Thermal protection of high temperature polymer-material-carbon fiber composites

摘要

Two evaporative-cooling materials were studied which are (i) salt hydrates and (ii)polyacrylic acid for the purpose showing proof of concept of being able to putevaporative-cooling materials into a composite with the Air Force polyimide AFR-PEPAN.The salt hydrates were observed to absorb water and then evaporate water, but due tohaving a collapsible lattice, made them incapable of reabsorbing water. Polyacrylic acidwas mixed into an epoxy sheet at polacrylic acid weight percentages of 5, 10, 12.5. Foreach weight percentage there was a hydrated epoxy specimen and a dry epoxy specimen.All specimens were individually shot with a hot air stream (temperature approximately1300C). Temperature readings were taken for each sheet. The hydrated specimenexhibited greater evaporative cooling over its dry counterpart. 12.5 wt% was shown tohave the best evaporative cooling mechanism. Experiments were repeated to show thatthe polyacrylic could reabsorb water. This study illustrates proof of concept utilizingpolyacrylic acid as an evaporative cooling material.