水辅助超临界二氧化碳制备TPU发泡颗粒

Preparation of TPU Foamed Particles with Water-Assisted Supercritical Carbon Dioxide

利用水和超临界二氧化碳作为共发泡剂,采用快速泄压法制备热塑性聚氨酯弹性体(TPU)发泡颗粒,分别考察了加水量、饱和温度和饱和时间对TPU发泡颗粒性能的影响。结果表明,当饱和温度为180℃、饱和时间为30 min时,随着加水量的增加,TPU发泡颗粒的边缘厚度明显降低,当加水量为4 mL时,发泡颗粒的边缘厚度比不添加水时下降了63.0%,同时发泡倍率提高了89.8%。当加水量为2 mL、饱和时间为30 min时,饱和温度的升高使得发泡倍率随之升高,饱和温度为190℃时的发泡倍率比饱和温度为150℃时提高了94.8%。当加水量为2 mL、饱和温度为180℃时,饱和时间超过1 h后,随着饱和时间的延长,发泡倍率和泡孔密度减小,边缘厚度和泡孔平均直径增大,并出现通孔结构。

Using water and supercritical carbon dioxide as co-blowing agents,the rapid pressure relief method was used to prepare thermoplastic polyurethane elastomer(TPU)foamed particles.The effects of water addition,saturation temperature and saturation time on the foaming properties of TPU were investigated.The results show that when the saturation temperature is 180℃and the saturation time is 30 min,the edge thickness of TPU foamed particles decreases significantly with the increase of water addition.When 4 mL of water is added,the edge thickness of the TPU foamed particles decreases by 63.0%,and the expansion ratio increases by 89.8%.When the amount of water added is 2 mL and the saturation time is 30 min,the increase in the saturation temperature increases the expansion ratio.When the saturation temperature is 190℃,the expansion ratio is 94.8%higher than when the saturation temperature is 150℃.When the amount of water added is 2 mL and the saturation temperature is 180℃,after the saturation time exceeds 1 h,as the saturation time increases,the expansion ratio and cell density decrease,the edge thickness and average cell diameter increase,and the through-hole structures appear.