The present work adopts the one-step batch foaming technique to develop microcellular foams from polysulfone (PSU) and polyethersulfone (PES) using supercritical carbon dioxide (CO₂) as a physical blowing agent. The results illustrates that the high temperature polymers can successfully generate highly uniform cellular structures with CO_2, exhibiting cell densities in the order of 10¹⁰ cells/cm³ but limited volume expansion ratios of up to 4 times. The cell densities of both systems, PSU/CO₂ and PES/CO₂, were observed to be highly affected by the foaming pressure, showing significant enhancement of over 5 orders of magnitude with an increase in pressure from 3.4 to 13.8 MPa. On the other hand, the expansion ratio showed a strong dependence on the foaming temperature. Especially, the foams produced at pressures below 13.8 MPa exhibited a unique double peak behavior consisting of two maximum expansion ratios obtained at two different temperatures. In the temperature range of the first expansion peak, nanostructures were observed on the cell walls of the foams. The surficial features appeared in the form of a nanofibril network and gradually disappeared as the temperature approached the region of the second peak. Based on the observation, the unique double peak behavior may be correlated to the presence of the nanostructures. The work also encompassed measurement of CO₂ solubility and high pressure thermal analysis of the two polymers, which were incorporated in the discussion of the distinctive foaming behavior.

目前的工作采用一步间歇发泡技术，以超临界二氧化碳（CO ₂）为物理发泡剂，由聚砜（PSU）和聚醚砜（PES）开发微孔泡沫。结果表明，高温聚合物可以成功地生成具有CO _{2 的}高度均匀的细胞结构，其细胞密度约为10 ^{10 个}细胞/cm ³，但体积膨胀率有限，最高可达4倍。两个系统的细胞密度，PSU/CO ₂和 PES/CO ₂, 观察到受发泡压力的影响很大，随着压力从 3.4 增加到 13.8 MPa，显示出超过 5 个数量级的显着增强。另一方面，发泡倍率对发泡温度有很强的依赖性。特别是，在低于 13.8 MPa 的压力下生产的泡沫表现出独特的双峰行为，包括在两个不同温度下获得的两个最大膨胀比。在第一个膨胀峰的温度范围内，在泡沫的细胞壁上观察到纳米结构。表面特征以纳米纤丝网络的形式出现，并随着温度接近第二峰区域而逐渐消失。基于观察，独特的双峰行为可能与纳米结构的存在相关。₂两种聚合物的溶解度和高压热分析，它们被纳入了对独特发泡行为的讨论。