环氧树脂和大分子量聚醚胺之间的反应,需要催化剂吗?聚醚胺D4000为近末端含胺基的长链二胺,按照2015的一篇Macromolecules (2015, 48, 7495?7502)的文章,与 环氧树脂 在80度反应,他们是用的 近红外光谱 检测固化过程,发现在20个小时固化度为70%,但是我们一样的条件,直接将环氧树脂和聚醚胺D4000共混反应,但是在80度反应24个小时,还是颜色不怎么变,用中远红外检测,发现环氧树脂基团变化不大,请高手赐教,是否需要加 催化剂 ,加什么催化剂,加多少呢?文献原话:PRS was produced by adding/mixing stoichiometric blends of PPODA(Jeffamine D-4000) and DGEBA at 80 °C. The chemical conversion of thesemixtures was monitored using a Nexus 870 FTIR spectrometer (Thermo Nicolet Corp.) in the near-IR region. Figure 2a shows representative FTIR spectra taken over a period of time for this reaction. The peak at 4530 cm?1 corresponds to the stretching and bending of oxirane bands, and the peak at 4930 cm?1 corresponds to the NH2 combination bands.19,20 The decrease of epoxy and amine concentrations signifies the presence of epoxy?amine reactions. Figure 2b shows the fractional conversion of epoxy with respect to time obtained using the epoxy peak area. Additionally, the approximate gel point was measured using a steady shear viscosity measurement during curing reactions using a TA rheometer apparatus AR2000. Gelation is known to happen at the point where steady shear viscosity rises rapidlyto infinity.21 A combined viscosity?conversion measurement on DGEBA?PPODA systems at 80 °C showed that the approximate gel point for these systems is taking place at around 84% oxirane conversion.查看更多3个回答 . 13人已关注