抄録
Characteristics of polyurethane foam such as sound absorption depend on its inner porous (cell) structure. Double layered porous absorbing material from combination of different cell structure has wide band performance of sound absorption. In our study, new foaming technology for polyurethane foam was reported. It is named “Magnetic Induction Foaming (MIF)”. MIF is the method of cell control through magnetic induction. The polyurethane polymer is generated by the polyaddition reaction of polyol and polyisocyanate, and carbon dioxide gas is formed by the foam reaction of polyisocyanate and water (premixed into the polyol starting material). In this paper, we focused on catalyst effect on the inner porous structure of polyurethane foam and used water-based magnetic fluid to MIF in the purpose of making double layered functional gradient materials. Under a non-uniform field, the magnetic fluid (catalyser effect) tends to drift to one side of the structure where the field is strongest. It is found that the polyurethane foam sample made by using this method have the continuously-distributed cell structure, experimentally.
