• Macromolecular Research
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• v.10 no.4
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• pp.230-235
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• 2002

Alternating polyols of oxymethylene and oxyalkylene were synthesized and used as precursors for thermoplastic poly(ether-ester) elastomers (TPEs). The polyols were synthesized by reacting diols having different methylene units with dichloromethane in the presence of a phase transfer catalyst. The number of methylene units in the alkylene oxides was varied from 3 to 6. TPEs were prepared using the polyols as soft segments and poly(butylene terephthalate) units as hard segments. The polyols and TPEs synthesized were characterized using FTIR, NMR, GPC, DSC, and polarized optical microscopy. The polyols showed a profound odd-even effect on the melting (T$_{m}$) and glass transition temperatures (T$_{g}$). Polyols with odd numbers of methylene groups in the alkylene units have higher transition temperatures than polyols with odd number of methylene groups. The tendency is still kept in TPEs, even though the T$_{g}$ of soft segment in TPEs are slightly higher than those of corresponding neat polyols. The T$_{m}$ and T$_{g}$ of soft segments are almost constant in the range of 20 to 60 wt % contents of soft segments. On the other hand, the normalized heat of fusion of hard segment decreased with increasing the content of loft segment.ent.t.ent.

• Journal of the Korean Applied Science and Technology
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• v.26 no.4
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• pp.422-427
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• 2009

We have investigated the effects of polyols and NaCl on the rheological behaviours of surfactant mixtures. Sodium lauryl ether sulfate (SLES), cocamidopropyl betaine (CAPB), disodium cocoamphodiacetate (DSCA), cocamide DEA (CDEA) and lauroyl/myristoyl DEA (LMDE) were used as surfactants. The polyols added into the surfactant mixture were 1,3-butylene glycol, propylene glycol, glycerin, sorbitol, dipropylene glycol, PEG 1500 and PEG 400. The addition of amphoteric surfactant to SLES aqueous solution lead to increase the height of foam and the viscosity of the system. The addition of nonionic surfactant, LMDE or CDEA to the SLES aqueous solution increased the viscosity and the effect of LMDE was better than that of CDEA. The effect of adding polyols and NaCl into the surfactant mixture aqueous solution lead to increase or decrease the viscosity of the systems depending on the concentration of NaCl and the kinds of polyols. These results can be explained through the salting in or salting out of surfactant of the systems.

• Journal of Microbiology and Biotechnology
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• v.6 no.1
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• pp.60-62
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• 1996

Aureobasidium pullulans produced three kinds of extracellular polyols e.g. glycerol, mannitol, and sorbitol from either sucrose, glucose, fructose or mannose. Sorbitol was selectively produced when urea was used as a sole nitrogen source, and the amounts of sorbitol produced rapidly reached a plateau after 50 h where its maximum quantity was about 20 g/l with sucrose.

• Journal of the Korean Applied Science and Technology
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• v.25 no.4
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• pp.477-484
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• 2008

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 $\cong$ DPG $\cong$ 1,3BG > HG > 1,2-PD > 1,2-HD $\cong$ 1,2-OD. The $2{\sim}3\;wt%$ 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.

• Applied Chemistry for Engineering
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• v.8 no.2
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• pp.230-236
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• 1997

Polyurethane dispersions(PUD) were prepared from IPDI, PBEAG and PTMG as respectively ester type and ether type polyols and DMPA as anionic site. The effect of composition and type of polyols on the particle size of PUD and mechanical, thermal properties of PUD cast film were investigated. As the PTMG contents in mixed polyols increased, the particle size asymptotically increased and tensile strength showed a mild drop followed by a mild increase. This results from the incompatibility of two polyols, which was possibly identified by DSC analysis.

• Clean Technology
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• v.17 no.3
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• pp.238-243
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• 2011

We investigate new polyols based on castor oil for polyurethane. In order to introduce primary alcohol groups, which exhibit higher reactivity with isocyanate than secondary alcohol groups, the secondary alcohol groups on castor oil were modified with maleic anhydride and aminoalcohol derivatives ($H_2N$-R-OH). The reactions with various molar ratio of castor oil and maleic anhydride were done at relatively low reaction temperature in the absence of catalyst. The polyols based on castor oil with flexible side-chains exhibit better miscibility with conventional synthetic polyols.

• Elastomers and Composites
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• v.58 no.1
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• pp.32-43
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• 2023

The worldwide use of polyurethane foam products generates large amounts of waste, which in turn has detrimental effects on the surroundings. Hence, finding an economical and environmentally friendly way to dispose of or recycle foam waste is an utmost priority for researchers to overcome this problem. In that sense, the glycolysis of waste flexible polyurethane foam (WFPF) from automotive seat cushions using different industrial-grade glycols and potassium hydroxide as a catalyst to produce recovered polyol was investigated. The effect of different molecular weight polyols, catalyst concentration, and material ratio (PU foam: Glycols) on the reaction conversion and viscosity of the recovered polyols was determined. The obtained recovered polyols are obtained as single or split-phase reaction products. Besides, the foaming characteristics and physical properties such as cell morphology, thermal stability, and compressive stress-strain nature of the regenerated flexible foams based on the recovered polyols were discussed. It was observed that the regenerated flexible foams displayed good seating comfort properties as a function of hardness, sag factor, and hysteresis loss compared to the reference virgin foam. With the growing demand for a sustainable and circular economy, a global valorization of glycolysis products from polyurethane scraps can be realized by transforming them into profitable substances.

• Journal of Adhesion and Interface
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• v.20 no.2
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• pp.61-65
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• 2019

In this study, phosphorus polyols, having a molecular weight of 880 to 1,560 g/mol, were synthesized by reacting phenylphosphonic dichloride (PPDC), allylphosphonic dichloride (APDC), and ethylene glycol (EG) in solvent, to enhance flame retardance of polyurethane. Phosphorus polyurethanes were polymerized using the synthesized phosphorus polyols, polycarbonate diol (PCD), and 4,4'-diphenylmethane diisocyanate (MDI) by a melt polymerization method. As increasing phosphorus contents of the phosphorus polyurethanes, we observed that the remaining char amount increased. This tendency was also confirmed in the following UL-94V test. We found that when the synthesized phosphorus polyols were applied, the resulting phosphorus polyurethanes show UL-94V0 grade at above 0.5 wt% phosphorus contents.

• Journal of the Korean Applied Science and Technology
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• v.18 no.3
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• pp.241-247
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• 2001

Aqueous urethane dispersion resin begins to assume commercial importance due to increasing environmental awareness of VOC in coating industry. Moreover there have been strong industrial needs for the development of reactive-type polyurethane flame retardant coatings. In this study, chlorinated polyester polyols were synthesized by two step polycondensation reaction using mono chloroacetic acid, adipic acid, trimethylol propane, and 1,4-butanediol. In the next step polyurethane dispersion was prepared using these chlorinated polyester polyols and isophorone diisocyanate with dimethylol propionic acid(DMPA) and trimethylamine. The structure of chlorinated polyol was characterized by GPC, FT-IR and NMR. Particle size and its distribution were examined in terms of various dispersion parameters including molecular weight and composition of polyol, amount of DMPA, and NCO/OH ratio, etc. The effect of chlorinated polyols on flammability was also evaluated.

• Culinary science and hospitality research
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• v.21 no.6
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• pp.303-311
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• 2015

This study was carried out to evaluate the possibility of polyols for coating material of chewing gum. Five polyols xylitol, maltitol, isomalt, erythritol, and sorbitol were compared the coating quality, coating and drying time, and color differences. Maltitol was evaluated to be the best quality for coating the gum, whereas erythritol and sorbitol were not considered for coating materials for gum. These results derived from irregular surface layer and low productivity due to increased coating time. According to changes in color of chewing gum, samples coated maltitol and xylitol and isomalt stored at high temperature. In addition, color difference of sample coated maltitol was calculated 2.88 stored at $80^{\circ}C$ for 1 day, but those of xylitol and maltitol were highly evaluated. Sample coated maltitol in polypropylene bag was stored and measured for 1 month. Changes in color of sample was slightly occurred at below $40^{\circ}C$ and the color difference was not more than 3 at $60^{\circ}C$. Chewing gum coated maltitol as coating material was expected more stable in the quality of color during distribution. Current study was performed to color changes during storage, further study will be proceeded about shelf-life of chewing gum coated polyols.