Abstract The global energy crisis has been widely concerned by the public due to the massive energy requirement caused by rapid-developing economy and society. Ultra-lightweight, super-insulating, and strong polymer foams exhibit a promising prospect, in terms of saving materials and resources, and reducing energy consumption. However, there exists a great challenge to achieve highly expanded microcellular polymer with satisfactory thermal insulation performance. Herein, polypropylene (PP) with carbon nanotubes (CNTs) was used to prepare multifunctional foams by using batch foaming process with carbon dioxide. This cost-efficient and facile process endowed PP/CNT composite a variety of unprecedented advantages, including over 50-fold expansion ratio, a rather low thermal conductivity of 28.69 mW/m·K, and remarkably improved compressive strength. Acting as both crystal and cell nucleating agents, CNTs contributed to the fabrication of such ultralight foams with refined cell structure, which led to significantly reduced solid thermal conduction and enhanced mechanical properties. Moreover, thanks to CNTs’ outstanding infrared radiation shielding capacity, the thermal radiation through the ultra-lightweight PP/CNT foam was significantly suppressed. Thus, ultra-lightweight, super thermal-insulation, and strong PP/CNT composite foams were achieved by using microcellular foaming technology, paving a way for designing and synthesizing multifunctional polymer-based composite foams for high-performance thermally insulating applications.

中文翻译：

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超轻、超隔热和坚固的 PP/CNT 微孔泡沫

摘要 经济社会快速发展对能源的需求巨大，全球能源危机已引起公众的广泛关注。超轻、超绝缘、高强度的聚合物泡沫在节约材料和资源、降低能耗方面具有广阔的前景。然而，实现具有令人满意的隔热性能的高度膨胀的微孔聚合物存在巨大挑战。在此，具有碳纳米管 (CNT) 的聚丙烯 (PP) 用于通过使用二氧化碳的间歇发泡工艺制备多功能泡沫。这种经济高效且简便的工艺赋予了 PP/CNT 复合材料多种前所未有的优势，包括超过 50 倍的膨胀比、28.69 mW/m·K 的较低热导率以及显着提高的抗压强度。作为晶体和细胞成核剂，碳纳米管有助于制造具有精细细胞结构的超轻泡沫，从而显着降低固体热传导并增强机械性能。此外，由于碳纳米管出色的红外辐射屏蔽能力，通过超轻质聚丙烯/碳纳米管泡沫的热辐射得到显着抑制。因此，通过使用微孔发泡技术实现了超轻、超隔热和坚固的 PP/CNT 复合泡沫，为设计和合成用于高性能隔热应用的多功能聚合物基复合泡沫铺平了道路。这导致显着降低固体热传导和增强机械性能。此外，由于碳纳米管出色的红外辐射屏蔽能力，通过超轻质聚丙烯/碳纳米管泡沫的热辐射得到显着抑制。因此，通过使用微孔发泡技术实现了超轻、超隔热和坚固的 PP/CNT 复合泡沫，为设计和合成用于高性能隔热应用的多功能聚合物基复合泡沫铺平了道路。这导致显着降低固体热传导和增强机械性能。此外，由于碳纳米管出色的红外辐射屏蔽能力，通过超轻质聚丙烯/碳纳米管泡沫的热辐射得到显着抑制。因此，通过使用微孔发泡技术实现了超轻、超隔热和坚固的 PP/CNT 复合泡沫，为设计和合成用于高性能隔热应用的多功能聚合物基复合泡沫铺平了道路。