| 초록 |
Aqueous polyurethane dispersions (PUDs) can be a binary colloidal system in which hydrophobic PU chains are dispersed in a continuous aqueous medium by incorporating ionic groups into hydrophobic PU. However, they are subject to such disadvantages as long time drying and loss of thickness. We controlled the position of ionic groups to increase the solid contents. When ionic groups are located at the chain end instead of the center, they easily migrate toward the water phase during phase inversion because the chain ends have lower free energy than the main chain segments. It is expected to attain the high solid content due to the stability of the dispersions. We evaluated the effects in terms of particle size and the viscosity of the dispersion, contact angle, thermal, mechanical, and dynamic mechanical properties of the dispersion cast films. Results showed that the drying time and the thickness loss of cast films decreased as a result of increasing the solid contents. |
