Mechanically Strong and Thermally Stable Chemical Cross-Linked Polyimide Aerogels for Thermal Insulator

Abstract

High-performance thermal insulating materials are highly desirable in several fields, especially for thermal insulation of buildings to reduce energy consumption. Owing to the remarkable thermal stability, high porosity, low density, and outstanding mechanical features, polyimide (PI) aerogels have attracted great attention. In this work, chemical cross-linked PI (CCPI) aerogels were fabricated via freeze-drying and thermal imidization, which possess outstanding mechanical properties, good thermal stability, and excellent thermal insulation characteristics. The chemically cross-linked structure can effectively inhibit shrinkage, while retaining the structural integrity, resulting in the lower density and lower shrinkage of the materials. In this paper, completely imidized and highly cross-linked polyimide aerogels were synthesized by using p-phenylenediamine (PDA), 3,3′,4,4′biphenyltetracarboxylic dianhydride (BPDA), and the cross-linker 2,3,6,7,14,15-hexaaminotriptycene (HMT). The CCPI aerogels with excellent properties, such as covalently cross-linked chemical structure, low density (0.069 g/cm 3 ), low volume shrinkage (10%), high decomposition temperature (T d5% = 587 °C), and low thermal conductivity (25 mW m −1 K −1 ) are in high demand in the field of thermal insulation. This work furnishes a new method for the development of polymer-based thermal insulation materials for various prospective applications.

Preparation of robust and light‐weight anisotropic polyimide/graphene composite aerogels for strain sensors

“…Synthesis of the solid PI precursor PAA was carried out in accordance with the previously reported study 33 . Initially, a homogenous solution of PAA was prepared through the polycondensation reaction of BPDA and PDA in DMAc under constant stirring.…”

“…Synthesis of the solid PI precursor PAA was carried out in accordance with the previously reported study. 33 Initially, a homogenous solution of PAA was prepared through the polycondensation reaction of BPDA and PDA in DMAc under constant stirring. A PAA solution was obtained by sequentially introducing 5.4 g of PDA and 16.2 g of BPDA into a 250 mL three-neck flask containing 100 g of NMP.…”

Mechanically Strong and Thermally Insulating Polyimide Aerogel Fibers Reinforced by Prefabricated Long Polyimide Fibers

“…Additionally, chemically crosslinked polyimide aerogels promote strength and reduce shrinkage. 30 Therefore, polyimide aerogel fiber has been demonstrated as a promising material for thermally insulating clothing.…”

“…Moreover, polyimide aerogels’ heat resistance is better than most organic aerogels, such as cellulose and protein. , Therefore, polyimide aerogels can be employed in high-temperature environments. Additionally, chemically crosslinked polyimide aerogels promote strength and reduce shrinkage . Therefore, polyimide aerogel fiber has been demonstrated as a promising material for thermally insulating clothing.…”

Microstructure controllable polyimide/MXene composite aerogels for high-temperature thermal insulation and microwave absorption

“…Polyimide (PI) aerogels exhibit ultralow thermal conductivity, high-temperature structural stability and good mechanical properties. 15–17 These excellent properties make PI aerogels well-suited candidates for high-temperature thermal insulation applications. Recently, the microwave absorption capability of PI aerogels has attracted attention from scientists.…”