| 초록 |
Polyurethane foams (PUFS) have low thermal conductivity due to the presence of a skeleton made of more or less open or closed regular cells. It is well known that the thermal conductivity of PUF depends on the foam density, cell size, cell orientation, ratio of close to open cell content and also on the thermal conductivity of the gases (blowing agent). In our study, PUFs structures such as cell density, cell size and cell shape are well controlled using expandable microspheres. In order to find a proper PU matrix, several polyols such as PEG (Mn=200), PEG (Mn=400), PCL (Mn=300), PCL (Mn=530) and PCL (Mn=900) are used as prepolymers. The thermal conductivity behaviors of resulting PUFs are discussed with scientific principles and mechanism. |
