Evaluation of Mechanical Properties of Rigid Polyurethane Foams concerning on Distribution of Cell Direction

摘要

Polyurethane foam is formed by various molds. The internal structure of rigid polyurethane foam is very complex. Moreover, the cell shape shows elongated shape in foaming direction, so that rigid polyurethane foams exhibit anisotropy in mechanical properties. Therefore, this study investigates the relationships between cell morphology (cell shape, angle of major axis of cell, and cell area), density, and the mechanical properties of polyurethane foams. . Two mold sizes using cylindrical molds are used to study. The cell shape was evaluated by the ratio of the longitudinal diameter to the transverse diameter. The relationship among density, cell shape and compressive properties of two kinds of rigid polyurethane foams were investigated. It was found that compressive properties depended on cell shape in compared with density.