水性聚氨酯活性及其对复合材料性能影响的探究

通过合成未封端型水性聚氨酯(WPU)并控制其保存时间发现其反应活性可控，然后将反应活性不同的WPU与淀粉密炼制备一系列水性聚氨酯-淀粉(WCS)复合材料，并对所得复合材料的基本性能进行表征，以此来探索WPU作为反应型增容剂的可行性.研究发现WPU的活性随时间的变化趋势为：未封端型WPU在不超过3 d的时间内仍保持反应活性，超过3 d就表现出失活的特性.进一步探究活性不同的WPU制备的WCS复合材料的基本性能，发现具有活性的WPU由于含有—NCO反应性基团可以与淀粉的—OH基团之间形成氨基甲酸酯键和部分氢键，从而使制得的WCS复合材料体系的界面具有很好的相容性.研究中使用WPU作为复合材料的反应型增容剂是一种新的尝试，可以克服传统制备聚氨酯需要加入有机溶剂而不环保的缺点，而且其操作过程也更为简便.此外，本工作也为具有反应活性的WPU在复合材料方面的应用奠定了一定的基础.

The activity of waterborne polyurethane and its effect on the properties of composite materials

In this paper， unblocked water-based polyurethane (WPU) was synthesized and its preservation time was controlled for its activity. Then， WPU and starch were mixed to prepare a series of water-based polyurethane-starch composite materials (WCS). Finally， the basic properties of the WCS were characterized to explore the feasibility of unblocked WPU as a reactive compatibilizer. Firstly， the variation tendency of the activity of the waterborne polyurethane over time was explored. It's found that the unblocked WPU remained reactive within 3 days but showed inactivation after 3 days. Then， by exploring the basic properties of WCS composites prepared from WPU with different activities， it is revealed that only active WPU have －NCO reactive group， indicationg that the interface of the prepared composite system has good compatibility. This is due to the formation of urethane bonds and partial hydrogen bonds between the －NCO of WPU and the －OH of starch. The use of WPU as a reactive compatibilizer for composite materials is a new attempt， and the operation process is simple. In addition， it is environmentally friendly and overcomes the shortcomings of traditional polyurethanes that require the addition of organic solvents. This work also lays a foundation for the application of reactive WPU in composite materials.