| Abstract:The biodegradability of modified collagen sizing agent (MCSA) was evaluated by the methods of BOD5/CODCr and OECD-301B, and its biodegradability was compared with that of alkyl ketene dimer (AKD) and styrene-acrylic ester copolymer (SAE) which were commercial products. The results showed that the BOD5/CODCr values of MCSA, AKD and SAE were 0.32, 0.28 and 0.21, respectively, they belonged to biodegradable material, poor biodegradable material and recalcitrant biodegradable or non-biodegradable material, respectively. On the other hand, their biodegradation index IB were 102.55%, 95.63% and 92.11%, respectively on 28th day, which showed that MCSA was biodegradable material while AKD and SAE were recalcitrant biodegradable materials. The experimental results obtained by the two methods were consistent. The biodegradation trends were: MCSA>AKD>SAE. Meanwhile, the relationship between molecular structure and biodegradability was studied. There were benzene structures in MCSA and SAE molecules, but MCSA had strong molecular polarity and excellent biological affinity. So MCSA had better degradability. It indicated that it is necessary to comprehensively consider the effect of chemical structure on the biodegradability． |
