Aging‐ and Moisture‐Resistant Pectin‐Based Aerogels: A Breakthrough in Bio‐Based Thermal Superinsulation

ABSTRACT

Bio‐based aerogels are a compelling class of sustainable materials, with some of them distinguished by their exceptional thermal superinsulating performance, i.e. conductivity lower than that of air. However, their practical use is limited by poor stability in humid environment. Pectin/polyurea aerogels were developed to address this issue. Pectin was combined with polyurea precursors to explore how polyurea chemistry affects thermal performance at 25°C and high relative humidity (RH). ATR‐FTIR and NMR analyses confirmed the formation of a conformal polyurea network coating pectin nanofibrils. All aerogels displayed high specific surface areas (350–520 m ² g ⁻¹ ) and exceptionally low thermal conductivity, 0.015–0.018 W m ⁻¹ K ⁻¹ . Among the formulations tested, the aerogel based on pectin/rigid aliphatic polyurea network demonstrated superior performance, maintaining a stable thermal conductivity of 0.015 W m ⁻¹ K ⁻¹ in 80% RH for nearly 300 days (duration of test). In addition to thermal superinsulation, this optimized formulation showed high mechanical strength, good flame retardancy, and effective acoustic reflectivity. This is the first report on biopolymer‐based aerogels retaining long‐lasting thermal superinsulating properties under extended humid exposure, with their performance matching that of the best silica aerogels. Pectin/polyurea aerogels possess strong potential as multifunctional and sustainable insulation materials.