• Preventive Nutrition and Food Science
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• v.10 no.1
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• pp.88-91
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• 2005

To improve the physical properties of protein films, various plasticizers and cross-linking agents were used in the preparation of the films. For zein film, 3% polypropylene glycol with 3% glycerol was the best plasticizer, while 2.5% glycerol was the most suitable for soy protein isolate (SPI) film in terms of tensile strength (TS), % elongation, and water vapor permeability (WVP). Formaldehyde, glutaraldehyde, glyoxal, and cinnamaldehyde as cross-linking agents of protein films were used to further improve the physical properties of the films. All aldehydes used as cross-linking agent in this study improved TS of zein and SPI films. In particular, cinnamaldehyde was the best cross-linking agent due to its safety in foods. These results suggest that appropriate use of plasticizer and cross-linking agent like cinnamaldehyde should improve the physical properties of protein films for use in food packaging.

• Corrosion Science and Technology
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• v.12 no.6
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• pp.295-303
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• 2013

Silane surface treatments have been developed as an alternative for toxic and carcinogenic chromate-based treatments for years. It is consistently observed that ultra-thin films offer excellent corrosion protection as well as paint adhesion to metals. The silane performance is comparable to, or in some cases better than, that of chromate layers. Based on the tetra-ethylorthosilicate(TEOS) and methlyl trieethoxysilane(MTES), inorganic sol was synthesized and formed hybrid networks with $SiO_2$ nano particle and polypropylene glycol(PPG) on Zn alloyed steel surface. According to SST results, addition of 10nm and 50nm $SiO_2$ nanoparticle in synthesized solution improved anti-corrosion property by its shear stress relaxation effect during curing process. Also, SST results were shown that anti-corrosive property was affected by the amounts of organic compounds.

• Proceedings of the Materials Research Society of Korea Conference
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• 2010.05a
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• pp.12.1-12.1
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• 2010

We have developed a facile method to position different dyes (N719 and N749) sequentially in a mesoporous TiO2 layer through selective desorption and adsorption processes. Only upper part of the first adsorbed N719 dye was selectively removed by the desorption solution formulated with polypropylene glycol and tetrabutylammonium hydroxide without any damages of the dye. The desorption depth was controlled by the number of desorption process. Multi-dyed dye-sensitized solar cells (MDSSC) were fabricated by utilizing the method and their photovoltaic properties were investigated. From the incident photon-to-current conversion efficiency (IPCE) measurement, it was found that the MDSSC exhibited the extended spectral response for the solar spectrum while without decrease of maximum IPCE value compare to the DSSCs using one kind of dye (N719 or N749). The highest photocurrent density of 19.3 mA/cm2 was obtained from the MDSSC utilizing $15\;{\mu}m$ N719 / $14\;{\mu}m$ N749 bi-layered mesoporous TiO2 film. The photocurrent density was 25% and 8% higher than that of the DSSC using only N719 and N749 dye as a sensitizer, respectively. The power conversion efficiency of 9.8% was achieved from the MDSSC under the AM 1.5G one sun illumination.

• Proceedings of the Membrane Society of Korea Conference
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• 1998.04a
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• pp.97-98
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• 1998

1. Introduction : Polypropylene(PP) membrane is widely used in the field of microfiltration and ultrafiltration. However, the hydrophobicity of PP causes the adsorption of hydrophobic and amphoteric solutes in the feed. Surface modification techniques of membrane through the treatment of hydrophilizing agents, coating of hydrophilic compounds, UV, plasma and high energy irradiation, etc. can have a great effect on propensities to prevent the protein from staining membranes. Among them, the modification to hydophilize membrane surface using UV is very simple and effective. Recently many studies for more effective surface modification have been conducted. Iwata et al. prepared membranes by grafting polyethylene glycol diacrylate macromer(PEGDA) onto polysulfone with plasma using a glow discharge reactor which prevent the oil from staining the membrane. The primary mechanism contributing to the membranes is preventing the oil from directly contacting the surface of the membrane as the PEGDA chains dissolved into emulsion. To evaluate their feasibility for use as a anti-fouling separation membrane, we prepared hydrophilic membranes by UV irradiation method and investigated their characteristics.

• Journal of the Korean Applied Science and Technology
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• v.38 no.1
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• pp.178-185
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• 2021

In this study, polyvinyl alcohol (PVA) and polypropylene glycol (PPG)-based polyurethane dispersion resin for wound coating was synthesized. And the physical properties of the sample were coated on the surface of the film sample and the leather (Full-Grain) to study the physical properties change. In the case of tensile strength, PUD-PA1, which reacted with the least amount of PVA, showed the highest resistance at 2.00 kgf/㎟. Likewise, the rate of elongation was measured as high as 554% for PUD-PA1, which reacted with the least amount of PVA. The abrasion resistance measurement result showed that as the PVA response increased, the strength of the surface decreased to 36.77 mg.loss.

• Applied Chemistry for Engineering
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• v.3 no.4
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• pp.627-638
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• 1992

PPG and BPA-type polyurethane prepolymers(NCO terminated) were obtained from bisphenol A and four types of PPG, having different molecular weight and numbers of functional groups. PPG and BPA-type polyurethane dimethacrylates were synthesized by reacting PPG and BPA-type polurethane prepolymer with 2-HEMA respectively. PPG-type polyurethane dimethacrylates were formulated with initiator(CHP), inhibitor(hydroquinone) and reactive diluent(TEGDMA). The effect of formulation on the torque changes was studied. Four kinds of PPG-type polyurethane dimethacrylates, having different molecular weight and numbers of functional group, were formulated with the same amount of CHP, TEGDMA and hydroquinone. The effects of the molecular weight of PPG-type polyurethane dimethacrylate and functional group numbers of PPG-type polyurethane dimethacrylates on the torque were investigated. These results showed that the torque of PPG-type polyurethane dimethacrylates, having same numbers of functional group, increased with decreasing molecular weight of dimethacrylates and torque of PPG-type polyurethane dimethacrylate, having similar molecular weight, was increased with increasing the number of fuctional group. The glass-transition temperature(Tg) of gels obtained by thermosetting cure for the four kinds of PPG-type polyurethane dimethacrylates were measured by DSC and molecular weights between cross-links(Mc) were calculated from Tg changes.

• Applied Chemistry for Engineering
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• v.24 no.2
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• pp.196-200
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• 2013

We conducted investigation on polymeric binders for anti-static coating agent which can maintain stability under the high-voltaic condition. Various polyesters composed of polyethylene glycol (PEG) and polypropylene glycol (PPG) were synthesized and studied in term of the variation in the surface resistance of the film made from coating solution composed of a conductive polymer and these polyesters as a binder. We found that the surface resistance displayed $10^7{\sim}10^8{\Omega}/{\square}$ regardless of chemical composition of binders under the potential of 10 V. Whereas, the surface resistance surged to higher than $2{\times}10^{10}{\Omega}/{\square}$ when 1000 V was applied, rendering it improper for anti-static purpose. When 1,4 butanediol (BD) was incorporated into polyesters ([PEG]/[PPG]/[BD] = 25.0/67.5/7.5), the surface resistance showed $2.8{\times}10^9{\Omega}/{\square}$ under 1000 V, acceptable for anti-static application. These observations may indicate that the hydrophobic nature of BD makes a significant contribution to the surface resistance at a high positive potential.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.33 no.2
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• pp.93-97
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• 2007

Even in the moderately concentrated anionic surfactant system, some special encapsulation method can shield the papain enzyme from proteolytic attacks. The stabilization of enzyme has been a major issue for successful therapies. In this study, we first stabilized an enzyme, papain in the microcapsules by using polyols, polyethyleneglycol (PEG), poly-propyleneglycol (PPG), and PEG-PPG-PEG block copolymer. In the analysis of EDS and CLSM, it was demonstrated that polyols are effectively located in the interface of papain and polymer. Polyols located in the interface had an ability to buffer the external triggers by hydrophobic partitioning, preventing consequently the catalytic activity of papain in the micro-capsules. Second. we introduced multi-layer capsulation methods containing ion complex. Such a moderately concentrated anionic surfactant system as wash-off cleansers, surfactants and waters can cause instability of entrapped enzymes. Surfactants and water in our final products swell the surface of enzyme capsules and penetrate into the core so easily that we can not achieve the effect of enzyme, papain. In this case, the ion complex multi-layer capsule composed of sodium lauroyl sarcosinate and polyquaternium-6 could effectively prevent water from penetration into the core enzyme, followed by in vivo test, and evaluate the stratum corneum (SC) turn-over speed.

• Polymer(Korea)
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• v.34 no.2
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• pp.104-107
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• 2010

Polyurethane (PU) sheets were fabricated by the reaction of polypropylene glycol (PPG) and liquid diphenyl methane diisocyanate (L-MDI) with various trimethylol propane (TMP) contents. The $T_g$ value was varied from 34.8 $^{\circ}C$ to 49.9 $^{\circ}C$ according to the TMP content. As the content of TMP was increased from 4 to 12 wt%, the modulus of the PU sheet was increased from 322 MPa to 423 MPa, its tensile strength was increased from 10.6 MPa to 14.8 MPa, and its elongation was decreased from 62.8% to 49%. In case of acoustic properties, the sound speed of PU sheet was increased while its attenuation coefficient was decreased as the content of TMP was increased. The fabricated PU sheet was stable in water bath for 4 weeks.

• Journal of the Korean Applied Science and Technology
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• v.35 no.2
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• pp.463-471
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• 2018

In this study, analyzed of changes resulting from the spread of carbon black in casein grafted water dispersed polyurethane using PPG. For this purpose, casein-grafted water-dispersed polyurethane and (PUD and CPUD's) samples were prepared and samples of CPCB's dispersed with carbon black were prepared. As a result of measuring the tensile strength using prepared samples, the tensile strength was increased to $3.01kgf/mm^2$ with CPUD3, which contains highly casein, in CPCB's tensile strength was measured as low as $2.54kgf/mm^2$ with increasing carbon black. Elongation was measured in 278% of PUD samples containing less casein, and CP3CB4 in CPCB's was measured as 157%. The abrasion resistance of the samples was 36.97 mg.loss for CPUD3 and 41.11 mg.loss for CP3CB4. The solvent resistance of the PUD 's sample and the CPCB' s sample were not changed.