supercooling points (SCPs) of P. bremeri vary from -10℃ to -48℃ among season. Especially, the young larvae during Jan – Mar kept SCPs at below -20℃. Larval plasma contained high level of glycerol (39.7 mM) at March, but it decreased the level (2.4 mM) at May. Transcriptome analysis indicated high levels of gene expressions associated with glycerol synthesis. Temporal expression patterns of polyol synthesis genes supported the change of glycerol. This study suggests that glycerol is a major cryoprotectant of P. bremeri to be cold-handy against freezing temperatures during winter.

금속이 도핑 된 산화아연 나노클러스터를 합성하기 위해 마이크로웨이브를 이용한 폴리올 공 정은 빠르고 경제적인 합성 방법이다. 디에틸렌글리콜은 높은 분극률과 마이크로파의 흡수 능력이 뛰어 나며, 높은 온도상승 비율과 반응시간을 짧게 해준다. 본 연구에서는 금속이 도핑 된 산화아연 나노클러 스터를 합성하기 위해서 첨가되는 seed의 부피비를 다르게 하여 얻었으며, 전구체로는 아세트산 아연 2 수화물, 도핑 금속은 아세트산 금속 염을 그리고 용매로서 디에틸렌글리콜을 사용하였다. 금속이 도핑 된 산화아연 클러스터는 FE-SEM, XRD, Raman, PSA로 특성을 확인하였다.

본 연구에서는 hard segment를 형성하고 있는 폴리우레탄을 합성한 다음 피혁산업에서 마감 코팅시 많이 사용되고있는 폴리에틸렌왁스의 적하량을 점차 증가시켜 필름 및 Lam skin에 코팅에 적용하여 변화하는 물성을 측정하였다. 내용제성 측정 결과 높은 내용제성 물성을 지닌 폴리우레탄 수지에 폴리에틸렌왁스의 함량에 따른 물성적 변화는 크게 나타나지 않았다. 인장 강도 측정치에서는 폴리우레탄 단독 필름의 측정치가 1.235 kgf/㎟로 가장 높은 수치를 나타내었으며, 폴리에틸렌왁스의 함량이 제일 높은 PUD-EW3가 가장 낮은 인장력 1.022 kgf/㎟를 나타내었다. 또한 내마모도 측정에서는 PUD가 제일 높은 52.22 5㎎.loss로 우수한 물성변화를 나타내었고, 연실율의 경우 역시 우레탄 단독 코팅인 PUD가 698%로 가장 높은 수치를 나타내었다.

본 실험에서는 투명비누를 만드는데 사용되는 폴리올의 최적 농도를 실험계획법을 이용하여 결정하였다. 짧은 사슬을 보유한 디프로필렌글리콜과 1,3 부틸렌글리콜은 비누의 투명도를 증가시켰으나 폴리에틸렌글리콜 400, 글리세린과 디글리세린은 비누를 불투명하게 하였다. 프로필렌글리콜, 디글리세린, 디프로필렌글리콜 및 폴리에틸렌글리콜의 농도를 증가시키면 비누의 경도는 증가하였다. 경도, 투명도, 물의 흡수성 및 마찰 용해도는 디프로필렌글리콜, 폴리에틸렌글리콜, 설탕과 트리에탄올아민의 농도를 조절하여 최적화할 수 있었다.

In this study DMT(Dimethylterephthalate), NDC(Dimethyl-2, 6-Naphthalene Dicarboxylate) were used to synthesize polyester polyol which shows enhanced storage stability, improved flame retardancy, and good compressive strength. If DMT and NDC react respectively with DEG(Diethylene Glycol) which is kind of linear diol, the obtained polyester polyols tend to crystallize easily after the reaction. In case of DMT, PA(Phthalic Anhydride) which has asymmetric structure was introduced to retard the crystallization. In case of NDC, DPG(Dipropylene Glycol) which has an methyl side chain was introduced to prevent the crystallization. It was found that to introduce DPG was much more effective method to prevent the crystallization than PA. NDC and DMT were reacted together with DPG for various compositions of NDC:DMT(8:2, 6:4, 4:6 mol ratio). The obtained NDC-DMT-DPG based polyester polyol showed improved flame retardancy, and good compressive strength with increasing the content of NDC.

Conventional additives were added to a newly synthesized base oil to create synthetic lubricants. Commercial polyol ester prepared in this laboratory were obtained as esterification of 1,1,1-trimethylol propane and respectively. This newly synthesized base oil had a variable chemical structure that could achieved the following properties; oxidation or thermal stability, low temperature fluidity, and higher flash points. When compared with commercial mineral lubricants, the synthetic lubricants show superior thermal and oxidation stability, and anti-wear properties.

It is inevitable to use chemical germicidal agents like paraben, imidazolidinyl urea and phenoxyethanol to preserve the emulsions which is usually used in cosmetics. Although these chemical preservatives are good enough to reduce the microbiological contamination, they are irritative, allergenic to the skin. Several kinds of polyols are used in cosmetics as moisturizer and solvent. In this study, we evaluate the effects of polyols on anti-microbial activities, safety and resistant index. MIC(minimal inhibitory concentration) of polyols determined against 6 germs including Staphylococcus aureus. The order of MIC was PG ≅ DPG ≅ 1,3BG 〉 HG 〉 1,2-PD 〉 1,2-HD ≅ 1,2-OD. The 2~3 wt% of 1,2-HD(hexanediol) shows good anti-microbial effects in emulsions without allergenic response. Resistant index of 1,2-HD was less than 2 and this value was smaller than that of chemical preservatives. The mechanism of antimicrobilogical effect might be disturb the membrane of germs by investigating using electron microscope. Added to that, using this paradigm, low preservative contents, paraben-free system, and even preservative-free systems can be expected from these results.

The material design and synthesis are of important to modem science and technology. Here, we report the synthesis of multifunctional nanomaterials with different properties: feroelecties and multiferroic materials such as nano-composites by using a chemical synthesis process. These results provide a simple and convenient synthesis process to produce multifunctional nanocomposites.

This study investigated a mechanism for controlling the shape of Cu nanocrystals fabricated using the polyol process, which considers the thermodynamic transition from a facetted surface to a rough surface and the growth mechanisms of nanocrystals with facetted or rough surfaces. The facetted surfaces were stable at relatively low temperatures due to the low entropy of perfectly facetted surfaces. Nanocrystals fabricated using a coordinative surfactant stabilized the facetted surface at a higher temperature than those fabricated using a non-coordinative surfactant. The growth rate of the surface under a given driving force was dependent on the surface structure, i.e., facetted or rough, and the growth of a facetted surface was a thermally activated process. Surface twins decreased the activation energy for growth of the facetted surface and resulted in rod- or wire-shaped nanocrystals

Monodispersed flaky silver powder was obtained by controlling the ratios of and Agin in a mixed solution of ethylene glycol and ammonia with an addition of PVP. The effects of on its morphology and size were investigated. In molar ratio was found to be an important reaction factor for the nucleation and crystal growth of Ag powder. The synthesis of flaky powder was optimized at over 6 of molar ratio increased, the size of precipitates was increased regardless of the amount of Pt. In the absence of , the morphology and size of reduced Ag powder were found to be irregular in shape in diameter. However, homogenized fine Ag powder was obtained due to heterogeneous nucleation when used as a cat-alyst, and flaky one was synthesized with the addition of Pt over of Pt/Ag.