| 초록 |
The interest about environmentally friendly materials, and about restriction of volatile organic solvent are growing in these days. The replacement of organic solvent by water is an effective way for the reduction of VOC. So waterborne polyurethanes(PUs) have been actively studied recently, although some properties are inferior to those of solvent-based PUs. In this study, to improve thermal and mechanical properties of waterborne PU, we used nanometer-scale layers of organoclay and nanometer-scale silica to get nanocomposites. The waterborne PU was synthesized from isophoronediisocyanate(IPDI), poly(tetramethyleneglycol) (PTMG), dimethylolpropionic acid(DMPA), triethylenetetramine(TETA) ,triethylamine(TEA) and 1,4-butandiol(1,4-BD). For the fabrication of nanocomposite materials, organoclay and silica were mixed with polyol or PU prepolymer under high shear at melt state. The exfoliation of organoclay in PU was ascertained by X-ray diffraction pattern. Thermal and mechanical properties were examined with dynamic mechanical thermal analyzer (DMTA), differential scanning calorimeter(DSC), tensile tester, and other methods.
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