| 초록 |
Waterborne polyurethane dispersions (PUDs) were prepared using polycarbonate-diols, dimethylol propionic acid, and three different aliphatic diisocyanate: isophorone diisocyanate, 4,4'-methylenedicyclohexyl diisocyanate, and hexamethylene diisocyanate. To enhance thermal stability of the PUDs, organo-nanoclay were introduced into the reactants before synthesizing the prepolymers for the PUDs, followed by ordinary PUD processes, such as neutralization, chain extension water dispersion, and solvent distillation. The effect of aliphatic diisocyanate types and organo-nanoclay on the thermal stability of the PUDs were investigated. The extent of the reaction and the amount of produced urea and urethane groups of the polyurethanes were semi-quantitatively identified using FT-IR and wet-chemistry method. The degree of the organo-clay dispersion in the polyurethane composites was studied with X-ray scattering. The thermal properties of the PUD films were characterized using DSC and TG-DTA. |
