聚醚砜超临界CO2发泡行为研究

以超临界CO₂为发泡剂，采用间歇发泡法制备了聚醚砜（PES）泡沫。采用旋转流变仪和扫描电子显微镜分析表征了PES发泡的均相成核行为，继而分别以滑石粉和二氧化硅（SiO₂）作为异相成核剂，探究了PES发泡过程中的异相成核行为。结果表明，间歇发泡法制备PES泡沫的发泡区间为200~230 ℃；最佳浸泡压力为20 MPa；最佳浸泡时间为3 h；未改性PES的泡孔直径均可在10 μm以下，泡孔密度在10⁹~10¹⁰ 个/cm³之间，但泡孔壁较厚；SiO₂相对于Talc，表现出更显著的异相成核作用；在210 ℃、3 h、20 MPa的发泡条件下，添加0.9 %（质量分数，下同）的SiO₂，可得到泡孔直径为0.77 μm，泡孔密度为7.14×10¹¹ 个/cm³的PES微孔泡沫。

Study on Foaming Behavior of PES Using Supercritical CO2 as Foaming Agent

Polyether sulfone （PES） foams were prepared through a batch?foaming method using supercritical CO₂ as a foaming agent， and their homogeneous nucleation behavior during the foaming process was investigated with talc and SiO₂ as heterogeneous nucleating agents. The results indicated that the foaming parameters were determined to be a temperature of 200~230 °C， an optimal immersion pressure of 20 MPa， and an optimum soaking time of 3 h for the intermittent foaming method. The pore diameter of unmodified PES foams was less than 10 μm， and their pore density was 10⁹~10¹⁰ /cm³ with a thicker pore wall. SiO₂ was found to show a more obvious heterogeneous nucleation effect than Talc. Under the foaming conditions of 210 °C， 3 h， 20 MPa， PES foams achieved a diameter of 0.77 μm and a cell density of 4.16×10¹¹ cells /cm³ in the presence of 0.9 wt% SiO₂.