Abstract: A bi-soft-segment PUF was prepared from a mixture of polyether N303 and H303,and the latter was prepared from glycerol. The effect of the weight ratio of N303/H303 and SiO2 filler on the properties of PUF was investigated. The mechanical stability at higher temperature was tested. It was found that the compress modulus and impact strength of the bi-soft-segment PUF were higher than those of either single-soft-segment PUF. The compress modulus and impact strength increased first and then decreased as a function of H303 weight ratio and reached a maximum when the ratio of N303/H303 was 50∶50. Pre-mixed SiO2 played a role to improve the cell uniformity and stabilize mechanical properties at higher temperature.

Key words: polyurethane, mixed soft segment, heat-resistance, mechanical properties