(612b) Bark-Based Polyurethane Foams Through Solvent Liquefaction

Liquefaction of bark is an appealing route to produce polyols for the synthesis of bio-based polyurethane foams (PUFs). Bark is inexpensive since it is a waste material of the logging industry, and its composition is rich in extractive compounds, especially condensed tannins. These phenolic compounds have high hydroxyl functionality, are extracted more easily compared to cellulose or lignin and their aromatic structure can impart thermal stability. However, depending on the liquefaction conditions the polyol structure can vary greatly. These differences are manifested in the foam properties. By characterizing both foam and polyol, a greater understanding of this unique system can be achieved.

Liquefactions reactions were carried out at different temperatures producing polyols with increasing degrees of modification and degradation, respectively. It was found that bark-based polyols can produce polyurethane foams with comparable mechanical properties with commercial standard polyols. However, liquefaction conditions had a significant impact on the polyurethane foam performance.