The changes of the polyurethane foams derived from wattle tannin (WT- PU) before and after biodegradation were studied by several methods, including gel permeation chromatography (GPC), Fourier-transform infrared spectroscopy(FT-IR), scanning electronic microscope (SEM). The results showed that the tannin crosslink points were degraded foremost in a random manner. The hydrogen bonding in both the hard and soft segments of PU were weakened during the whole process of degradation.

Key words: TANNIN, POLYURETHANE, SOIL, BIOLOGICAL DEGRADATION, GEL PERMEATION CHROMATOGRAPHY, FOURIER TRANSFORM, INFRARED SPECTROPHOTOMETRY, SCANNING ELECTRON MICROSCOPES, MOPHOLOGY STRUCTURE