Poly (vinyl alcohol) (PVA) foam is a promising environment‐friendly packaging material due to the good biodegradability and excellent mechanical properties. Besides, PVA can be produced on a large scale viathe non‐petroleum routes. However, the preparation of complex‐shaped PVA foam products has not been realized, because PVA is a water‐soluble and semi‐crystalline polymer with a high melting temperature (226°C), which cannot be welded through the conventional bead foaming technology. In this article, a clean and efficient strategy based on microwave foaming and sintering was innovatively developed to manufacture the PVA bead foam products. First, the expandable PVA beads were prepared through polar solvent‐plasticization, followed by supercritical carbon dioxide (scCO₂)‐impregnation in solid‐state. The impregnated beads were then surface plasticized with polar solvent by simple coating. Thus, the incorporated polar solvent in the internal and superficial regions of PVA beads was rapidly heated upon exposure to the microwave irradiation, which simultaneously induced the CO₂ foaming and interfacial melting, respectively. In this way, the expansion and welding of PVA beads were completed in a one‐step procedure. Meanwhile, the complex‐shaped PVA bead foam products with excellent elasticity and intra‐bead adhesive strength were prepared within a short period of 30 seconds. Therefore, the microwave heating can be considered as an efficient strategy for preparing the high‐performance polymer bead foam products, especially for these high‐melting temperature or glass‐transition temperature polymers.

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一种超快速，清洁的制造聚乙烯醇珠泡沫产品的方法

聚乙烯醇（PVA）泡沫具有良好的生物降解性和出色的机械性能，是一种有前途的环保包装材料。此外，可以通过非石油路线大规模生产PVA。但是，由于PVA是一种水溶性高且熔点高（226°C）的水溶性半结晶聚合物，因此无法通过常规的珠粒发泡技术进行焊接，因此无法制备复杂形状的PVA泡沫产品。在本文中，创新地开发了一种基于微波发泡和烧结的清洁高效策略，以制造PVA珠状泡沫产品。首先，通过极性溶剂塑化制备可膨胀的PVA珠粒，然后通过超临界二氧化碳（scCO ₂）固态浸渍。然后将浸渍的珠粒用极性溶剂通过简单的涂层进行表面增塑。因此，在暴露于微波辐射下，PVA珠的内部和表面区域中掺入的极性溶剂被迅速加热，同时诱导了CO ₂起泡和界面熔化。通过这种方式，PVA珠粒的膨胀和焊接只需一步即可完成。同时，在短短30秒内制备了具有出色弹性和珠内粘合强度的复杂形状的PVA珠泡沫产品。因此，微波加热可以被认为是制备高性能聚合物珠粒泡沫产品的有效策略，尤其是对于这些高熔点或玻璃化转变温度的聚合物。