In this article, a facile melt blending and solid batch foaming approach was proposed to prepare microcellular polystyrene/thermoplastic polyurethane (PS/TPU) blending foams with supercritical carbon dioxide (CO2). Compared with those of pure PS and pure TPU, an interesting phenomenon about the enhanced complex viscosity and storage modulus, as well as decreased loss factor of PS/TPU blends, was found. The solubility of CO2 in the PS/TPU blends was enhanced, owing to the CO2 solubilization effects of TPU. An interesting bimodal cell structure (BCS) was observed in the PS/TPU blending foams with the TPU content of 10, 15, and 20%. Consequently, a significant conclusion could be speculated that the generation of BCS in the PS/TPU blending system depended on not only the viscosity and morphology of the polymer blends but also the solubility and diffusivity of the CO2 as well as the type of cell nucleation. The thermal insulation property of PS foam was improved by the introduction of TPU.

中文翻译：

---

超临界 CO2 存在下聚苯乙烯/热塑性聚氨酯共混物的微孔形态演变

在本文中，提出了一种简便的熔融共混和固体间歇发泡方法来制备微孔聚苯乙烯/热塑性聚氨酯 (PS/TPU) 与超临界二氧化碳 (CO2) 的共混泡沫。与纯 PS 和纯 TPU 相比，发现了一个有趣的现象，即 PS/TPU 共混物的复数粘度和储能模量增强，损耗因子降低。由于 TPU 的 CO2 增溶作用，CO2 在 PS/TPU 共混物中的溶解度提高。在 TPU 含量为 10%、15% 和 20% 的 PS/TPU 共混泡沫中观察到有趣的双峰泡孔结构 (BCS)。最后，可以推测一个重要的结论是，PS/TPU 共混体系中 BCS 的产生不仅取决于聚合物共混物的粘度和形态，还取决于 CO2 的溶解度和扩散率以及细胞成核的类型。TPU的引入提高了PS泡棉的隔热性能。