• Elastomers and Composites
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• v.49 no.1
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• pp.31-36
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• 2014

Polyester polyols were synthesized by using each one mole of sebacic acid, isophthalic acid, ethylene glycol, and neopentyl glycol. The synthesized polyol had 56.6 mg KOH/g of hydroxy value and 1980 g/mole of molecular weight. From FT-IR structure analysis of polyester polyol, Hydroxy group(-OH) was observed around 3600 $cm^{-1}$, -CH shoulder of sebacic acid at 2950 $cm^{-1}$, carbony group of ester around 1730 $cm^{-1}$, and benzene ring of isophthalic ring was represented at 1600 $cm^{-1}$, 740 $cm^{-1}$. In case of polyurethane, hydroxy peak was showed at 3600 $cm^{-1}$, and -NH group around 3300 $cm^{-1}$, 1530 $cm^{-1}$. From $^1H$ NMR measurement of polyester polyol, it was found that sebacic acid was represented at 1.3, 1.5, 2.1 ppm, isophthalic acid at 7.3, 8.1, 8.7 ppm, ethylene glycol at 4.2 ppm, and neopentyl glycol at 0.8, 3.2, 3.9 ppm, respectively. In the polyurethane, it is almost the same as spectrum of polyester polyol, but showed very week peak at 7 ppm by benzene ring of toluene diisocyanate.

• Journal of the Korean Applied Science and Technology
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• v.30 no.2
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• pp.305-311
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• 2013

PLA(polylactic acid), one of biodegradable polymers was blended with various amounts of wood pulp powder through solution blending technic to verify the effect of reinforcing pulp amount on the mechanical properties of blend films. Also these blend films were further modified with TDI(toluene diisocyanate) as crosslinking agent to introduce urethane functions by reaction of pulp hydroxyl groups and isocyanate. As a result, the tensile strength of blend film with 0.25 wt% pulp was increased from $565.25kg_f/cm^2$ for PLA film itself to $624.20kg_f/cm^2$. However, elongation of this film was decreased by 50% of that of PLA film itself. Only PLA/pulp blend film further modified with 500% of TDI/0.25 wt% pulp showed the slightly increased tensile strength but decreased elongation. Melting point and glass transition temperature of PLA/pulp blend films were confirmed by using Differential Scanning Calorimeter(DSC). Thermal stability of these blend films measured by TGA showed only a slight increase at temperature lower than $300^{\circ}C$.

• Polymer(Korea)
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• v.27 no.5
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• pp.470-476
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• 2003

In order to obtain high refractive plastic materials, 1,2 -ethylenedisulfanylbis(2-mercaptomethyl-1-ethanthiol) (ESTT) was newly prepared in good yield by the reaction of 1,2-ethylenedisulfanylbis(2-bromomethyl-1-ethanthiol) (ESTB) with thiourea followed by hydrolysis using an aqueous ammonia solution and characterized by $^1$H-NMR (-SH at 1.7 ppm), $\^$13/C-NMR(-CH$_2$SH at 28.4 ppm) and FT-IR (-SH at 2540 cm$\^$-1/) spectroscopy, etc. Polythiourethanes (PTU) were obtained from the combinations of ESTT with each of 4,4＇-methylenebis(phenylisocyanate) (MDI), tolyene 2,4-diisocyanate (TDI), isophorone diisocyanate (IPDI), mxylene diisocyanate (XDI), and 1,6-diisocyanatohexane (HMDI) in the presence of dibutyltin dilaurylate as a catalyst, in a casting mold, and characterized by FT-IR (existence of N=C=O) spectroscopy and elemental analyzer (sulfur content). Accordingly, their thermal, mechanical and optical properties were investigated by using DSC, TGA, hardness tester and refractometer: both the melting point on DSC and crystallinity on X -ray diffraction (XRD) for specimens of PTUs were not observed. PTUs with T$\_$g/s above 110 $^{\circ}C$ showed good hardness (Shore D) in the range of 86 to 89. Thermal stabilities of PTUs obtained by using ESTT and each of diisocyanates containing aromatic rings were especially good. Also, the optical transmittances of amorphous PTUs through UV-visible source in the range of 400 to 600 nm were good. PTUs showed refractive indexes above 1.60, and their refractive indexes gradually increased with increase of sulfur contents.

• Analytical Science and Technology
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• v.18 no.6
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• pp.511-519
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• 2005

A method for determination of toluene diisocyanates (TDI) in toluene diisocynate (TDI)-based polyurethane (PUR) packing material was investigated, and also the migration of TDI to food was studied. TDI was extracted using food simulants such as n-haptane and 4% aqueous acetic acid. The determinations were performed using gas chromatography/mass spectrometry (GC/MS). One of major components for polyurethane, toluene diisocyanates, were detected in ten samples among twenty six food contact materials with the concentration range of $0.51{\sim}60.88{\mu}g/ml$. However the highest extracted amount was just 0.7% of $60.88{\mu}g/ml$ if the contact surface of food packing for extracting liquid was limited to the outer layer without exposure of the cutting edge of food packing multi-layers. The result of this study and the analysis method for TDI diisocyanate will be very useful for further study about food contact material, and the monitoring result could be used for evaluating the safety of food contact material before it is to be used for food, preservation.

• Journal of the Korean Institute of Gas
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• v.2 no.4
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• pp.18-24
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• 1998

Polyurethane (PU) synthesized from 4,4'-diphenylmethane diisocyanate having high functionality (f=2.9) and polyester polyol have been investigated by differential scanning calorimeter (DSC), dynamic mechanical thermal analyzer (DMTA), and Fourier transform infrared spectroscope (FT-IR). From the DSC measurement of polyurethane, a single transition temperature ($T_g$) was observed. This result indicates that polyurethanes synthesized in this work have homogeneous network structure due to high functionality of diisocyanate. It was also found that the $T_g$ of polyurethane was increased as hard segment content was increased. The results from DMTA measurement are consistent with DSC results. In order to investigate the effect of thermal annealing on the $T_g$ of polyurethane, the samples were annealed at various annealing conditions. $T_gs$ of polyurethanes were found to increased with annealing temperature. From swelling experiment and FT-IR studies, it was found that the $T_g$ was increased as crosslinking density of polyurethane was increased.

• Textile Coloration and Finishing
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• v.5 no.3
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• pp.188-193
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• 1993

Aqueous polyurethanes(APU) were prepared from polypropylene glycol(PPG), dimethylol propionic acid(DMPA), and isophoron diisocyanate(IPDI) following a prepolymer mixing process. APUs were applied as binder for nonwoven fabrics processing. APU treated nonwoven fabrics generally showed better tear and tensile strength as compared with the untreated ones. In addition, depending on the soft segment length and crosslinking density of the PU, tear strength of APU treated fabrics was favorably compared with solvent type treated one. Similar results were obtained with microfiber nonwoven fabrics, however, the effect was less significant.

• 한국가스학회:학술대회논문집
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• 1998.09a
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• pp.183-187
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• 1998

• Proceedings of the Korean Fiber Society Conference
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• 1998.04a
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• pp.1-4
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• 1998

Segmented Polyurethanes Elastomers are a class of polymers having interesting properties which arise from their unique phase-separated structures resulting from the thermodynamic incompatibility of the ingredients[1]. Segmented polyurethane Elastomer generally consists of a segment derived from a polymeric diol and a hard segment from a diisocyanate and a low molecular weight diol(chain extender).(omitted)

• Proceedings of the Korean Fiber Society Conference
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• 1998.04a
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• pp.5-8
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• 1998

Polyurethane elastomers are segmented cocoplymer with an [HS]n-type structure. Typically, these materials are two-phase systems, prepared from relatively polar and stiff component called the hard segment(H) and relatively flexible component known as the soft segment(S). Diisocyanate and chain extender together form the hard segment, which is dispersed within a matrix of the soft segment, composed of the macrodiolos.(omitted)

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2008.10a
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• pp.9-10
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• 2008

Tricrecyl phosphate(TCP)-containing polyurea microcapsules were prepared by interfacial polymerization using aromatic 2,4-toluene diisocyanate(TDI) and Ethylene diamine(EDA) as wall forming materials. The effects of the protective colloids of polyvinylalcohol(PVA) and gelatin were investigated through experimentation.