Limited processability of high molecular weight poly(p-phenylene terephthalamide) (PPTA) results in complex, time-consuming, and high-cost procedure of preparing PPTA aerogel. Herein, the chopped PPTA fiber reinforced PPTA aerogel was prepared by spontaneous low molecular weight PPTA (LMW-PPTA) gel. The pore structure and thermal insulation characteristics of composite PPTA aerogel were effectively controlled by varying the concentration of LMW-PPTA solution. Then, the PPTA/phase-change composite (PPTA/PCM) was obtained by dipping process. It was confirmed that the composite PPTA aerogel acquired superior thermal insulation, mechanical properties and great thermal stability above 500 °C. Furthermore, the infrared stealth property of PPTA/PCM composite material was also studied systematically. Significantly, the facile-procedure and lower-cost PPTA aerogel and its composites may have a great potential to be applied as thermal insulation and infrared stealth materials in industrial applications.

高分子量聚对苯二甲酰对苯二甲酰胺（PPTA）的加工性能有限，导致制备PPTA气凝胶的过程复杂，耗时且成本高。在此，通过自发的低分子量PPTA（LMW-PPTA）凝胶制备短切PPTA纤维增强的PPTA气凝胶。通过改变LMW-PPTA溶液的浓度可以有效地控制复合PPTA气凝胶的孔结构和隔热性能。然后，通过浸渍工艺获得PPTA /相变复合材料（PPTA / PCM）。证实了复合PPTA气凝胶在500°C以上具有优异的隔热性，机械性能和出色的热稳定性。此外，还对PPTA / PCM复合材料的红外隐身性能进行了系统的研究。重要的是