Directly rapid depressurization foaming process has been successfully applied to prepare microcellular epoxy foams using supercritical CO₂ as blowing agent. It is found that both curing reaction and CO₂ diffusion are crucial for controlling cell morphology. For epoxy of tetraglycidyl-4,4′-diaminodiphenyl-methane (TGDDM) and 4,4-diaminodiphenylsulfone (4,4-DDS) system, the experimental and molecular simulation results displayed that higher CO₂ pressure always promotes curing reaction, and CO₂ diffusion is more sensitive to pressure at low curing degree, while limited by high curing degree. The foaming experimental results showed that there existed a suitable curing degree range, in which both unsaturated CO₂ concentration and curing degree contribute to good cell structure. Higher CO₂ pressure can broaden this foamable window. The microcellular epoxy foam with an average cell diameter of 14.6 µm and cell density over 10⁹ cells/cm³ as well as volume expansion ratio of 14.5 has been obtained at 85% curing degree under 22 MPa CO₂ pressure.

直接快速减压发泡工艺已成功应用于以超临界CO ₂为发泡剂制备微孔环氧树脂泡沫。发现固化反应和CO ₂扩散对于控制细胞形态是至关重要的。对于四缩水甘油基-4,4'-二氨基二苯甲烷（TGDDM）和4,4-二氨基二苯砜（4,4-DDS）体系的环氧树脂，实验和分子模拟结果表明，较高的CO ₂压力总是促进固化反应，而CO ₂扩散在低固化度时对压力更敏感，而受高固化度限制。发泡实验结果表明存在合适的固化度范围，其中不饱和CO ₂浓度和固化程度有助于形成良好的泡孔结构。更高的 CO ₂压力可以拓宽这个可发泡的窗口。在22 MPa CO ₂压力下以85%固化度获得平均泡孔直径为14.6μm、泡孔密度超过10 ^{9 个}/cm ³以及体积膨胀比为14.5的微孔环氧泡沫。