| 초록 |
Rigid Polyurethane foam was synthesized from the polyol, polymeric 4,4’diphenylmethane diisocyanate (PMDI), and blowing agents. Thermal conductivity and cell size of the rigid polyurethane foam was investigated with the blowing agents such as water, cyclopentane, HFC-365mfc, and HCFC-141b. In addition, polyurethane foam/clay nanocomposites were synthesized with the clay modified by polymeric 4,4'-diphenylmethane diisocyanate (PMDI) with and without the application of ultrasound. Thermal conductivity of the PUF/clay using HCFC-141b showed the lowest value among the blowing agents used. Also, thermal conductivity of the PUF/clay nanocomposites applying the ultrasound showed the lowest value for all the samples. Cell size of the PUF/clay nanocomposites was decreased when the ultrasound was applied to the mixture of the MDI/clay solution. This decrease of the cell size of the PUF/clay nanocomposites was observed for all the samples. |
