端异氰酸酯基聚醚接枝环氧树脂的性能研究

Studying on Epoxy Resin Grafted with Isocyanate-terminated Polyethers

合成了端异氰酸酯基聚醚(ITPs)改性双酚A型环氧树脂,通过红外光谱(IR)、动态热机械分析(DMA)研究了ITPs和EP之间的化学反应及改性环氧树脂酸酐固化体系的热性能,并测试了固化体系的力学性能。结果表明:ITPs作为枝链接枝到环氧树脂上。随着加入ITPs质量分率增加,其固化体系的冲击强度和弯曲强度上升,当ITPs含量为10%时,两者达到最大值。动态热机械分析(DMA)结果表明改性环氧树脂固化体系的玻璃化转变温度(Tg)随ITPs的含量增大而降低。当ITPs质量分率大于15%时,过量的ITPs与改性环氧树脂会形成相分离。

The bisphenol A epoxy resin modified with isocyanate-terminated polyethers （ITPs） was synthesized in this paper, The progress of the reaction and the structural changes during modification process were studied by using IR spectroscopy. The thermal properties of the cured epoxy were studied by using DMA and the mechanical properties were also studied. The resuits showed that ITPs could be connected with epoxy as grafted polymer, The impact strength and the flexural strength of the cured modified-epoxy increased with the increasing the ITPs weight fraction, And they showed the maximum values at the ITPs content of 10%, The DMA indicated that the glass transfer temperature（Tg） of the cured modified-epoxy decreased with the increase in the ITPs content and overmuch ITPs separated from the modified epoxy resin and formed another phase at the ITPs weight content acessive 15 %.