Zeolite-Modified Polyimides as Absorption Materials for Molecular Contamination

Polyimide is a unique spacecraft material because of its high strength, heat and chemical resistance. Modifying polyimide with chemical specificity while retaining its material properties is important to develop multi-functional materials to solve challenging contamination, thermal regulation, and space environment problems. A particular contaminant of interest is water. Moisture contamination leads to deterioration of both absorbance and transmittance properties of optical surfaces. Zeolites have been widely known to absorb water and other molecular contaminants. These moisture absorption properties are further enhanced when synthesized on the nanoscale level. Nanozeolite particles were surface modified to promote uniform inclusion into the polyimide matrix. The polyimide-nanozeolite composite material shows only little deviation from the parent material when characterized for thermal and optical properties. However, the composite material exhibits outstanding moisture absorption properties when compared to the unmodified parent material. The amount of nanozeolite was varied in the composite material and there appears to be a threshold value of nanozeolite that produces the best water absorption characteristics as well as comparable thermal and optical characteristics to the unmodified polyimide.