• Journal of the Korean Applied Science and Technology
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• v.28 no.3
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• pp.359-366
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• 2011

In this study we experimented that how polyurethane effect to acrylic-polyurethane resin in Full-Grain leather coatings. First of all, we consummated waterborne acrylic emulsion and waterborne polyurethane resin, Than we prepared F.G leathers which were coated by acrylic resin and acrylic-polyurethane resins. According to measured data for solvent resistance, acrylic resin and acrylic-polyurethane resins had good property. Sample a(WAC) had most low strength($2.10kg_f/mm^2$) and sample d(WAC 93 : WPU 7) had most high strength($3.41kg_f/mm^2$). Also we knew that most good property of abrasion is d(47.4 mg). In elongation case, a(WAC) had most good result(645 %) in this experiment.

• Polymer(Korea)
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• v.25 no.3
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• pp.391-398
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• 2001

Two-component polyurethane (PU) flame-retardant coatings were prepared by blending tribromo modified polyesters ($TBAO_s$) and isocyanate.$TBAO_s$ were synthesized by condensation polymerization of tribromoacetic acid, a flame-retardant component, with 1,4-butanediol, adipic acid, and trimethylolpropane. The content of tribromoacetic acid was varied by 10, 20, and 30 wt% for the reaction. Various physical properties of these new flame-retardant coatings were comparable to nonflame-retardant coatings. Coatings with 20 wt% tribromoacetic acid did not burn during the vertical burning test.

• Corrosion Science and Technology
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• v.5 no.1
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• pp.33-38
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• 2006

Current coating practice requires the thickness of anti-corrosion organic coatings to be over $250{\mu}m$ for immersion parts of ships and offshore structures and the corrosion resistance of these coatings has been evaluated by destructive and qualitative analysis. Recently, Electrochemical Impedance Spectroscopy(EIS) method has been employed, as an alternative, to evaluate corrosion resistance of organic coatings. This method is characterized as being nondestructive, reproducible, and quantitative in evaluating aging of organic coatings. In this study, EIS method was adopted to quantitatively and effectively select the coating systems having optimized protective performance. Evaluations of several epoxy and epoxy/polyurethane coating systems typically used for ships and offshore structures were carried out in wet($50^{\circ}C$, $90^{\circ}C$) and dry(room temp.) environments to accelerate the degradation of the organic coatings. These results were compared with the conventional scribed(scratched) test results. The plausible prediction model for determining the remaining life-time of coating systems was also proposed based on variations of impedance data, FT-IR and $T_g$ measurements results.

• Journal of the Korean Applied Science and Technology
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• v.36 no.4
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• pp.1358-1364
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• 2019

The mechanical properties of Heavy duty resin of synthetic polyurethane-epoxy resin for stainless steel were measured by SEM, FT-IR, tensile properties, and specific mass loss by EIS analysis, etc. As interest in eco-friendly medium coatings increased, the Heavy duty coatings were synthesized for various metals such as stainless steel composed of Polyol, MDI, water bored Epoxy resin, filling agent, silicon surfactant, catalyst etc. The coatings of synthetic Heavy duty resin were increased tensile strength due to various temperature change, and the low-Specific Mass Loss was measured in a highly electrolytic solution. In conclusion, the Heavy Duty coatings composed of polyurethane and waterbored Epoxy resin were synthetic microstructure with cross linkage can be good material for coating of anticorrosion of metal substrates such as stainless steel.

• Polymer(Korea)
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• v.26 no.2
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• pp.200-208
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• 2002

Two-component polyurethane flame-retardant coatings were prepared by blending trichloro lactone modified polyesters (TAPTS) and isocyanate, Desmodur IL. Polycondensation reaction of trichlorobenzoic acid (TBA) as a flame-retardant component, and adipic acid with trimethylolpropane, polycaprolactone 0201, and 1,4-butanediol gave the corresponding TAPTs. The content of TBA was adjusted from 10 to 30 wt% in our experiment. It was found that various properties of these new flame-retardant coatings were comparable to other non-flame-retardant coatings. We also carried out three different tests for the measurement of flammability of flame -retardant coatings. The results of vertical burning test for the coatings containing more than 20 wt% of TBA were determined as 'no burn'. The results of flammability test for the coatings with 20 and 30 wt% of TBA contents indicated the limiting oxygen index (LOI) values of 25% and 27% respectively, which implied relatively good flame retardancy. They also showed the char length of 3.6-5.2 cm according to $45^{\circ}$ Meckel burner test, which can be classified as the first grade flame-retardant coatings.

• Journal of the Korean Applied Science and Technology
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• v.28 no.2
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• pp.203-212
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• 2011

In this study we experimented that how chain extension influences to waterborne urethane-acrylic hybrid resin for leather garment coatings. We knew that polyurethane-acrylic hybrid resins had 5 grades of solvent resistance. Tensile strength measured in the polyurethane-acrylic resin(EDA 5.37 g, 1.928 kgf/$mm^2$) had the most strong strength. Also polyurethane-acylic hybrid resin(EDA 5.37 g. 30.2 mg. loss) had better result than other hybrid resins. EDA contents higher, we obtained low elongation and low flexibility. In this result, chain extension of waterborne polyurethane-acrylic hybrid resin showed the effect in leather coating with ratio of EDA.

• Journal of the Korean Applied Science and Technology
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• v.15 no.3
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• pp.77-84
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• 1998

Two-component polyurethane flame retardant coatings were prepared by blending phosphate-containing modified polyesters(PMPEs) and TDI-adduct. PMPEs were synthesized by polycondensation of dimethyl phenylphosphonate, a flame retardant component, with 1,4-butanediol, adipic acid, and trimethylolpropane. The content of dimethyl phenylphosphonate was varied 10, 15, and 20wt% for the reaction. Various physical properties of these new flame retardant coatings were comparable to non-flame retardant coatings. Coatings with 20wt% dimethyl phenylphosphonate did not burn during the vertical burning test.

• Corrosion Science and Technology
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• v.17 no.6
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• pp.257-264
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• 2018

Anti-graffiti coatings have become more important. These layers must guarantee excellent corrosion protection properties, and graffiti must be easily removable, without reducing protection and aesthetic properties. In this study, anti-graffiti and corrosion behavior of two anti-graffiti polyurethane powder coatings were studied. These layers were deposited on aluminum substrate, with two different surface finishes, smooth, and wrinkled. The action of four different removers are investigated. Graffiti were drawn on coatings by means of red acrylic spray paint. Methyl-ethyl-ketone (MEK) and a "commercial" remover were the most effective solvents, in terms of graffiti removal capability, producing limited change in aesthetical surface aspect for smooth finishing. The wrinkled surface was less resistant. Corrosion protection properties, after removal action and contact with the remover, were evaluate by electrochemical impedance spectroscopy. After approximately 5 hours, coatings were no longer protective due to formation of defects. To simulate the weathering effect, UV-B cyclic test (4 hours of UV exposure followed by 4 hours of saturated humidity at $50^{\circ}C$) were performed for 2000 hours. Gloss and color changes were measured, and electrochemical impedance spectroscopy measurements were performed after aging and graffiti removal.

• Journal of the Korean Applied Science and Technology
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• v.27 no.2
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• pp.188-195
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• 2010

In this study, we experimented that how to synthesis waterborne urethane-acrylic hybrid resin for leather coatings. First of all, We had analyzed data by FT-IR, SEM and TGA for the machanical properties. By TGA analysis polymers showed heat distortion temperature. and by FT-IR measurement we confirmed that synthesis of urethane and acrylic. In the experiment, solvent resistance, polyurethane and acrylic grades 4-5 showed both a high. Tensile strength measured in the waterborne polyurethane > Acrylic emulsion showed strength in the order. Films were obtained by coating the water born resin on leveled surfaces and allowing them to dry at room temperature for 72hrs. After demolding, the films were kept in a desiccator to avoid moisture contant at $25^{\circ}C$ for 45hrs before the measurements. In this result, the mechanical propersies of waterborne polyurethane-acrylic hybrid resin showed that how effect to resin in leather coating between polyurethane content and acrylic content. Therefore, acrylic emulsion had most high solvent resistance glade and waterborne polyurethane had good result in abrasion test and tensile strength.

• Journal of the Korean Applied Science and Technology
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• v.38 no.6
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• pp.1533-1542
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• 2021

Eco-friendly polyurethane can be defined as a highly utilized material used in various fields. The various structural properties of the synthesis of isocyanates and polyols provide versatility and customization for use in the manufacturing field. The characteristics of polyurethane vary widely from soft touch coatings to hard building materials like rocks. These mechanical, chemical and biological properties and ease of alignment are drawing tremendous attention not only in the field of research but also in related industries. In order to improve the performance of water-dispersible polyurethane materials, it can be derived through processes such as adjusting the blending of raw materials and adding additives and nanomaterials. This study highlights the basic chemical structure of eco-friendly water-dispersible polyurethane in the fields of medical science, automobiles, coatings, adhesives, paints, textiles, marine industries, wood composite materials, and clothing.