聚醚复配对全水发泡聚氨酯泡沫形态和物理力学性能的影响

为探究聚醚多元醇配比聚氨酯泡沫形态以及物理力学性能的影响,采用SEM并结合常规物理力学性能测试,对不同聚醚配比下制备的全水发泡聚氨酯泡沫进行了表征,结果表明:随着聚醚Ⅰ用量从70增加到85 phr,发泡聚氨酯物料的凝胶时间和不粘手时间逐渐变短,泡沫平均孔径由348.21μm减小到323.79μm,Gibss三角区域的尺寸由23.16μm增大到29.8μm;泡沫的压缩强度由279.5 kPa增加到474.4 kPa,高低温尺寸变化率也逐渐降低。聚醚多元醇作为全水发泡聚氨酯泡沫的主要原料,参与大分子链的形成并影响发泡体系的活性,其不同官能度的聚醚用量不仅影响泡沫的形成过程,同时也会影响聚氨酯泡沫的基体结构,进而影响泡沫形态和物理力学性能。利用通用硬泡聚醚与低粘度聚醚复配的方法可以制备性能良好的全水发泡聚氨酯泡沫。

Effects of polyether combination ratio on morphologies and physic-mechanical properties of water-blown PU foams

In order to investigate the effects of polyether combination ratios on morphologies and physic-mechanical properties of water-blown PU foams,the properties of water-blown PU foams with various polyether combination ratios were characterized by SEM and physi-mechnical evaluations.The results indicated that with the level of polyetherⅠ increased from 70 to 85 phr,the foaming time became short and the average diameter of bubbles reduced from 348.21 μm to 323.79 μm,the size of Gibss triangle area increased from 23.16 μm to 29.8 μm and the compression strength increased from 279.5 to 474.4 kPa,while the volumetric changes gradually reduced.These results proved polyether combination ratio had various effects on the foaming process and chemical compositions of water-blown PU foams,and,therefore affected the morphologies and physi-mechanical properties because polyether can not only involve with the chain-extension of polyurea-urethane but also influence the activity of raw materials.The water-blown PU foams with good performances can be prepared by blending polyether which used for general rigid foam and low viscosity polyether.