| 초록 |
Polyurethane dispersions (PUDs) based on polycarbonate-diol were synthesized using 4,4′-methylenebis(cyclohexyl isocyanate), dimethylol propionic acid, and three polycarbonate-diols whose molar mass were 495, 1085, and 2028, respectively. The molecular structure and size of the PUDs were mainly modulated with the (isocyanate equivalents/hydroxy equivalents) and the molar mass of the polycarbonate-diols. In addition, the chemical structures were finely tuned with chain extenders (1,4-butanediol and ethylene diamine). By varying the type of raw materials and their compositions, we prepared the various PUDs and then determined the molecular sizes and chemical compositions using wet chemistry, FT-IR technique, and DLS size measurement. The amount and kind of hard- and soft-segment, the extent of crystallization, and the thermal properties of the PUDs were identified using XRD, IR, DSC, and TGA. We interpreted the relation between the molecular structure and the thermal properties |
