Tannin based foams modified to be semi-conductive: Synthesis and characterization

The objective of this study was to modify highly insulative and lightweight biorenewable foam thermosets to be semi-conductive for primarily building material applications. The foams were formed and then post-treated with in-situ polymerization of polyaniline, both doped and undoped, adsorbing and possibly absorbing (observed by SEM-EDX) to the foam structure at levels of 100-120 wt%. The modified tannin foams were shown to be semi-conductive in comparison to the highly insulative structure prior to polyaniline modification. While the 50% protonated polyaniline modified foams, or doped foams, had a higher conductivity than the undoped polyaniline modified foams, the acid used in fabrication of the foams provided some degree of conductivity to the undoped PANI modified foams. Moreover, the modified foams had an increased volume of 15% after modification, were more sensitive to moisture, and the polyaniline did not affect the degradation temperature of the foams.