以甲苯二异氰酸酯（TDI）、聚四氢呋喃二醇（PTMEG）、自制混合扩链剂和填充油为原料，采用预聚体法制备聚氨酯弹性体，研究自制混合扩链剂中三官能度扩链剂与二官能度扩链剂的物质的量比以及填充油的用量对聚氨酯弹性体的性能影响。结果表明：混合扩链剂的组成对聚氨酯弹性体的力学性能影响最为显著，随着三官能度扩链剂用量的增加，聚氨酯弹性体的玻璃化转变温度、储能模量和硬度逐渐升高，拉伸强度先升高后降低，内耗和断裂伸长率逐渐降低，其中，样品PU-3的综合力学性能最优；随着填充油用量的增加，聚氨酯弹性体的玻璃化转变温度、储能模量、拉伸强度和硬度逐渐降低，内耗和断裂伸长率有升高的趋势。

Polyurethane elastomers were prepared by the prepolymerization method using toluene diisocyanate (TDI), polytetrahydrofuran diol (PTMEG), self-made mixed chain extender and filling oil as raw materials. The effects of the mole ratio of trifunctional chain extender to difunctional chain extender in the self-made mixed chain extender and the amount of filling oil on the properties of polyurethane elastomers were investigated. The results show that the composition of the mixed chain extender has the most significant effect on the mechanical properties of the polyurethane elastomer. With the increase of the amount of three-functional chain extender, the glass transition temperature, energy storage modulus and hardness of the polyurethane elastomers gradually increase, the tensile strength first increases and then decreases, and the internal friction and elongation at break gradually decrease. Among them, the comprehensive mechanical properties of the sample PU-3 are the best. The glass transition temperature, energy storage modulus, tensile strength and hardness of polyurethane elastomers decrease gradually with the increase of the amount of filling oil, and the internal friction and elongation at break tend to increase.