聚醚酰亚胺均相成核发泡行为研究

以超临界CO₂为发泡剂，采用间歇式发泡技术制备了聚醚酰亚胺（PEI）微孔泡沫。通过改变发泡温度、发泡压力与样品浸泡时间等工艺条件，研究了PEI的均相成核发泡行为。实验还通过二次降压法制备了具有复合泡孔结构的PEI微孔泡沫材料。结果表明，复合泡孔结构提高了PEI微孔泡沫的发泡倍率，第一次压力降ΔP₁与第二次保压时间Δt₂是影响复合泡孔结构参数的重要影响因素。

Study on Polyetherimide Foaming Behavior under Homogeneous Nucleation

Polyetherimide （PEI） foams were prepared by a batch foaming method using supercritical CO₂ as a foaming agent. The effects of foaming temperature， foaming pressure， and foaming time on the foaming behavior of PEI were explored under the homogeneous nucleation condition. The PEI microcellular foam materials with a composite foaming structure were preparing by a two?step depressurization batch foaming technology. The results indicated that the foaming rate of PEI microcellular foams was improved by the composite foaming structure. The first pressure drop and the second holding time were consi?dered as two key factors that influenced the cell structure.