交联对聚氨酯脲弹性体的结构与性能影响

The Effect of the Crosslink on the Structure and Properties for PUU Elastomer

化学交联键的存在使得极性基团间的氢键化作用减弱，氢键化的NH吸收位置（3280cm^-1）向高波数（3290cm^-1）方向移动，羰基区内完全有序的氨酯羰基（1693cm。）吸收谱带观察不到，脲羰基吸收谱带（1643cm^-1）变得较弱。交联点越多，回弹性越小，压缩生热越大。交联PUU弹性体的硬度在同温度下高于线性PUU的硬度。随着温度的升高，交联PUU的回弹性增加速度高于线性PUU的增加速度，交联PUU的硬度减少速度高于线性PUU的减少速度。

Because of the presence of crosslink, the band site for hydrogen bonded NH group shifted to the high wavenumbers from 3280cm^-1 to 3290cm^-1 , the absorbance of the band for the ordered urea carbonyl at 1643cm^-1 became weaker than that of linear PUU, and the absorbance for the ordered urethane carbonyl wasn＇t observed in the spectrum for the crosslinked PUU. The higher of the crosslink density, the lower of the resilence of the PUU. With an increase in temperature, the enhance of the resilence for the crosslinked PUU was faster than that of the linear PUU. Both an increase in crosslink density and the hard segment content made the heat buildup strong, and the decrease of the hardness for the crosslinked PUU was faster than that of the linear PUU.