以聚丙二醇（PPG）与甲苯二异氰酸酯（TDI）制备3种—NCO基团质量分数分别为2.6%、3.6%、5.6%的预聚体，采用丙三醇为扩链交联剂制备3种聚氨酯弹性体。探究—NCO基团含量的变化对聚氨酯弹性体的力学性能、热性能等的影响。结果表明：随着—NCO基团含量的增加，聚氨酯弹性体的玻璃化转变温度上升，拉伸强度提高1.76 MPa，储能模量升高，邵A硬度提高20，内耗和断裂伸长率逐渐降低。其中，—NCO基团质量分数为5.6%的预聚体制得的聚氨酯弹性体具有最优的热性能和力学性能。

Three prepolymers with different —NCO group mass fractions of 2.6%, 3.6%, and 5.6% were prepared using polypropylene glycol (PPG) and toluene diisocyanate (TDI). Polyurethane elastomers were then synthesized using glycerol as chain extender. The effects of the —NCO group content on the mechanical properties and thermal properties of the polyurethane elastomers were investigated. The results showed that as the —NCO group content increased, the glass transition temperature of the polyurethane elastomers rose, the tensile strength increased by 1.76 MPa, the storage modulus increased, the Shore A hardness improved by 20 units, while the internal damping and elongation at break gradually decreased. Among them, the polyurethane elastomer prepared from the prepolymer with a —NCO group mass fraction of 5.6% exhibited the best thermal and mechanical properties.