Department of Industrial Engineering and INSTM Research Unit, University of Trento, Via Sommarive 9, 38123 Trento, Italy.
Molecules. 2022 Dec 3;27(23):8520. doi: 10.3390/molecules27238520.
polypropylene (PP) syntactic foams (SFs) containing hollow glass microspheres (HGMs) possess low density and elevated mechanical properties, which can be tuned according to the specific application. A possible way to improve their multifunctionality could be the incorporation of organic Phase Change Materials (PCMs), widely used for thermal energy storage (TES) applications. In the present work, a PCM constituted by encapsulated paraffin, having a melting temperature of 57 °C, was embedded in a compatibilized polypropylene SF by melt compounding and hot pressing at different relative amounts. The rheological, morphological, thermal, and mechanical properties of the prepared materials were systematically investigated. Rheological properties in the molten state were strongly affected by the introduction of both PCMs and HGMs. As expected, the introduction of HGMs reduced both the foam density and thermal conductivity, while the enthalpy of fusion (representing the TES capability) was proportional to the PCM concentration. The mechanical properties of these foams were improved by the incorporation of HGMs, while they were reduced by addition of PCMs. Therefore, the combination of PCMs and HGMs in a PP matrix generated multifunctional materials with tunable thermo-mechanical properties, with a wide range of applications in the automotive, oil, textile, electronics, and aerospace fields.
含有空心玻璃微球（HGM）的聚丙烯（PP）复合泡沫具有低密度和增强的机械性能，可根据特定应用进行调整。提高其多功能性的一种可能方法是掺入有机相变材料（PCM），广泛用于热能存储（TES）应用。在本工作中，将相变材料封装在石蜡中，其熔点为 57°C，通过熔融共混和热压在不同的相对含量下嵌入到相容化的聚丙烯 SF 中。系统研究了制备材料的流变、形态、热和机械性能。熔融状态下的流变性能受到 PCM 和 HGM 的引入的强烈影响。正如预期的那样，HGM 的引入降低了泡沫的密度和热导率，而熔融焓（代表 TES 能力）与 PCM 浓度成正比。HGM 的加入提高了这些泡沫的机械性能，而 PCM 的加入则降低了它们的机械性能。因此，在 PP 基体中结合 PCM 和 HGM 生成了具有可调热机械性能的多功能材料，在汽车、石油、纺织、电子和航空航天等领域有广泛的应用。
