| 초록 |
Diisocyanates can be classified into aromatic and aliphatic by the structure of hydrocarbon between isocyanate functional groups. The aromatic diisocyanates are more reactive with polyol than aliphatic diisocyanates because electrons on benzene rings stabilize the unstable state during the reaction the resonance structure. Therefore, through the mixing of aromatic and aliphatic diisocyanates, the reaction rate of the polyurethane foam can be controlled, and the morphology of the foam can be effected. Moreover, the different of hardness caused by delocalized pi electron can affect physical properties. To analyze the morphology effect, SEM was used and the sizes of pores and cavities and the pore-to-pore distance were measured. Also, FTIR were used to analyze another morphology effect, which appears on polyurethane foam surface. |
