Abstract

A series of high comprehensive performance composite phase-change materials (PCMs) were designed and prepared by a physical blending and evaporation method. Cellulose nanofibers (CNF) were introduced as supporting materials to keep the shape of polyethylene glycol (PEG) stable during the phase-change process, and expanded graphite (EG) was used to synergize with the PEG to enhance the infrared thermal stealth performance. The comprehensive performance and structure–property relationships of the composite PCMs were investigated by means of various characterization techniques. The CNF30/PEG69/EG1 composite exhibited the best comprehensive performance: a high PEG melting enthalpy of 144.3 J/g due to a high crystallinity of the PEG, good thermal stability, a shape stabilization effect and superior IR attenuation performance. The EG was proved to be an effective supporting material which contributed to the enhancement of the crystallinity of PEG, and played an important role as a nucleating agent in the crystallization process of the PEG. The synergistic effect of PEG and the small amount of EG gave the composites excellent infrared stealth performance.

摘要

采用物理共混和蒸发方法设计并制备了一系列高综合性能复合相变材料（PCMs）。引入纤维素纳米纤维 (CNF) 作为支撑材料以在相变过程中保持聚乙二醇 (PEG) 的形状稳定，并使用膨胀石墨 (EG) 与 PEG 协同提高红外热隐身性能。通过各种表征技术研究了复合相变材料的综合性能和结构-性能关系。CNF30/PEG69/EG1复合材料表现出最佳的综合性能：由于PEG的高结晶度，PEG熔化焓高达144.3 J/g，良好的热稳定性，形状稳定效果和优异的红外衰减性能。EG被证明是一种有效的支撑材料，有助于提高PEG的结晶度，在PEG的结晶过程中起到了重要的成核剂作用。PEG和少量EG的协同作用使复合材料具有优异的红外隐身性能。