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