Attapulgite-reinforced polyimide hybrid aerogels with high dimensional stability and excellent thermal insulation property

Tingting Wu, Jie Dong∗∗, Guofen Xu, Feng Gan, Xin Zhao, Qinghua Zhang∗

Polymer. 2019, 176, 196-205. https://doi.org/10.1016/j.polymer.2019.05.007

ABSTRACT：Dimensional instability has been regarded as one of issues that limits the wide application of polymer aerogels in harsh temperatures. In present work, polyimide aerogel, one of the strongest polymeric aerogels, was reinforced with attapulgite (AT) nanorods, one of natural fibrillar minerals, through the strong hydrogen-bonding interaction. In hybridized aerogels, AT nanorods act as the rigid skeleton that supporting the framework of aerogels, which is just like the steel bars in the reinforced concrete structures. The resultant hybrid aerogels exhibited improved mechanical properties. At the 80% strain, the compressive stresses for both flexible ODA- and rigid DMBZ-based composite aerogels containing 10 wt% AT were 100% as high as those of the pure polyimide aerogels. Meanwhile, the compression Young's and specific modulus increase by 50% and 52% for the hybrid DMBZ-based aerogel with 10 wt% AT compared with the pristine sample. Furthermore, the AT nanorods showed strong supporting effects in retaining the structural integrity of aerogels, especially for the specimens derived from flexible ODA as the diamine, which produced a significant effect on reducing the shrinkage of composite aerogels at high temperatures and maintaining their excellent thermal insulation behaviors, implying that AT is an effective and low-cost additive for preparing high performance polymer nanocomposites aerogels with improved mechanical property and thermal dimensional stability.