Synthesized Tannin Foam from Tannin Resole Dehydrated by Hot Air Oven

A simple method for synthesizing tannin foam (TF) from tannin resole (TR) was studied. Tannin was used as a substitute for phenol with a 10 wt% substitution ratio to form TR. The mixture of TR was dehydrated to get the TR with a solid content of 80% using a hot air oven. The dehydrated TR was used as an essential component for the formation of the TF. The functional groups, density, and compressive strength of the synthesized TF were tested by using an FTIR, ASTM D1622, and ASTM D1621, respectively. From the FTIR spectra, it was found that functional groups of TF were similar to phenol foam (PF). The addition of tannin increased the density and compressive strength of the TF. The density of tannin foam was 90.92 kg/m3, and the compressive strength of tannin foam was 0.25 MPa. Using tannin resole to make synthesized tannin foam proved to be a simpler method in dehydrating resole by hot air oven as compared with the conventional method. Moreover, the thermal performance of the TF was performed, and it was found that the TF showed a similar thermal performance to the PF.