水分散聚氨酯交联剂的制备及解封过程的原位FTIR跟踪

Preparation and in-situ FTIR detection of deblocked process for waterborne polyurethane crosslinking agent

以异佛尔酮二异氰酸酯(IPDI)、N-甲基二乙醇胺(MDEA)和丁酮肟(MEKO)为原料,制备出水分散封端型聚氨酯交联剂。采用NMR法优化了亲水剂MDEA扩链反应的最佳反应时间;用"原位FTIR"跟踪了交联剂的解封过程。实验结果表明:当亲水扩链的反应时间为60 min,亲水扩链反应完全;当温度高于70℃,分子间的氢键化作用遭到严重破坏,相关特征官能团(—NH和—C O)的谱带位置移向高波数;当温度达到120℃时,交联剂的活性基团NCO开始解封出来,参与交联反应。

A waterborne polyurethane crosslinking agent was synthesized with isophorone diisocyanate（IPDI） as initial materials,N-methyl diethanolamine（MDEA） as the hydrophilic chain-extender and methyl-ethyl ketoxime as blocking agents.The proper extension reaction time of MDEA hydrophilic chain extension was discussed by NMR,and the deblock process of waterborne polyurethane crosslinking agent was detected by in-situ FTIR.The results showed that the proper extension reaction time of 60 mins was determined by NMR.When the temperature was over 70℃,the bands sites,such as NH and —CO groups associated with hydrogen bond interaction,shifted to the higher wavenumbers,and the NCO groups were de-blocked and to participate in crosslinking reaction at or above 120℃.