• Elastomers and Composites
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• v.37 no.1
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• pp.39-48
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• 2002

Linear and crosslinked polyurethane dispersions were synthesized with 2,4-toluene diisocyanate, dimethylol propionic acid, polyoxypropylene glycol and polyoxypropylene glycerin. The structures of these polyurethanes were characterized by $^1H-NMR$ and FT-IR and the properties were measured with DSC, TGA, Instron and AFM etc. In case of linear polyurethane dispersion, the particle size, viscosity and glass transition temperature of polyurethanes increased with higher molecular weight of polyol and the degree of crosslinking. The crosslinked polyurethanes which contains more than 15% of polyoxypropyleneglycerin didn't from dispersion, when mixtures by polyoxypropyleneglycol and polyoxypropyleneglycerin were used as polyols. Thus, we synthesized crosslinked polyurethanes with 5%, 8%, 13% and 15% weight percents of polyoxypropylene glycerin as polyol mixtures.

• 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.

• Elastomers and Composites
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• v.41 no.2
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• pp.108-115
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• 2006

A series of thermotropic polyurethanes containing biphenyl units was synthesized by polyaddition reaction of diisocyanates such as 2,6-tolylene diisocyanate, 2,5-tolylene diisocyanate, 2,4-tolylene diisocyanate, 1,4-phenylene diisocyanate, and hexamethylene diisocyanate with 4,4'-Bis(9-hydroxynonoxy)biphenyl (BP9). 4,4'-bis(9-hydroxynonoxy)biphenyl exhibited a smectic type mesophase. Mesophase was found for all synthesized liquid crystalline polyurethanes except 1,4-PDI/BP9 based polyurethane. Structures of the monomer and the corresponding polymers were identified using FT-IR and $^1H-NMR$ spectroscopies. Their phase transition temperatures and thermal stability were also investigated by differential scanning calorimetry and optical polarizing microscopy.

• Proceedings of the Korean Fiber Society Conference
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• 1999.10a
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• pp.509-512
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• 1999

• Proceedings of the Korean Society of Rheology Conference
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• 2003.05a
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• pp.61-64
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• 2003

• Proceedings of the Korean Fiber Society Conference
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• 1997.04a
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• pp.11-15
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• 1997

• Proceedings of the Korean Fiber Society Conference
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• 1991.06a
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• pp.37-37
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• 1991

• Proceedings of the Korean Fiber Society Conference
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• 1991.06b
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• pp.13-14
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• 1991

• Elastomers and Composites
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• v.52 no.4
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• pp.249-256
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• 2017

The history of polyurethane is relatively shorter compared to that of the other polymers, though its importance has grown rapidly. Due to its unique properties, polyurethanes are widely applied in various fields. In particular, the automotive industry is one of the important application fields. To date, polyols and isocyanates used in the polyurethane industry are generally of petrochemical origin. Recently, owing to the oil crisis, legislation, and growing awareness towards environmental preservation, the demand for more sustainable and eco-friendly raw materials has increased. In this paper, the latest research and development trends in polyurethane applications were reviewed, with a focus on the automobile industry in areas such as seat comfort, noise reduction, light weight, biomass-based polyurethane, and recycling.

• Macromolecular Research
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• v.8 no.3
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• pp.137-141
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• 2000

3,4-Di-(2'-hydroxyethoxy)-4-nitrostilbene (2) was prepared by the reaction of 2-iodoethanol with 3,4-dihydroxy-4-nitrostilbene (1). Diol 2 was condensed with 2,4-toluenediisocyanate ,3,3-dimethoxy-4,4'-biphenylenediisocyanate , and 1,6-hexamethylenediisocyanate to yield polyurethanes 3, 4, and 5 containing the NLO-chromophore. Polymers 3-5 were soluble in common organic solvents such as acetone and DMSO. The glass transition temperatures(T$\sub$g/) of the resulting polymers 3-5 were obseved around 100-114$^{\circ}C$. Electrooptic coefficients (r$\sub$33/) of the poled polymer films were in the range of 18-25 pm/V at 633 nm. Polymers 3-5 began to decompose around 250$^{\circ}C$ in TGA thermograms.