| 초록 |
Waterborne polyurethanes(WPUs) are versatile materials which can be easily prepared by a number of methods such as prepolymer mixing process. Despite the possibility of tailoring their properties according to the specific requirement, WPUs have a limit in their thermal stability. Aromatic polyimides are well-known thermally stable polymers with good mechanical properties, though their processability is generally poor. We designed the hard segment WPU with pyromellitic dianhydride(PMDA) in addition to diol and isophorone diisocyanate(IPDI) to improve heat resistance. In addition, the transparency and optical properties of WPU films are improved by introduction of silica. Mechanical, thermomechanical properties of the cast film were measured to evaluate the performance of the WPU films. |
